SURVEYING & MAPPING

Upgraded RTK Rover
Features MFi certification

The Reach RX Network real-time kinematics (RTK) rover has been upgraded to include new MFi (Made for iPhone/iPad) certification and is fully compatible with ArcGIS, QGIS and other GIS apps for both iOS and Android. Reach RX can be seamlessly integrated into GIS workflows to help industry professionals and teams collect accurate geodata at scale.

The Reach RX offers precise positioning while receiving corrections through NTRIP and tracks GPS/QZSS, Galileo, GLONASS and BeiDou. It gets a fix in less than 5 seconds, delivering centimeter-level accuracy even in challenging conditions.

It can be used for engineering, utility inspection, landscaping and other projects of any scale. According to the company, the rover will soon be compatible with QField, Blue Marble’s Global Mapper, Mergin Maps, Avenza Maps and more.

The Reach RX weighs 250 grams; is IP68-rated, waterproof and dustproof; and withstands temperatures from -20° C to +65° C.Emlid, emlid.com

Photogrammetric Software
Upgraded coordinate system functionalities

3Dsurvey 3.0 is an all-in-one photogrammetric software solution designed to unify lidar sensors, cameras on UAVs and various ground control points. Users can transition between orthophotos, point clouds and textured meshes.

Version 3.0 features upgraded coordinate system functionalities to obtain georeferenced spatial data without local transformations.

It includes improved coordinate system support, which handles transformations requiring special grid files and offers accurate GPS-to-local coordinate conversions. Additionally, the platform can automatically fetch missing geoid models.

The revamped coordinate system selection process includes presets for users to find the correct system by entering their country name, with the appropriate settings applied automatically. It has PRJ file support to enhance compatibility with various GIS standards. 3Dsurvey, 3dsurvey.si

RTK Evaluation Kit
Includes L1+L2 RTK GNSS

This real-time kinematics (RTK) evaluation kit (EVK) serves as a development platform for fixed or mobile high-precision positioning and navigation needs.

The RTK EVK comes with a range of options for prototyping, including L1+L2 RTK GNSS, with L-Band correction built-in if needed, running on an agile processor.

It features custom open-source software pre-loaded with RTK Everywhere firmware. Users can configure the EVK as an RTK base and push corrections to an NTRIP Caster or use corrections delivered through WiFi or Bluetooth.

The integrated u-blox NEO-D9S offers L-Band reception and access to correction services such as PointPerfect. The u-blox LARA-R6001D provides global cellular connectivity, and Zero-Touch RTK offers users a simple way to receive corrections. Users can register the device and enable PointPerfect — no NTRIP credentials are required. Sparkfun Electronics, sparkfun.com

GNSS Receiver
With tilt compensation

The R980 features communication capabilities to support uninterrupted field operations. It can be used for land surveying, transportation infrastructure, construction, energy, oil and gas, utilities and mining projects.

The system features Trimble’s ProPoint GNSS positioning engine and inertial measurement unit (IMU)-based tilt compensation, making it suitable for dense urban environments and under tree canopy, removing the need to level the pole when capturing data points.

It includes a dual-band UHF radio and an integrated worldwide LTE modem for receiving corrections from a local base station or VRS network. It supports the Trimble Internet Base Station Service (IBSS) for streaming RTK corrections using Trimble Access field software and features Trimble IonoGuard technology, which mitigates ionospheric disturbances for RTK GNSS. Trimble Geospatial, geospatial.trimble.com

Nautical Chart Production
Generate charts in PDF/TIF from ENC data

CARIS AutoChart, a nautical chart production solution, is tailored to the needs of nautical chart producers. It can automatically generate charts in PDF/TIF from ENC data. Users can seamlessly import data from ENC files to create comprehensive nautical charts in PDF and/or TIF format. CARIS AutoChart can generate chart templates from existing chart portfolios maintained with CARIS paper chart composer or CARIS HPD paper chart editor.

The software is designed to accommodate the unique needs of chart production facilities of all sizes. It can be used by hydrographic offices, port or waterways authorities.Teledyne Geospatial, teledyneimaging.com

Upgraded GIS Platform
Featuring native database integrations

Felt 3.0 includes new features and native database integrations to improve the capabilities of geographic information systems (GIS). It provides modern GIS tools for teams to visualize, analyze and present important insights and map data relevant to their operations.

Operators can directly connect Postgres/PostGIS and Snowflake databases for automated live data updates. The API allows users to create and style elements and listen to map updates via webhooks, while providing a Python SDK for professionals to continue to work in their preferred tools. Felt, felt.com

UAV

Gimbaled Camera
For UAV missions

The Gimbal 155 is a gimbaled camera designed for the UAV Survey Mission program. The GOS-155 meets UAV requirements for surveillance and rescue missions. Its optimized size, weight and power (SwaP) profile, advanced day and night ISR imaging, and embedded video processor make it ideal for any mid-sized UAV — whether VTOL or winged. With its low weight of 1.8 kg, and 155 mm, UAV platforms can increase endurance without sacrificing optical performance.

The GOS-155 two-axial gimbal is an EO/IR system, comprising a 30x optical zoom HD (1280 x 720) visible camera paired with a fixed focal length uncooled thermal LWIR (1280 x 1024) camera. This allows users to collect intricate visuals across visible and infrared spectrums.

It includes embedded video processing with electronic stabilization and object tracking and can be integrated with external GPS/INS with real-time target location at 20 m across multiple environments, and around 5 m using UAVOS’ Ground Control Station software. UAVOS, uavos.com

Tactical Grade INS
Tailored to unmanned systems

The FN 200C combines multiple functions into a single integrated platform. It features a three-in-one strapdown system compromising motion reference unit (MRU), attitude and heading reference system (AHRS) and inertial navigation system (INS) capabilities for precise positioning, velocity and orientation data in both static and dynamic movements.

It is equipped with fiber optic gyroscopes (FOG) and MEMS accelerometers. The FN 200C’s inertial measurement unit (IMU) offers accurate and reliable navigation data even in challenging conditions. The system supports various correction methods such as SBAS, DGPS, RTK, and PPP for real-time navigation and positioning in a wide range of applications.

The FN 200C utilizes NovAtel OEM7, u-blox ZED-F9P or Septentrio mosaic-H GNSS receivers to provide precise positioning information across multiple GNSS constellations. With embedded anti-jamming and spoofing features, the FN 200C offers reliable operation in environments where signal interference may be present.

The FN 200C is ideal for unmanned systems applications, including land-based surveying, aerial mapping, maritime navigation and more, delivering precise and reliable navigation data to meet the most demanding requirements. According to FIBERPRO, the system’s advanced technology, robust design and comprehensive feature set ensure that it will revolutionize navigation and operation in today’s dynamic and challenging environments. FIBERPRO, fiberpro.com

Upgraded UAV
With a modifiable flight controller

The RDSX Pelican extended-range hybrid vertical take-off and landing (VTOL) delivery UAV is now offered with an easily modifiable flight controller, designed for users to more readily integrate customized flight systems and companion software.

The RDSX Pelican combines the reliability and flight stability of a multirotor craft with the extended range of a fixed-wing airframe. Its customizable payload bay can be factory-integrated with the A2Z Drone Delivery RDS2 commercial delivery winch to support a variety of logistics operations.

Engineered to operate within the FAA’s 55-pound max takeoff weight for Part 107 compliance, the Pelican is rated to carry payloads up to 5 kg on operations up to 40 km roundtrip. The flexibility of the Pelican’s cargo bay makes it ideal for logistics missions or deployment with payloads customized for aerial mapping, UAV inspection, forestry services, search and rescue operations, water sample collection, offshore deliveries, mining and more.

With the RDSX Pelican now operating on the Cube flight controller (CUAV X7+), users can integrate their preferred systems — including ground control software, radio beacons and other companion software systems. A2Z Drone Delivery, a2zdronedelivery.com

GNSS Positioning Modules
Compatible with UAVs and robotics

The Linnet ZED-F9P is built around u-blox’s ZED-F9P RTK module. It offers multiband signal reception including GPS L1 and L2 for precise positioning, even in areas with low satellite coverage. In addition to USB-C connectivity, it features UART, SPI and I2C interfaces for easy integration into a variety of UAV and robotics platforms.

Linnet Mosaic X5 RTK-GNSS module is based on Septentrio’s mosaic-X5 module, with multifrequency signal tracking including GPS L5. The module features an onboard CPU that runs a full internal web-based user interface for configuration and monitoring, as well as integrated NTRIP corrections. Other capabilities include built-in anti-jamming and anti-spoofing protection and a spectrum analyzer. Systork, systork.io

MOBILE

“Patch-In-A-Patch” Antenna
Maintains dual-band L1/L5 performance

Inception is a new GNSS L1/L5 ultra-low-profile “patch-in-a-patch” antenna. The HP5354.A offers dual-band stacked patch performance in a single 35 mm x 35 mm x 4 mm form factor. This design integrates the second antenna within the first, eliminating the need for stacking parts and reducing the antenna height by 50%.

The HP5354.A antenna features a passive, dual-feed surface mount design (SMD) to decrease weight and conserve horizontal space. This makes it suitable for GNSS applications requiring high precision and limited space. The antenna improves positioning accuracy from 3 m to 1.5 m while maintaining dual-band L1/L5 performance.

With a passive peak gain of 2.61 dBi, the HP5354.A can be used for GPS L1/L5, BeiDou B1, Galileo E1, and GLONASS G1 operations. Its dual-feed design maintains circular polarization gain even when the antenna is de-tuned or requires in-situ tuning.

It is ideal for applications such as asset tracking, smart agriculture, industrial tracking, commercial UAVs and autonomous vehicles. The HP5354.A uses Taoglas’ custom electro-ceramics formula, ensuring high-quality performance and seamless integration into devices requiring high-precision GNSS.

The Taoglas HC125A hybrid coupler can combine the dual feeds for the L1 patch, offering high RHCP gain and optimal axial ratio for upper constellations including GPS L1, BeiDou B1, Galileo E1 and GLONASS G1. The Taoglas TFM.100B L1/L5 front-end module can be incorporated into the device PCB, aiming to save valuable real estate and up to two years of complex design work, according to the company. Taoglas, taoglas.com

Waterproof GNSS Antenna
Built-in LNA

The external antenna features an adhesive mount and sealed IP67-rated waterproof protection. It is an active GPS/GNSS antenna that includes a built-in low noise amplifier (LNA) for enhanced performance, making it ideal for applications where the receiver is close to the antenna and in environments where signal strength is strong, such as open areas with a clear line of sight.

