Mike O’Connor

Satelles, which developed the Satellite Time and Location (STL) system, recently became part of Iridium, which already owned a large share of the company. I spoke with Michael O’Connor, previously Satelles’ CEO, who is now Executive Vice President of Iridium’s PNT Division.

Besides the ownership change, has anything changed in your organization?

What was the Satelles business is now part of the broader Iridium company. We’ve been partnered very closely with Iridium since the genesis of Satelles more than a decade ago. It really made strategic sense to become a part of Iridium. The industry is clearly at an inflection point. We don’t have to look too far to understand that the mainstream is catching on to the things that you have been writing about for years. Now, people are realizing what’s actually happening. Various users — especially those near conflict areas — are starting to truly experience jamming and spoofing events. The world is starting to recognize that there’s a need for solutions. The U.S. Department of Transportation has just come out with a complementary PNT plan. They put out a request for a quotation recently to engage the industry.

Companies like ours, and others in the industry who have been developing solutions to this problem for many years, will finally start to see traction with customers. We just signed an agreement with L3 Harris to roll out GNSS augmentation or complementary PNT for the Federal Aviation Administration (FAA) to networks. Not just industry, but also the U.S. government is now taking steps to implement the resilience that’s needed to protect critical infrastructure. So, the timing is good.

Does being now fully part of Iridium give you any additional access to the company’s satellite network?

We will be rolling out, over time, some additional capabilities and expanded service areas. We will be announcing ways in which, by integrating the companies, we can expand more quickly into new geographic areas, providing additional signal coverage in areas where Satelles had not previously been able to do so. As Satelles, we were very focused on timing and national critical infrastructure. Iridium’s business lines align with some of the directions in which Satelles was already intending to grow in any case — such as maritime, internet of things (IoT) and possibly even someday aviation. There are areas where we will be able to expand our reach much more quickly than we ever would have been able to do as a standalone company.

STL makes indoor positioning possible because the signal is much stronger due to Iridium’s satellites’ much lower orbit than that of GPS satellites, correct?

Exactly right. It’s really about the signal power. Part of it is being closer to Earth, part of it is that we are on a channel that was dedicated to paging, back when people had pagers on their belts and was designed with a higher power signal than the Iridium satellites’ two-way voice and data channels. Additionally, we’ve designed the signal itself to also have some coding gain. So, all those things ultimately increase the receive sensitivity of a receiver by about 30 dB, which makes the signal 1,000 times stronger.

In the mix of complementary PNT options and systems, what are your system’s strengths?

There is no single silver bullet solution to complementary PNT. We can offer our solution, but different applications have different needs, for sure. What Iridium offers with the Iridium STL service is a system that’s available today to protect critical infrastructure — we’ve been delivering this to customers, we have thousands of users; it’s available globally — we effectively have a global license, a global capability, a global satellite constellation. We also have the distinct advantage of a high-power signal that can reach places where GNSS cannot. So, we focus on applications for which we can offer some unique value. A lot of that is based on the underlying Iridium satellite network. A long time ago, Iridium secured global rights for the L-band spectrum. Besides being in LEO, the network has inter-satellite links that enable it to cover the whole world from a finite, manageable set of ground monitoring sites.

Because of all these aspects of its network, Iridium can offer something unique in the industry. Other solutions have different advantages and disadvantages. There is a breadth of solutions across the industry. All these entities are trying to solve the same important problem. Different users of PNT and different users who have a need for complementary PNT will see the advantages and disadvantages of different solutions out there. So, we like that there’s a thriving ecosystem of solution providers.

Iridium Communications will provide its Satellite Time and Location (STL) service to more than three dozen L3Harris-operated communications network backbone nodes and a similar number of Federal Aviation Administration (FAA) facilities throughout the United States. (Image: Iridium)

Regarding markets, end users and user applications, what’s your focus?

Our focus today is very much around timing and national critical infrastructure. We are in that market today, but it is one where we also see the greatest growth. We already have several partners who are selling products into those markets — including Adtran Oscilloquartz, VIAVI and Safran — and products available today. That market is just starting to recognize the need for complementary PNT and accelerate its adoption.

Our primary focus today is making those customers successful with our solutions. Looking at new market opportunities, we are exploring the next products and markets we will pursue, but it is likely to be in an area that overlaps with those in which Iridium already has great partners and customers to which we can provide additional value. Maritime is a good example. Aviation may be a longer sales cycle. It would be speculating as to what that next big market will be because right now we are very focused on that initial market.

