Photo: Xona Space Systems

Spirent has implemented Xona Space Systems’ PULSAR production signals for seamless integration into the existing SimXona product line. The PULSAR X1 production signal implementation has passed a diligent Xona certification and the PULSAR X5 signal verification process is currently underway. It is expected to pass certification during the summer of 2024. Spirent is now accepting orders for SimXona with production signals capability.

Xona is developing PULSAR, a high-performance positioning, navigation and timing (PNT) service built on a backbone of low-Earth orbit (LEO) small satellites. Xona’s smallsat signals will improve PNT resilience and accuracy by augmenting GNSS while operating with an independent navigation and timing system architecture. Xona is fully funded to launch its production class satellite, the In-Orbit Validation mission, in 2025.

Spirent is the leading provider of PNT test solutions and recently launched a sixth-generation simulation system, PNT X. Designed for navigation warfare (NAVWAR) testing, PNT X is an all-in-one solution with a native implementation of SimXona.

<p>The post Spirent accepting orders for Xona PULSAR simulator first appeared on GPS World.</p>

Photo: Xona Space Systems

Aerospacelab and Xona Space Systems have entered a strategic partnership to integrate Xona Space Systems’ positioning, navigation and timing (PNT) technology into Aerospacelab’s satellite platforms.  

Under the partnership, Aerospacelab will use its Versatile Satellite Platform (VSP) for the design, manufacture and launch of Xona Space Systems’ first navigation satellite equipped with its PNT payload.  

Xona is developing a commercial PNT service through a constellation of low-Earth orbit (LEO) satellites. The company plans to offer the service as a backup to PNT provided by GPS. 

The collaboration aims to use Aerospacelab’s capabilities in small satellite design, manufacturing and operations alongside Xona’s specialized knowledge in PNT payloads to provide enhanced navigation solutions that address current and future needs in satellite navigation and applications.  

<p>The post Xona Space Systems, Aerospacelab target PNT technology first appeared on GPS World.</p>

<p>The post ION GNSS+ 2023: Spirent Communications first appeared on GPS World.</p>

Image: Spirent

Spirent has concluded a review of Xona Space Systems’ PULSAR production signals, and has deemed them feasibile for integration into the SimXona product line. Spirent will integrate the Xona production signals as an evolution of the SimXona platform.

Support will become available to existing and new users throughout 2024.

Xona is developing PULSAR, a high-performance positioning, navigation, and timing (PNT) service built on low-Earth orbit (LEO) small satellites. Xona’s high-powered smallsat signals aim to improve PNT resilience and accuracy by augmenting GNSS while operating with an independent navigation and timing system architecture.

<p>The post Spirent to generate Xona PULSAR production signals via SimXona first appeared on GPS World.</p>

What are your roles?

MH: Our business is based in the UK. I am responsible for the vision and direction of the Technology portfolio required by Spirent’s Positioning Technology business unit.

RH: I am responsible for the U.S. add-on components to the simulator, the restricted signals, and support for the U.S. government labs and contractors.

How have the need for simulation or the requirements for it changed in the past five years, with the completion of the BeiDou and Galileo GNSS constellations, the rise in jamming and spoofing threats, the sharp increase in corrections services, and the advent of new LEO-based PNT services?

MH: I would say that the need for thorough and comprehensive testing has never been greater. That need is being driven on multiple fronts due to the understandable pressure on PNT systems needing to deliver enhanced accuracy, reliability and resilience, in the presence of emerging threat vectors and an expanding application space that’s utilizing ever more complex combinations of new and enhanced signals and sensors of opportunity. Underpinning Spirent’s leadership in ensuring the test needs for this evolving, challenging and increasingly diverse market are its team, its technology and its partners. That team is well-established, dedicated and highly experienced — their sole focus is designing, manufacturing and supporting PNT test solutions. The technology focuses around our pioneering dedicated SDR hardware platform and software simulation engine, which allied provide performance, scalability and flexibility, within an open accessible architecture. In addition, close collaboration with our selected partners ensures the opportunity to support and integrate new and emerging PNT technologies through their tools, applications and hardware.

You mention the advent of LEO. A key reason why Spirent was first to market and successfully supported an early LEO + GNSS receiver test-bed (through close and collaboration with Xona and NovAtel) was driven by team, technology and partners.

Two other important areas that have definitely continued to grow and evolve in importance and priority have to be increased realism and test automation. Both are areas in which Spirent continues to prioritize and invest R&D dollars.

