GPS World

Tag: M-code

  • New military code about to board 700+ platforms

    New military code about to board 700+ platforms

    Rolling out Military Code

    Photo: U.S. Air Force / Staff Sgt. Scott H. Spitzer
    Photo: U.S. Air Force / Staff Sgt. Scott H. Spitzer

    Much development has been necessary to enable the new M-code capability on more than 700 weapon systems that require it. This article overviews M-code, the updates to antenna and receiver technology to make these varied platforms M-code ready, and perspectives from key stakeholders in the M-code community.

    December 23, 2018, marked an important milestone for GPS. The successful launch of satellite USA-289 represented a key success in what has been a monumentally expensive government program, beset by delays and overspends.

    The launch of the first GPS Block III satellite, the first that can provide the full military M-code capability, effectively commenced the physical roll-out of modern M-code hardware.

    Ground Control. As far as the space segment is concerned, M-code is finally underway. What about the ground segment? The next-generation GPS operational control system, GPS OCX, is essential for use of the full capabilities of the new Block III satellites. It has been under development for some time.

    OCX has drawn Congressional criticism and correlative media attention, but recent reports have been more positive. Since the Nunn-McCurdy breach of 2016, when the project’s future hung in the balance, accounts have grown gradually optimistic. Budget and schedule were re-baselined, and contractor Raytheon’s corrective actions generated results. In the fall of 2017 the Air Force took delivery of OCX Block 0, marking a significant milestone. Block 0, also known as the Launch and Checkout System (LCS), demonstrated compliance with contractual requirements and was accepted by the Air Force.

    In spring 2018, Block 0 underwent a series of cybersecurity tests and passed, validating the security architecture of the system. All this puts Raytheon on track to deliver OCX Block 1 in 2021, providing full operational capability. Block 1 and Block 2 are intended to be delivered together, adding operational control of the modernized satellites and signals, including L1C and the modernized M-code.

    “There have been no schedule slips with the GPS OCX program since 2017, and the GPS III launch last December was clear proof of our progress,” stated Dave Wajsgras, president of Raytheon’s Intelligence, Information and Services business. “We will continue to meet all of our commitments, and importantly, we will meet our June 2021 contractual deadline.”

    Col. Steve Whitney of the GPS Directorate wrote in this magazine in December 2018 that “The journey over the past few years has been challenging, but we have emerged stronger, armed with better metrics, and a culture of integrated development (often called DevOps) which puts us on a path to success. There will be challenges and risks in the path ahead but rather than mountains to climb, I see these more as standard blocking and tackling of a software-intensive program.”

    Meanwhile. The Air Force plans to deploy M-code capability in 2020, and OCX seems unlikely to be ready. For this reason, Lockheed Martin was awarded a contract to modernize the existing ground infrastructure as a “gap filler.”

    The GPS Control Segment Sustainment II (GCS II) contract was awarded on Dec. 21, 2018, and is worth $462 million. GCS II will support operational capability of M-code in 2020, and continues until 2025, and so there will be a period of overlap between GCS II and OCX, essentially providing two options for controlling the new GPS III constellation. In one view, the Air Force is backing two horses to improve chance of winning: OCX the preferred solution, with GCS II almost like an insurance policy.

    With the GPS III ground and space segments looking relatively healthy, attention turns again to the user segment.

    WHY M-CODE?

    Until now, the military has used the classic P(Y) signal: a binary phase shift keying (BPSK)-modulated encrypted wideband signal. It offers both greater accuracy and increased jamming resistance when compared to the civilian C/A code still employed by the vast majority of GPS receivers.

    But the P(Y) code has its drawbacks in the modern world: its wide main lobe sits directly over the top of the C/A code signal (see Figure 1), essentially occupying the same spectrum. When the civilian C/A signal is jammed, the military P(Y) signal is at the very least degraded, if not also jammed itself. It also uses a relatively simple encryption scheme that does not meet today’s cyber security requirements.

