Category: Simulators

High-powered satellites go beyond

Jackson Labs Technologies PNT-6200 Series, an STL-based time and frequency reference system installed in a 5G application. Photo: Satelles

We discussed Satellite Time and Location (STL) services and complementary PNT with Michael O’Connor, CEO at Satelles.

What is the problem with GPS/GNSS that Satelles aims to solve?

GPS and GNSS are amazing. We designed Satellite Time and Location (STL), the service that we offer, to complement those capabilities. We have focused on three unique aspects in the areas where GPS could use complementary service. First, we provide a fully independent backup. We all know that things can happen, so we aim to provide an independent source of position navigation, and timing (PNT). Second, we focused the high-power aspect of STL to enable us to reach indoors and other places where GPS does not reach. Because STL comes from low Earth orbit (LEO) satellites, the signals are naturally at a higher power.

We also focused on improving the indoor penetration capability by enhancing the signal design and doing some other things. Third, we use modern cryptographic techniques to ensure the security and resilience of the system, specifically to intentional misdirection attacks. If you can ensure that the signal is coming from the satellite and not from a third party you can have a more secure and resilient solution.

To what extent can you replace GPS during an extended outage?

We have never considered LEO PNT as a replacement for MEO (medium Earth orbit) GNSS. GNSS are the primary domain of PNT but there are applications that have additional needs. The more independence you can get, the fewer the common modes of failure, if you can at least have some survivability in the absence of GNSS. That’s one of the services we can offer. It is probably not the most important thing to our customers, honestly. The service we offer is similar to GPS and GNSS in that we have a space segment (the satellites), a ground segment, and a user segment. We have space vehicles, user equipment, and ground infrastructure that supports the space infrastructure.

What’s interesting about the way we work with the Iridium satellite constellation is that the satellites themselves include inter-satellite links. That provides a lot of resilience to ground-based events. The satellites themselves have a time transfer capability between them. So, we don’t require a direct connection to every satellite to propagate a time throughout the network. That’s one unique aspect we can take advantage of with this particular network, Iridium, which is pretty amazing.

Additionally, we have multiple ground infrastructure and monitoring sites and multiple sources of time at those ground monitoring and control stations. For example, some of them rely on GNSS combined with atomic clocks as their master timing source but we also have one installed at the National Institute of Standards and Technology facility in Boulder, Colorado. So, we have multiple primary time sources that we can integrate into our filtering across the network. That, combined, with satellite links, allows us to maintain time for substantial periods independent of GNSS.

How do you define “complementary PNT” and how does Satelles fit in that mix?

Several applications have additional needs beyond what GNSS offer. There are many technologies that can come to bear on that. There’s the LEO satellite base, which is where Satelles fits in, but there are also local and wide-area terrestrial radio navigation sources, network-based time transfer, signals of opportunity, and so on. They all have something important to offer, depending on the application. Satelles’ LEO satellite solution is available today, has global coverage, and is relatively affordable. It leverages the capital investments that have been made to launch the satellites to provide this service globally. The industry is working together to make sure that an awareness of these capabilities is propagated throughout the industries that we serve.

Besides the orbit height, which requires many more satellites, how does your system differ from GNSS?

We do not consider LEO PNT as something that might replace MEO PNT. The fundamental difference is being in lower Earth orbit, which results in a higher received power. That is what allows us to penetrate, just based on the 1/r2 losses. The measurable Doppler signatures give additional observables for PNT calculations, and higher satellite dynamics that can help with multipath. This service relies on many of the same physics and geometry as GPS. We measure the time of arrival of a very similar signal. The signals from the Iridium satellites are even in the L band. Very often we’re using a GPS chip that’s been reprogrammed to track and utilize our service as well as GPS or instead of GPS.

If I explained how GPS works to, say, a high school science class, how much of that basic explanation—about trilateration, spread spectrum, etc.—would also apply to your system?

It’s fundamentally the same. It relies on a lot of the same physics and geometry. We measure the time of arrival of a very similar signal. The signals from the Iridium satellites are even in the L band. Very often we’re using a GPS chip that’s been reprogrammed to track and utilize our service as well as GPS or instead of GPS. There are subtle differences—for example, a lower Earth orbit is faster—but it is very similar.

How would GPS user equipment have to be modified to make use of your service?

We don’t think of STL as something where we are modifying GPS user equipment. Rather, we think about what must be done in an end-user application to meet their needs. For example, one of our partners, Orolia, has a GNSS + STL secure synchronization product that we have delivered to customers in data centers and major stock exchanges around the world. Those are operational and in service. They integrate through standard interfaces, such as PPS or PTP, depending on the type of equipment to which they are connecting.
Ultimately, we don’t think of it is as replacing GPS user equipment. Rather, where a user has a need for PNT, they’re opting for this GNSS + STL solution because they have an indoor need, such as a data center, or they have a need for resilience in the case of a stock exchange.

Another example is Jackson Labs. The Jackson Labs 2600 is also a GNSS + STL solution that generally is integrating with existing 5g. It has a specialized transcoder interface that can work with any existing GNSS-type equipment. In some cases, we’ve taken a chip that was originally designed for GPS and modified its firmware.

Who are the earliest adopters?