As far as timing for critical infrastructure — cell phone towers, electrical distribution, data centers, etc. — are your boxes replacing the previous ones or sitting next to them?

They can do either. The products that our partners offer include GNSS plus STL, so it can replace the GNSS-only solution in those systems. A lot depends on the customer and the application, of course. Our partner would provide a solution that includes GNSS plus STL; it typically would replace a GNSS-only solution and provide resilience by having a complementary PNT capability.

The solutions we’re providing to the FAA are not on-aircraft solutions. They are ground infrastructure solutions that keep the integrity of the ground networks, which are of course Safety of Life critical to the operation of our national airspace. We are providing the timing solution for the FAA within that data center infrastructure.

<p>The post Iridium focuses on timing and critical infrastructure first appeared on GPS World.</p>

Photo: Safran Federal Systems

GNSS — delivering up to millimeter accuracy from 20,200 km in space with a received signal of one tenth of one millionth of one billionth of a Watt — is, in Arthur C. Clarke’s famous definition, “indistinguishable from magic.” Yet, in addition to the inherent errors in the transmission, propagation, and reception of their signals, GNSS are increasingly challenged by jamming and spoofing attacks, especially in and near conflict zones.

For that reason, as any regular reader of this magazine knows, combating jamming and spoofing and building resilience in positioning, navigation, and timing (PNT) systems has been a constant theme of many of our articles and industry news items for years.

The U.S. National Space-Based Positioning, Navigation and Timing Advisory Board has been focusing on how to “protect, toughen and augment” GPS, with the third word referring both to enhancements to GPS and to the “provision and use of alternate sources of PNT that complement, back up, or replace (partly or entirely) use of GPS.”^(*)

For this cover story, I discussed complementary sources of PNT with executives from four companies that design, produce, and/or operate them. They cover a wide range of complementary PNT technologies. Read the exclusive interviews below: 

• Iridium owns and operates a constellation of satellites in low-Earth orbit (LEO) and has global rights for L-band spectrum. This enables it to operate the Satellite Time and Location (STL) system developed by Satelles before it recently became part of Iridium. STL protects critical infrastructure by providing a timing signal that is independent of GNSS constellations and 1,000 times stronger than the GPS signal.
• Spirent Communications’ latest simulation system brings together GNSS and a wide range of other PNT systems. It simulates L-band, S-band, alternative navigation signals, signals of opportunity and emulated inertial outputs. It focuses particularly on the new and emerging LEO constellations, including Xona Space Systems’ PULSAR signals, and enables users to inject new signals via I/Q data files.
• SpacePNT has developed an FPGA-based hardware/software/firmware spaceborne GNSS receiver technology specifically targeting the fast-growing New Space satellite market. The company’s innovations include a precise orbit determination algorithm that can process signals from the Galileo High Accuracy Service and from geostationary orbit (GEO) satellites.
• VIAVI Solutions has developed a system that aggregates signals of opportunity, as well as Iridium LEO and Inmarsat GEO sources; weighs and cross-verifies them; then converts the output to the legacy GPS L1 signal and feeds it to a GPS receiver. It can also aggregate a stand-alone cesium clock.

(*) From Dr. John Betz’s presentation on “Augmenting GPS for Critical Infrastructure” at the April 24, 2024, meeting of the PNT Advisory Board.

<p>The post PNT without GNSS: Exclusive interviews first appeared on GPS World.</p>

Photo: American Aerospace Technologies (AATI)

American Aerospace, an Iridium partner, has received a waiver from the Federal Aviation Administration (FAA) to conduct UAV surveillance of critical infrastructure in California’s San Joaquin Valley for Chevron, an oil and gas company.

Enabled by Iridium’s global L-Band satellite connectivity, AATI’s AiRanger UAV will conduct remote aerial surveillance of the energy company’s pipeline and production facilities. Iridium’s network offers beyond visual line of sight (BVLOS) connectivity, including remote command and control (C2) and detect and avoid (DAA) capabilities. The UAV will send information via Iridium satellites to conduct routine inspections.

Iridium partner Blue Sky Network customized and integrated its SkyLink 7100 voice, data and BVLOS terminal on the UAVs. The SkyLink 7100 offers continuous tracking and C2 capabilities for aviation and UAV operations.