    Figure 1. C/A, P(Y), and M-Code signal power spectra. (Graphics: Mike Jones)
    Figure 1. C/A, P(Y), and M-Code signal power spectra. (Graphics: Mike Jones)

    The M-code signal, on the other hand, is the first military GPS signal to use the BOC modulation scheme. BOC modulation gives signals their distinctive two-lobe appearance, spreading the signal’s energy away from the band center.

    The wide spacing of the two sidebands separates the M-code signal from the civilian signals (the legacy C/A signal or the new L1C signal on the L1 frequency, and the L2C signal on the L2 frequency).

    Amongst other things, this allows the military to jam the civilian codes without noticeably degrading the M-code signal. Often referred to as blue force electronic attack (BFEA), this is essentially a new facet to navigation warfare (NAVWAR), where enemy use of GPS can be denied whilst allowing friendly forces to continue using it.

    The wider occupied bandwidth and increased signal power also help to make M-code more resistant to jamming. M-code also makes use of more modern and flexible encryption methods, ensuring it will be secure and safer from threats such as spoofing attacks.

    Scepticism. Defense programs are known for their long procurement cycles, but even by these standards, M-code has taken an extremely long time to get where it is today. Given the enormous cost of the program, and the fact that there is still, as yet, no operational benefit to show from it, many people have questioned its worth. At the time it was conceived it represented a dramatic step forward in military capability but, because it has been so long in development, its operational benefit is becoming diluted.

    When M-code was conceived, GPS was still the only operational GNSS in town: everybody had to use GPS — or nothing. Today, the picture differs greatly. During M-code’s insanely slow progress, other GNSS systems have come along, offering their own encrypted signals of a similar ilk. Looking at Figure 2, M-code no longer appears as special as it once was. Its BOC(10,5) signal sits inside the main lobes of Europe’s Galileo PRS signal, which uses a BOC(15,2.5) scheme, and China’s Beidou B1A signal using BOC(14,2).

    Figure 2. GNSS encrypted signals around the L1 frequency. (Graphics: Mike Jones)
    Figure 2. GNSS encrypted signals around the L1 frequency. (Graphics: Mike Jones)

    If you were China, you might consider jamming the central 24 MHz of the L1 band, taking out M-code, whilst still having an operational military service for yourself. Or if you were Russia, you might jam 34 MHz of bandwidth, taking out the US, Chinese, and European systems, whilst still having your GLONASS L1SC military service to use. The situation is more complex than that, of course: each service has the potential to increase signal power in times of conflict, and there is more than one frequency that can be used. But it does demonstrate the essence of the problem: The modern battlespace has moved on, and M-code hasn’t.

    CHALLENGES OF RECEIVER DESIGN

    Figure 3. C/A code ACF.
    Figure 3. C/A code ACF.

    With complex signals come complex receivers, and there several headaches when it comes to M-code receiver design. The first is the nature of the BOC signal itself, which has a complex correlation function. Consider Figure 3, which shows the autocorrelation function (ACF) of the traditional civilian C/A code signal. The single peak of the function makes acquisition and tracking a simple process; traditionally early, prompt and late (E,P,L) correlator arms can be used in the tracking process.

    Figure 4. L1Cd ACF.
    Figure 4. L1Cd ACF.

    The newer BOC-type signals have a more complex ACF. Figure 4 shows the ACF of the new L1Cd civilian GPS signal, which uses a form of BOS(1,1) modulation. In addition to the main lobe, there are now two side lobes. Receivers must be careful not to lock on to one of the side lobes instead of the main lobe: the receiver architecture starts to become a little more complex.

    Figure 5. M-code ACF.
    Figure 5. M-code ACF.

    Now consider the ACF of the M-code signal, shown in Figure 5. Like other high-order BOC-type signals, M-code exhibits multiple lobes in the ACF, making robust acquisition and tracking a far more troublesome process. Furthermore, the high bandwidths require high sample rates, which lead to higher power consumption in the hardware.