Satelles’ LEO satellite solution is available today, has global coverage, and is relatively affordable. It leverages the capital investments that have been made to launch the satellites to provide this service globally. Data centers, stock exchanges and cell phone providers are implementing these capabilities today. The major wireless operators are seeing that more and more of the 5G infrastructure they roll out is going indoors, where GPS doesn’t reach. We provide a solution that integrates with their existing solutions and can provide reliable timing capabilities.

If your solution can survive on its own, why does it need GNSS at all?

In some cases, the user is not using GNSS at all. The product itself has a GNSS capability. User equipment is very affordable and the service is taxpayer-funded. In many cases, especially for indoor installations, the equipment that is installed is capable of tracking GNSS and STL signals, but often it relies on the STL signal itself for timing.

How do you predict STL spreading through various applications and industries?

We have our hands full with the markets we’re going after now, but there are certainly going to be other markets in which the customers will recognize that they have a critical need to implement a backup solution.

In the long run, could LEO satellites replace MEO ones for GNSS?

Sometimes there have been misperceptions in the industry. I’ve never considered that LEO PNT satellites might replace MEO ones. There are excellent reasons why Brad Parkinson, Jim Spilker, Gaylord Green and others decided almost 50 years ago to put GPS in MEO. Those physics haven’t changed. You can cover a large portion of Earth with each satellite. LEO will not replace MEO, but it has unique characteristics that make it a great complement to the GNSS MEO solutions.

Do you have any additional comments about complementary PNT?

It’s good to see that the federal government is encouraging the adoption of complementary PNT, which they often call “GPS backup.” It is encouraging to see the amount of activity on this issue that’s been going in Washington over the last couple of years. Although our company is very focused on delivering a LEO-based PNT service, which has several advantages for customers that need a global capability, many technologies can play an important role in those solutions.

The U.S. Department of Transportation did a fantastic job of looking at several of those technologies across those different categories. The European Union has also had a similar activity recently. Some reports will be coming out soon about that. It is very important that the government understands that this is an important issue for our society and encourages industry to adopt these solutions and is even starting to make some investments toward that. That includes executive order 13905 and some recent funding increases by Congress.

All of that has been very important and positive, as has modifying some of the legislation to be more inclusive of multiple technologies, such as removing the words “land-based” from the National Timing, Resilience, and Security Act this year.

I am involved in an industry consortium, the Open PNT Industry Alliance, with several other companies whose CEOs are in alignment that there is no single answer. Having a thriving ecosystem of technologies and companies trying to solve this important problem is incredibly important and it’s exciting to see.

July 11, 2022
New approaches improve PNT resilience

Data shows how successful baseline validation testing of Spirent’s inertial simulation model as compared to real world inertial system performance. Photo: Spirent Federal Systems

We discussed complementary PNT with Roger Hart, head of engineering and Jeff Martin, head of sales at Spirent Federal.

What are some of the most promising approaches to complementary PNT sources and how does simulation technology help?

Roger Hart: The vulnerabilities of GNSS have been recognized. Legacy GNSS are all operating on pretty much the same frequencies and power levels, so, they have some significant common vulnerabilities. There is great interest in finding ways to complement or even replace those capabilities.

Dead reckoning, magnetic and inertial systems have been around for a long time. There are emerging markets to make use of alternative radio frequencies for navigation. In some cases, we are piggybacking on communications signals and deriving PNT from them. In other cases, we are using new PNT signals. A couple that we’ve been focusing on are the alternative navigation systems.

They may be using different orbits, different frequencies, different encoding schemes that set them apart from the legacy GNSS systems, so that, used together, they provide greater resiliency and even stand alone when one or the other system may be affected by interference.

Not to be forgotten is inertial navigation. It’s been around for a long time and is still a standard of navigation. Together with GNSS, it makes it a terrific navigation system. It almost defines complementarity because where GPS is vulnerable inertial can fill in the gaps and where inertial drifts GPS does not. So, paired, they make a very strong system.

At Spirent, we’ve been working with customers to provide a variety of options for both those alternative navigation systems and inertial. Both are a very active field of development and we’re keeping abreast of that.

Jeff Martin: Some good points, Roger. This is something we’ve been engaged in for quite a long time. Since we provide test equipment to the community, it’s critical that we understand what they’re worried about, what the vulnerabilities are. It keeps things exciting, it keeps us on our toes and looking ahead to what’s coming.

What are some of the remaining challenges of integrating GNSS receivers with inertial sensors and, again, how does simulation technology help with that?

Hart: Inertial works by integrating sensor measurements that come in. Therefore, any errors that are present just accumulate over time and can corrupt your navigation solution. So, there’s a strong focus on updating error models and on translating them so that everyday users can use them and get real-life-type performance out of them.

There’s a tendency to think of integrating GPS-INS as putting everything together in one box. There are packages that do that. However, the push now is to go to more distributed systems that are integrated but not packaged in the same box. One example is the all-source positioning and navigation standard that is being developed by the Department of Defense. It will allow you to swap one sensor for another as long as they adhere to the standard. That information all goes back to a sensor fusion engine.

Martin: We have known GNSS simulators well for about four decades. We have been playing in the inertial sandbox for at least a couple of decades as well. This has given us the opportunity to build relationships with the with the key manufacturers and designers of inertial systems. Those relationships have been expanding well beyond inertial to many other sensors and systems that are now coming online. It’s been exciting.