This type of antenna can amplify weak signals received from satellites by improving signal quality and reducing noise. It requires an external power source to operate the built-in LNA and is less sensitive to signal loss due to longer cable lengths. It is connected to an SMA connector at the end of a 3 m pigtail. The antennas can be used in navigation, location-based services and fleet management applications. Amphenol RF, amphenolrf.com

DEFENSE

AI and Quantum-Powered Navigation System
When GPS signals are compromised

AQNav is designed for navigation across air, land and sea when GPS signals are jammed or unavailable.

AQNav is a geomagnetic navigation system that uses proprietary artificial intelligence (AI) algorithms, powerful quantum sensors and the Earth’s crustal magnetic field. The system seeks to provide an un-jammable, all-weather, terrain-agnostic, real-time navigation solution in situations where GPS signals are unavailable, denied or spoofed.

The system uses extremely sensitive quantum magnetometers to acquire data from Earth’s crustal magnetic field, which exhibits geographically unique patterns. It uses AI algorithms to compare this data against known magnetic maps, allowing the system to quickly and accurately find its position.

It is available globally, does not rely on visual ground features or satellite transmissions to function and is not affected by weather conditions. AQNav can be integrated into a wide variety of platforms. Its passive technology emits no electronic signals, which reduces the aircraft’s detectability. SandboxAQ, sandboxaq.com

PNT Solution
Operates with or without GNSS signals

TRNAV is a terrestrial navigation solution designed to operate with or without GNSS signals.

It establishes a mesh network of ground stations capable of operating independently from GNSS by using precise pre-established locations or connecting to GNSS when available. TRNAV’s synchronized timing system ensures a minimal drift of 10 ns during a week without GNSS.

The system features a re-synchronization capability that allows the entire network to be updated instantly when just one station reconnects to a GNSS satellite, maintaining high precision across all platforms. Users can integrate mobile stations to enhance network flexibility and range, with the potential to cover distances up to 250 km.

TRNAV also offers a high-bandwidth communication channel for communication capabilities within the established network. The system employs AES-256 encryption and advanced waveform technologies, including DSSS/FHSS for robust and secure operations in challenging environments. TUALCOM, tualcom.com

Software-Defined Radio
Designed for mission-critical systems

Calamine is a four-channel wide tuning range software-defined radio (SDR) that can be integrated into mission-critical systems for the defense, GNSS, communications and test and measurement markets.

The SDR offers a tuning range from near DC to 40 GHz with four independent receiver radio chains, each offering 300 MSPS sampling bandwidth. It is tailored to government, defense and intelligence communities and civil users with direct applications for radar systems, signal intelligence, spectrum monitoring and satellite communications systems. Per Vices, pervices.com

C-UAS Solution
For electronic warfare

The Skyjacker is a multi-domain electronic warfare counter unmanned aerial system (C-UAS), suitable against swarms and high-speed threats. It is designed as a response to threats posed by UAVs in the battlespace and at sensitive installations.

Skyjacker alters the trajectory of a UAS by simulating the GNSS signals that guide it toward its target.

Skyjacker is particularly well suited to countering saturation attacks, such as swarming UAVs. The system also can defeat isolated drones piloted remotely by an operator and deliver effects at ranges from 1 km to 10 km (6 mi).

It can be integrated with an array of sensors, such as optronic sights, radars, radiofrequency detectors, lasers, communication jammers and other effectors. Skyjacker can be deployed as a mobile version or interconnected with existing surveillance and fire control systems on land vehicles or naval vessels. Safran Electronics & Defense, safran-group.com

<p>The post Launchpad: GNSS antennas and receivers, UAV upgrades, defense solutions and more first appeared on GPS World.</p>

Photo: Emlid

Emlid has released upgrades for its ultralight Reach RX Network real-time kinematics (RTK) rover. It features MFi (Made for iPhone/iPad) certification and is fully compatible with ArcGIS, QGIS and other GIS apps for both iOS and Android. Reach RX can be seamlessly integrated into GIS workflows to help industry professionals and teams collect accurate geodata at scale. 

Reach RX offers precise positioning while receiving corrections through NTRIP. The device tracks GPS/QZSS, Galileo, GLONASS and BeiDou. It gets a fix in less than 5 seconds, delivering centimeter-level accuracy even in challenging conditions. 

The rover does not require configuration or additional training— surveyors only need to add NTRIP credentials. With its intuitive and straightforward workflow, Reach RX allows users to achieve high precision for engineering, utility inspection, landscaping and other projects of any scale. 

According to the company, the rover will soon be compatible with QField, Blue Marble’s Global Mapper, Mergin Maps, Avenza Maps and more. 

The Reach RX rover weighs 250 grams. The battery provides 16 hours of operation on a single charge and can be recharged from a power bank. The receiver works in a variety of survival environments. The IP68-rated rover is waterproof, dustproof, and withstands temperatures from -20 to +65°C (-4 to 149°F).  

<p>The post Emlid upgrades RTK rover first appeared on GPS World.</p>

SURVEYING & MAPPING

Upgraded surveying software
With an improved CAD engine

Survey Master 3.5.0 includes an enhanced CAD engine. A measurement grade has been added to the CAD to improve the software’s utility in design and planning projects. Additionally, the latest version features expanded CAD drawing and survey functions to offer users a comprehensive toolset — including point, line, polyline, curve, arc, square, rectangle, polygon, circle and text. Survey Master 3.5.0 features CAD capture mode from any point and allows users to easily display or hide point icons.

The system added the Dominican predefined coordinate system, SBAS configuration, PPP and RTK PPP fusion, updated satellite frequencies and an external datalink CDL7 configuration. Existing software users can update directly in Survey Master.
Comnav Technologies, comnavtech.com

Scanning kit
Combines photogrammetry with RTK precision

The Pix4D & Emlid Scanning kit combines advanced photogrammetry with real-time kinematics (RTK) precision for quick data capture when documenting trenches and as-builts, performing volumetric measurements and enhancing aerial data with terrestrial scans. It includes the PIX4Dcatch app and the Emlid Reach RX RTK rover.

The PIX4Dcatch app allows precise scanning for both photogrammetry and lidar projects. The hardware features the Emlid Reach RX RTK rover, which comes with an ergonomic handle and accessories. It is integrated with PIX4Dcatch and provides real-time positioning through NTRIP.

The kit works with any correction network or GNSS base station broadcasting RTCM3. The rover gets a fix in less than five seconds, offering centimeter-accurate positioning in challenging conditions. It can also be used with the survey pole as an RTK rover for data collection and stakeout.

Designed for urban surveying, the Reach RX rover is lightweight, rated IP68, sealed and protected from water and dust.

The PIX4Dcatch mobile app allows users to use a smartphone for scanning, access RTK precision data through integration with Reach RX and generate a digital model within minutes. Users can also store, annotate, measure and share data online in PIX4Dcloud as well as verify geolocated positions and visualize the project in AR. It extracts insights from both terrestrial and aerial data and features online and offline processing, advanced photogrammetry capabilities, team collaboration and AR for CAD overlays.
Emlid, emlid.com

UAV surveying software
Now with planimetric survey capabilities

Virtual Surveyor version 9.5 is a smart UAV surveying program featuring new planimetric survey capabilities. Users can survey 2D features from UAV orthophotos and add them to a 3D topographic model generated from the same data set.

The integrated Terrain Creator app photogrammetrically processes UAV photos to build survey-grade digital surface models (DSMs) and orthomosaics. These transfer seamlessly to the traditional Virtual Surveyor app where users can generate CAD models, create cut-and-fill maps and gather other 3D topographic information.

No third-party software is needed to create surveys from UAV data. The system is ideal for users in construction, surface mining and excavation projects.
Virtual Surveyor, virtual-surveyor.com

RTK technology
For GIS needs

RTK Torch is designed for high-precision geolocation and GIS needs. It has tri-band reception and tilt compensation.

The RTK Torch can provide millimeter-grade measurements. Users can connect a phone to the device over Bluetooth and receive the NMEA output and work with most GIS software.

The RTK Torch features Zero-Touch RTK technology, which gives connected devices WiFi credentials for a hotspot or other WiFi network. The device will begin receiving corrections without any further setup, with no NTRIP credentials required. These corrections are obtained over WiFi from u-blox PointPerfect and are available in the United States, Europe and various parts of Australia, Canada, Brazil and Korea.

The RTK Torch includes a one-month free subscription to PointPerfect. Additional subscriptions can be purchased if desired. If PointPerfect coverage is not available in the area, corrections from a local base station or service can be provided to the device over NTRIP, delivered via Bluetooth or WiFi.

It is housed in an IP67-rated enclosure. It is waterproof when submerged up to 1 m for up to 30 minutes when the USB cover is closed. Under the hood of the SparkFun RTK Torch is an ESP32, a UM980 L1/L2/L5 high precision GNSS receiver from Unicore, and an IM-19 for tilt compensation. The addition of the L5 reception makes this portable GNSS device ideal for densely canopied areas where normal L1/L2 reception may have problems.
SparkFun, sparkfun.com

3D laser scanner
For indoor and outdoor mapping

The VZ-600i terrestrial laser scanner offers a broad range capability from 0.5 m up to 1,000 m and is suitable for indoor and outdoor 3D mapping applications. It features 3D position accuracy of 3 mm, less than 30 sec scan time for high-resolution scans with 6 mm point spacing at 10 m, weight less than 6 kg (13 lbs), 2.2 MHZ PRR, three internal cameras and is GNSS integrated.

Designed for mobile mapping applications, the system is suitable for architecture, engineering and construction (AEC), building information modeling (BIM), as-built surveying, forensic and crash scene investigation, archeology, forestry and more.
RIEGL, riegl.com

OEM

Application suite
Featuring GRIT Technology

The NovAtel Application Suite Version 2.0 now includes GNSS Resilience and Integrity Technology (GRIT). The GRIT Monitor application allows users to observe radio frequency (RF) interference through a comprehensive dashboard to make informed decisions to maintain robust positioning.

GRIT is RF interference detection and mitigation technology available on all OEM7 GNSS receiver products, including individual cards and enclosures such as smart antennas, PwrPak and MarinePak.
It includes positioning and device status overviews to serve as a mitigation assistant that indicates whether interference is detected. It features an interactive spectrum viewer, which shows all constellations and frequency bands (spectrum and waterfall), and a signal matrix indicating the signal quality and interference status by frequency band and constellation.

The updated suite also introduces firmware compatibility and improvements to the user interface and extends support to include MarinePak, among other enhancements. The Manage application, previously known as Setup and Monitor, now supports satellite tracking for L-Band and SBAS and offers a global map view of connected receivers.