Spirent’s integrated, software-defined wavefront simulation system for a 5-element controlled reception pattern antenna (CRPA). Spirent solutions support 16+ antenna elements. (Image: Spirent)

With all these additional signals, is it still a single simulator or do you have to somehow split it up into different modules?

MH: Good point. Again, a key element with the Spirent solution is that it is very scaleabale and flexible. Spirent has a generic SDR that can be re-purposed to simulate whatever signals are required. That way, we can compile different signals from either one radio or multiple radios coming from the same system. Together with being able to bring in multiple chassis to gradually grow the simulation solution, while also maintaining for each of those signals the fidelity, channel count, and accuracy that customers demand.

Including every signal currently available?

MH: Absolutely, sir. In fact, signals that are still on the drawing board as well. We can enable the user with effectively an arbitrary waveform simulator or ‘sandbox’ to experiment with different modulation schemes, different chipping rates, codes, bandwidths and navigation data content. So, in addition to using that architecture to generate the signals, we allow customers to experiment with it themselves. That’s certainly accelerated over these last five years, and there’s no sign of it stopping. We’re currently working with customers and partners all over the globe who are developing both brand new and emerging PNT systems, whilst also providing all the vital simulation tools to aid the R&D of existing and planned SIS evolutions.

RH: The increasing number of signals that we can support multiplies the permutations and combinations of test cases that users can do. There is a lot of emphasis also on the user interface side of things, so that from one interface you can also easily control all these interfaces with third-party tools, because proliferation of signals produces a huge possible test volume.

What are the specific challenges in realistically simulating new LEO-based signals and any new services being developed for which you don’t have any live sky signals to record yet, only ICDs and other documents?

MH: Again, great question. The key reason Spirent excels in this arena is that the core simulation engine and SDR are agnostic of the constellation and signal type that’s being generated. So, the underlying principles of accuracy, range rate, pseudo-range control, and delay, together with the RF fidelity from Spirent’s SDR+ Sim engine, can be readily manipulated to simulate the wealth of emerging signals, including LEO.

The other area that becomes very important is that if we do not have sight of the ICD, we can enable customers to use our tools to readily populate elements of that ICD themselves. That way, the best of both worlds is achieved, i.e. a turnkey SIS solution, or we can just enable the customer to do it themselves.

Are accuracy requirements or any other requirements for simulation increasing to enable emerging applications?

MH: They are. Both current and emerging test needs are continuing to drive the need for enhanced simulation realism. Always a tough nut to crack, but our hard-won experience and expertise, allied with continuing adoption of latest-generation technology, is allowing us to take some significant strides forward. Real-world testing has an incredibly important role to play and that’s why at Spirent we continue to invest in and develop the GSS6450 Record & Playback System (RPS). However, we are also on that quest for the ‘Holy Grail’ that has all the well understood and necessary advantages of lab-based testing but with the simulation environment being as true to the real world as possible.

A German Armed Forces test center, WTD-61, recently used Spirent’s new Field Simulator to conclusively demonstrate the susceptibility of some UAS to spoofing. (Image: Spirent)

A further area where both current and emerging test needs are demanding more and more from the test environment is resilience testing. Spirent now supports a multitude of vulnerability and corresponding mitigation/prevention test cases. Those test cases become increasingly complex as multiple combinations of the threat/mitigation surface evolve — including jamming, spoofing, cyber-attack and CRPA.

Many of these test cases are driving the state of the art and, especially in the case of CRPA testing, Spirent’s purpose-designed SDR comes into its own. Technology bakeoffs and corresponding customer adoption have shown that only through the use of that dedicated purpose-built technology, the simulator test bed can deliver the necessary carrier and code phase stability, very low levels of uncorrelated noise across antenna elements and high J/S that is demanded.

Again, with respect to flexibility, we also support ways to let customers generate their own IQ data. That data can be streamed into the Spirent simulator and combined sympathetically and coherently with the signals generated inside the platform. So, you can layer new signals on existing ones, or introduce a completely new dedicated IQ stream.Finally, hardware-in-the -loop (HIL) testing requirements continue to be a crucial aspect in test coverage. Whether that application is automotive, projectiles or autonomous vehicles, the need for lower latency and higher 6DOF sampling to capture as many trajectory nuances as possible continues to grow. Spirent’s 2KHz system achieves very high iteration rates (SIR) and <2msec latency.

What are the key differences between your simulators for use in the lab and those for use in the field? I assume that the latter are lighter, smaller, and less power hungry. Do they use modules so that users can pick the ones they need for a particular test?