Much work is going into using low Earth orbit satellites for PNT—whether piggybacking on the Iridium satellites or launching new ones. How does simulation help with that?

Hart: It certainly helps with the development of the receivers. The groups that are using these alternative RF and LEO or MEO systems need simulation as they develop the receivers. It gives you the ability to try things certainly before you launch them. At this conference there is considerable interest in making things reprogrammable. We have the NTS-3 satellite, which will be running experiments for different waveforms that can be generated. Even M-code is a step in the direction of giving more flexibility to the signal. It has a lot more flexible cryptography and signal generation than the legacy system with the C/A and P/Y codes.

Our simulation platforms are software based, so we can generate and receive data that can be useful for developing software-defined receivers. It gives you the opportunity to try different waveforms. We have already delivered a satellite-based alternative navigation system simulator. Now, we can build on that one to help the other Leo constellations as they come forward.

Martin: Roger put it well. This is where things get fun. People are concerned with PNT vulnerabilities, so we’re seeing these alternative navigation solutions coming forward. Spirent has done a good job over its nearly 40 years of existence of manufacturing and designing its own hardware and software. It has given us the opportunity to respond quickly. These things are coming fast. People need solutions quickly. We have some solutions already and the platform that we have created gives us the flexibility to develop more. We’re seeing more and more ideas come to fruition and people need to test them. So, this is where it gets fun. We’re excited.

Much work has gone into addressing the enduring challenge of urban canyons. How does simulation technology help?

Hart: Urban canyons are the worst nightmare for GNSS signals. If you’re surrounded by tall buildings, signals are blocked. You may have few or even no satellites in a direct line of sight and many multipath reflections. So, diminished and corrupted signals are available to you. Of course, the more GNSS satellites you have, the better chance you have of getting good signals. But complementing that are radar and vision systems. Those are the ones that will stand out, particularly the vision systems that can read the street signs, see where the curb is, look for parked cars. All those kinds of things will help fill in when you have poor GNSS coverage.

You can observe what’s going on in the environment and simulate it. You can also use our forecasting tool to look ahead.

Martin: This is where things get exciting, isn’t it? In these terrible environments where GNSS is contested—whether it’s an urban environment or one with intentional jamming—there is a lot we can do to help our industry. When this happens in real life, it’s bad news. But when you create that scary situation in the controlled environment of a laboratory, it is great. You can pick things apart and see where you need to improve. I get excited about it. It’s probably the geek in me. It gives us and our partners a lot to look forward to.

How does simulation technology help with sensor fusion?

Hart: It definitely helps you put all the pieces together. You can’t know how your system will work by individually testing each piece. System is the key word here. Simulation enables you to generate the signals and bring them together into a sensor fusion engine. You can test different algorithms. It’s certainly much cheaper and quicker than trying to build this into a product and then test it. Over the decades, simulation has proved itself as a very valuable way in both basic development and integrating the final product.

Martin: That system-wide fusion is where the magic happens.

It sounds like simulation technology—and Spirent Federal in particular—are very much at the center of a lot of the current developments and discussions about complementary PNT. Do you have any final comments?

Hart: As Jeff said, it’s an exciting time. There are many things going on—new technologies, new ways of communicating. It’s a busy time and a bit of a scramble sometimes to keep up with all the new things that are coming.

Martin: People look to Spirent to be their testing resource and it puts us right in the middle of it.

July 11, 2022
5G LBS features verified on R&S TS-LBS test solution

Photo: Rohde & schwarz

Rohde & Schwarz and MediaTek have verified new location-based services (LBS) features for 5G new radio (NR), which are now available on the R&S TS-LBS test solution.

The features will improve emergency caller location and support LBS-related use cases in challenging indoor and outdoor environments with both satellite-based and terrestrial technologies. The R&S TS-LBS now support these and other 3GPP Release 16 network-based positioning features.

A 5G chipset from MediaTek also has been verified for Release 16, which ensures the chip’s positioning features.

The two companies verified the NR positioning reference signals (NR-PRS), which are central to network-based positioning features such as round-trip time (RTT), time difference of arrival in uplink and downlink (UL- TDOA and DL-TDOA), or angle of arrival and departure (AoA and AoD), and which meet the 5G requirements for indoor and outdoor positioning use cases.

With R&S TS-LBS supporting these features, mobile device and chipset manufacturers as well as test houses and network operators can carry out verification for GCF, PTCRB and network-operator certification using a single test solution.

About the R&S TS-LBS System

The R&S TS-LBS is a test system for testing GNSS and network-based positioning. It consists of an R&S CMX500 OBT one-box signaling tester as the network simulator and an R&S SMBV100B GNSS simulator.

The R&S CMX500 OBT setup provides full network simulation capabilities including the support of multiple 4G or 5G cells at a time. In addition, it provides LBS assistance data to the DUT while the R&S SMBV100B simulates the GNSS satellites.

The R&S TS-LBS test system can be used for pre-conformance tests and to obtain GCF and PTCRB certification as well as network-operator-specific certification acceptance and validated tests.

“Adding network-based positioning features such as DL-TDOA based on NR-PRS to the existing satellite based location signals shows the advanced level of our test solution,” said Christoph Pointner, senior vice president, Mobile Radio Testers, Rohde & Schwarz. “We are happy to continue our collaboration with MediaTek to push 5G location-based services further for 3GPP Release 16.”