Version 2.0 of the NovAtel Application Suite is designed to assist users in maintaining accurate GNSS positioning by quickly identifying and responding to RF interference. This update is targeted to industries that require precise location data, such as aerial mapping, agriculture and autonomous vehicle navigation.
NovAtel, novatel.com

DEFENSE

Upgraded UAS
With silent VTOL capabilities

The VXE30 Stalker unmanned aerial system (UAS) features the new “Havoc” configuration, designed to double the system’s flight endurance and payload capacity.

With the Havoc upgrades, the VXE30 can now support the complex demands of both small tactical units and larger brigade-level operations without extensive reconfiguration. The upgrades are designed to make the UAS more versatile across various military applications.

The VXE30 Stalker UAS has silent, vertical take-off and landing (VTOL) capabilities and is payload agnostic with the Havoc configuration. It supports easy integration of third-party payloads and subsystems through a Modular Open Systems Approach (MOSA), requiring no additional training for current operators.
Edge Autonomy, edgeautonomy.io

CUAS technology
Adheres to NDAA standards

This counter-unmanned aircraft system (CUAS) is a high-speed kinetic interceptor UAS that utilizes advanced autopilot algorithms for calculating and tracking precise target trajectories, neutralizing Group 1 and 2 aerial threats with pinpoint accuracy.

The system is manufactured in accordance with the National Defense Authorization Act (NDAA) to ensure it meets the federal requirements necessary for immediate deployment in both military and industrial settings in the United States.
Nearthlab, nearthlab.com

GPS integrity module
Seamlessly integrates with existing platforms

The Shift5 GPS integrity module is a platform-agnostic solution for military, aviation, rail, maritime and space applications.
With real-time access and analysis of onboard data, the module assesses changes in navigational position through multi-faceted anomaly detection methods, which alert operators to GPS spoofing attacks as they happen.

Using data collected from onboard systems, the module uses algorithmic position analysis to identify significant position deviations and GPS data validation to verify GPS information accuracy. Discrepancies or deviations that indicate tampering trigger an immediate notification, allowing operators to initiate standard operating procedures (SOPs) rapidly and accurately.

The module is designed for cross-platform deployment, across commercial and military planes, locomotives, vessels and aircraft, as well as on other critical systems such as radar, unmanned aircraft systems (UAS) and weapon guidance systems. It seamlessly integrates with existing platforms and can deploy directly to onboard hardware.

It offers multi-faceted detection and alerts for GPS spoofing attempts, designed to improve the safety and reliability of navigation systems. It uses physics-based spoofing detection to determine whether reported changes in position are physically possible to provide an effective method for initial spoofing detection. The system analyzes data from all sources to detect subtle, sophisticated spoofing attempts, which is essential for identifying more complex spoofing strategies that may evade traditional spoofing detection techniques.

Shift5 alerts can be integrated into existing SOPs to help preempt contamination of other positioning and navigation data, such as inertial navigation calibration against false GPS data. Metadata about the time, location, duration and estimated position of the attack can be passed for inclusion in threat mapping and other geospatial systems for future route avoidance.
Shift5, shift5.io

VTOL UAS
Designed for military forces

The Rogue 1 loitering munition UAS is designed to provide military forces with enhanced versatility, survivability and lethality in modern combat environments.

The Rogue 1 is an optionally lethal, vertical takeoff and landing (VTOL) capable of engaging both moving and stationary targets, including armored vehicles and dismounted threats. It features a unique mechanical interrupt fuzing system that allows for the drone to be safely recovered and reused if the mission is aborted or targets are disengaged.

Equipped with advanced electro-optical and FLIR Boson 640+ thermal cameras, Rogue 1 offers day and night long-range reconnaissance and surveillance capabilities. The system’s gimballed payload allows for precise targeting, facilitated by a novel coupling between sensors and warhead. Operators can customize the munition with various modular, mission-specific payloads to effectively engage different types of enemy targets.

It has a flight time of 30 minutes, can reach burst speeds exceeding 70 mph and has an operational range of over six miles, making it suitable for missions in harsh battlefield conditions, including communication- and GPS-denied environments.
Teledyne FLIR Defense, flir.com

UAV

Delivery winch
Improves safety and operational capabilities

A2Z Drone Delivery has released new safety features and hardware upgrades for its RDS2 commercial UAV delivery winch, including a weatherproof cover and an auto-releasing bag hook. This aims to improve safety and operational capabilities as well as aid in regulatory compliance for beyond-visual-line-of-sight (BVLOS) operations.

The system features entanglement auto-detection, which autonomously detects tether entanglements and allows the system to safely abandon the tether to prevent damage to the UAV. This feature can be customized to recognize different types of obstructions, whether at altitude or during the landing phase, enhancing safety across a variety of operational scenarios.

Additionally, the overweight payload rejection feature ensures that the payload weight does not exceed the 5 kg limit. This is useful when picking up payloads from third parties, as it automatically confirms that the weights are within safe flying limits before proceeding with the mission. The RDS2 now includes Tether Lifecycle Alerts, which notify operators when the winch’s tether, rated for up to 800 deliveries, requires replacement.
A2Z Drone Delivery, a2zdronedelivery.com

Integration platform
For fully autonomous operations

Flinks is designed for one-click integrations with third-party applications and devices. The platform aims to streamline the coordination of various systems involved in UAV operations, creating end-to-end automated workflows for fully autonomous systems.

It allows users to connect the FlytBase platform with critical business systems such as alarm systems, video management, data processing and more. By eliminating the need for complex, time-consuming manual interventions, Flinks is designed for users to seamlessly incorporate autonomous drones into their existing operations.

By joining the Flinks Partner Program, organizations can access FlytBase’s global network of UAV service providers, system integrators and enterprise customers.
FlytBase, flytbase.com

MACHINE CONTROL

Antenna
Integrates with heavy construction equipment

The iCON 120 machine smart antenna offers scalable and flexible machine control solutions for construction professionals.

The iCON 120 is a GNSS antenna intended for integration within the existing Leica MC1 platform. Using the iCON 120, operators can benefit from a tailor-made, Leica MC1-based machine control, allowing for more streamlined operations and consistent workflows with a variety of heavy construction equipment and application requirements.

Leica iCON 120 users can start with a single GNSS solution using a satellite-based augmentation system (SBAS), such as WAAS or EGNOS, or a HxGN SmartNet service. The HxGN SmartNet family offers network real-time kinematics (RTK) with RTK bridging and precise point positioning (PPP) services that work exclusively with Leica Geosystems GS sensors. The new smart antenna can be easily switched, with quick mounting and dismounting, between Leica MC1-prepared machines.

Users can optionally upgrade their basic-level machine-control solution with the Leica CR50 communication unit to receive RTK correction data via radio or modem. The CR50 features a web interface, automotive ethernet communication, worldwide cellular modem and integrated dual-frequency UHF radio.
Leica Geosystems, leica-geosystems.com

GNSS smart antenna
For construction Site Positioning

The R780 GNSS Smart Antenna is designed for construction site positioning. It features a dual-band radio (450/900 MHz) that connects to diverse base stations and job sites without additional external radios. The dual Trimble Maxwell 7 GNSS ASIC chip allows the system to perform in challenging GNSS environments such as a blocked sky, multi-path or degraded signal.

An activated and ready-to-use Trimble CenterPoint RTX subscription is included for the first 12 months. CenterPoint RTX is point positioning technology that provides real-time, centimeter-level corrections via satellite or cellular/IP.

Using the R780 with Trimble FieldLink software supports underground and long-distance layout projects as well as QA/QC and field positioning tasks. The R780 can serve as a GNSS rover or as a base station for other GNSS operations including machine control.
Trimble Civil Construction, heavyindustry.trimble.com

<p>The post Launchpad: Upgraded surveying software, application suite, GPS integrity module first appeared on GPS World.</p>

Photo: Emlid

Emlid has launched the Pix4D & Emlid Scanning kit. The kit combines advanced photogrammetry with real-time kinematics (RTK) precision for quick data capture when documenting trenches and as-builts, performing volumetric measurements and enhancing aerial data with terrestrial scans. It includes the PIX4Dcatch app and the Emlid Reach RX RTK rover.

The PIX4Dcatch app is at the core of the kit’s software, which allows precise scanning for both photogrammetry and lidar projects. The hardware part features the Emlid Reach RX RTK rover, which is equipped with an ergonomic handle and accessories.

It is integrated with PIX4Dcatch and provides real-time positioning via NTRIP. To begin scanning, users can select Emlid in the RTK settings of PIX4Dcatch and add their NTRIP network credentials.

The kit works with any correction network (NTRIP) or a GNSS base station broadcasting RTCM3. The rover gets a fix in less than five seconds, offering centimeter-accurate positioning in challenging conditions. Apart from the scanning tasks, it can be used with the survey pole as an RTK rover for data collection and stakeout.

Designed for urban surveying, the Reach RX rover is lightweight, rated IP68, sealed and protected from water and dust and features an industrial-grade battery, which offers 16 hours of work on a three-hour charge.

The solution does not require additional setup or surveying skills. It is designed for professionals and non-surveyors in a range of applications, including underground utility documentation, construction inspection, volumetric measurements, crash reconstruction and combined aerial and terrestrial surveys.

The PIX4Dcatch mobile app allows users to use a smartphone for scanning, access RTK precision data through integration with Reach RX and generate a digital model within minutes. Users can also store, annotate, measure and share data online in PIX4Dcloud as well as verify geolocated positions and visualize the project in AR. It extracts insights from both terrestrial and aerial data and features online and offline processing, advanced photogrammetry capabilities, team collaboration and AR for CAD overlays.

