Tag: M-code

Directions 2023: Advancing GPS to Meet the Future
GPS is the gold standard for precise positioning, navigation, and timing (PNT), impacting the lives of more than six billion users worldwide. The United States economy alone depends on the free, government-provided service across 900 million GPS receivers supporting vehicle navigation systems, general aviation, financial transactions, the electrical grid, precision agriculture, surveying and construction. The GPS enterprise must remain consistent and reliable, while keeping pace with emerging technology without interruption for the end user.

Space Systems Command (SSC) at Los Angeles Air Force Base in El Segundo, California — the U.S. Space Force’s space development, acquisition, launch and logistics field command — is responsible for maintaining and modernizing the GPS enterprise. The enterprise consists of three segments: the space segment, the control segment and the user segment. Each achieved specific milestones during an exciting and productive 2022.

A new MGue for warfighters is moving closer to completion. (Image: EvgeniyShkolenko/iStock /Getty Images Plus/Getty Images)

Space Segment

There are currently 37 GPS satellites on-orbit with 31 set healthy. The constellation requires 24 operational satellites for worldwide coverage and a receiver needs to receive transmissions from four of them to determine its position in three dimensions. GPS continues to operate impressively with an average 45-cm accuracy throughout the past year with the most precise day on record at 31.5 cm. The space segment of GPS modernization focuses on GPS III and GPS IIIF satellite development with significant milestones rounded out in 2022.

For GPS III, after the successful launch of Space Vehicle 5 (SV05) on June 17, 2021, it was set healthy (usable) on May 25, 2022. The significance of SV05 is its full operational capability of the improved civilian L2 (L2C) signal. L2C improves service speed for commercial users via access to two frequencies, improves accuracy when combined with legacy civil GPS signals (L1 C/A), and is less susceptible to ionospheric interference. SV05 is the 24th satellite enabled with the Military Code (M-code), providing worldwide M-code coverage. M-code is designed to give military receivers better defense against jamming, improved accuracy, a more secure and flexible cryptography architecture, and the ability to detect and reject false signals.

On Jan. 18, 2023, SV06 successfully launched into orbit aboard a SpaceX Falcon 9 Block 5 rocket from Cape Canaveral Space Force Station, Florida. The launch of SV06 marks a key step in the larger goal of modernizing the GPS constellation. Additionally, the 10th and final satellite in the GPS III fleet finalized production and has a target launch date of 2026. GPS III Space Vehicles 7–10 are in storage and available for launch.

The next generation of GPS satellites continues development. The October 2022 contract award for GPS III Follow-On (GPS IIIF) satellites will onboard additional capabilities. In addition to introducing new civil signals designed to enhance search-and-rescue efficacy and aviation safety, laser retroreflector array for precise ranging, and a fully digital navigation payload, the GPS IIIF satellites will offer a new Regional Military Protection (RMP) capability providing up to 60 times greater anti-jamming measures. A new port on the Lockheed Martin LM2100 Combat Bus supports a substantial increase in flexibility, providing rapid integration of payloads in response to emerging threats in space.

GPS Enterprise interrelated segments. (Image: Space System Command)

Control Segment

The Next Generation Operational Control System (OCX) will replace the current GPS Operational Control System (OCS), supporting the latest U.S. Department of Defense standards and practices for cybersecurity. The updated system includes a modernized and expanded monitor station network, improved anti-jam capabilities, and enhanced operational capability to control modernized military signals.

In March 2022, OCX completed its fourth and final legacy ground antenna element (LGAE) installation on Kwajalein Island in the Republic of the Marshall Islands. OCX Block 1 and 2 are undergoing Hewlett Packard (HP) Formal Qualification Test (FQT). This event will qualify much of the system’s previously certified mission software functions. The event will also demonstrate system maturity and readiness for system acceptance, operator training, and specific developmental testing milestones with both GPS space and user segments.

The next-generation control system, OCX 3F, will modify OCX Blocks 1 and 2 to use the enhanced capabilities of GPS IIIF satellites. OCX 3F received Milestone B and Acquisition Program Baseline (APB) approval from the Milestone Decision Authority (MDA) and was authorized to enter the Engineering and Manufacturing Development (EMD) phase in May. In November, the OCX 3F program deployed 3F mission software into OCX’s Near Operations Environment (NOE) for the first time after completion of the program’s first Integration Readiness Review (IRR). The IRR event ensures that the software meets integrity standards and receives approval to be integrated and tested on the NOE prior to software releases to the operational users. OCX 3F anticipates achieving operational acceptance in 2027.

The GPS III government and industry team recently core mated GPS III SV10 and nicknamed it “Hedy Lamarr” after the actress and inventor. (Image: Lockheed Matin)

User Equipment Segment

Among the arsenal of GPS user equipment, very few pieces have the technology to use the M-code signal. Maintaining a competitive advantage against the adversary requires use of these signals; the GPS Enterprise is focused on developing Modernized GPS User Equipment (MGUE) capable of accessing these signals. The MGUE program is a joint service program developing modernized M-code-capable military GPS receivers. The program is broken into two increments (Inc 1 and Inc 2). Both are designed to deliver secure PNT performance, allow navigation warfare operations, enhance anti-jam, enhance anti-spoof and anti-tamper, and enable Blue Force Electronic Attack.