July 7, 2022
Orolia releases Skydel GNSS simulation software upgrade

Skydel 22.5 features advanced hardware-in-the-loop testing

Orolia has released Skydel 22.5, a significant software upgrade to its Skydel simulation product line that features advanced hardware-in-the-loop (HIL) testing solutions providing very low to zero effective latency.

The enhanced visualization tools can monitor internal latency through real-time curves showing when the data is generated and sent to the RF signal. Users can also review the transmission of HIL packets for optimizing the entire network’s latency, checking its stability (jitter), and that data is available and used at the right time in Skydel.

HIL testing is an essential step in the verification process of the model-based design (MBD) approach because it involves all the hardware and software that will be used operationally. HIL verification can test a standalone device-under-test (DUT) or, more generally, an entire complex system consisting of multiple DUTs in both open- and closed-loop architectures.

“The vast majority of problems encountered by engineers on HIL systems are related to poor control of the latency of the entire simulation chain, as they are insufficiently accessible, transparent and controlled on the competing systems,” said Pierre-Marie Le Veel, principal system architect and product manager for GNSS simulation. “Thanks to these tools, our high-end performance and well-known intuitive automation, Skydel dramatically reduces the implementation time of a HIL system (which can be very significant) and, therefore, the project’s overall cost.”

Photo: Orolia

In addition to these tools, Skydel implements modern extrapolation algorithms that achieve zero effective latency. These algorithms make it possible to keep position errors negligible, even for equipment with very high dynamics used in national defense applications such as missiles, rockets and guided shells.

“These advanced HIL algorithms and tools are available – and with the same performance – on our Wavefront simulation systems to test controlled reception pattern antenna (CRPA) systems,” Le Veel added.

Additional constellations, signal types and options such as real-time kinematic (RTK) and multi-instance are available along with dedicated bundled simulation starter packages for automotive.

The upgrade is available at no additional cost for existing users operating Skydel 22.5. Application notes, support documents and tutorials are available online.

June 29, 2022
Reliable navigation with interference-free GNSS signals

By Markus Irsigler and Sebastian Kehl-Waas

Interference-free GNSS signals are essential for more than just military vehicles and aircraft. Anti-jam systems usually suppress signals from interference sources by means of spatial filtering.

These solutions can likewise be used to protect satellite navigation signals for autonomous driving and flying against interference signals. To allow GNSS receivers to detect interference sources and suppress transmitted interference signals, they must be designed as multichannel systems.

This way the direction of the interference signal can be determined using phase-coherent signal processing of signals from multiple antennas, and the interference can be suppressed. Rohde & Schwarz offers a solution for the verification of interference immunity and interference suppression.

FIGURE 1a. The GNSS antenna in the example on the left has only one element, so its characteristic cannot be modified. A sufficiently strong interference signal can prevent the receiver from processing the GNSS signals, making satellite-based navigation impossible.

FIGURE 1b. In contrast to the individual antenna, the characteristic of the antenna array can be modified by combining and weighting the received signals. The interference signal is suppressed at its angle of arrival, and the GNSS signals can be received. A disadvantage is that GNSS signals from the same direction as the interference signal are also suppressed.

Multi-channel receivers can simultaneously process signals from multiple distributed antennas or from an antenna array. This is useful for determining the direction of incoming signals by means of signal analysis, and for adjusting the antenna pattern so that undesired signals are suppressed. For GNSS-based position determination, this means that signals from global navigation satellite systems (GNSS) can be strengthened and jamming or spoofing signals originating from the ground or the air can be suppressed. Up to now this technology has primarily been used for military applications, but in the future it can also make an important contribution to robust navigation for autonomous driving or flying. Typical interference sources in this regard are harmonics of transmitters in the vicinity, tactical air navigation (TACAN) signals, DME air navigation signals for civil aviation, and LTE signals. Another factor is the growing popularity of so-called personal privacy devices (PPD), which are GNSS jammers that radiate narrowband or broadband signals to disrupt GNSS localization. A new solution from Rohde & Schwarz enables comprehensive testing of the resistance of GNSS receivers to interference signals, if necessary in a realistic hardware-in-the-loop (HIL) environment.

Multi-Channel GNSS Receivers for Interference Suppression

GNSS receivers often use controlled reception pattern antennas (CRPA) to suppress undesired signals. These antennas consist of an antenna array and a signal processing unit. The connected antennas are generally arranged in a strict geometric pattern to achieve full coverage of all possible signal directions. The overall receive characteristic of the antenna array can be altered by suitable weighting of the signals from the individual antennas in the signal processing unit (Fig. 1). This way, interference signals can be specifically blanked out (nulling) or the required GNSS signals can be amplified at their angle of arrival (beamforming). A combination of these two methods is also possible. The antenna arrays typically consist of four to seven elements. The number of interference signals that can be simultaneously suppressed increases with the number of elements.

FIGURE 2a. A four-channel GNSS test system consisting of two R&S SMW200A vector signal generators and an R&S SMA100B analog signal generator for the LO signal (left). The vector network analyzer is used to calibrate the overall system at a user-selectable reference plane in terms of amplitude, phase and propagation time.

FIGURE 2b. A four-channel GNSS test system consisting of two R&S SMW200A vector signal generators and an R&S SMA100B analog signal generator for the LO signal (left). The vector network analyzer is used to calibrate the overall system at a user-selectable reference plane in terms of amplitude, phase and propagation time.