<p>The post Emlid, Pix4D launch mobile terrestrial scanning kit first appeared on GPS World.</p>

SURVEYING & MAPPING

MEMS IMU
Suitable for rugged environments

The TAC-440 MEMS inertial measurement unit (IMU) is designed for demanding, mission-critical, rugged environments in a wide variety of defense, commercial, industrial, and marine applications. The TAC-440 features 1°/hr gyro bias and 1 mg accelerometer bias stability with 0.05°/√hr angle random walk over a wide temperature range. The solid-state quartz sensors and hermetically sealed IMU construction provide reliable MTBF and storage life, EMCORE stated. The TAC-440 supports four data message synchronization methods with either input synchronization pulse capability or an output time of validity capability. The user can choose whether the synchronization pulse is internally generated and output as a time of validity of the output data or whether the TAC-440 software will identify the synchronization pulse input and synchronize the output data to the input pulse.
EMCORE Corporation, emcore.com

RTK GNSS Tablet
A rugged device designed for geospatial and mapping operations in the field

The LT800H offers users robust outdoor performance, data security and centimeter-level accuracy for a variety of applications, including construction, environmental surveying and any industry in which Android tablets are used. Featuring a high-performance 1,408-channel GPS, GLONASS, Galileo and BeiDou module and a tracking GNSS helix antenna, the LT800H RTK Android tablet offers centimeter-to-decimeter positioning accuracy in challenging environments. It also comes equipped with a 4G modem to simplify connectivity to GNSS RTK network corrections. The technology also offers an eight-hour battery life, allowing users to collect data in the field uninterrupted.
CHC Navigation, chcnav.com

PPK Software
For land surveying, hydrography, airborne surveys, construction, and applications that require precise positioning

The Qinertia 4 contains an enhanced geodesy engine that has an extensive selection of preconfigured coordinate reference systems (CRS) and transformations, making it a suitable solution for applications that use diverse geodetic data. To tackle the challenges of variable ionospheric activity, Qinertia 4 features an Ionoshield post-processed kinematic (PPK) mode. This feature compensates for ionospheric conditions and baseline distances, enabling users to perform PPK even for long baselines and/or harsh ionospheric conditions. This ensures surveyors can achieve centimeter accuracy even in regions with unpredictable ionospheric disturbances. Another addition to the Qinertia 4 is an extended network support for continuously operating reference stations (CORS). This feature gives users access to a network of 5,000 SmartNet CORS for reliable GNSS data processing. These base stations add to the network of base stations directly available in Qinertia, bringing the total to more than 10,000 bases in 164 countries.

For data that cannot be processed using PPK, Qinertia 4 offers an alternative solution with its tightly coupled precise point positioning algorithm. This new processing mode, available for all users with active Qinertia maintenance, provides post-processing anywhere in the world without a base station, with a horizontal accuracy of 4 cm and a vertical accuracy of 8 cm.
SBG Systems, sbg-systems.com

Airborne Lidar + RGB System
Designed to enhance the details of aerial mapping operations

The AlphaAir 10 (AA10) features a high-precision navigation algorithm that provides 5 mm repeated range accuracy and achieves absolute precision in the 2 cm to 5 cm range, even in complex environments. The AA10 is capable of long-range measurements of up to 800 m, rapid scanning at 500,000 points per second, and features a continuously rotating mirror that enables scanning speeds of 250 scans per second. The AA10 enables the creation of mesh models by generating high-quality point clouds. It is powered by a 45 MP orthographic internal camera that provides high-resolution image mapping textures for 3D model reconstruction with realistic point cloud colorization. The AA10 also supports automated reality capture and real-time data visualization accessible directly from the UAV controller. The AA10 lidar system is lightweight and compact, weighing 1.55 kg, and provides a 30 min operating time when integrated with UAVs such as the DJI M350. The system is also IP64-rated.
CHC Navigation, chcnav.com

GNSS Receiver
Designed for survey projects

The Reach RS3 is a GNSS receiver that features inertial measurement unit (IMU) tilt compensation and a dual-band radio for enhanced compatibility with third-party receivers. The Reach RS3 enables users to survey at large tilt angles while maintaining survey-grade accuracy. The multi-band receiver works both as a base and a rover and comes factory calibrated. The receiver offers versatile options to get corrections from continuously operating reference stations (CORS), another Reach device, or a third-party base, so users can mix and match real-time-kinematic (RTK) receivers in a fleet. Its NTRIP connectivity enables corrections from CORS, NTRIP service, or a GNSS receiver using Emlid NTRIP Caster. When connected over NTRIP, Reach works on a baseline of more than 60 km in RTK and 100 km in post-processed kinematic.
Emlid, emlid.com

GNSS Receiver
Includes Trimble ProPoint and delivers survey precision and productivity in the field

The R580 GNSS receiver enables professionals in surveying, mapping and GIS, civil construction, and utilities to capture centimeter-level positioning. With the Trimble ProPoint GNSS engine embedded, users can measure points in challenging environments, such as under tree canopy or near buildings, while EVEREST Plus technology can identify and remove unwanted multipath signals for improved accuracy and data confidence. Using the Maxwell 7 chipset technology, the receiver provides fast processing, anti-spoofing capability and the ability to track all available GNSS constellations. The R580 supports Trimble RTX correction services for RTK-level precision without the use of a local base station or VRS network wherever correction sources are available. The receiver can be paired with all current mobile devices on a variety of operating systems and platforms —from a Trimble handheld or controller to a modern smartphone or tablet. It can also be mounted on a pole, vehicle or backpack.
Trimble, trimble.com

OEM

GNSS Module
Supports L1/L5 GNSS bands from multiple constellations, including NavIC

The NEO-F10N positioning module is based on the u-blox NEO form factor and is equipped with u-blox F10 dual-band GNSS technology. The NEO-F10N supports L1/L5 GNSS bands from multiple constellations — including NavIC — to provide meter-level position accuracy in urban areas. Its firmware is upgradeable and configurable to support several applications such as the vehicle telematics and micromobility markets or industrial applications requiring meter-level position accuracy. The NEO-F10N improves position accuracy in urban environments with its enhanced resilience against multipath interference. By leveraging signals from both the L1 and L5 bands, this module achieves better accuracy than using the L1 band alone. Users currently employing receivers based on modules such as the u-blox NEO-M8 and NEO-M9, can migrate to the new NEO-F10N generation. The module enhances accuracy, reduces power consumption, and offers an alternative solution to users who do not want to deploy dead reckoning set-ups.
u-blox, u-blox.com

Multi-Band GNSS Antenna
Designed to enhance meter-level positioning solutions

The ANN-MB5 is a multi-band (L1/L5/E5a/B2a) GNSS antenna that is optimized for the u-blox F10 platform and enables precise, reliable, and robust positioning, even in challenging environments. The antenna features concurrent reception of multiple navigation systems, including NavIC. The ANN-MB5 has a compact design with a magnetic base.
u-blox, u-blox.com

INS
A product for mobile mapping, autonomy, and more

The xRED3000 inertial navigation system (INS) offers quad-constellation GNSS support for multiple applications. The INS weighs 20 g, making it suitable for aerial payloads. At 53.6 mm x 50.6 mm x 9.5 mm in size, it can be incorporated without drastically changing a user’s design. When in a GNSS-denied area, the xRED3000 provides a position accuracy of 0.5 m even after 60 seconds. It features gx/ix tight-coupling algorithms, which improve accuracy in urban canyons and speed up real-time kinematic reacquisition after temporary GNSS outages. The xRED3000 features lidar inertial odometry, which takes data from lidar in post-processing to reduce inertial measurement unit drift and improve accuracy in areas with poor or no GNSS signal. Additionally, embedded NTRIP makes it easier to get GNSS corrections.
OxTS, oxts.com

Triple Frequency GNSS Receiver
Complete with a compact design for mobile applications

The BD990 supports triple frequency for the GPS, GLONASS, BeiDou and Galileo constellations. The receiver offers quick and reliable real-time kinematic (RTK) initializations for centimeter positioning. It features Trimble Maxwell 7 technology, which provides 336 tracking channels, Trimble Everest Plus multipath mitigation, and advanced RF spectrum monitoring and analysis. With the option of utilizing OmniSTAR or RTX services, the BD990 delivers varying levels of performance down to centimeter-level without the use of a base station. The BD992 also supports dual antenna GNSS heading while the BD992-INS supports position and orientation at high update rates.
Trimble, oemgnss.trimble.com

MACHINE CONTROL

Automated Steering System
Designed for precision agriculture applications

The SAgro150 automated steering system aims to provide farmers with an easy way to get started with auto-steering. With full-constellation tracking capability, the SAgro150 realizes ±2.5 cm auto-steering accuracy to maximize land use and yield while saving resources such as water and fertilizer. When compared to the first-generation SAgro100 system, the SAgro150 auto-steering system uses a single-antenna solution instead of a dual-antenna solution. It also features simpler integration options, only requiring a strong magnetic chuck to securely attach the antenna to the top of the tractor for satellite signal tracking. The new system also adopts dual gyroscope mode, enhancing the heading data reliability and compatibility with different tractors. The new system aids in applications such as rotary tillage, ridging, sowing and harvesting in straight line, curve, U-turn and more.
SingularXYZ, singularxyz.com

Positioning and Heading Receiver
Designed for multiple applications

AsteRx SB3 Pro+ is a housed multi-frequency GNSS receiver that uses triple-band GNSS technology for reliable centimeter-level real-time kinematic (RTK) positioning and sub-degree heading. With flexibility to be used as a rover or a base station, AsteRx SB3 Pro+ also has an ultra-high update rate and logging functionality. Enclosed in a ruggedized IP68 housing, the device is suitable for harsh environments. The AsteRx SB3 Pro+ has a high update rate and low latency for fast moving vehicles or machine parts.
Septentrio, septentrio.com

GPS Antennas
Offers enhanced navigation and tracking for automotive applications

The KP Performance vehicle GPS antennas come equipped with a gain of 28 dB to capture weak signals, even in the most challenging environments. The antennas also feature high out-of-band rejection. By minimizing signal interference and multipath effects, the antennas provide good signal quality and stability. The features of the antennas enable more precise navigation and enhanced user experiences for personal vehicles, commercial fleets, or autonomous systems. The antennas have a IPX6- or IP66-rated waterproof and dustproof design for reliable operation in harsh conditions.
KP Performance, kpperformance.com

<p>The post Launchpad: New GNSS receivers, antennas and PPK software first appeared on GPS World.</p>

Image: Emlid

Emlid has launched a GNSS receiver, the Reach RS3. It features inertial measurement unit (IMU) tilt compensation and a dual-band radio for enhanced compatibility with third-party receivers.

The Reach RS3 enables users to survey at large tilt angles while maintaining survey-grade accuracy. The multi-band receiver works both as a base and a rover and comes factory calibrated.

The receiver offers versatile options to get corrections from continuously operating reference stations (CORS), another Reach device, or a third-party base, so users can mix and match real-time-kinematic (RTK) receivers in a fleet.

Its NTRIP connectivity enables corrections from CORS, NTRIP service, or a GNSS receiver using Emlid NTRIP Caster. When connected over NTRIP, Reach works on a baseline of more than 60 km in RTK and 100 km in post-processed kinematic. Emlid has launched a GNSS receiver, the Reach RS3. It features inertial measurement unit (IMU) tilt compensation and a dual-band radio for enhanced compatibility with third-party receivers.

The Reach RS3 enables users to survey at large tilt angles while maintaining survey-grade accuracy. The multi-band receiver works both as a base and a rover and comes factory calibrated.

The receiver offers versatile options to get corrections from continuously operating reference stations (CORS), another Reach device, or a third-party base, so users can mix and match real-time-kinematic (RTK) receivers in a fleet.