As part of the multiple elements under the MGUE Inc 1 umbrella, L3Harris delivered its final Build 7 ground card to the government on Nov. 16, 2021, and completed regression testing on that kit in February 2022. The final Delta Security Certification and Approval were completed on April 13 and April 29, 2022, respectively. Development of the L3H Ground-Based GPS Receiver Applications Module (GB-GRAM-M) card, which delivers geolocation and precise positioning capabilities for space-constrained applications while providing increased security and anti-jam capabilities, is complete and available for services procurement. MGUE Inc 1 completed qualification testing for the aviation and maritime cards on Sept. 9, 2022, with updated software builds. This build allows the program to progress to 98% of the requirements verified and enables B-2 Bombers and Guided Missile Destroyers (DDG) to continue progress toward operational testing. Completion of this commitment means significant progress toward operational testing for stakeholders and warfighters.

MGUE Inc 2 held Preliminary Design Reviews for the Miniature Serial Interface (MSI) in summer 2022, bringing the project another step closer to finalizing the EMD phase. Once all closure and action items are completed for the reviews, the government will consider each event complete. Critical Design Review (CDR) is scheduled for this summer and will validate the system design and the ability to meet system performance requirements. MGUE Inc 2 continues to execute the second competitive objective under Phase I for the Joint Modernized Handheld component; the effort is moving closer to completion of the handheld prototype and will ultimately make for a more seamless transition to operations.

GPS ground antenna at Schriever Space Force Base in Colorado. (Image: U.S. Air Force)

Conclusion

The SSC’s mandate is paramount to maintaining our modern way of life. The space professionals dedicated to developing GPS technology are committed to delivering advanced capabilities to the warfighter, the civil sector, and the world. An interconnected world is ready for us. We’re on our way.

SSC is the U.S. Space Force field command responsible for acquiring and delivering the capabilities needed by warfighters to protect our nation’s strategic advantage in and from space. It manages an $11B budget for the U.S. Department of Defense and works in partnership with joint forces, industry, government agencies, academic and allied organizations to outpace emerging threats.

For analogous updates on the other three GNSS constellations, please see:
March 6, 2023
Launchpad: handheld mapping, excavator guidance, cesium clock

A roundup of recent products in the GNSS and inertial positioning industry from the September 2022 issue of GPS World magazine.

OEM

Receiver Upgrade

OSNMA anti-spoofing tech now on PolaRx5 GNSS reference receivers

Photo: Septentrio

Open Service Navigation Message Authentication (OSNMA) is now available on the high-end PolaRx5 reference receiver series. OSNMA offers end-to-end authentication on Galileo’s civilian signals, protecting receivers from GNSS spoofing attacks. OSNMA adds another layer of security to the receivers’ existing AIM+ anti-jamming and anti-spoofing technology. The PolaRx5 product range also now supports RINEX format versions 3.05 and 4.0.

Septentrio, septentrio.com

Anti-Jam Antennas

Developed with the United States military

Photo: Mayflower Communications

The MAGNA-F and MAGNA-I GPS anti-jam antennas provide simultaneous L1/L2 protection and can protect commercial and military GPS receivers on aircraft. The MAGNA products were developed with sponsorship by the U.S. Navy and further improved by the U.S. Army to support GPS protection requirements for air, sea and ground platforms, such as fixed-wing/rotary aircraft, ships, UAVs and tactical vehicles. The MAGNA-F uses a 3.5-inch-diameter controlled reception pattern antenna (CRPA) compatible with existing fixed radiation pattern antenna (FRPA) footprints. The MAGNA-I (NavGuard 730) is a high-performance yet small GPS anti-jam integrated solution with a 4.5-inch diameter FRPA-compatible footprint.

Mayflower Communications, mayflowercom.com

Single-board computer

Centimeter-level GNSS for mass-market applications

Photo: ArduSimple

The SimpleRTK2B single-board computer (SBC) is built around up to three u-blox ZED-F9P high-precision GNSS receivers. It simplifies development of centimeter-level positioning solutions supporting real-time kinematics (RTK), making the technology accessible to broader audiences. The SimpleRTK2B-SBC was developed to make RTK technology as close to plug-and-play as possible. In addition to working as a stand-alone solution, customers can program their own applications with the company’s microPython API. The SimpleRTK2B-SBC delivers mechanical integration with centimeter position on three axes (heading, pitch and roll), outputting on NMEA, RTCM, RS232 and CANBus interfaces via Ethernet, Bluetooth, Wi-Fi and 2G/3G/4G communication. It offers configurable input/output and an inertial measurement unit.

u-blox, u-blox.com; ArduSimple, ardusimple.com

Optical cesium clock

For assured positioning, navigation and timing (PNT)

Photo: ADVA

The OSA 3300-HP is a high-performance optical cesium clock with a 10-year lifetime compared to the five-year lifetimes of high-performance magnetic clocks. It provides the resilience required for PNT assurance in critical infrastructure and empowers service providers to deliver differentiated service-level-agreement timing offerings with integrated GNSS backup. The OSA 3300-HP has embedded Ethernet- and IP-based management as well as a user-friendly touchscreen graphical user interface.

ADVA, adva.com

Vehicle Navigation System

With M-Code capabilities and upgrade paths for other GNSS systems

Photo: Collins Aerospace

NavHub-200M is a vehicle navigation system for the international market with military code (M-code) receiver capabilities. NavHub-200M provides assured positioning, navigation and timing (APNT) while improving overall resistance to threats to GPS, such as jamming and spoofing. Its message formats and signal modulation techniques ensure faster and more accurate performance for ground vehicles on the connected battlespace, while advanced security features prevent unauthorized access or exploitation. NavHub-200M also includes the open interface standards and sensor-fusion capabilities required for a GNSS upgrade path, such as that for Europe’s Galileo constellation, as well as the ability to interface with key vehicle sensors such as the inertial measurement unit (IMU) and odometer.