    Another major headache associated with M-code receivers is, of course, the encryption process. Not because encryption is difficult, but again because of the power consumption implications. Consider that each GPS receiver needs to run an encryption engine instance, for each satellite it might wish to receive. Running a high-grade encryption algorithm at a high chipping rate, for a dozen satellites, is a power-consuming process. For dismounted soldiers with limited battery capacity, this is a big deal.

    Some people argue that the high-grade encryption process for M-code is too complex. Consider why we want to encrypt a GNSS signal in the first place: firstly to prevent someone from spoofing our signal, and secondly to prevent unauthorised users from using the service. Given that the encryption keys are rolled regularly, how much does it matter if an adversary manages to compromise the encryption? This isn’t a communications security problem: we are not talking about loss of classified information, so there’s an argument that a simpler, less power-hungry form of encryption might have been used instead.

    ANTI-JAM ANTENNA COMPATIBILITY

    Although M-code offers a certain level of jamming resistance, it is still vulnerable to attacks. As a signal it might have a bit more power, and a bit more bandwidth, than some other signals. But it is, after all, still a GNSS signal, and it can be jammed by an adversary. Where an operational threat analysis indicates that an increased level of jamming resistance is required, then M-code receivers need to be integrated with anti-jam antennas.

    Anti-jam antennas, usually referred to in the GNSS community as controlled reception pattern antennas (CRPAs), have been the anti-jam tool of choice for several decades now. I overviewed these in an April 2017 newsletter column. CRPA manufacturers have had to ensure that their products are “M-code ready,” such that they can be seamlessly attached to M-code receivers as and when they appear.

    This hasn’t been a recent process: as far back as 2002, the GAS-1 antenna (Raytheon) underwent a series of qualification tests to ensure compliance with M-code. Around 2005, the ADAP antenna (also Raytheon) was launched with a host of M-code features — again an illustration of just how slow the M-code program has moved, given that other technology has been “M-code ready” for 10 or 15 years already.

    What’s involved in making a CRPA M-code compatible? Firstly the increased bandwidth: the antenna electronics must digitize the wider bandwidths. Along with the wider bandwidth comes new filtering shapes to ensure optimum performance.

    Space-time adaptive processing (STAP) and space-frequency adaptive processing (SFAP) techniques potentially require more taps to ensure high null depths can be maintained across the full bandwidth. The increased power of the M-code signal, particularly if features like spot beam are used, presents another complication to CRPAs: they must not treat the high-power satellite signals as jammers, and try to remove them.

    Testing CRPAs presents a challenge to manufacturers: how do you prove that your antenna doesn’t corrupt the M-code signal, when there’s no M-code signal to test it with? To work around this issue, pseudo M-code signals have been used for testing, where representative BOC(10,5) signals without the real encryption are passed through the CRPA and examined for distortion.

    RECEIVER DEVELOPMENT STATUS

    Due to the security considerations surrounding M-code, only three US organizations are authorized to produce modules: Collins Aerospace, Raytheon and L3. Here are the answers from Collins Aerospace and L3, the answers from Raytheon will appear in later issue.

    What are the technical challenges associated with developing an M-code receiver?

    Collins Aerospace. The Collins Aerospace Modernized GPS User Equipment (MGUE) Increment 1 development like the SAASM PPS receiver developments faced very challenging technical requirements to support our war fighter needs in an ever-evolving threat environment. Like other complex developments the challenges are initially technical and then transition to integration/test and certification. On the technical front optimizing receiver performance balanced against power consumption are always at the forefront. In addition, it is important to maximize backwards compatibility so as to minimize downstream integration costs while adding an entirely new signal that runs in parallel to the existing system. Collins Aerospace is pleased with the technical development and are actively supporting the integration with both receivers and technical support.

    To date, we have delivered more than 770 MGUE receivers to the Air Force to support Air Force, lead platform and DoD-wide Integration and test. Soon the total will grow to nearly 1,100 receivers to support expanded integration and test following the completion of Collins Aerospace security certification.