Its NTRIP connectivity enables corrections from CORS, NTRIP service, or a GNSS receiver using Emlid NTRIP Caster. When connected over NTRIP, Reach works on a baseline of more than 60 km in RTK and 100 km in post-processed kinematic.

<p>The post Emlid releases GNSS receiver with tilt compensation first appeared on GPS World.</p>

Image: Emlid

Emlid has released Emlid Studio, a new post-processed  kinematic (PPK) application designed specifically for post-processing GNSS data. The app is free and available for Windows and Mac users.

Emlid Studio features a simple interface to make post-processing easy. The app allows users to convert raw GNSS logs into RINEX, post-process static and kinematic data, geotag images from drones (including DJI brand), and extract points from survey projects completed with Emlid’s ReachView 3 app.

With Emlid Studio, users can post-process data recorded with Emlid Reach receivers and other GNSS receivers or NTRIP services. Post-processing requires RINEX observation and navigation files. Raw data in UBX and RTCM3 format also can be used — Emlid Studio will automatically convert them into RINEX.

The post-processing workflow is straightforward. Users can receive precise positioning of a single point or track depending on the positioning mode. Users can simply add several RINEX files and enter the antenna height, click the Process button, and Emlid Studio will do the rest. Once the resulting position file is ready, the plot will show the result.

Another tool is available for the users of Reach receivers and the ReachView 3 app. The Stop & Go feature allows users to improve the coordinates of points collected in single or float modes.

Geotagging for drone mapping. Adding geotags to images’ EXIF data requires aerial photos and the POS file with the events. Emlid Studio also provides a chance to update data from the RTK drone in case of a float or single solution during a survey. A set of RINEX logs from a base and drone, an MRK file and images from the drone are dragged and dropped into specific file slots, providing result in seconds.

<p>The post Emlid Studio released for GNSS post-processing first appeared on GPS World.</p>

By Gavin Schrock, PLS

For many on the development side of high-precision real-time kinematic (RTK) GNSS, like those we interviewed for this article, the incorporation of high-rate solutions into their RTK products is a given — and has been for a very long time. Yet, in some end-user communities there may still be many question marks: Does my gear do it? Does other gear do it? What can it do for me? What are the pluses and minuses?

We asked for insights from 10 prominent firms that develop and manufacture RTK-enabled high-precision GNSS solutions and equipment, spanning multiple applications:

• Bad Elf
• CHC Navigation
• Emlid
• Hemisphere GNSS
• Hexagon | NovAtel
• Leica Geosystems
• Septentrio
• Tersus GNSS
• Topcon
• Trimble

First, however…

What is high-rate RTK?

By high rate, we mean higher than 1 second (1 Hz) increments, such as 0.2 second (5 Hz), 0.1 second (10 Hz), etc. Part of the confusion about high-rate RTK is that there are two scenarios. One is transmitting corrections from a base or network at high rate, receiving and solving on-the-field sensors or rovers at a high rate (for example, 5 Hz base + 5 Hz rover).

The other is base transmission of corrections at a lower rate and receiving/solving on the rover at a higher rate (for example, 1 Hz on the base + 5 Hz or more on the sensor/rover).

While both can be valuable for different applications, what has been adopted as standard for most surveying, construction, agriculture and mapping applications is the latter.

What are applications that would run the base and rover at higher than 1 Hz? “Moving Base” applications are prime examples, where you are seeking to resolve positions for one or more sensors relative to a base that is also on a moving platform. Think of a barge on the ocean where a helicopter (or rocket) might be landing. Here is a definition from the user manual for a popular OEM receiver that has been in many makes and models since 2003:

“Moving Baseline RTK is an RTK positioning technique in which both reference and rover receivers can move. Moving Baseline RTK is useful for GPS applications that require vessel orientation. [For example, the] reference receiver broadcasts [correction] data at 10Hz, while the rover receiver performs a synchronized baseline solution at 10Hz. The resulting baseline solution has centimeter-level accuracy. To increase the accuracy of the absolute location of the two antennas, the Moving Reference receiver can use differential corrections from a static source, such as a shore-based RTK reference station.”

Beyond such specialized applications, running the base at a high rate is a burden on radios or bandwidth. Additionally, as industry experts explain below, it is of little (or no) value and may only unnecessarily use excess bandwidth and burden broadcast radios.

When would you run the base at 1 Hz and the rover at higher than 1Hz, such as 5Hz, 10Hz, or more? When the base is static. That pretty much covers nearly all surveying, mapping, precision agriculture and construction applications. What is meant by high rate in the sensor/rover receiver and its RTK engine, in the context of such applications? As one of the firms interviewed stated:

“The number of RTK position fixes generated per second defines the update rate.”

For most of the surveying, mapping, precision agriculture and construction applications, that means base 1 Hz + rover 5 Hz or 10 Hz. Then there are specialized applications, such as structural monitoring and geophysical studies, that may run sensors/rovers at 20 Hz, 50 Hz or (though rare) as high as 100 Hz. Whether a higher rate is a default, or 1 Hz is the default, changing the rate is almost always a user-configurable option.

A general perception is that base-rover gear defaults to base 1 Hz + rover 1 Hz. However, as the experts below note, that is not necessarily the case — often the rover rate is higher by default.

By any other name…

The respective approaches, and their appropriateness for different end-use applications, may seem fairly straight forward. However, part of the confusion about the subject for end users comes from the wide range of terminology used to describe how high rate is applied across the industry.

The understanding of processing approaches is clear among GNSS engineers, and in specific terminology, but this rarely gets translated well or consistently in terms meaningful to end users in documentation or marketing.

Developers might have different approaches to achieving high-rate solutions and would of course not wish to completely reveal their cards, but many of the fundamentals are the same. A mutual recognition of parallel development among GNSS engineers, and the manufacturers they develop for, in that each strives to continually improve solutions, means that the high-rate element of RTK generally does not get much marketing hype.

Often, when high-rate RTK does get laterally mentioned — in manuals, marketing or labeled as configuration options in GNSS field software — the mix of terms can confuse the user. Such terms as extrapolation, prediction, update rate and solution rate could evoke a negative connotation to an end user who is used to hearing one set of terms, and they might view otherwise like terms as contrasting terms.

GNSS engineers do not have issues with mixed terms. As some indicated in their respective interviews, they seem a bit puzzled as to why anyone would misunderstand the subject, and how marketing spin might lead users to be confused.

In recent years, the subject seemed to get discussed a lot more than usual in various high-precision end-user social media platforms. Perhaps this was a natural progression in growth of understanding of the nature of GNSS among these constituencies, and a desire to know more about what goes on in those black boxes — a positive thing. There may also have been some instances of marketing nudge.

For whatever reason it became a subject of discussion, we heard from readers who asked us to look into it. So here, in alphabetical order, are insights from of the experts in this field. You can jump ahead to the specific section for your equipment vendor, but we encourage you to read through each; combined, they provide a more complete picture of the subject.

Bad Elf

With Larry Fox, VP for Marketing and Business Development

Larry Fox uses the Bad Elf Flex. (Photo: Bad Elf)

Bad Elf has long provided GNSS solutions for aviation- and mapping-grade field applications. Several years ago, the company introduced a survey-grade-precision system, Flex. It is offered with an option for a modest initial investment in the hardware, and an innovative token system for enabling and operating at centimeter precision.

Larry Fox has been in the industry for a long time and has seen the evolution of real-time GNSS. He is Bad Elf’s vice president for marketing and business development, but he also had a key role in the development of the Flex system. Fox said that, of course, high-rate RTK is supported. “We allow options up to 20 Hz on the rover if the user has this enabled.”

For the approach of 1-Hz base and higher rates on the rover, he said that Bad Elf does not have a specific term for this. “For purposes of description, I could refer to it as high update rate, but I suspect high solution rate is pretty much synonymous.”

Fox explained how the standard approach works. “The rover knows the location of the fixed base and therefore applies the same processing techniques by simply reusing the last received data.”

He also mused about various hypothetical scenarios. “Given that the converse is also possible — a slow data rate from the base, say, 0.2 Hz at the base and 1 Hz at the rover — is there fundamentally any difference?”

For many applications, Fox does not see a substantial advantage in running at higher rates: “I see no benefit for higher data rates in a static situation such as a survey. I would argue that in a survey workflow, one should allow the RTK algorithm to settle over the static shot being taken, as the RTK algorithm likely benefits from aging out some of the data it used while moving.”

He adds, “I would suggest that once you have occupied a point for a modest amount of time and you remained fixed, I can’t see any benefit. My argument here is that by the time you have leveled and prepared your collector of choice, any decent RTK receiver with a good sky portrait and good corrections will not observe any benefit.”

As for disadvantages and trade-offs, “More and faster data,” Fox said, “must be better, correct? Sarcasm included. Unless there is a tangible need for more samples, what is one going to do with all the extra data? I could have seen a possible argument that a single constellation receiver may benefit from averaging, but that could be a be a whole different subject as multi-constellation is now standard. Arguably, at a higher data rate one could capture more epochs and reduce the time on station. With multi-constellation receivers I am just not convinced that these techniques have the same merit they may have had in the past.”

Bad Elf doesn’t  support higher correction transmission rates from the radio. “The current module only supports RTCM3 at a 1Hz rate,” Fox said. “Even if we could transmit faster, the payload required would exceed the capability of the message transmission rate of the radio. The battery life of a radio is directly correlated to the transmission duty cycle. The more you are transmitting, the less battery life you will have. I would argue this would impact the useful field time you would have without an external battery solution.”

Fox notes that any application where a rover is moving — such as on a vehicle or for machine control — could benefit from high rate. “I could see a potential application for drones,” he added. “I would want to have the epoch of an image recording very tightly coupled to the image captured. Fundamentally, an RTK drone’s imagery is only as good as that. If one was taking video at any reasonable framerate, a higher frequency RTK GNSS may benefit the geolocation of more individual frames with less extrapolation.”

What about rates higher than 20 Hz? “We have run our receiver up to 20 Hz on the rover side. Although there are units capable of even higher rates, I don’t have any data that would convince me that this is viable, for mapping or surveying.”

I asked about some of the misunderstanding out there about high-rate RTK, and Fox replied, “We can be creatures of habit and tie ourselves to beliefs that ‘this is the way I did it and it worked then.’ People should always ask themselves the question, ‘do I still need to do it this way?’ Again, there is the premise that more is better. I can’t tell you how many times I have seen people collect very high-rate data for lines and poly features only to decimate the data because it reduced performance, increased storage, or lowered the performance of the apps rendering the data.”