Collins Aerospace, collinsaerospace.com

MAPPING

Mapping Handheld

High-performance data collector

Photo: Trimble

The Trimble TDC650 handheld is built for data collection, inspection and asset management activities. The rugged solution provides scalable high-accuracy GNSS positioning for professional field workflows, including apps such as Esri ArcGIS Field Maps and Trimble TerraFlex software. The TDC650 is scalable, allowing customers to choose their desired accuracy down to the centimeter level.

Trimble, trimble.com

Lidar Scanner

Powerful solution for manned and unmanned aircraft

Photo: YellowScan

The Voyager long-range lidar scanner has a wide field of view, with all points collected oriented toward the ground so there is no loss of points. In all, 1.5 million points per second will be usable. Voyager combines a Riegl VUX-120 laser scanner with a Trimble Applanix AP+ 50 AIR or Applanix AP+ 30 AIR GNSS-inertial board, providing a precision of 0.5 cm and an accuracy of 1 cm. Voyager’s detection and processing of up to 15 target echoes per laser pulse allows for excellent vegetation penetration. It has an extremely fast data-acquisition rate of up to 1,800 kHz, suitable for projects requiring the highest point density. The laser scanner’s specifications can be customized and can be combined with YellowScan’s software solutions.

YellowScan, yellowscan-lidar.com

ArcGIS Pro Add-In

Extends 3D Tiles Next workflow into Esri ArcGIS Pro

Photo: ArcGIS

The 3D Environments Add-In application for Esri ArcGIS Pro allows ArcGIS users to rapidly transform 3D Tiles Next data formats, such as One World Terrain, into ArcGIS Pro projects to create 3D scenes from 2D vector data and 3D models. The add-in leverages Presagis’ building templates and texture libraries that analysts use to create enhanced 3D visualizations of GIS environments, helping increase collaboration across the enterprise. The 3D Environments Add-In contains tools to create, transform and extract a wide variety of 3D formats to provide seamless interoperability between ArcGIS Pro and modeling and simulation applications. It is available on the Esri ArcGIS Marketplace.

Presagis, presagis.com

Cloud-Based GIS

Energy performance data helps tackle climate change

Photo: XMAP

Municipal geographic information system XMAP can now incorporate the energy-performance ratings of individual properties to help local authorities tackle climate change, improve housing standards, and ensure landlords comply with legislation. The Energy Performance Certificate (EPC) data layer uses a rating system similar to the one used on new appliances, ranging from A (very efficient) to G (inefficient). It allows tenants and house buyers to make informed decisions. In addition to a color-coded visualization of current ratings, the XMAP EPC layer contains enhanced analysis including generalized ratings and the potential for improvement. Bath and North East Somerset Council, UK (pictured), has embraced this resource and is looking at how the data can be used to raise housing standards.

XMAP, xmap.geoxphere.com

Caged Drone

For mapping and inspection in dangerous areas

Photo: Flyability

The Elios 3 is a collision-tolerant drone equipped with a lidar sensor for indoor 3D mapping. The drone is powered by a new SLAM engine called FlyAware that lets it create 3D models as it flies. It also hosts a new version of Flyability’s software for inspectors, Inspector 4.0. The Elios 3 comes with an Ouster OS0-32 lidar sensor, allowing inspectors to collect data for the creation of survey-grade 3D models using Connect software from Flyability’s partner GeoSLAM. Protected by a cage, the Elios 3 has advanced collision-tolerance features that allow inspectors to fly it inside dangerous confined spaces such as boilers, pressure vessels and mines.

Flyability, flyability.com

SURVEYING

Data Collector

Ergonomic yet rugged for fieldwork

Photo: ComNav

The R60 is a powerful handheld with an ergonomic design. It runs on Android 12 OS, providing a suitable workhorse for surveying professionals in the field. Survey Master field software works seamlessly on the R60, which features a Qualcomm 8-core processor for massive data processing. Its 64-GB memory allows ample data storage and enables the opening of CAD drawings in seconds. Other features include a QWERTY keyboard, a 5.5-inch sunlight-readable high-resolution screen, an IP67 rating (dustproof and waterproof), and a 9,000 mA Li-ion battery for more than 30 hours of continuous functioning.

ComNav Technology, comnavtech.com

Base Station

Mobile station provides cm positioning

Photo: HYFIX

The Mobile Centimeter (MobileCM) Space Weather Station is a ready-to-use GNSS device that will act as a real-time kinematic (RTK) base station and collect space weather data. The device is pre-configured to securely connect with the Global Earth Observation Decentralized Network (GEODNET) using a home Wi-Fi network. The full four-constellation GNSS base station has built-in NTRIP server functionality and is packaged with a survey-grade triple-band roof antenna and required cables.

HYFIX, hyfix.ai

MACHINE CONTROL

Guidance System

Upgradeable for precision agriculture

Photo: SingularXYZ

The SAgro10 GNSS guidance system is an entry-level guidance system for precision agriculture, providing users with higher navigation precision and higher productivity, which can be upgraded to an automatic steering system. Embedded with a high-precision GNSS module, the SAgro10 system tracks all four global constellations. For users with network coverage or a UHF base station, the system provides centimeter-level accuracy navigation in real-time kinematic mode. In the absence of base stations, the SAgro10 system provides sub-meter navigation accuracy in single-point smoothing mode. Compatible with most agricultural tractors, its components can be installed within 15 minutes. The 10-inch sunlight-readable touchscreen has a clear and simple graphic interface.