The AiRanger is the first UAV to comply with industry standards for the DAA system and meet FAA BVLOS operation requirements. This achievement aims to pave the way for broader use of BVLOS UAVs to enhance situational awareness, reduce inspection costs and maximize value.

<p>The post American Aerospace granted FAA waiver for BVLOS operation first appeared on GPS World.</p>

Iridium STL is being deployed by L3Harris to protect critical FAA data center infrastructure. (Photo: Iridium)

Iridium Communications has entered a five-year agreement with L3 Harris. Under the agreement, Iridium will provide its satellite time and location (STL) service to more than three dozen L3Harris-operated communications network backbone nodes and a similar number of Federal Aviation Administration (FAA) facilities throughout the United States.

L3Harris, responsible for operating a private network for the FAA, provides voice, data and video communications for the National Airspace System operations and mission support functions. Given the critical nature of timing synchronization within the L3Harris communications network, particularly for supporting various critical infrastructure applications, the Iridium STL service plays a pivotal role in the overall network timing architecture by eliminating dependencies on GPS as the primary timing source.

The solution for L3Harris includes compact devices provided by Adtran’s Oscilloquartz division, which are designed to receive Iridium STL signals. These devices seamlessly integrate into the network and meet nationwide network timing synchronization requirements.

In April 2024, Iridium acquired Satelles, a secure satellite-based time and location service provider.

<p>The post Iridium partners with L3 Harris for FAA infrastructure protection first appeared on GPS World.</p>

Image: SparkFun Electronics

SparkFun Electronics has released the 2J7426MPz by 2J antenna, a high-performance magnetic mount antenna designed to communicate with the Iridium satellite communication system. It is manufactured with high-quality polycarbonate (PC) and acrylic-styrene-acrylate terpolymer (ASA), a thermoplastic combination that offers strong resistance to UV, moisture, and heat and enhances mechanical properties.

The antenna housing is waterproof to IP69 standards and designed to operate in extremely harsh environments, including those with frequent exposure to water, dust and debris. It has a recommended operational and storage temperature of -40°C to +85°C. The magnetic mount allows for easy installation and removal between vehicles or assets, and it is easily converted to an adhesive type for greater flexibility.

It is delivered with a standard SMA-male connector and a standard 300 cm long coaxial LL100 cable. Iridium has certified the 2J7426MPz antenna for commercial use in connection with the Iridium communications system.

<p>The post SparkFun launches Iridium antenna first appeared on GPS World.</p>

Image: Iridium

Iridium Communications, a satellite network operator, will acquire Satelles for $115 million. Satelles is a provider of secure satellite-based time and location services that complement and protect GPS and other GNSS-reliant systems.

While Satelles primarily focuses on providing its satellite time and location (STL) services for digital infrastructure companies, there are potential applications for aviation, the company said. Satelles offers smaller form factor devices that can be integrated with data processing and storage servers to provide critical positioning, navigation and timing (PNT) data.

According to Iridium, the STL service uses the stronger broadcast paging channels of the Iridium satellite constellation to deliver precise timing information. This aims to provide global, secure time and location signals that are more powerful than GNSS constellations, the company continued. The service is resilient to regional GNSS outages, works inside buildings and is being used to secure digital infrastructure for financial markets, governments and major corporations.

The company is now working to reduce the size and cost barriers to improve integration with autonomous systems, consumer devices, vehicles and traditional markets such as aviation, maritime and land mobile. STL can help mitigate GNSS jamming and spoofing, with dedicated STL receivers incorporated into aircraft avionics.

“The most immediate application would be in aviation/Federal Aviation Administration (FAA) ground infrastructure to support PNT resilience in their networks,” Iridium CEO Matt Desch told AIN. “[In the] longer term, there would be an opportunity for avionics providers to build STL into their avionics to protect the integrity of the GPS signals their boxes use and provide a way to tell if GPS signals were compromised or spoofed. We don’t think we’ll be an alternative to GPS or other GNSS applications—only a backup to constantly check signal integrity.”

A long-standing investor in Satelles, Iridium had an ownership stake of 20% from three previous investments in the company. Iridium expects to complete the acquisition in the next few weeks.

<p>The post Iridium acquires Satelles to boost PNT capabilities first appeared on GPS World.</p>

How many Iridium satellites carry your system?