Emlid

With Svetlana Nikolenko, Lead Application Engineer

Photo:Svetlana Nikolenko with an Emlid GNSS receiver. (Photo: Emlid)

Emlid, a relatively new entrant to the market for high-precision GNSS, has made a splash with their line of affordable systems, such as the Reach RS2 rover and base-rover kits, and RTK systems for UAVs.

“All our devices support this,” said Svetlana Nikolenko, lead application engineer. “We do not have a special term for this, as it is simply a standard. We recommend 5 Hz and higher for a moving rover, but it can be overkill for a stationary one.”

Asked why one would want to run at high rate, Nikolenko explained, “The need to set a higher update rate depends on the rover’s velocity and acceleration. The higher the update rate, the more solutions per second are calculated. So, if you’re moving fast, the higher update rate simply allows you to keep your position current. If the rover is stationary, there are no issues with working at 1 Hz. Still, there is nothing wrong with running a stationary rover at 5 Hz or higher: it is excessive,  but produces more samples with different satellite geometries.”

For moving applications such as UAVs, higher rates are of value. “It really depends on velocity,” Nikolenko said. “For example, if the rover is on a drone flying at a speed of 5-20 m/s and the update rate is set to 1 Hz, you won’t have the actual positions of the images. The higher update rate our devices have is 10 Hz, and at a drone speed of 20 m/s, even if you take photos each second (which might be a bit excessive), you’ll get accurate positions.”

Using an Emlid receiver in harsh conditions. (Photo: Emlid)

Emlid does not support a moving base. However, if there is a strong demand from users, they will consider adding this. For non-moving applications, Nikolenko said, an approach of broadcasting from the base at a high rate is excessive. “This increases the load on the radio (or any other connection link) because the base sends its position and corrections to the rover as often as it calculates it. Anything excessive simply adds load to processors and batteries.”

CHC Navigation

With Carlos Cao, Technical Manager for the Asia-Pacific region

CHC Navigation, or CHCNAV, has steadily grown as a recognizable brand of GNSS and other geospatial products internationally. While the brand might be new to some in North America, in some regions of the world CHC has a substantial share of the market, selling hundreds of thousands of units over the past 15 years. The company develops its own solutions, but also incorporates OEM components. In all cases, CHCNAV has provided high rate as standard from its earliest days.

Multi-constellation rover with tilt compensation. (Photo: Schrock)

Carlos Cao, technical manager for the Asia-Pacific region, said that his company supports the approach of broadcasting at 1 Hz and solving at higher rates on the rover. “For example, you can get coordinates every 0.2 seconds in the Landstar 7 Topo Survey software,” said Cao. “Meanwhile, with different OEM boards, RTK models and supported software, [the equipment] can also reach 10-Hz or 20-Hz static data recording and NMEA data output (including GNGGA coordinate data).” Their term for solving RTK solutions at a high rate on the rover is “high update rate.”

This can bring advantages, specifically for moving applications, Cao said. “When you stake out, the 5-Hz update rate brings faster coordinate updates, especially when surveyors walk quickly. When you survey by time during movement, you can get denser points; while you survey by distance, the accuracy will be better if you are at high speed. For example, speed is 6 m/s, and you want to survey a point every 5 meters; 1 Hz update rate cannot do this with high accuracy.”

When would 1Hz be sufficient? “Normally,” Cao said, “a 1 Hz update rate is enough for a topography survey because users won’t survey at a high speed, so our default setting is 1 Hz, though you can choose higher rates if enabled and as needed. Unless you are moving, however, such as when some surveyors mount a rover on a vehicle, there is no significant difference in the final results.” He added that running at high rates can drain the battery faster.

Broadcasting at higher rates has several major issues. “With more satellites launched, especially BeiDou, correction data becomes much larger,” Cao said. “It means that network RTK requires more data flow, and UHF radio RTK needs a UHF modem that can send data at a high rate. It is a very big challenge for base RTK.”

Meanwhile, notes Cao, “The rover could even have a correction age of 5 or 10 seconds, and it will use the previous package to calculate the position. Since 1-Hz base and 5-Hz rover can work without degradation of precision, there’s no need to change the base to 5 Hz.”

Other applications CHC supports often use higher rates. “Navigation, machine control and precision agriculture normally use a 10-Hz, 20-Hz or 50-Hz update rate,” Cao said, “because these devices work under high-speed movement status, especially navigation. Also, they need to combine with high-update inertial measurement unit (IMU) data. The max update rate is 50 Hz. Normally the application data for these uses is NMEA data output by COM port or TCP/IP protocol. For surveying applications, such as topography, 1-Hz base and 5-Hz rover is enough. For other applications that need higher rates, we also provide such devices.”

Hemisphere GNSS

With Kirk Burnell, Senior Product Manager

Kirk Burnell

“At Hemisphere, we simply refer to this as RTK,” said Kirk Burnell, senior product manager for Hemisphere GNSS. Burnell added that they do not have any special term for this — it is simply a standard.

We were discussing specifically the approach of solving on the rover at higher rates than the base corrections. “All Hemisphere RTK products can work in this way, meaning corrections can come in at 1 Hz or slower, and rover output can be at 1 Hz, 5 Hz or 10 Hz as the user sees fit and as the application demands.”

Hemisphere develops GNSS and multi-sensor solutions for many industries: surveying, construction, agriculture and more. While Hemisphere has its own branded survey rovers, its OEM boards are in many other popular rover brands, makes and models. So, whichever you are running, you get high rate as a standard option.

Hemisphere’s receivers are frequently used in construction applications. (Photo: Hemisphere GNSS)

Burnell explained further that this is a given in the industry. “This is the standard expectation for RTK amongst our competitors, based on their product offerings, documentation, and standard operation. When describing RTK, the expectation is for 1-Hz base-station corrections, and a user-selectable rover output rate. Understandably, when people discuss RTK in technical terms, they may use different phrases to help distinguish between different techniques, which is why there might be different phrases out there. For us, it is simply RTK.”

As for the benefits of high rate, Burnell explained that inside the receiver, the measurement engine and RTK algorithms are typically running at 10 Hz or 20 Hz, and the selected output rate of the solution does not impact the RTK engine’s performance. The receiver will fix as fast and as accurately as possible given the quality of the RTK correction stream. Survey users could see a smoother update rate on their screen using 5 Hz compared to 1 Hz. This makes such tasks as leveling the rod or watching the change in height on screen while moving from the bottom to the top of a curb feel more natural. The user is not waiting an extra second each time to see the stability of the output. “A 5-Hz update rate is a good tradeoff for smooth workflows versus consuming CPU and battery power, compared to 10 Hz or 20 Hz,” he explained.

Would there be a disadvantage to simply running the rover at 1 Hz? “When using a 1-Hz update rate to the data collector, there will be fractions of a second spent waiting for the screen to update,” Burnell said. “Over the course of a day’s work, this could add up to a few minutes of extra time spent. In reality, this does not impact the ability to deliver a job on time. If the user does not feel impeded by the slower update rate of the screen, there is not a significant difference between the quality of the data, comparing 1 Hz and 5 Hz.”

Addressing one misconception that some users have about high rate, that it might significantly improve precisions, Burnell clarified, “For classic RTK surveying, outside of the workflow differences for the surveyor, the same quality of data is produced.”

Disadvantages? “Once you move beyond 5 Hz you start to exceed people’s hand-eye coordination ability, and the benefits diminish,” said Burnell. “Additionally, the data collector has a lot of communication to process, data to unpack, calculations to do, and screen refreshes to accomplish. Faster than 5 Hz leads to stresses in these aspects of the user experience, and ultimately can consume the data collector’s batteries at a faster rate.”

There have been instances of high rate being marketed as enabling users to save a lot of time, but as Burnell noted, this might actually be a potential problem. “There could be a false sense of having no latency, which could lead to rushing through a job, increasing the chances of making a mistake. A surveyor’s observations and measurements are the currency of their trade, and they should be made with care and attention to the work being done. Most surveyors take pride in a job well done.”

Regarding the other scenario, broadcasting at a high-rate and solving on the rover at the same high rate, “This mode of RTK operation has little or no benefit and a host of drawbacks,” Burnell said. “The biggest issue is the volume of data. For a multi-frequency multi-GNSS solution, there is an immense amount of data to be transmitted from the base to the rover. Running a link at 5 Hz requires huge data bandwidth generally only possible using an internet link as compared to a 450-MHz or 900-MHz radio link. Drawbacks for internet links are data volume costs. For dedicated radio links, the issue is most likely to impact radio range. To send five times as much data, the over-the-air baud rate needs to be five times greater. This means that the energy per bit of data is five times less when at high speed. The signal will lack the ability to punch through obstacles. While some may suggest that having five times as many corrections reach the rover compensates for this, some radio protocols can be configured to transmit multiple retries with 1-Hz data.”

However, there are advantages to running at higher rates for specific applications, Burnell said. “If data is being collected in a kinematic fashion as compared to shooting individual points, there will be more detail when collecting at 5 Hz. For example, driving along a road with a receiver mounted to the roof, in 1 minute of driving there will either be 60 measurements at 1 Hz or 300 measurements at 5 Hz. For many non-survey applications, this is critical. For example, at highway speed, 1-Hz data means 1 point every 30 meters (100 feet) or so. In machine control, the systems are not relying on hand-eye coordination and reaction time, and 20 Hz or 50 Hz are common speeds. Autonomous applications also typically use between 10 Hz and 50Hz for GNSS, and often combine this with 100-Hz or 200-Hz IMU data. Aerospace and defense applications have demanding conditions and use 100-Hz to 200-Hz IMU data to navigate, often combined with 1-Hz, 10-Hz or 20-Hz GNSS data.

There are even some applications for which it is warranted to broadcast corrections at rates slower than 1 Hz. “One example was a user in Japan, where radio links are often throttled to 4800 baud,” said Burnell. “They were looking to see how to slow down corrections to less than 1 Hz so that they could take advantage of multifrequency multi-GNSS RTK. Another example: I recently asked for some 10-Hz rover data for analysis. With very large files, analysis took much longer — I wished I had asked for 1-Hz data!”

Hexagon | NovAtel

Hexagon | NovAtel is a prominent tech firm providing positioning, navigation and timing (PNT) solutions for multiple industry segments, including defense, surveying, construction, agriculture, autonomy and more. While GNSS is a core technology, NovAtel develops multi-sensor systems (including inertial) and has a broad reach with its OEM products. Surveyors, for instance, might not be familiar with NovAtel first-hand, but have likely used its technology via NovAtel’s many OEM customers.

Iain Webster

Iain Webster, senior director of Geomatics and Software Engineering for NovAtel, said that not only does NovAtel support high-rate RTK, but the customer can choose the position output rate desired — 1 Hz, 5 hz, 10 Hz, 20 Hz, etc. — and the receiver will output RTK positions at that rate.