SingularXYZ, singularxyz.com

Excavator Guidance

Brings 3D mapping to small sites

Photo: iDig

iDig 3D Connect is a solar-powered excavator guidance system with a GNSS receiver that can be removed and used as a rover, rather than permanently installed on the machine. 3D excavator guidance has seldom been used for small projects such as house foundations because of the need for a surveyor to stake out points and map a site. The removable receiver enables contractors to complete these tasks. The software provided creates a GNSS-generated site map, enabling precision digging relative to the area and making the process quicker, simpler and more eco-friendly than with 2D.

iDig, idig-system.com

MOBILE

Asset Tracking

Cloud-based service uses GNSS and Wi-Fi

Photo: onurdongel/iStock/Getty Images Plus/Getty images

The Cloud Locator service takes data from LoRa Edge-enabled devices and uses Semtech’s LoRa Cloud Geolocation and Modem services for asset tracking both indoors and outdoors. It features built-in serverless technology and enables testing of ultra-low-power asset tracking on either a private or public LoRaWAN network. It is designed to work with trackers using Semtech’s LoRa Edge LR-series chips. The LR-series chips combine Wi-Fi and GNSS to obtain the latitude and longitude of devices in any indoor or outdoor location. Once configured on the service, together with Semtech’s LoRa wireless radio frequency technology for transmission to the cloud, customers can view the tracker location on a map in less than 15 minutes.

Semtech, semtech.com & locator.loracloud.com

Bike Computer

Features multi-band GNSS receiver

Photo: Garmin

The Edge 1040 bike computer features solar charging and multi-band GNSS technology. Its multi-band GNSS receiver (GPS, GLONASS and Galileo) provides accurate positioning in challenging ride environments, such as dense urban areas or under deep tree cover. Advanced navigational tools help cyclists stay on track, such as turn-by-turn navigation and alerts that notify riders of sharp curves ahead. Route guidance and off-course notifications can be paused for exploring and turned back on for return to the original route. When using the Trailforks app, Forksight mode automatically displays upcoming forks in the route and where a rider is within a trail network.

Garmin, garmin.com

SIMULATORS

Simulator Upgrade

Features advanced hardware-in-the-loop testing

Photo: Orolia

Skydel 22.5 is a significant software upgrade to the Skydel simulation product line. It features advanced hardware-in-the-loop (HIL) testing solutions providing very low to zero effective latency. 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 approach because it involves all the hardware and software that will be used operationally.

Orolia, orolia.com

Synchronizer and Simulator

Contained in an easily deployable suitcase

Photo: Focus Telecom

The Time-Loader is designed for defense and mission-critical applications, for deployment in environments where GNSS signals are denied or disrupted. It supports any ground, naval or airborne system that needs real time of day (TOD) and 1PPS external synchronization aligned to the UTC or GNSS. It generates a GPS L1 C/A code RF output as if the signal were coming from a live-sky GPS antenna. It provides full-constellation GPS output and is compatible with external GNSS receivers. Its GPS-disciplined oscillator (GPSDO) is the Microsemi MAC-SA53/55, which provides excellent UTC accuracy with outstanding hold-over rubidium clock performance. A self-contained, miniature GPS simulator provides real-time extremely accurate signals. The 18-channel full-constellation simulator stores location/time/date data in internal memory and stores complex vector data to simulate dynamic scenarios. The simulator also can be used to transcode NMEA or SCPI position/ velocity/time (PVT) data into GPS RF signals.

Focus Telecom, focus-telecom.com

September 13, 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
Collins Aerospace launches M-code-compatible system for ground vehicles in Europe

Photo: Collins Aerospace

Collins Aerospace has introduced NavHub-200M, a vehicle navigation system for the international market compatible with military code (M-code) receiver technology. The NavHub-200M is not controlled by the International Traffic in Arms Regulations (ITAR).

Collins Aerospace made the announcement at Eursatory 2022, taking place June 13-17 in Parsis.

NavHub-200M’s message formats and signal modulation techniques ensure faster and more accurate performance for ground vehicles on the connected battlespace, the company said.

NavHub-200M provides assured positioning, navigation and timing (APNT) capabilities while improving overall resistance to existing and emerging threats to GPS, such as jamming and spoofing.

“With GPS-based Selective Availability Anti-Spoofing Module (SAASM) receivers set to become obsolete, it is critical that M-Code receiver technology is made available to ground forces around the world as quickly as possible so they can trust that the signals they receive in a fast-moving, hostile environment are accurate and actionable,” said Ryan Bunge, vice president and general manager, Communication, Navigation and Guidance Solutions for Collins Aerospace. “Our NavHub-200M provides an improved resistance to jamming and interference, as well as advanced security features to prevent unauthorized access or exploitation.”

NavHub-200M also includes the open interface standards and sensor-fusion capabilities required for a GNSS upgrade path, such as that for Europe’s Galileo constellation, as well as the ability to interface with key vehicle sensors such as the inertial measurement unit (IMU) and odometer, among others.

Collins, a leader in APNT solutions for ground platforms, has delivered more than 10,000 navigation systems to military armed forced around the world.