MH: We do support in-the-field test use cases. Spirent has record-and-replay (RPS) systems to take soundings in a wide-band RF environment, record them, then bring them back into the lab for replay. They are sized to fit into a backpack, battery-powered, accessible, and easy to use.

Recently, we have also taken some of our signal generator IP and been able to create a smaller form factor portable simulator for outside use. Its footprint is considerably smaller than that of one of our lab-based simulators. It’s primarily a mechanism for testing the resilience in the field of devices under test. Armed with a Spirent simulator and the appropriate transmit licenses, a customer can put their DUT through an array of vulnerability test cases in a live real-world environment.

You mentioned licenses. As far as jamming, specifically, and maybe spoofing, I presume that you’ll need a license for a specific time and place and that you will have to be far away from, say, an airport.

Absolutely. Right. The details will vary depending on the jurisdiction, but you will need a license to transmit. And, as you rightly say, often those places will be very remote so as not to interfere with the public. We’ve had instances where we’ll work with a customer who has those appropriate licenses and then we can provide this equipment for them to be able to put it through a battery of tests.

You generate the spoofing in your simulator, of course. Do you also generate the jamming inside the same box or from a separate jammer nearby?

It could be either. We can use our simulators to generate internally wide range of interference signals supporting a wide bandwidth, high max o/p power and large dynamic range. This is especially important in instances of CRPA testing, in which it is vital to accurately reproducing a jamming wavefront commensurate with the arrival angle and delay incident at each antenna element. Correspondingly, we support turn-key solutions to connect, control and integrate 3rd party external signal generators into the test scenario.

Are you at liberty to describe any recent success stories?

We have a Xona simulator. So, this is back on the topic of LEO. We’ve recently released that in partnership with Xona. We are also working closely with Hexagon. All those things I mentioned earlier about enabling the customer to use the flexible features that we have, that is where it came into its own. That’s certainly a significant recent success.

We’re continuing to add many realism-related capabilities, including simulating the vibration and temperature effects of inertial systems. Working with a Swiss partner called Space PNT, we’ve recently introduced another LEO-based product, called SimORBIT. That tool enables us to generate incredibly representative and accurate LEO orbits that also include gravitational effects based upon the SV size. We recently introduced a new software tool to support “GNSS Assurance” requirements.

We have a newly patented cloud-based software application called GNSS Foresight that enables users to understand the GNSS coverage they would expect during a particular time, date location and trajectory inclusive of the 3D environment they would be experiencing. We continue to evolve the tool to support real-time operation to enable it to deliver aiding content to appropriately equipped systems.

We continue to be able to support more and more automation. Automation has always been important, but with ever increasing demands of test asset utilization and in a post-pandemic world of remote working, it’s more important than ever right now. The number of test cases and corner cases required and the amount of equipment, coverage, and efficiency required, which was being demanded by using our kit means that automation is vital. So, we’ve introduced several new automation tools to build up on top of our current SimREMOTE interface.

Spirent has also developed a simulation test solution for the Galileo Open Service Navigation Message Authentication (OSNMA) mechanism. SimOSNMA is designed to work with Spirent’s GNSS simulation platforms to test OSNMA signal conformance, which will bring new levels of robustness for both civilian and commercial GNSS uses. SimOSNMA provides developers with vital new simulation tools to test for OSNMA, the security protocol that enables GNSS receivers to verify the authenticity of signals distributed from the Galileo satellite constellation. Designed to combat spoofing, OSNMA ensures that the data received is authentic and has not been modified in any way. It is currently completing the test phase before its formal launch, and SimOSNMA enables developers to simulate and test OSNMA signals and features, allowing GNSS receiver manufacturers and application developers to accelerate and assure development programs.

<p>The post Faux signals for real results: Spirent Communications / Spirent Federal Systems first appeared on GPS World.</p>

Image: Syntony

Syntony GNSS has doubled the SDR L1C/A equivalent signals of its multi-GNSS simulation solution, Constellator.

With Constellator’s computation power doubled from 660 L1C/A equivalent signals to 1200, users can simulate a complex RF environment for GNSS testing with a powerful and high-fidelity machine, the company said. Additionally, users can now test equipment with multiple traditional GNSS constellations and new ones to come, such as Xona’s PULSAR.