    L3. M-code GPS User Equipment (MGUE) technologies exist today.L3’s Ground Based GPS Receiver Application Module – Modernized (GB-GRAM-M) is a fully-functioning unit that is currently baselined and undergoing an independent Technical Requirements Verification (TRV) by the GPS Directorate.During TRV, each requirement from the Technical Requirements Document (TRD) is independently evaluated for compliance. Upon completion of the TRV, the design is baselined with complete documentation enabling platforms and prime equipment to integrate from a known baseline with low risk. Following integration, operational testing can start immediately to support fielding when M-Code Early Use (MCEU) becomes operational. The TRV of L3’s GB-GRAM-M is planned to be completed by the second quarter of 2019.

    L3 resolved numerous technical challenges in developing M-code GPS technologies. The first and ever-present challenge is changing and evolving requirements. Most of these requirement changes are in response to evolving threats that have driven changes into the GPS receiver and/or to higher-level systems. Asan example, the U.S. Army’s Assured PNT (A-PNT) is implementing M- code GPS along with external sensors to establish and maintain an assured solution even in GPS-challenged environments. Other challenging requirements include meeting the security requirements, implementing and testing anti-spoofing algorithms, and ensuring backward compatibility with legacy receivers.

    What are the intended platforms for your MGUE?

    Collins Aerospace. The Collins Aerospace MGUE receivers are intended to support all warfighter domains: ground, airborne, maritime and munitions to support compliance with Public Law 111-383 SEC. 913 issued in Fiscal Year 2011. Per this directive, M-code is intended for all DoD applications with the exception of passenger vehicles or commercial vehicles with GPS installed. Now that the satellite and control segments of the capability are coming on line, we are working diligently to ensure that user equipment is available for all domains.

    L3. L3 has products to meet current market demand. Under the MGUE program, L3 developed a GB-GRAM-M, which is a standard Modular Open Systems Architecture (MOSA) design. The GB-GRAM-M is designed to fulfill retrofit replacements of SAASM receivers, as well as being a primary component of A-PNT systems. L3’s M2GRAM ASIC is the core of our receiver, a GPS module that incorporates signal processing, cryptography, and positioning, velocity, and timing (PVT) processing. The M2GRAM ASIC is capable of being implemented in other form factors for applications beyond ground-based applications. As an example, the M2GRAM is implemented in a GPS receiver specifically designed for Precision Guided Munitions (PGM) applications and was used in a gun launched, guide-to-target demonstration operating as a PGM receiver.

    L3 is also augmenting the GPS receiver through the integration of several other technologies, including controlled reception pattern antennas with digital antenna electronics, inertial systems and external sensors, and GPS-denied capabilities. M-code technologies are being implemented in Mounted A-PNT Systems (MAPS), Dismounted A-PNT Systems (DAPS), and handheld systems to bring capabilities to the warfighter.

    What is the expected timeline for your MGUE development, acceptance testing, and delivery?

    Defense Advanced GPs Receiver (DAGR) from Collins Aerospace, equipping infantry and other warfighters. (Photo: Collins Aerospace)
    Defense Advanced GPs Receiver (DAGR) from Collins Aerospace, equipping infantry and other warfighters. (Photo: Collins Aerospace)

    Collins Aerospace. The Collins Aerospace receivers are supporting ongoing DoD integration and test and our MGUE Increment 1 program is aligned with the Air Force GPS Enterprise roadmap. Ultimately, the Department of Defense (DoD) M-code programs will set the production delivery schedules.

    We anticipate that the M-code production ramp-up and continued SAASM PPS receiver production will have a production overlap. Our Collins Aerospace in-house PPS GPS receiver manufacturing capability is ready to support the DoD demand for both M-code and SAASM. Collins Aerospace is fully committed to manufacturing Increment 1 M-code receivers to meet the warfighter’s needs across Airborne, Weapons and Ground, we know the transition from SAASM to M-code will take years. Therefore, Collins Aerospace will continue to manufacture SAASM receivers for years to come as the International MOD Policy for M-code use is still being formulated.