Attendees at Eurosatory can learn more by visiting Collins Aerospace at booth number C523.

June 14, 2022
BAE unveils advanced M-code receiver at ION Joint Navigation Conference

New M-code GPS receiver enables precision strike capabilities in contested environments

Image: BAE Systems

BAE Systems unveiled its newest advanced M-Code GPS receiver for guided weapons and other small applications at the ION Joint Navigation Conference, taking place this week in San Diego.

The Strategic Anti-jam Beamforming Receiver – M-Code (SABR-M) enables precise geolocation and strike capabilities in highly contested battlespaces. It delivers accurate position, velocity, altitude and timing data, as well as strong protection against GPS signal jamming and spoofing – critical capabilities for unmanned aerial vehicles (UAVs), precision-guided munitions (PGMs), and missiles in threat environments.

SABR-M integrates receiver technology with advanced antenna electronics in a small, hardened package designed to meet challenging performance requirements, such as weapons applications. It is the most capable integrated anti-jam GPS receiver and the first integrated M-Code receiver available for weapon systems, according to BAE Systems.

“We’re making our full portfolio of military GPS solutions M-code-compatible to meet warfighters’ need for reliable positioning, navigation, and timing data to achieve their missions,” said Doug Lloyd, director of weapon systems GPS at BAE Systems. “SABR-M enables small platforms with challenging environmental conditions to get where they’re going despite interference.”

The compact (4.5 x 6 x 1 inch) SABR-M meets size, weight, power, cost (SWaP-C) and thermal requirements for space-constrained military applications. It uses advanced beamforming technology to improve GPS signal reception and counter threat signals. SABR-M is form-compatible with previous generations of the field-proven SABR receiver, which are integrated on low-cost precision weapon systems and long-range cruise strike missiles.

SABR-M will be fully qualified for production by the end of 2022. Production will take place at BAE Systems’ modern facility in Cedar Rapids, Iowa, which is in the final stages of construction. The purpose-built 278,000-square-foot factory and research center will be home to 700 military GPS experts in BAE Systems’ Navigation and Sensor Systems business.

June 7, 2022
BAE Systems broadens compatibility of anti-jam GPS receiver

Image: BAE Systems

BAE Systems has expanded the capabilities of its Digital GPS Anti-Jam Receiver (DIGAR) by enabling beamforming with Trimble receivers, in addition to its own receivers.

DIGAR’s beamforming capabilities increase the level of GPS jamming protection for aircraft by a million-fold, helping pilots execute their missions in contested environments.

BAE Systems’ engineers in Cedar Rapids, Iowa, developed software to ensure the compatibility of its antenna electronics with industry-standard embedded GPS inertial navigation system (GPS/INS) technology, enabling fast communication with transmitter electronics for superior beamforming.

BAE Systems is exhibiting at the ION Joint Navigation Conference, which takes place June 6-9 in San Diego.

DIGAR beamforms with both BAE Systems receivers and Trimble GPS receivers embedded in aircraft GPS/INS, as well as federated GPS systems and stand-alone GPS receivers.

“The modern battlespace has evolved, and peer state positioning, navigation, and timing threat systems are challenging our ability to conduct combat operations in the place and manner of our choosing,” said Greg Wild, director of Navigation and Sensor Systems at BAE Systems. “By combining DIGAR’s beamforming with trusted inertial navigation system data, we offer the highest level of jamming protection available today.”

DIGAR is a high-performance military GPS-based system for fixed-wing, rotary-wing and unmanned airborne platforms. It combines field-proven antenna electronics, advanced signal-processing, and beamforming techniques to improve the reliability of positioning, navigation and timing data in the presence of disruptive electromagnetic signals.

DIGAR is also compatible with the advanced M-code – delivering additional security to the warfighters who rely on it.

BAE Systems’ anti-jamming GPS technology has defeated powerful and sophisticated adversary threat systems in testing and combat, and is available for airborne, shipborne and ground vehicle applications. The company’s military GPS business is based in Cedar Rapids, Iowa, where it is building a 278,000-square-foot state-of-the-art research and manufacturing facility scheduled to open this year.

June 6, 2022
Realism in chamber-based CRPA testing

Spirent Federal Systems, a PNT simulation company, offers its government customers and contractors a unique solution for anechoic-chamber-based CRPA testing: a patented “zoned chamber” approach using multi-output, multi-constellation GNSS signal simulators to emulate the movement of satellites in orbit.

To address the limits of a standard anechoic chamber, Spirent has created independent zones configured to represent the real-world sky view, using genuine constellations and improved satellite azimuth and elevation arrival angles. Test scenarios can be multi-constellation and multi-frequency with customizable time, date and duration — now lasting hours instead of minutes.

Because scenarios are valid for longer time periods without sacrificing realism, the zoned chamber is effective for validating all aspects of the CRPA system including beamforming, null steering and space-frequency adaptive processing/space-time adaptive processing (SFAP/STAP). CRPA systems with inertial sensors can be tested with static and dynamic scenarios using a positioner within the chamber.

Additionally, to account for multipath and signal obscuration, Spirent has integrated a 3D environment modeling tool which generates all the variables of a multipath-rich environment in real time, including ground reflection. Interference sources such as jammers and spoofers can be added anywhere in the chamber and concurrently simulated with the GNSS signals. Authorized users can also test classified RF signals such as MNSA M-code and Y-code.