“We distinguish between a matched solution (where a correction is matched with a rover observation at the same time tag), and a low-latency solution, where base observations are extrapolated for position computation at the rover,” Webster said. He provided a description from a company manual:

“The RTK system in the receiver provides two kinds of position solutions. The Matched RTK position is computed with buffered observations, so there is no error due to the extrapolation of base station measurements. This provides the highest accuracy solution possible at the expense of some latency, which is affected primarily by the speed of the differential data link. The MATCHEDPOS log contains the matched RTK solution and can be generated for each processed set of base station observations.

The Low-Latency RTK position is computed from the latest local observations and extrapolated base station observations. This supplies a valid RTK position with the lowest latency possible at the expense of some accuracy. The degradation in accuracy is reflected in the standard deviation. The amount of time that the base station observations are extrapolated is in the “differential age” field of the position log. The Low-Latency RTK system extrapolates for 60 seconds. The RTKPOS log contains the Low-Latency RTK position when valid, and an “invalid” status when a Low-Latency RTK solution could not be computed. The BESTPOS log contains either the low-latency RTK, PPP or pseudo range-based position, whichever has the smallest standard deviation.”

NovAtel does not brand this as a specific feature — it is just a standard part of its RTK solutions, but the company refers to it in their documentation as a “low-latency” solution.

The main benefit of this solution, Webster explained, is for kinematic users to allow better representation of their actual trajectory (such as in applications on moving vehicles). “The higher the dynamics, the more impact the latency of the matched solution will have to the point that we recommend the low-latency solution to all but specialist customers with known static positioning needs. For surveyors, there may be improved workflow with the low-latency solution as they will be able to move from point to point more quickly.”

NovAtel produces GNSS and inertial hardware and software, including OEM boards, for multiple applications. (Photo: NovAtel)

Webster noted that for applications where the rover is static for observations, 1 Hz can be fine, but for moving rover applications — kinematic — running at 1 Hz is probably unacceptable, so low latency is quite standard.

Additionally, he pointed out, there are applications where longer periods between corrections may not necessarily be detrimental. “Note that some manufacturers, including NovAtel and Leica, offer the possibility of using PPP corrections to extend RTK solutions beyond, for example, a 60-second timeout,” Webster said. “There are various proprietary methods to achieve this, but ultimately the RTK solution could be extended without limit in this way.”

Are there tradeoffs to using extrapolation or other high-rate approaches? “With corrections coming in at 1 Hz,” Webster said, “there is very little error over that period, so for most users, there is little disadvantage and perhaps some productivity advantage with a higher rate. If there is any trade-off, it is between getting the highest accuracy possible versus the lowest latency solution.”

As for the other scenario — the base broadcasting at greater than 1 Hz and the rover solving at greater than 1 Hz — “There is little advantage,” Webster said, “except in some specialized applications such as when the base is moving (called moving baseline) to provide a cm-level baseline between the base and the rover for relative positioning. For typical surveying applications with a static base, the rover would have to wait until the corrections arrived before outputting a solution. Other downsides include increased bandwidth on the communication link and more loading on the rover CPU, meaning lower battery life.”

What are the non-surveying applications where a high rate (in either scenario) can yield a specific benefit? Webster noted that, in fact, they deal mostly with non-surveying applications. “Most use cases need 10 Hz or 20 Hz for machine control or precision ag. We do have some very specialist applications that have required up to or beyond 100 Hz — but it is often best in those cases to do a GNSS/inertial navigation system (INS) solution and use the IMU to output at that a high rate. As previously mentioned, there are other specialist applications where the base is moving. In this case, we run a matched solution at a high rate between the base and the rover.”

Leica GeoSystems

With Xiaoguang Luo, Senior Product Engineer, GNSS Product Management Group 

Rover with calibration-free tilt compensation and camera-based offset point capabilities. (Photo: Schrock)

Leica Geosystems (part of Hexagon) has been a major global developer and manufacturer of GNSS systems for multiple disciplines for several decades, introducing its first GPS receiver, WM101, in 1985. Since then, Leica has been among the leaders in GNSS receiver innovation, including integrated systems such as a rover that incorporates calibration-free tilt compensation and an image-point capture feature (GS18 I). Therefore, it is no surprise that for Leica Geosystems equipment features high-rate RTK as standard.

Xiaoguang Luo is a senior product engineer in the GNSS Product Management group at Leica Geosystems. He confirms that this option is supported in all Leica Geosystems RTK rovers of the current product portfolio, and this option is enabled by default in the Leica Captivate (surveying field) software. A term Leica Geosystems uses is prediction for its high-rate RTK approach.

Xiaoguang Luo

The standard positioning rate is 5 Hz on the rover. “As far as GNSS processing is concerned, there is no fundamental need to go to higher positioning rates,” Luo said. “The need for high rates is mainly driven by applications. For example, we are using the 5-Hz position update rate at the rover by default for an improved staking workflow and user experience. The 10-Hz rate is also supported in Captivate, for example, when streaming NMEA messages.” He added that 10 Hz is supported for other applications, such as structural monitoring, and 20 Hz for machine control.

As for the advantages of a rate higher than 1 Hz, Luo said that working at high observation and solution rates enables the possibility of modeling fast-changing error effects with a period below 1 second, and allows for high-rate non-surveying applications such as bridge monitoring. Does a high rate have any significant effect on the final results? He said that it strongly depends on the use case where high-rate observations and positions are involved. In addition, the quality of prediction also affects the final results.

Bernhard Richter

By this he means that while the standard approach for applications where the base is stationary, such as surveying, can work so well with a base data rate at 1 Hz and rover at 5 Hz, the key conditions do not change much over a single second.

Luo’s colleague Bernhard Richter, vice president of geomatics, explained it. “To understand this, you need to separate the elements of corrections into those that are fast changing and range dependent (see the graphic below). If the errors change slowly, then they can be estimated and predicted very well. Or, if the range dependency is low, errors could come from a different source than the base station. If the range dependency is medium or high, then the corrections are more difficult to estimate on the rover side, but if such errors change very slowly, they can still be predicted very well with the precondition that corrections have been received at least once.”

The rate of change and dependencies for the elements of corrections. (Source: Leica GeoSystems)

You’ll notice that multipath is high in both regards. This brings up another misconception about high-rate RTK — some users have an expectation that it will improve their performance in limited sky-view situations (like thick tree canopy) or high multipath environments. This is not so. Any improvements in such environments come from having more satellites, more observations, and more modernized signals. With regard to high-rate and multipath, Richter said, “It is anyway futile, since multipath decorrelates so quickly that the advanced mitigation has to happen both in an analog and a digital way on the rover.”

While there are benefits to running at high rate, such as for staking, a balance has to be struck — for instance, in not running it at too high a rate. Luo outlined disadvantages that must be considered when performing high-rate RTK.

• High processing load and battery drain, particularly with multi-constellation and multi-frequency RTK.
• High temporal correlations between observations, which may not be considered in a sophisticated manner in the RTK algorithms.
• High base rates provide challenges for the RTK data link devices, such as radios.

In addition, he noted that while any kind of predictive solution will introduce some amount of error, that would be so small in, for instance, a base data rate at 1 Hz and rover at 5 Hz solution, as to not even be noticeable in the positioning results.

Septentrio

With Bruno Bougard, Research and Development Director 

Bruno Bougard

“Our rover solution computes RTK up to 100 Hz,” said Bruno Bougard, R&D director at Septentrio. “Update rate requirements for industrial machine control applications are typically 20 Hz. This is necessary to capture the motion dynamics. Also, it is not only the update rate that matters in those applications, but also the latency, which should be low (<20 ms typically) and constant.”

Septentrio NV is a designer and manufacturer of high-end multi-frequency GNSS receivers and integrated solutions. Markets they serve include surveying, mapping, construction, science, timing, agriculture, marine, autonomy, and more — all with specific applications where high-rate RTK may be employed They also provide OEM boards and modules for further integration by others.

Surveying users for instance may be familiar with their Altus line of rovers, such as the NR3, where high rate is a standard option. “There are new applications where a higher update rate is required,” said Bougard. “Surveying with UAV, using photogrammetry or lidar scanning requires at least 10Hz. In mobile mapping in general, RTK-INS solutions such as SPAN, Applanix or Septentrio SBi, require update rates up to 200Hz.”

Bougard acknowledged that manufacturers use many terms for their high-rate solutions. “Some may be used to masquerading a low-rate solution as a high-rate one. This is not what we do. The rover observables are captured at high rate and can be up to 100 Hz. The rover RTK filter is also run on high rate. Fixed base-station data does not have to be high rate. 1 Hz is typically enough. For moving base applications — for example, when the base station is on another vehicle, and we want to compute the baseline between the moving base and the rover — 10 Hz is required.”

Bougard said that the benefit is to track the motion of the rover. This is critical in machine control, but also relevant for new survey flows (such as UAV-based and mobile mapping). The disadvantage, he explained, is that it requires higher CPU loads. “Suppliers, who focus on cost, tend to compromise on this, notably running higher rate only for a subset of the constellation or signals. We use them all.”

Is running the base station at a higher rate advantageous? “It is possible to increase the output rate of our base station correction stream but, as explained, this is not needed if the base is static,” Bougard said. “This is applicable to moving base scenarios as explained above. Indeed, if you increase the base-station correction rate, the bottleneck becomes the datalink.”

Tersus GNSS

With Xiaohua Wen, Founder and CEO, Tersus GNSS

Xiaohua Wen with a Tersus GNSS receiver.

Xiaohua Wen, based in Melbourne Australia, is the founder and CEO of Tersus GNSS, another new entrant in the centimeter-grade GNSS market. One distinction about Tersus is that the company has developed and produces its own GNSS boards, instead of using OEM boards from other companies. Tersus implements its own tech, including GNSS receivers and IMUs in its own survey rovers, such as the Oscar, and for other high-precision applications. Additionally, it produces OEM boards for integration by others. Tersus entered the market with full multi-constellation support and, of course, high-rate RTK options, and has recently announced a PPP (precise point positioning) service.

“Our RTK boards support up to 20 Hz,” said Wen. “Often, surveyor will choose 5 Hz. We do a 5-Hz solution in this manner: the baseband takes raw measurements at a wanted moment, say at 1.2 s or 1.4  s, and RTK calculates solutions with the raw measurements. We understand that some older solutions might simply extrapolate or interpolate based on a position and velocity sequence, which is sometimes called predicted RTK or extrapolated RTK (though those terms get used in different ways by different developers). That is not how we approach our RTK solution updates. All Tersus RTK boards also support a maximum 20 Hz raw measurements outputs.”