As a result of doubled computation, massive new constellations can be simulated. When fully deployed, the Xona constellation will count hundreds of satellites on multiple bands, in complex RF environments including specific atmospheric parameters, jamming, spoofing and multipath. It also introduces the controlled reception pattern antenna (CRPA) testing capacities of the device, when the demand is increasing for resilient multi-GNSS and low-Earth orbit (LEO) position, navigation and timing (PNT) solutions.

Syntony said it was the first PNT services provider to integrate all Xona demo signals into Constellator, in 2022. However, to offer a full testing solution, Syntony also developed a Xona-enabled GNSS receiver.

<p>The post Syntony doubles multi-GNSS simulation solution computation power first appeared on GPS World.</p>

What are currently the key challenges for simulation?

One of our big challenges is determining what performance requirements are necessary for our users. Often, they can’t determine what the specs need to be. All they know is that they need it to work. “I need this receiver from one company, this IMU from another company, and the simulator I got from you guys to work together and I need the performance to match reality.” It can be very challenging to say, “What are the requirements for the simulator? How accurate does it need to be? What types of things matter in this integration?”

Often, we’re left trying to figure that out. So, that’s an interesting, maybe unexpected challenge. It’s easy to look at the datasheet and see what some specs are, but it’s a much harder thing to say, “Well, what do you need the specs to be?” So, we’ve been working with our customers to try to nail down some of those specs, particularly with Wavefront. We have some specs on such things as phase alignment and phase stability. But how do you translate that into something like “Well, I just want the CRPA to work the same in the lab as it does in the real world?” There’s not a direct, easy way to do that. We’re in the middle of trying to figure that out. That’s definitely one of our challenges.

What about the increase in jamming and spoofing threats?

In the last five years, we’ve seen a lot more open talk about jamming and spoofing in the world. The receiver manufacturers must think about this a lot more. What’s interesting from a simulator point of view is that this is not actually new for us. We have the advantage that we’ve been designing to program requirements for years and they have included jamming and spoofing for years. So, in a way, simulation is ahead of this state of the world. Jamming and spoofing are not new or hard ideas for us. In fact, spoofing is similar to simulation. So, we already know how to do that.

Image: Safran Federal Systems (formerly Orolia Defense & Security)

However, jamming and spoofing are new to programs and integration labs. So, there might be platforms where they’re now testing against jamming or spoofing requirements where in the past, maybe they didn’t do that. They certainly can use our simulators to help them do that. However, we’re not seeing a lot of new requirements coming to us saying we need new jamming or spoofing capabilities, because we already have them. Luckily, we are future oriented regarding the jamming and spoofing requirements, so those really haven’t been a challenge for us yet.

That can always change, right? If new requirements come up, such as higher data rates or wider bandwidth waveforms or different types of waveforms, then we would have to adapt and add support for that kind of stuff. As of right now, however, we aren’t really seeing that. So, luckily, we’re prepared for that. As for the industry as a whole, there has definitely been a big movement in the last few years to understand the effects of jamming and spoofing. Simulation is a big part of that.

What about the completion of the BeiDou and Galileo constellations?

For a long time, we simulated four constellations. Then that began to get fuzzy. Do you consider SBAS a constellation or is that just an augmentation? Do you count EGNOS and other supplemental constellations for the other constellations? What about NavIC and QZSS? Before you know it, you start to lose track of exactly how many you have. We just released our 8th constellation, Xona.We’re going to be demonstrating it at JNC.

Tell me more about that.

We are trying to have all the constellations and that can be a fuzzy definition. Does that mean all that are up there right now or all that will be up there in the future? We’re trying to be forward looking and add everything that is going to be up there or might be up there so that lab users can develop and test. Multi-constellation simulation is a particularly challenging problem for groups that don’t have simulators. If you’re just doing research on, say, GPS, and want a new code, you might be able to do that in a lab on your own. But as soon as you say, “I want to do research on whether this LEO constellation helps navigation on a receiver that also uses Galileo and GPS,” suddenly, your research requires a full multi-constellation simulation.
There are two choices. One is to have a simulator do the constellations that already exist, and then you have some research to add constellations. That can be very challenging, especially with time alignment and things like that. The other is to have a simulator that can do all the constellations. That would be the easy choice, right? That presents a problem with such things as LEO navigation being on the rise and these constellations that are just emerging, that are still not even fully defined.