“Spirent Federal’s goal is to get new technologies to U.S. warfighters at a speed that outpaces near-peer threats,” said Jeff Martin, vice president of Sales. “The realism of our patented zoned chamber allows advanced CRPA systems to be deployed faster with confidence they will perform in GPS-contested environments.”

Illustration of a simulated test environment incorporating GNSS, multipath and jamming in a Spirent zoned chamber. (Image: Spirent Federal)

May 16, 2022
The transition to M-code begins

BAE Systems has produced more than one and a half million military GPS receivers. The company is transitioning receiver designs to use the modernized military code (M-code) signal for added resiliency in RF-challenged environments. We asked Luke Bishop, director and product line engineering lead for the company’s Navigation & Sensor Systems, a few questions.

BAE Systems’ MPE-M provides the benefit of M-Code operation in a challenged RF environment. Image: BAE Systems

Why transition to M-code?

There are three key reasons for users to transition to M-code as supported by Military GPS User Equipment (MGUE). First, MGUE provide U.S. forces and our allies with enhanced PNT capabilities while improving resistance to threats, such as accidental and intentional jamming. Compared to the current P(Y)-code signal specs, M-code signals are stronger. Second, MGUE provides improved resistance to spoofing. Third, MGUE is field programmable, enabling updates to accommodate future enhancements to the GPS enterprise, such as regional military protection (RMP).

Which user equipment is transitioning to M-code?

Successful MGUE Inc 1 prototype development is being leveraged into a full portfolio of weapons, ground and aviation/maritime M-code GPS receivers. Our first production M-code receiver, MPE-M, achieved production deliveries in CY2021, with more than 1,000 delivered. Additional M-code GPS form factors are under development.

We are also underway with the Foreign Military Sales (FMS) M-code program with MPE-M.

How is the transition to M-code proceeding?

As indicated by the January 2021 GAO report (GAO-21-145), M-code-capable user equipment is in the initial stages of Department of Defense (DOD) fielding for select weapon systems. Also noted by the GAO report, the DOD has conducted bulk purchases of the Increment 1 ASICs [application-specific integrated circuits] to ensure that “sufficient supplies of [them] are on hand for future integration into M-code card …based on estimated need through 2028.” We are at the beginning of M-code (MGUE). Time and the market will tell what ultimately happens.

Which of your receivers operate with an anti-jam (AJ) antenna?

BAE Systems’ receivers support both stand-alone AJ and integrated AJ. Receivers with integrated AJ include the NavFire-M, NavStorm-M and SABR-M receivers supporting high-dynamic weapons applications. Receivers directly supporting external AJ via a digital beamforming interface include the MPE-M and AMR. Our external AJ DIGAR offering provides exceptional performance for many stakeholders.

Do you use advanced signal simulation equipment?

We integrate Spirent Federal and other signal simulators in both our test and development environments, where modeled RF signals are coordinated with other sensor measurements and host vehicle messages for high-fidelity hardware-in-the-loop test cases. Our engineers create hundreds of test cases and scripted test procedures to exercise our products under all required conditions. These simulations allow us to run thousands of trials to qualify and validate performance of our products in extreme scenarios.

BAE Systems’ hardware-in-the-loop simulation environments build upon Spirent Federal signal generators to test products under extreme dynamic and threat environments. (Photo: Spirent Federal)

May 16, 2022
Directions 2022: GPS positioned for the future

By Michael J. Dunn, Space Systems Command, Capability Area Integrator for Positioning, Navigation and Timing

The Global Positioning System is the premier positioning, navigation and timing (PNT) source for more than six billion users worldwide. It is vital to the function of all 16 of the United States’ essential critical infrastructure components. Life as we know it relies on the essential services that GPS provides.

The United States Space Force (USSF) is committed to maintaining a healthy GPS constellation that continues to deliver the “gold standard” of PNT availability and reliability throughout the world. Continuous improvements in equipment and performance have been a hallmark of the enterprise since its inception. 2021 was no exception, with a continued record-setting delivery of new capabilities.

Space Systems Command (SSC) at Los Angeles Air Force Base in El Segundo, California, is laser-focused on delivering the most important modernization in GPS history. The government and industry team are committed to bringing major upgrades to the space, control and user-equipment segments. It is an exhilarating time for the GPS enterprise. The specific updates within each segment cement the continued evolution in GPS and the USSF commitment to delivering advanced capabilities to the nation and the world.

Space Segment

Currently, 37 GPS satellites are on orbit, with 29 satellites set healthy. The baseline constellation requirement is 24 satellites. The system continues to perform in stellar fashion, providing an average 48-centimeter position accuracy throughout 2021.

Orbital systems modernization is focused on the GPS III satellite fleet, and the program continues to deliver peerless capabilities. GPS III space vehicles (SV) 1–4 were all operationally accepted in 2020. In 2021, the most notable event was the launch of GPS III SV05 in June. The satellite successfully achieved operational acceptance and mission-capable status for USSF in just under two weeks: a new record. SVs 6–8 are available for launch and are awaiting their launch windows. SV09 system-level testing is in progress. SV10 component deliveries continue. GPS III provides up to eight times better anti-jam and a new L1C signal to improve user connectivity.

For the GPS IIIF program, the long-range picture remains bright as the contract for GPS IIIF SVs 15–17 was awarded in October 2021. The delivery of the first GPS IIIF is expected early in 2026. GPS IIIF will build upon the tremendous increase in capability provided by GPS III with the addition of a search-and-rescue payload, a laser retroreflector array for precise ranging, a fully digital navigation payload, and a Regional Military Protect capability that will provide 60 times greater anti-jam for operations in electromagnetically hostile environments.