Mike O’Connor

Iridium has 66 active satellites. There are also several spares on orbit. The satellites were all launched between 2016 and 2018, so they are all relatively new. They cover the entire globe, 24 hours a day, seven days a week, so they have universal coverage.

How will your constellation grow?

Today, our Satellite Time and Location (STL) service is offered only over the Iridium satellites. There’s nothing else that we’re discussing publicly. It could expand over time to other satellites. The signal and the capability are flexible. In terms of how Iridium could change, that’s more for Iridium to discuss than us.

Who makes chipsets that can use your system? And how does that work?

We work with partners. For example, with Adtran (through their Oscilloquartz product line), Jackson Labs (now VIAVI Solutions), Orolia (now Safran Trusted 4D). Companies like that provide the solutions that are favored by critical infrastructure providers today. We provide them either reference designs or effectively referenced designs. They ultimately integrate our STL capability into their solutions. We help them to do that. They can use our reference designs or create their own custom designs based on our reference designs. So, that’s the model that we use.

Is the STL receiver on top of a traditional GNSS receiver and passing certain data to it?

STL is used in two ways. In some cases, users are trying to do positioning or timing in an environment where GNSS signals will not reach, such as indoors, or are otherwise unavailable. In those cases, it wouldn’t be overlaid with GNSS, it would just be a standalone solution.

In many other cases, the goal is having a solution that is resilient to an outage, interference, jamming, spoofing, those sorts of things. In that case, the receiver card that might be provided by one of our partner companies would have both GNSS and STL capabilities and would take the best of both worlds. If GPS is jammed or there’s interference, then the STL signal alone would be sufficient to do PNT. However, whenever both signals are available and can be authenticated, then it would use both and leverage the benefits of having two systems.

Does the location calculation take place in a GNSS chip or separately in the STL?

The chain to take measurements of the STL satellite signals is different. It’s not a single chip that’s measuring both satellites, it’s ultimately two chips that are making those measurements. Then how the position calculation and the integration of those signals is done is left to our partners. In some cases, it is proprietary to the partners that are doing that integration work. It can be integrated loosely or tightly.

When it’s just the STL chip, is that usually for timing purposes, or both timing and location?

Generally, an STL-only solution is best suited for timing. It’ll do timing at about 100 ns, depending on what kind of oscillator is being used and the exact configuration of the product.

What positional accuracies can you achieve?

Generally, in the 10 m to 20 m range, depending on the product configuration.

Most of the correction services refer to variables that are not relevant to your system.

That’s right. There are other techniques, such as integrating with other sensors, that can improve the accuracy. The primary uses for STL today are in delivering timing in environments where GNSS is not able to do so today, such as for national critical infrastructure. That’s been our commercial focus as a company.

Who currently uses the STL receivers? Which markets are you targeting first?

Most of our users are in the data center space. Stock exchanges around the world are also using our service as a source of resiliency, and now wireless infrastructure. So, think 5G infrastructure. As 5G networks are rolling out, they need about five to ten times more nodes to cover a geographic area than 4G networks. GNSS has been used for years to time 4G networks, but most 5G network sites — such as femtocells and picocells — are indoors or in places where GNSS is challenged. We deliver that timing service indoors, outdoors, everywhere. So, those are the three commercial markets where we have the highest adoption rates.

You still have plenty of room for expansion in that market before you must start thinking about expanding into other areas.

Yes, there’s plenty of room for expansion into those markets, so I wouldn’t say that they’re fully saturated. We are also looking into other opportunities. We’ve seen interest in the energy area. I think the industry is a little bit slower moving, but the need is ubiquitous, right? We all recognize that a black swan event in our society would really represent a bad day and we want to avoid that.

There are several companies across the industry that are trying to solve that important problem. Everyone involved in critical infrastructure that requires a timing reference — which is anything that is associated with a network activity — should have an alternative or augmentation to GNSS as a timing source. It’s great that we’re seeing tailwinds from the U.S. Government, from the European Union, and from others to try to encourage that adoption. However, there’s still a long way to go before we really feel that that’s been sufficiently covered.

What, if any, have been the major developments in the past year or so?

One of the most interesting things that has happened over the last year and a half has to do with our capability regarding STL. We’ve been demonstrating more publicly, and with more independent authorities, the capabilities, resiliency, and operational characteristics of our service.