Test System Requirements

Rohde & Schwarz offers a test system for GNSS receivers that use CRPAs. First, it acts as a multichannel GNSS simulator that considers all aspects of a satellite navigation system. It must be able to generate the signals of all standard satellite navigation systems in all GNSS frequency bands, with attention to correct satellite orbits, signal propagation characteristics and realistic modeling of the dynamically changing receive environment. Configuration of the antenna array in terms of geometry and the receive characteristics of the individual antennas also must be included.

Simulating the Interference Signals

Second, the system can simultaneously generate jamming or spoofing signals in order to test the interference suppression functions of the device under test (DUT). A second, identical test system is necessary for freely definable configuration of interference sources with very high transmit power. Here the R&S Pulse Sequencer software assists in the definition of complex interference scenarios. The scenarios cover requirements such as long simulation times, moving interference sources and GNSS receivers, user-defined antenna patterns and antenna scans. In addition, the software calculates the correct amplitude, phase angle and propagation time of the signals as a function of signal frequency, antenna arrangement, and the positions of transmitters and receivers in three-dimensional space for each individual antenna element. Signal generation is handled by the R&S SMW200A high-end vector signal generator.

For the tests, the required GNSS signal as well as the unwanted interference signals must be generated for each antenna input of the GNSS receiver. In order to test a CRPA receiver with four antenna inputs, this means that four signal sources are needed to generate the GNSS signals and an additional four signal sources are needed to generate the interference signals. Fig. 2 shows a pair of test systems that can be used to generate coupled GNSS signals and interference signals for a four-channel CRPA receiver.

Calibration Against the DUT

In order to correctly simulate the directions of the satellite signals and the interference signals, the test systems must be calibrated at the RF interface to the DUT with regard to amplitude, phase and propagation time. This means that the amplitude, phase and propagation time differences between the individual RF paths, resulting for example from cables or RF components, must be compensated. The vector signal generators of each system are phase coherently linked using suitable synchronization. A high-end R&S SMA100B analog signal generator in each system provides the shared LO signal.

Using the R&S RF Ports alignment software, the complete system can be calibrated at any desired reference plane with regard to amplitude, phase and propagation time, so that the properties of the test system do not corrupt the simulated signal differences between the individual antennas. The required measurements are performed with a vector network analyzer.

It is not necessary to calibrate the two test systems relative to each other. For the simulation of realistic scenarios, it is sufficient to run the GNSS and interference source simulations at the same time, since in the real world there is usually no correlation between GNSS satellites and interference sources.

FIGURE 3. Aircraft with a multichannel radar warning system consisting of multiple receive channels, a central processing unit and a display.

Integration in an HIL Environment

The GNSS test system also can be embedded in a hardware-in-the-loop (HIL) environment. In this case a computer streams the motion profile of the GNSS receiver under test, with position, speed, acceleration and vehicle attitude, to the test system at a high data rate. The test system then generates the corresponding satellite navigation signal in real time. This requires very high update rates and low latencies.

Summary

Multichannel GNSS CRPA receivers considerably improve the navigation of ground vehicles and aircraft of all kinds. With the new Rohde & Schwarz test system, realistic multi-channel test signals can be generated for both GNSS simulation and interference simulation. For tests in an HIL environment, motion data also can be streamed to the GNSS test system.

June 14, 2022
Spirent positioning technology business wins Queen’s Award for Enterprise

GNSS positioning company recognized for continued international trade success

The positioning technology business of Spirent Communications has been honored with a prestigious Queen’s Award for Enterprise.

Spirent is one of only 226 organizations in the United Kingdom to be recognized with the Queen’s Award, which acknowledges the company’s excellence in international trade.

Spirent is headquartered in the UK, with its positioning business in Paignton, Devon, developing and manufacturing positioning, navigation and timing (PNT) test solutions. It also has a research and development facility in Daventry, Northamptonshire.

“As reliance on PNT technology continues to grow, our positioning technology business is the trusted partner of the world’s foremost PNT developers, delivering maximum performance without compromise through our dedicated test and validation solutions,” said Martin Foulger, general manager, Spirent Positioning. “We are honored to receive the prestigious Queen’s Award accolade, which is testament to the hard work of our employees in enabling us to achieve such tremendous success worldwide.”

Powered by its international trade, its exports outside of the UK represent a significant proportion of its business, serving a global customer base across five continents and more than 40 countries. Its technology has represented the global gold standard for commercial and government research and development facilities since the inception of GPS.

Its core business is the simulation of GNSS signals in laboratories for the development of applications used in advanced aircraft, chipsets, satellites, smartphones, cars, autonomous systems, marine vessels and defense systems, as well as the navigation systems themselves.

“Market leaders who are developing PNT applications have placed their trust in our test solutions for decades due to our unrivaled performance, realism and reliability,” said Foulger. “Furthermore, Spirent expertise is directly enabling and driving innovation in connected and autonomous vehicles and machine learning, as well as helping to make the world more sustainable through working closely with fields such as smart cities and precision agriculture.”

Now in its 56th year, the Queen’s Award are the most prestigious awards for businesses in the UK and a globally recognized royal seal of approval for companies. As a winner of the award, Spirent is permitted to display the esteemed Queen’s Awards Emblem for the next five years.