GPS III space vehicle 05 (GPS III-SV05) launched in June 2021 from Cape Canaveral Space Force Base, Florida, aboard a SpaceX Falcon 9 launch vehicle. (Photo: SpaceX)

Control Segment

The next-generation Operational Control System (OCX) continues to execute within its program baseline. OCX will provide enhanced command and control capabilities, modernized architecture, robust information assurance and cyber security.

OCX’s incremental development approach began with OCX Block 0, which is the launch and checkout system (LCS) for GPS III. The LCS successfully supported the launch and checkout of GPS III SV 01–05. OCX Blocks 1 and 2 will control all legacy GPS III satellites and both legacy and modernized signals.

Despite barriers presented by the global COVID-19 pandemic, all 17 global OCX monitoring station installations were completed in July 2021. Most of the remaining equipment was fielded throughout December 2021. System integration and verification continues with transition to operations scheduled for early 2023.

The Next Generation OCX 3F contract was awarded in April 2021. The program will modify OCX to launch and control GPS IIIF satellites with enhanced capabilities. Acquisition Milestone B is expected in 2022, and operational acceptance is planned for 2027.

MGUE: The future warfighter’s battlespace edge. (Image: Space Systems Command Production Corps)

User Equipment Segment

Millions of GPS receivers are fielded, but very few of them can use the military code (M-code) signal that is being broadcast by 24 GPS SVs. To keep our competitive advantage against the adversary, the GPS enterprise is focused on developing modernized GPS user equipment (MGUE) that takes advantage of these signals. The MGUE program is a joint service program developing modernized, M-code-capable military GPS receivers. The program is broken into two increments (Inc 1 and Inc 2). Both are designed to deliver secure PNT performance, allow navigation warfare operations, enhance anti-jam, anti-spoof and anti-tamper, and enable Blue Force Electronic Attack.

MGUE Inc 1 achieved a major milestone in September 2021 with successful testing on the Marine Corps Joint Light Tactical Vehicle (JLTV). The event took place in an electromagnetically degraded GPS environment at White Sands Missile Range, New Mexico. The JLTV is a pathfinder lead platform for the MGUE program. Lead platforms for the other services, the Army Stryker combat vehicle, Air Force B-2 bomber, and Navy Arleigh-Burke Class Guided Missile Destroyer, will commence integration testing in FY23 and FY24.

MGUE Inc 2 development continues to make progress in maturing the next generation ASIC technology required for all weapon-system platforms to provide functionality and backward compatibility. It will deliver a miniature serial interface card in CY26 to support handheld and ground applications. Eventually, MGUE receiver cards will be loaded onto hundreds of Department of Defense (DOD) weapon systems.

GPS III SV04 in Highbay (Photo: Lockheed Martin)

Partner Community

The GPS enterprise is committed to cooperation on a global basis. It works closely with the DOD, the armed services, the U.S. Coast Guard, other federal agencies, the International Civil Aviation Organization and all the other global and regional navigation satellite systems toward the development of PNT in the global commons.

A highlight of this cooperative work is GPS enterprise involvement in the National Executive Committee for Space-Based PNT (PNT EXCOM), which supports the interests of the various federal bodies, especially the Department of Transportation (DOT) and the Federal Aviation Administration (FAA). The PNT EXCOM is applying GPS technology to a broad variety of governmental activities, including the development of the Next Generation Air Transportation System and intelligent transportation systems.

The GPS enterprise commitment to international partners is unwavering. Our support to the North Atlantic Treaty Organization (NATO) is ongoing with support to the Capability Panel 2 for Navigation working toward the integration of MGUE and compatibility arrangements with Europe’s Galileo system. A highlight this year was the first delivery of MGUE loan equipment to the United Kingdom, Canada, Germany, and the Republic of Korea. Germany is the first country to purchase MGUE equipment.

Conclusion

GPS is the foundation of global PNT and a cornerstone of modern life. Improvements to the enterprise are continual. As the nation moves into the complex and dynamic world of the coming decades, the dedicated military, civilian and industry professionals that provide this world-changing capability will continue their challenging and rewarding work. Semper Supra!

The “encapsulation” of a GPS satellite. (Photo: U.S. Department of Defense)

May 2, 2022
Protect GPS from threats, foreign and domestic

Matteo Luccio

Currently, 37 Global Positioning System satellites are on-orbit, with 29 of them set healthy. The system continues to provide an average 48-centimeter position accuracy. Despite this achievement, the U.S. government — specifically, the Space Force — continues to modernize GPS’s space, control and military user equipment segments.

Modernization of the space segment is centered on the GPS III satellites, which provide up to eight times better anti-jam capability and a new L1C signal to improve user connectivity. GPS IIIF satellites, scheduled for delivery starting in early 2026, will add a search-and-rescue payload, a fully digital navigation payload, and greatly enhanced anti-jam capability for military operations.

Modernization of the control segment is focused on the next-generation Operational Control System (OCX), scheduled to become operational early next year. OCX will sport an updated architecture to provide enhanced command-and-control capabilities and enhanced cybersecurity. Despite the pandemic, all 17 global OCX monitoring station installations were completed last summer, and most of the remaining equipment was fielded by the end of 2021.