So, we’re trying to build those into our simulation products, to help researchers and decision makers determine whether these will be useful features to add to their receivers or their systems. We have the advantage of having a software-defined architecture. We designed the software so that it is easy to add new constellations to it. Basically, once we’re given a proper ICD, we’re only a couple of months away from a first draft implementation of that new signal. Then we iterate. There used to always be a government-driven, multi-year program to develop an ICD. Now, we have this new concept of the signal manufacturers. We’re seeing private companies release signal specs. That’s a very different way of creating a signal in a constellation. So, sometimes you don’t get much time between when the ICD is available and when simulator users want to use that constellation. Having a software-defined architecture really helps us move quickly. We can add such things as Xona very fast.

Xona told me a couple of days ago that they will soon put out an ICD. What’s the difference between actual signals that you can record and play versus something that’s only on paper?

That’s a great point. Probably many people don’t realize, when they first look at this, that what’s in the ICD and what’s on live sky are sometimes very different. Is the simulator supposed to match live sky? Or is it supposed to match the intended final state of the constellation, according to the ICD? This is a huge topic for M-Code, which is ever changing, and has a very large ICD that’s been released. Space Systems Command/Military Communications & Position, Navigation, & Timing (MCPNT) controls the features and releases them incrementally. We’re constantly having to make changes to the simulator to match those releases. The same is true for the other ICDs. At the Institute of Navigation Joint Navigation Conference (JNC), we will demonstrate an expanded PRN. I think this showed up in the ICD a couple of years ago, but it’s not used by any users yet. Some of the receiver manufacturers are starting to look at using PRNs beyond 32. So, we’re adding that to the simulator. This has already happened for BeiDou as well. I think their ICD goes up to more than 60 satellites. It’s an ever-changing race. The ICDs are constantly being updated and we’re trying to update the simulator.

Image: Safran Federal Systems (formerly Orolia Defense & Security)

Meanwhile, live sky is many years behind the paper, right? This creates an interesting challenge: when you design a system, are you designing it for today or for the future? We have users in both groups. We have users that only care about what is happening today, because they need a model. Maybe you want to model a specific mission and you want to make sure that everything’s going to go properly. Or maybe you’re designing a system that you want to release in three or four years, and you want to make sure that it’s going to work with the state of the system then.

A big challenge is to make sure that we’re keeping pace with all these ICDs. There are more constellations than ever and the technology makes it easier to change signal architectures. We’re seeing signals change faster than we’ve ever seen them change before. We go to conferences and hear about such things as on-orbit reprogramming and signals that might even change specs while they’re being transmitted. Maybe they don’t even have to have a fixed bandwidth or fixed bit rate. We’re going to start talking about signals that can reprogram on the fly. That’s going to make simulation more and more challenging. The technology exists to do this.

Software-defined waveforms is a very logical step. In the software world, we have this concept of version nightmare. When you have 20 different pieces of software that are interdependent, it can get very challenging. We’re going to start to see that in simulators. We’re going to see, “Hey, what version of navigation authentication are you using? We updated it six months ago. Are you using the new one or the old one? Which one should we use?” Well, it depends on what your receiver is using. It’s going to be interesting and challenging to keep all this straight in the next few years as things evolve. Certainly, however, our goal is to be there for all of it and to be as fast and as forward thinking as we can for our customers. That means that we also need to know what our customers need. So, we’re always looking for feedback and requests, what challenges our customers face and we’re responding to those requests.

Tell me more about the difference between simulators used by receiver manufacturers in their labs as they’re tweaking receivers or developing new ones vs. simulators used for mission planning.

The simulators are the same, but they’re used in very different ways. In most lab simulation, what the constellation looks like that day doesn’t matter very much. They can just run with a default constellation for a given day. They’ll run that scenario hundreds or thousands of times and never need to change it because they’re testing parts of the receiver that don’t care a whole lot about the specifics of what’s happening.

Whereas missions are time- and location-specific.

Yeah, exactly. They want to know which satellites will be overhead at an exact time and place. It’s not so much a problem anymore, but there used to be certain days and times when you would not get enough satellites in view, or you might have very bad dilution of precision, and your mission might actually fail. We’re past those days. There are now enough satellites up there. Most receivers will navigate within their specs most of the time in most places. However, for critical missions, such as military operations or rocket launches, you might not want to just assume that any day is a good day. So, if you’re about to launch a rocket, you might want to check. “What does the constellation look like right now?” The challenges that brings is that simulators have a default constellation, but the constellations are constantly changing.

When you’re doing real day mission planning, the big problem isn’t so much how to generate a signal, it’s how to find out what’s happening today. That’s really the nature of the problem because what’s out there today is different from what was happening yesterday or what will happen tomorrow. You might have unhealthy satellites. You need to know that if you want to model them. It becomes a big challenge to get all the right data into the simulator. Once all that data is in there, then it’s the same as any other simulation.