For example, the JRC study.

It started with the U.S. Department of Transportation (DOT) a couple years ago, but there’s also been some work done by the Department of Homeland Security and with the National Institute of Standards and Technology (NIST). We’ve been working directly with NIST to do some validations, as well as with UK and European organizations. They have subjected STL to rigorous third-party, hands-off technology evaluations. They confirmed the timing accuracy specifications to UTC and validated the operational characteristics of STL, such as the resilience in the absence of GNSS, the ability to receive the signal indoors, and having global availability.

We’re delighted to see the third-party operational evaluation of things that we’ve known all along but are now being evaluated and confirmed by these government sources. Beyond that, of course, there are always going to be technology advancements, both with our company and with other companies.

The real focus of industry right now is on adoption. All the providers of these capabilities ultimately need adoption in industry to remain active and viable. These are good people trying to do the right thing to protect our society. There are many great technology solutions out there to do it. Hopefully, many of these solutions are adopted in the near term. That’s what our focus has been. Our focus has not been on squeezing an extra five nanoseconds out of performance, although, of course, we’re always doing that. I think the important focus of industry should be driving adoption. There are solutions available today, including ours, that are ready to go and are being proven operationally in use.

Can you say more about the study by the European Commission’s Joint Research Centre (JRC)?

If you look at the summary, all these technologies that were demonstrated worked. Both the DOT report and the JRC report effectively summarize that there are multiple technologies out there today that are ready to go.

<p>The post PNT by Other Means: Satelles first appeared on GPS World.</p>

Luccio

“The new LightSquared business plan and the new FCC rules significantly expand the terrestrial transmission increasing the potential for interference to GPS receivers,” the U.S. departments of Defense and Transportation (DOD and DOT) wrote to the Federal Communications Commission in 2011 after the FCC granted the company permission to offer broadband via its satellite and base station networks to a wide variety of mobile broadband partners. The move — heralded by supporters as hastening the advent of 4G services across the country, especially in underserved communities — sent shockwaves across the GNSS/PNT community, which opposed the plan forcefully for the threat it posed to GPS.

Reborn in December 2015 as Ligado Networks, the company obtained the FCC’s unanimous approval in April 2020 for the use of spectrum near the L-bands used by GPS for its 5G network. It is scheduled to launch its first deployment at the end of September.

Nearly all the federal government, including DOD and DOT, as well as most manufacturers of GNSS receivers, are very strongly opposed. On September 9, the National Academies of Science, Engineering and Medicine’s Committee to Review FCC Order 20-48 will release its independent evaluation of the issue, as mandated by the 2021 National Defense Authorization Act.

The study, begun in May 2021, considered three issues:

1. Which of two prevailing proposed approaches for evaluating harmful interference is most effective to mitigate the risk of harm.

2. The potential for harmful interference from Ligado to mobile satellite services — such as Iridium.

3. The feasibility and practicality of the remedies proposed by the FCC.

A summary of the report can be found here.

Welcome Penny Axelrad

I am very pleased to announce that Prof. Penina “Penny” Axelrad has joined GPS World’s Editorial Advisory Board.
Penny is a University of Colorado (CU) Distinguished Professor in the Ann and HJ Smead Department of Aerospace Engineering Sciences. She received her B.S. and M.S. degrees in Aeronautical and Astronautical Engineering from MIT and her Ph.D. in Aeronautics and Astronautics from Stanford University. She has been a member of the faculty at CU since 1992, serving as primary advisor for 25 Ph.D. graduates and many M.S. and undergraduate research students.

Penny has been active in research on GPS and PNT technology and applications for aircraft, spacecraft and remote sensing, as well as estimation of satellite orbits and attitude, since 1985, co-authoring more than 60 journal papers and 130 conference papers. She has served as principal investigator or co-investigator on grants and contracts totaling $17 million. She is a Fellow of the Institute of Navigation and the American Institute of Aeronautics and Astronautics, and a member of the National Academy of Engineering. Since 2013 she has served as a member of the National Space-Based Positioning, Navigation and Timing (PNT) Advisory Board.

I overlapped with Penny at MIT in the mid-1980s. Now, nearly 40 years later, I look forward to her contributions to this magazine.

<p>The post As launch looms, threat from Ligado returns first appeared on GPS World.</p>