Twenty-four GPS satellites are broadcasting the military code (M-code). The Modernized GPS User Equipment (MGUE) program is developing military GPS receivers able to take advantage of these signals to improve defenses against spoofing and jamming while allowing navigation warfare operations.

On the civil side, GPS modernization will play a key role in the development of the Next Generation Air Transportation System and intelligent transportation systems. The Department of Defense coordinates its GPS activities with the Department of Transportation (DOT), the Federal Aviation Administration (FAA) and many other federal departments and agencies via the National Executive Committee for Space-Based PNT. The term “space-based PNT” refers to GPS, GPS augmentations and other GNSS.

However, this government-wide coordination and cooperation is contradicted by the stand of the Federal Communications Commission (FCC) on the matter of Ligado Networks’ applications to modify its license for terrestrial service, which it approved in 2020. The FCC’s decision is opposed by the executive branch, represented by the National Telecommunications and Information Administration (NTIA), and by 14 federal agencies and departments individually (including the departments of Defense, Transportation, State, Treasury, Justice, Interior, Agriculture, Commerce, Energy and Homeland Security), as well as by the National PNT Advisory Board and by most GNSS receiver manufacturers and aviation organizations. NTIA took the unprecedented step of filing a still-pending petition for reconsideration with the FCC. The concern is that Ligado’s proposed transmission power exceeds the thresholds established by the DOT’s April 2018 GPS Adjacent Band Compatibility study to protect GPS users from harmful interference.

So, the list of threats to GPS now includes solar flares, spoofing, jamming, “legal jamming” by Ligado, and the Russian government’s recent threat to destroy GPS satellites. Modernizing GPS must proceed hand-in-hand with protecting it.

March 31, 2022
BAE Systems awarded a $316M contract to deliver military GPS modules

Image: BAE Systems

The U.S. Defense Logistics Agency has executed a $316 million contract option for BAE Systems’ advanced M-code GPS modules, raising the contract funding to $641 million.

The modules provide dependable positioning, navigation, and timing for ground troops, vehicles, aircraft and precision munitions. The contract will ensure the availability of Common GPS Modules (CGM) for advanced military GPS receivers with anti-jamming and anti-spoofing capabilities that enable operation in contested environments.

Under the contract option executed in November, BAE Systems will manufacture CGMs for future ground, airborne and weapon GPS receivers for the U.S. Department of Defense (DoD) and its allies. The award builds on a May $325 million contract and enables BAE Systems to continue to meet domestic and international demand for Military GPS User Equipment (MGUE) Increment 1 M-Code modules in GPS receivers through the end of the decade.

“Military operations require assured positioning, navigation and timing, and our customers are shifting to M-code to harden their GPS receivers against jamming and spoofing,” said Frank Zane, Navigation and Sensor Systems business development director at BAE Systems. “We’re ready to meet this need today with secure, reliable M-code GPS solutions, and we’re developing the next-generation of solutions to stay ahead of the threat.”

BAE Systems is delivering two advanced M-code GPS receivers: the Miniature Precision Lightweight GPS Receiver Engine – M-Code and the NavStrike-M GPS receiver.

Deliveries of the ultra-small MicroGRAM-M are expected in 2022, and deliveries of the Strategic Anti-jam Beamforming Receiver – M-Code are expected in 2024.

December 8, 2021
Spectranetix announces high-precision A-PNT card for Army

Photo: Spectranetix

Spectranetix Inc., a Pacific Defense company, has announced the SX-124 ruggedized 3U OpenVPX high-performance positioning, navigation and timing (PNT) card.

With an ability to provide timing and positioning information in a GPS-denied environment through sensor fusion, the SX‑124 switch is designed for highly integrated systems with a requirement for the U.S. Army’s C5ISR Modular Open Suite of Standards (CMOSS) and alignment with the Open Group Sensor Open Systems Architecture (SOSA) technical standard.

The SX-124 can accept external sources or use its onboard GNSS receivers as reference inputs for timing and positioning data. The positioning data can be fused with internal and external inertial measurement units (IMUs). It distributes 11 100-MHz outputs and 11 1PPS outputs in a phase coherent manner.

The SX-124 provides timing and position holdover from an internal chip-scale atomic clock (CSAC) and IMU. A built-in time-of-day clock provides accurate network time stamps on system startup without GPS availability.

The SX-124 also provides enhanced location information and can be connected to an external IMU as well as a controlled reception pattern antenna (CPRA).

The SX-124 supports the standard VICTORY shared PNT services from a built-in GNSS timing receiver with an optional built-in M-code GB-GRAM receiver, CSAC and barometer to provide altitude information.

With the option for expansion to support over-the-air rekeying (OTAR), external fiber-optic gyroscope (FOG), alternative navigation (ALTNAV), and additional GNSS systems such as Galileo, the SX-124 supports the defense community’s need for a high-performance assured PNT (A-PNT) solution in the 3U VPX form factor and aligned to the latest open set of standards.

“Reliable situational awareness and cooperative, networked maneuvers demand assured PNT capability,” said Daniel Kilfoyle, CTO of Pacific Defense. “Our A-PNT solution embraces the pntOS open sensor-fusion framework and supports multiple sensor connections including GNSS receiver, GB-GRAM, IMU, FOG, CRPA and a two-channel software-defined RF receiver for added flexibility. Combined with exquisite timing and frequency performance and CMOSS alignment, this PNT card is yet another example of our commitment to CMOSS and SOSA.”

The SX-124 card is on track for production release early next year.

November 30, 2021