April 29, 2022
Spirent Federal Training Seminar returns in person this July
Spirent Federal Systems is hosting its annual training seminar in person for the first time in two years. The event will take place July 12-13 in Huntsville, Alabama.

At the seminar, experts in positioning, navigation and timing (PNT) will share the latest GNSS and alternative radiofrequency navigation developments and provide advanced training on Spirent’s test equipment.

The two days of rigorous training includes hands-on workshops and a half-day for official use only (FOUO) session (restricted to U.S. citizens only).

The seminar is free, with breakfast and lunch included. Hotel rooms are additional.

Training topics will include:

Fundamentals of GPS/GNSS Testing
- GNSS updates
- Basic set-up and use of GNSS simulator
- Fundamentals of GPS/GNSS testing
- Calibration
Creating Realistic Scenarios
- Recreating realistic environments in the lab
- Multipath and obscuration modeling
- Utilizing remote control and motion
- Advanced simulation techniques
GPS/GNSS Vulnerabilities
- Interference
- Spoofing and other threats
Vulnerability Mitigation
- CRPA test systems & anechoic chamber applications
- MNSA M-code and Y-code
- Alternative PNT navigation
- Inertial navigation systems
- Flex power
- Multi-GNSS constellations
- LEO constellation testing
A full agenda will be released soon. The FOUO Session, for U.S. citizens only, will be held on the afternoon of Wednesday, July 13.

Venue. The event will take place 8 a.m. t0 5 p.m. July 12-13 in the Huntsville Marriott at the Space & Rocket Center, 5 Tranquility Base, Huntsville, Alabama.

The Huntsville Marriott is offering a discount for registrants and a limited number of rooms at the government rate. A link to reserve hotel rooms will be provided upon registration.

Space is limited. Register on the event website.
April 12, 2022
Using modern PCs to carry the load

An off-the-shelf PC provides the computing power for complex GNSS driving simulations. (Photo: Racelogic)

By Julian Thomas
Managing Director, Racelogic

Driving simulators are commonly used by vehicle manufacturers to expedite the test and development process of their many electronic systems. This not only saves the considerable time and expense of using a real car on a test track, but it is, of course, significantly more environmentally friendly.

LabSat simulators are used by many leading technology companies and car manufacturers to develop and verify the performance of their new products containing GNSS receivers. These tests are performed using either a pre-recorded or an artificially generated RF signal. This RF signal contains the combination of multiple satellite signals, which are decoded by the GNSS engine, tracking the artificial satellites as though they were real. Static or moving scenarios can be generated, and the user can select parameters to suit their own application, such as time, date and available constellations.

Julian Thomas
Managing Director
Racelogic

Recently, an automotive LabSat customer had a specific requirement to synchronize a GNSS receiver with the real-time trajectory data generated by one of their driving simulators. This was for a hardware-in-the-loop test rig where a human driver would navigate a route around a virtual test track, while the normal electronic systems reacted as if the vehicle were being driven around a real environment.

The challenge in this customer’s application was that the time delay between the trajectory coming from the simulator and the generation of the corresponding GNSS signals had to be less than 100 ms. This low latency was necessary to achieve realistic synchronization between the driver’s inputs and the resulting output from the GNSS-based device under test.

Traditionally, low-latency real-time simulators use bulky expensive hardware that relies on power-hungry field programmable gate arrays (FPGAs) to create the necessary satellite signals. However, due to the inevitable tick of Moore’s Law, and with some clever optimizations, your entry-level desktop PC now packs more than enough punch to simulate multiple constellations and signals with very low latency.

Using a standard PC to do the heavy lifting means that the hardware required to output the simulated signal is much easier to obtain, can be a lot simpler, and is considerably more cost effective. For example, an 8-core, 3-Ghz Intel i7 processor can generate the signals from 20 satellites in real-time, which normally is sufficient to simulate all but the most complex scenarios.

Our LabSat SatGen software has been continuously developed and optimized during the past 15 years, so it did not take us long to enable the reception of an NMEA trajectory stream with a latency of less than 100 ms. We then streamed this simulated data via USB to our LabSat Real-Time, which generated a corresponding RF signal that can be connected directly to the RF input of any modern GNSS engine.

Using a PC to generate the signals does not mean a loss of fidelity, with the resulting output achieving a repeatable position of less than 10 cm, while the trajectory data can be received at up to 100 Hz.

The resulting solution can take trajectory data from any kind of simulator that has an API to obtain real-time data, such as many popular off-the-shelf driving and flight software simulators, and use this to provide a real-time signal that can be utilized by the GNSS device under test.

Our future development roadmap includes synthesizing external signals, such as CAN-based sensors or inertial measurement units, and then synchronizing these signals with the incoming trajectory. With the amazing power of a modern PC, we are finding that this kind of complex simulation is now much more cost effective and easier to achieve.

February 28, 2022
US Air Force procures Orolia’s CRPA testing solution

Orolia Defense & Security, provider of software-defined simulation solutions for navigation warfare, will supply a BroadSim Wavefront to the U.S. Air Force Guided Weapons Evaluation Facility (GWEF). BroadSim Wavefront is an innovative, Skydel-powered advanced GNSS simulator.