    L3. L3’s GB-GRAM-M is now available. L3 received security certification and approval in 2016 and TRV is planned for completion in the second quarter of 2019. With TRV, L3 is receiving a new security certification and approval of the latest receiver update. Government agencies, prime contractors and laboratories can order GB-GRAM-M now with delivery in the fourth quarter of 2019.

    What does testing and verification process involve?

    Collins Aerospace. As with any Precise Positioning Service (PPS) GPS development, the testing involves functional verification of the receiver in a wide variety challenging of environmental, thermal, electromagnetic interference/ high-intensity radiated field (EMI/HIRF) environments. Collins Aerospace is leveraging proven test and verification approaches founded upon our long history of successful product introductions and field performance. As this is a PPS receiver it is also essential the receiver design comply with the government’s required Security Approval process.

    L3. The testing and verification of L3’s GB-GRAM-M included internal testing and independent testing through the GPS Directorate’s TRV process. Further risk reduction testing within the MGUE program is planned as Phase IV testing where the GB-GRAM-M is integrated into a lead platform for the U.S. Army and a lead platform for the U. S. Marine Corps. An operational assessment is performed on both lead platforms to assure common problems associated with integration and operational testing are addressed prior to implementing M-Code GPS Receivers across all of the platforms.

    Will the MGUE be compatible with CRPA anti-jam antennas; are there any special considerations for this?

    Collins Aerospace. The Collins Aerospace product family includes our Digital Integrated Anti Jam Receiver (DIGAR) product family that leverages CRPA anti-jam antennas for enhanced anti-jam (AJ) performance. Our DIGAR AJ technology enhances the performance with fixed reception pattern antenna (FRPA), CRPA and is compatible with all PPS waveforms. Regarding the interfaces between the receiver and the anti-jam antenna electronics, a GPS receiver with a standard RF interface is compatible with a CRPA in nulling mode and FRPA antennas. Advanced capabilities such as beamforming/beamsteering require tight coordination and additional interface with the GPS receiver.

    L3. The GB-GRAM-M is designed to operate with a fixed reception pattern antenna (FRPA). A CRPA antenna using digital antenna electronics to generate signals matching the characteristics of a FRPA is fully compatible with the GB-GRAM-M. With a higher level of integration of a GPS receiver and a CRPA, the system capabilities are greatly enhanced. L3 has performed this integration and can perform advanced capabilities such as angle of arrival and beamforming using M2GRAM, digital antenna electronics, and CRPA technologies. These capabilities can be found in L3’s Mounted Assured PNT System (MAPS) and Anti-Jam Antenna System (AJAS) products.

    Army Stryker ground combat vehicle. (Photo: Karolis Kavolelis / Shutterstock.com)
    Army Stryker ground combat vehicle. (Photo: Karolis Kavolelis / Shutterstock.com)

    OPERATIONAL DEPLOYMENT

    The U.S. Air Force GPS Directorate provided answers to the following questions regarding MGUE.

    Which platforms will be equipped with M-code-capable MGUE, and how many of each?

    GPS Directorate. The Air Force is developing M-code-capable GPS receivers under the MGUE Increment 1 program. The receivers in development will be provided to four service-specific lead platforms for integration, developmental, and operational testing. Lead platforms are:

    • the Army Stryker ground combat vehicle,
    • the Air Force B-2 Spirit bomber,
    • the Marine Corps Joint Light Tactical Vehicle (JLTV),
    • and the Navy Arleigh-Burke class destroyer (DDG).

    Following the lead platform efforts, procurement of M-code-capable GPS receivers will be decided by the Services and executed by individual platforms and programs.

    What are the timelines for rolling out M-code on these platforms?