Multi-constellation rover with calibration-free tilt compensation. (Photo: Schrock)

We asked about some of the advantages users may envision of high-rate RTK in general. Wen said there may be little or no gain with regard to faster initializations. Likewise, there is no significant gain with precision and accuracy. However, Wen said that higher rates can sometimes improve staking workflows. “For example, in the case of our Oscar rover with tilt compensation, the RTK outputs solutions at 10 Hz, while the IMU samples at 100 Hz. Oscar calculates the pole tip’s position at 10 Hz, aligned with the RTK solutions, and the data controller or tablet displays the point of the pole tip on the screen. We find that the point better refreshes at 2 Hz or higher to respond to the pole tip movements without noticeable lagging.”

That movement is an example of a key value of high rate,“Speed or movement,” Wen said. “For surveying applications, I would say that 1 Hz could suffice, considering the characteristic very low speed. Usually, applications like machine control and precision agriculture require an RTK update rate at 5 Hz or higher. Some UAV applications may use a 100-Hz position update. Most of these applications use an INS+RTK solution. With INS, it’s easy to get a 100-Hz position update, while for an RTK solution, a rate of 20 Hz is probably enough.”

Wen said that broadcasting corrections at a higher rate is pointless for most applications, “because the base data is highly correlated in the short term. If it’s a moving base, the high-rate base data would make some sense. Otherwise, it just imposes a greater load on communications and computation, with almost no gain.”

Topcon Positioning Systems

With Alok Srivastava, Director of Product Management

Alok Srivastava

“It is a standard option in our rovers,” said Alok Srivastava, senior director of Product Management (PM) at Topcon. “Around the time I joined the PM team, in 2010, the decision was made to make 10 Hz the standard, though this is user configurable and can be 5 Hz, 20 Hz, up to 100 Hz.” He explained that faster rates have been available through several generations of their receivers.

Typical applications consist of a static base and a moving rover. Fast-moving applications can benefit from higher rover position update rates since the RTK engine is computing real positions at a faster rate. Higher rates on the rover side provide accurate changes in position that can be missed by interpolating between positions computed at a slower rate.

A Topcon multi-constellation rover with tilt compensation. (Photo: Schrock)

High update rates on a base station do not provide advantages except in rare cases where the base is moving. While rovers are computing movements of the rover antenna, base stations are providing GNSS satellite corrections. A rate of more than 1 Hz for a static base station does not benefit rover accuracy; it only creates a burden on the communication between base and rover. Base and rover communication needs to be optimized to reduce bandwidth requirements. This is especially true as we continue to add constellations and signals to GNSS solutions.

Sufficiently high rates have been standard on Topcon rovers for a long time. Srivastava would rather see more focus put on other aspects of GNSS — such as interference, spoofing, the impacts of 5G, precise point positioning (which Topcon provides through its Topnet Live service) and sensor integration. “In many of our construction applications, we have IMUs,” Srivastava said. “When an application has an IMU for tilt compensation or for machine control, the IMU and GNSS complement each other. In kinematic mode, the IMU can help reject outliers.”

Trimble

With Stuart Riley, Vice President, Technology – GNSS

Stuart Riley

“High rate can be considered a common default mode of operation,” said Stuart Riley, vice president, Technology – GNSS, Trimble. “Typical rover position solution rates are 5 Hz, 10 Hz and 20 Hz.”

Trimble is one of the pioneering companies in GPS and GNSS, and Riley has been directly involved in the evolution of the company’s GNSS solutions for more than two decades. He has seen a lot of change, and in noting the nature of key technological advances, offered this intriguing observation about high rate: in many ways it has become less relevant.

“There have been considerable advances in RTK technology in recent years that make many of the earlier concepts related to how base and rover data should be combined for baseline processing largely irrelevant,” said Riley. “Most recently, survey receivers have included INS support for tilt compensation applications, and these receivers have available high-rate IMU data — at a much higher rate than GNSS observables — which drive the final GNSS/INS integrated solution. Thus, the rover GNSS data rate is not so important.”

Riley noted another relevant technology that Trimble has implemented: the use of precise satellite clock and orbit corrections — such as from the Trimble RTX precise point positioning (PPP) service — to augment RTK when there is a loss of the base correction stream. The implementation of PPP is broadening across the industry, and the company was an early implementer of a global service. It has the RTX-based xFIll feature that runs on and high-end survey receivers. One of the misconceptions about PPP services such as xFill is that it is just there to “take over” should the RTK or NRTK corrections be interrupted. Yes, it does that as well, but to be able to do that, it is running all the time, simultaneously with the RTK, so the rover is getting these enhanced PPP service clock, orbit and other data. This improves what the rover can do. “The emphasis in modern survey receivers,” Riley said, “is based more on the availability of rover data, and a fundamental base data rate of, say, 1 Hz, is all that is required.”

Along with various advances in the rover RTK engine, the GNSS constellations have expanded considerably, requiring increased bandwidth for the corrections from base to rover. “Our products can use various communication technologies to transmit corrections, such as Wi-Fi, cellular, and UHF (450 MHz or 900 MHz) radios,” Riley said. “Maintaining a 1-Hz correction rate enables all the GNSS observables to be broadcast from the base, providing a suitable highly compressed data format such as when Trimble’s proprietary CMRx format is selected.”

Many terms are used in the industry, and they typically refer to some proprietary aspect of an RTK engine. Riley said that a generic term would simply be high update rate. “Providing the position is based on the most current phase observables at the rover, a low latency solution is possible,” he said. “Thus low-latency solution goes hand-in-hand with a high update rate. Predicted RTK may refer to an old method where the static base corrections are propagated forwarded to account for radio latency and thus synchronize base/rover data. This is not used in modern PVT (position, velocity, time) RTK engines.”

Calibration-free tilt compensation. (Photo: Benchmark Surveys)

High rate on the rover is standard, but what benefits should the user expect from it? “A fast update rate provides the best user interface experience in the field, in particular for stakeout,” Riley said. “Quite simply, nobody wants to be working with a laggy display. For survey field work, 5 Hz is typical. Other applications, such as machine control, benefit from higher update rates where a default of 10 Hz would be used, with options for higher rates.”

If the user chooses 1 Hz on the rover, what would be the downside? “Running at a 1-Hz rate is not really suitable for stake out,” Riley said. “For occupying static points, 1-Hz updates would suffice, as a typical occupation has a minimum time of 1 or 2 seconds. Very high rates for survey applications do not really buy anything in terms of field look and feel or performance.” I asked him about any points of diminishing returns, and he responded, “The higher the rate, the wider the measurement bandwidth (that is, the noise increases — you cannot get something for nothing), so in fact going for an unnecessarily high rate would start to be a disadvantage. For example, there would be no advantage to using a 50-Hz or 100-Hz rate for a land survey application. There is a relationship between measurement bandwidth and position noise.”

When is a high base rate a good idea? High rates are supported for some machine control and “moving base” applications where the reference frame has to move with the moving base, Riley said. In this case, the base and rover observables must be synchronized and the final solution has a fundamental latency depending on the base rate. For this reason, moving base rates are more typically 10 Hz or 20 Hz. For a static base, it is possible to use a higher rate. However, as Riley noted, “It’s more likely that a lower rate such as 0.5 Hz might be desirable to accommodate the radio when using repeaters (time multiplexing the data) or low data rates. There are disadvantages to high base rates, mostly related to radio bandwidth. Other factors, such as ‘high rate = more radio transmit power’, may need to be considered (affecting battery life).”

Are there other cases for even higher rover rates? “As mentioned, machine control applications use higher rates — necessary to reduce position latency in control loops,” Riley said. “Other applications such as UAVs and autonomous driving clearly benefit simply because of the speed of the platforms (higher dynamics). Precision agriculture is an excellent example of machine control, where auto guidance is used. Although high rates are possible, nearly all applications manage perfectly fine at rates up to 20 Hz. A more important consideration is system performance in terms of positioning accuracy and convergence times, which is dependent on the technology used in the PVT engine, such as Trimble ProPoint technology, rather than the correction stream data rate. ProPoint also includes xFill, as mentioned earlier, which provides centimeter-level backup for continuous operation when RTK or VRS correction streams are interrupted.”

Other Manufacturers

This was only a sampling of the developers and manufacturers, but it should be noted that several of the above firms produce OEM boards featured in dozens of other brands and models, such as Carlson and GeoMax. To try to list them all would be a challenge and might be missing a key point: high rate is quite standard, is not big news anymore, and you probably have it by default (or optional) no matter what system you are using.

Hypeful

As the insights the from industry experts above show: high rate can be essential for many applications, but unnecessary for others. It seems more about user experience (staking workflows or moving rover) than some way to seek higher precision.

Additionally, to borrow the gaming term hypeful, some users believe (or have been led to believe) that running at high rate will yield higher precision or work some kind of magic in dense tree cover or high multipath environments. Some may argue that it could get a result faster, but in practical terms even that might not be the case.

High rate has been around for a long time. And like any tech, has gone through different development and adoption phases. Think about automatic transmissions for motor vehicles; they have been around in one form or another for more than a century. There was a period in the mid-20th century where the development of different approaches was promoted in marketing campaigns with fanciful product names, like Durashift, Presto-Matic, Geartronic and Torque-Flite. But rarely do you see auto transmissions highlighted with such marketing flourish since then.

High-rate RTK was never singled out like that; it is common, and any differences are mostly in how it has been adapted for different applications. I suppose a firm could choose to emphasize it for marketing purposes and give it a buzz name like “Turbo Thrusted RTK”, which his fine for marketing purposes (albeit a bit “cheugy”).  Every developer and manufacturer will have slightly different approaches, but if you believe, or are led to believe, that any represent high-rate fundamentals exclusively, that would be inadvertently misleading, if not subtle gaslighting.

As one of the experts said, “It does not really matter what manufacturers claim or don’t claim. You cannot beat physics. You can only understand and manage the physics.”

Coolness Ahead

While high-rate might seem a bit old hat, where GNSS development is going is not. The developers we interviewed are more interested in highlighting their complete high-precision solutions. For example, adding inertial measurement units (IMUs) for no-calibration tilt compensation, additional sensors for imaging (and likely soon, lidar), and multiple real-time GNSS solutions complimenting RTK, such as L-band precise point positioning (PPP).

The “high-rate” that is truly exciting is that of R&D, multi-sensor integration, automation of certain elements of workflows, artificial intelligence and multi-constellation/multi-signals.

<p>The post High-rate RTK: Helpful or hypeful? first appeared on GPS World.</p>