The BroadSim Wavefront simulator from Orolia Defense & Security. (Photo: Orolia)

The GWEF provides laboratory testing and simulation tools for developing precision-guided weapon technology, including a comprehensive scope of GPS plus inertial navigation systems (INS) and integrated components such as sensors, signals of opportunity and controlled reception pattern antennas (CRPAs). CRPAs are fundamental in many platforms due to their enhanced protection against electronic attacks in NAVWAR environments.

The Broadsim Wavefront simulator will be integrated into a test environment for networked, collaborative and autonomous weapon systems being developed under the Golden Horde program. Golden Horde is one of four Air Force Vanguard programs designed to rapidly advance emerging weapons systems and warfighting concepts through prototype and experimentation.

Of the several capabilities the GWEF required, features such as low-latency hardware-in-the-loop, automated calibration, and the flexibility to quickly integrate future signals and sensors were the most critical and serve as a key reason Orolia’s BroadSim Wavefront was selected. The system will also be capable of testing eight-element CRPA systems, eight simultaneous fixed radiation pattern antenna systems (FRPA), or a combination of CRPA and FRPA systems.

“When designing BroadSim Wavefront, we re-imagined every aspect for the user,” said Tyler Hohman, director of products for Orolia Defense & Security. “Though the GWEF unit contains eight nodes (corresponding to each antenna element), it can be scaled from four to 16 antenna elements. One of the greatest advancements is our continuous phase monitoring and compensation technique. It automatically monitors, aligns and adjusts the phase of each RF output continuously throughout the duration of a scenario.”

“Gone are the days of re-calibrating each frequency on your system, limiting your scenario duration or re-calibration every time you power cycle your system,” Hohman said. “Simply turn the system on, start the scenario, and your Wavefront system phase aligns and remains aligned for the entirety of the test.”

Leveraging the Skydel Simulation Engine, BroadSim Wavefront also supports high-dynamics, MNSA M-code, alternative RF navigation, open-source inertial measurement unit (IMU) plug-ins and a 1000-Hz iteration update rate.

“Because of the software-defined architecture, many upgrades don’t require additional hardware, which has been a crucial advantage for customers who are already using this solution,” Hohman said.

February 15, 2022
Location systems provider Syntony GNSS joins TCCA

Syntony GNSS has joined TCCA, a global representative body for the critical communications ecosystem.

With offices in France, the United States and Canada, Syntony designs and manufactures GNSS products, including receivers and simulators dedicated to mission-critical applications, transportation, aerospace and defense.

According to an industry report, the global GNSS simulators market size is set to grow from USD 106 million in 2020 to USD 165 million by 2025, at a CAGR of 9.3% during the forecast period. Various factors such as rapid penetration of consumer IoT, the contribution of 5G in enabling ubiquitous connectivity, and increasing use of wearable devices utilizing location information are expected to drive the adoption of the GNSS simulators hardware, software and services.

Syntony GNSS manufactures SubWAVE, a solution that enables GPS to work underground and makes possible critical safety services. SubWAVE enables emergency call location in underground tunnels and stations from any smartphone. It also provides the location of any first responder using a compatible P25 or TETRA receiver.

A Syntony team member in a Swedish road tunnel during SubWAVE testing shows the positioning in an underground environment on a smartphone. (Photo: Syntony GNSS)

SubWAVE is typically deployed in underground subway networks (stations and tunnels). It covers 100% of the underground stations of the Stockholm subway, for example. It is also suitable for underground road and rail tunnels, underground parking, and in the mining industry.

“We invented SubWAVE to save lives: to be able to precisely locate a firefighter inside a tunnel, for example, is critical to his or her safety, and this is what our system does,” said Joel Korsakissok, Syntony president and founder. “Also, being able to pinpoint the location of emergency calls made from road or rail tunnels will enhance first responders’ ability to provide assistance and rescue. We are very proud to become a member of TCCA, whose DNA is focused on life-saving through critical communications.”

“Reliable GPS/GNSS coverage in underground and denied locations such as subways, rail and road tunnels and mining is now an essential requirement for emergency services and asset operator personnel navigation and response as well as citizen safety,” said Kevin Graham, TCCA CEO. “General citizens and many businesses now rely on GPS/GNSS signals for their navigation and tracking use cases. We welcome the expertise of Syntony GNSS to enhance knowledge within TCCA of this critical area, and look forward to working with Joel and his team.”

February 2, 2022
Orolia Academic Partnership Program to support PNT research

Program will support positioning, navigation and timing (PNT) research at colleges and universities around the world

Orolia has created the Orolia Academic Partnership Program (OAPP) to build a community to help foster global PNT research and collaboration at top engineering schools and research institutions.

Orolia will provide qualified institutions with access to the company’s signature Skydel GNSS simulation engine, an advanced GNSS and PNT testing and simulation tool.

Webinar scheduled

Orolia will host a webinar on Dec. 14 at 11:00 a.m. EST to introduce OAPP and answer questions about the program and Skydel. Register here.

Orolia also created an online forum to support its vision to form an interactive community focused on the future of GNSS and PNT research and education.

The forum allows users to interact with other users and Orolia experts, share information, ask questions and receive feedback. A host of white papers, application notes and detailed technical documents are also available.

The Skydel platform

Skydel is an innovative GNSS simulation platform that leverages software, advanced graphics cards and software-defined radios. Users can build custom signals and connect to other systems and devices (such as sensors and inertial measurement units) through Orolia’s open-source plug-in capabilities.