    GPS Directorate. Early integration and test activities have already begun for each MGUE lead platform. Operational testing is expected to begin in 2020 and complete in 2021, which is a key activity to enable the fielding of M-code-capable systems.

    B-2 Spirit multi-role bomber capable of delivering both conventional and nuclear munitions. In December 2017, the Air Force completed a series of successful flight tests of M-code GPS using a Raytheon Company receiver on board a B-2 Spirit at Edwards Air Force Base, California. (Photo: U.S. Air Force/Bobby Garcia)
    B-2 Spirit multi-role bomber capable of delivering both conventional and nuclear munitions. In December 2017, the Air Force completed a series of successful flight tests of M-code GPS using a Raytheon Company receiver on board a B-2 Spirit at Edwards Air Force Base, California. (Photo: U.S. Air Force/Bobby Garcia)

    What advantages will M-code bring, over existing military GPS receivers?

    GPS Directorate. Modernized GPS receiver cards under development with the Air Force MGUE Increment 1 program will enable the use of M-code and provide U.S. forces with enhanced position, navigation, and timing capabilities, in addition to improving resistance to threats, such as jamming efforts by adversaries.

    How will keys and key distribution be managed?

    GPS Directorate. None of this is publically releasable.

    Will M-code be made available to other friendly nations? If so, how is this managed?

    GPS Directorate. The current policy allows for the sale of M-code equipment to all 57 authorized GPS PPS nations. The M-code technology will be made available to these nations through the Foreign Military Sales process.

    USER PERSPECTIVE

    The Department of Defense supplied answers to the following questions for users and warfighters.

    What are the benefits you perceive will come from new M-code GPS equipment?

    DoD. Provides U.S. forces with enhanced position, navigation, and timing capabilities, in addition to improving resistance to threats, such as jamming efforts by adversaries.

    Will it change how you perform military operations, or enable any new ones?

    DoD. Modernized GPS receivers provide the next-generation GPS capabilities to the warfighter. Operational testing will enable the services to determine operational utility of MGUE. It will ensure our soldiers, sailors, airmen, and marines have the ability to get in, accomplish their mission, and get home accurately.

    How will M-code-based GPS receivers be brought into operational service? Will there be a mass upgrade of assets, or a phased introduction?

    DoD. Procurement of M-code-capable GPS receivers will be decided by the Services and executed by individual platforms and programs.

  • Benefits coming from GPS III constellation

    Benefits coming from GPS III constellation

    That was then. This is now.

    When managed by a new ground control system, GPS III satellites will offer triple the accuracy and eight times the anti-jamming capabilities of the satellites currently comprising the U.S. Air Force’s GPS constellation. Users military and civilian will reap ample benefits.

    Everything changed for space-based positioning, navigation and timing around the world on Dec. 23, 2018. Or maybe it didn’t. The innovations heralded by the launch of the first GPS III satellite will take years more to occur. We tabulate here the advances that Generation Three will bring over GPS-to-date, and review the timeline for their actual arrival.

    While these new capabilities exist — in concept — in space, they can’t be leveraged on the ground (or in the air, or at sea) until a sufficient number of additional GPS III satellites have joined the constellation, and until a new ground control system comes online. This will occur — perhaps — in 2023. At that time the satellites’ talents will be unleashed.

    “As more GPS III satellites join the constellation, it will bring better service at a lower cost to a technology that is now fully woven into the fabric of any modern civilization,” stated Lt. Gen. John Thompson, commander of the U.S. Air Force’s Space and Missile Systems Center and the Air Force’s program executive officer for space.

    The many GPS III upgrades should make the service more reliable and accurate for civilians, more secure against those who want to jam military users, and more cyber-secure for everyone.

    TALKIN’ ‘BOUT OUR GENERATION

    GPS constellations have grown through six major iterations since 1978. The sixth, GPS IIF, rose during the years 2010 to 2016. Those 12 satellites are all designed to last 12 years. Some of their notable features include the ability to receive software uploads, better jamming resistance and increased accuracy.