Are there good sources for current data on GLONASS, BeiDou and Galileo?

Image: Safran Federal Systems (formerly Orolia Defense & Security)

There are a couple of websites that provide information about where the satellites currently are. However, we’ve found that each one of those sites has its own challenges. Some are maybe 30 minutes out of date, which is pretty good, but puts the satellites in slightly different spots. Some of those sites only support some of the constellations. We’re talking about multiple countries and they don’t all agree on how this should be done. So, there’s not a single point that you can visit to get all the satellite data. There are a couple of companies that try to fix this. U-blox has AssistNow; Qualcomm has an assist for its cellular receivers; Trimble, NovAtel, and a couple of other companies have their error correction services to which you can subscribe to get some of that data.

If you want real-time up-to-date ephemeris for all the constellations, that is challenging. There are one or two options we have found that seem to work, but they each have their disadvantages. Maybe they don’t have all the satellites. Again, we’re talking about versioning issues. So, if you’ve designed your system with a certain version of an ICD and they’ve added more satellites since, those new SVs maybe aren’t so important for your users, so you don’t publish them. Other users want those satellites. So, we see versioning issues in these data streams. For example, we use the CORS network to get a lot of GPS data but that whole network, as far as I know, is only running the legacy data. As far as I know, no network is distributing the L1C modernized data that we will need at some point. So, as we launch new signals and constellations, we need the networks to provide this new data.

What are some other challenges?

For us, being a software-defined simulator on a platform dependent on software-defined radio (SDR), we’re constantly looking at what’s changing in the SDR technology community. There’s always some interesting stuff happening there that we try to incorporate. We don’t have any big announcements this year, as far as new architectures or anything like that. However, the SDR community is evolving. It’s still a rather new industry. A few years ago, we were an early adopter of SDR technology for mass deployment. Now, we’re seeing some more mature SDRs starting to push such things as channel count and coherency. We will probably take advantage of that in the future.

The other interesting thing technology-wise is that we’re also a GPU-dependent technology. So, as the GPU industry continues to evolve and makes bigger and faster GPUs, we get a relatively low-cost way to upgrade. We don’t have to do a lot of R&D to upgrade to a new GPU. For our users that means that the number of signals they can generate on their simulators is always increasing even using the same hardware from one generation to the next. Our first simulator did 75 signals; the next version did 150. We could build a system that did more than 1,000 signals, but our users don’t need it.

I assume that the growth curve for GPUs is steeper than that for signals.

I think that you’re right about that. I’m sure glad they do, because then something like Xona shows up and we don’t have to rearchitect our system to generate 300 signals, right? At JNC we will show expanded PRN, 300 Xona satellites in the constellation, and a 10 fold improvement on Wavefront performance specs.. We will continue to build simulators that meet our customers’ requirements. Besides GPUs, a lot of the technology involves software R&D and signals. The stuff that we do digitally inside of our system that allows us to do things like extremely precise phase alignment on Wavefront, for example. We spent a lot of time developing that stuff.

<p>The post Faux signals for real results: Safran Federal Systems first appeared on GPS World.</p>

Image: Safran Federal Systems (formerly Orolia Defense & Security)

As the number of constellations, satellites, and signals has grown in recent years — especially in the past few years, with the completion of the BeiDou and Galileo constellations — simulator manufacturers have been challenged to keep up. Threats of jamming and spoofing also increased. Then, a few companies began to develop new positioning, navigation and timing (PNT) constellations in low-Earth orbit (LEO).

For the August 2023 cover story, I discussed these challenges and the prospect for the simulation industry with representatives of six companies: Safran Federal Systems (formerly Orolia Defense & Security), Racelogic, CAST Navigation, IFEN, Spirent Communications and Spirent Federal Systems.

Due to the limited space available in print, I was able to use only used a small portion of the interviews I conducted for our August cover story. For full transcripts of them see below:

• Full interview with Tim Erbes, Technical Director, Safran Federal Systems (formerly Orolia Defense & Security).
• Full interview with Julian Thomas, Managing Director, Racelogic.
• Full interview with Jürgen Pielmeier, Managing Director, IFEN.
• Full interview with Mark Holbrow, VP of Product Development, Spirent Communications and Roger Hart, Sr. Director of Engineering, Spirent Federal Systems.

<p>The post Online Exclusive: Faux Signals for Real Results first appeared on GPS World.</p>