Skydel also includes the ability to generate and test the vulnerability of GNSS/GPS with integrated interference, jamming and spoofing capabilities. Because Skydel leverages commercial off-the-shelf hardware, it can run independently of simulation vendors’ hardware.

“Skydel platform’s versatility and capabilities allow users to perform tests in the field, in the lab, and at home — whether you are running a turnkey system provided by Orolia, our partners, or through your own proprietary hardware,” said Lisa Perdue, director, PNT Testing and Simulation at Orolia. “Unlike other GNSS simulators, Skydel is the only professional platform offering a plug-in architecture that provides real-time and direct access to the core simulation engine. This plug-in architecture unlocks a new range of application and customization that is impossible to imagine with traditional instruments.”

Perdue added that plug-ins can be shared with the open-source community to leverage all the benefits from a collaborative ecosystem. “We believe this modern architecture is the perfect approach to support academic research as well as allowing users to go further into system integration and customization,” she said.

The University of Stuttgart in Germany is an academic partner. (Photo: Regenscheit, Universität Stuttgart)

Stuttgart Institute a Pioneer

More than 40 schools throughout North America, Europe, South and Central America and Asia-Pacific are enrolled in OAPP, including the Institute of Navigation (INS) at the University of Stuttgart in Germany, where Skydel is fueling pioneering student research.

“Skydel allows our students to carry out complex field tests, such as simulating laboratory scenarios in real time and using radio hardware to send signals to commercial or self-developed receivers,” said Thomas Hobiger, INS. “We can compare our navigation solutions with the simulated trajectories while showing the absolute accuracy of our algorithms, meaning the deviation from the actual position.”

Hobiger added the INS wants graduates to be well-prepared for the demands of the industry and future innovation. According to Statista consumer research, the installed base of GNSS devices worldwide stood at 6.4 billion units in 2019. The Asia-Pacific region led the way, accounting for 3.4 billion GNSS devices, with forecasts suggesting this is set to rise to 5.1 billion devices by 2029.

“OAPP members can contribute to this community to share their advancements, upload code or make their work available to others in our GitHub repository,” Perdue said. “The goal is to ensure that members can access ideas and expertise of other users across the globe.

“The need for continuous and reliable GNSS signals as well as methods to protect those signals from jamming, spoofing or meaconing is growing exponentially worldwide,” Perdue said. “These are the main reasons why engineering students should gain valuable experience using a platform that provides accurate PNT simulation and measurement.”

December 2, 2021
Orolia and Hoptroff partner on traceable timing to protect networks

Hoptroff’s Traceable Time as a Service to become an option for Orolia’s product portfolio; webinar scheduled for Dec. 15

Orolia and timing solutions provider Hoptroff are partnering to deliver a service combining Orolia’s resilient positioning, navigation and timing (PNT) solutions with Hoptroff’s timing synchronization software.

The collaboration will offer Hoptroff’s Traceable Time as a Service (TTaaS) as an add-on to Orolia’s suite of products, providing precise and verifiable time to customers in enterprise, financial, telecom, utilities, public safety, and other markets where traceable time is critical.

Webinar scheduled

Orolia and Hoptroff will host a joint webinar to discuss the partnership and new resiliency options for customers on Dec. 15 at 12 p.m. EST. Register here.

Hoptroff’s TTaaS offers an additional level of security and precision to meet stringent regulatory and resilient infrastructure requirements by delivering accurate time over the network using a VPN connection over broadband or fiber networks.

The bundled solution will simplify the challenge of getting accurate, traceable time in applications where GNSS access is not available or dependable. It can also serve as an accurate, reliable backup to GNSS to provide a high level of resiliency to timing systems being used in critical infrastructure.

“As industries evolve and computer applications become more complex and widely distributed, it is essential that devices in a distributed process share the same accurate timescale to reconstruct digital events after the fact,” said Tim Richards, COO at Hoptroff. “Network-based traceable timing, such as TTaaS, provides resilient backup to a GNSS installation in the case of signal disruption, monitors the quality of performance of time servers, and keeps a record of this timing quality at a location of the customer’s choice. Our partnership with Orolia means businesses will now be able to back up and monitor physical time servers and virtual servers in the cloud, so that they can be sure they share the same accurate timescale, and they have the records to prove it.”

“The partnership with Hoptroff aligns with Orolia’s resilient PNT strategy by providing a wireline solution to augment its space-based PNT solutions. This allows us to further simplify the challenge customers face when building a highly resilient timing solution,” said Jeremy Onyan, Orolia’s director of time sensitive networks. “By combining Orolia’s anti-jamming and anti-spoofing solutions, high-performance GNSS-based timing products, alternative signals like STL, a local high-quality oscillator, and now a wireline-based TTaaS we have one of the most robust portfolios of resilient PNT solutions in the market. Additionally, with the recent acquisition of Seven Solutions, we are well positioned to extend our capabilities into high-accuracy time distribution.”

Seven Solutions is a global innovator in White Rabbit sub-nanosecond time transfer and synchronization technology. “With the capability to distribute time with little to no accuracy loss, Orolia’s customers using Hoptroff’s TTaaS or other time references such as GNSS can extend that time to other parts of their networks and create a high level of resiliency against potential outages,” Onyan added.

Image: Panuwat Sikham/iStock/Getty Images Plus/Getty Images

December 2, 2021