    GPS III, the seventh generation, will launch nine more satellites to join SV01 already in space. GPS III SV02 is scheduled to launch in July of this year, SV03 in late 2019, and SV04 in 2020. The final III payload should rise in 2023. From that point on, the follow-on era of GPS IIIF takes over.

    How Long, How Long? “Projections for how long the current constellation will [continue to] be fully capable have increased by nearly two years to June 2021, affording some buffer to offset any additional satellite delays,” reported the Government Accounting Office at the end of 2017. This provided some schedule buffer for launching the first GPS III satellite, but it did not reduce the desire to launch as soon as the booster rocket became available.

    The new birds will introduce new capabilities to meet higher demands of both military and civilian users: once filled out, the GPS III constellation will bring three times better accuracy and up to eight times improved anti-jamming capabilities. Spacecraft life requirement will extend to 15 years, 25 percent longer than the latest GPS satellites and twice the original design life of the oldest satellites on orbit today.

    The new L1C civil signal broadcast by GPS III is an interoperable signal with other international global navigation satellite systems, like Galileo, improving connectivity for civilian users.

    GPS III will eventually actualize full M-code capability — carried aboard the IIR-Ms and IIFs but not yet completely implemented — in support of warfighter operations. GPS III M-code capability exceeds that of GPS IIR-M and GPS IIF.

    GPS III will complete the deployment of the L2C civil signal and the L5 safety-of-life signal capabilities that began with \GPS IIR-M and GPS IIF satellites.

    Finally, GPS III will enact improved integrity: the ability of the satellite to detect and issue alerts on its own reduced accuracy, should that phenomenon ever occur.

    Military Signal Power Up. Encrypted M-code signals will be up to eight times more powerful than currently. This makes them more reliable. but also enables the sats to overcome efforts to jam their signals.

    Other signals also offer increased signal power at the Earth’s surface. L1 and L2: −158.5 dBW for aC/A code signal and −161.5 dBW for the P(Y) code signal. L5 will be −154 dBW.

    Family Features. The most recent generations of the GPS constellation. IIR, IIR-M and III were produced by Lockheed Martin, while IIF was built by Boeing. One GPS IIA satellite is still in operation, at 25 years young (design life was 7.5 years). All satellites carry Harris Corporation payloads. (Graphic sourced from: Lockheed Martin and Boeing Co.)
    Family Features. The most recent generations of the GPS constellation. IIR, IIR-M and III were produced by Lockheed Martin, while IIF was built by Boeing. One GPS IIA satellite is still in operation, at 25 years young (design life was 7.5 years). All satellites carry Harris Corporation payloads. (Graphic sourced from: Lockheed Martin and Boeing Co.)

    L SIGNALS

    L2C, the second open GPS signal, after L1 C/A, has been available from every new GPS satellite since the first IIR-M launch in 2005. L5, the third open GPS signal, became available with the first IIF launch in 2010. Now L1C, the fourth open GPS signal, joins the band, broadcasting from every new GPS satellite, starting with the recent GPS III launch (see First Light).

    The first GPS III satellite is in checkout and testing that could last up to 18 months before it enters service. “After its Dec. 23 launch, GPS III SV01 successfully completed its orbit raising and deployment of all of its antennas and solar arrays. On Jan. 8, the satellite’s navigation payload began broadcasting navigation signals,” said Johnathon Caldwell, Lockheed Martin vice president for navigation systems. “On-orbit testing continues, but the navigation payload’s capabilities have exceeded expectations and the satellite is operating completely healthy.”

    Testing, Testing. Using the Air Force’s Back-to-Basics program, which involved early prototyping and simulations, Lockheed Martin developed GPS III with an approach that involved rigorous quality-build certificates, component testing and system-level testing. The comprehensive requirements verification and validation process ensured more than 30,000 requirements were achieved. The system functional qualification includes the performance verification in multiple environmental tests, including the acoustic, thermal vacuum (TVAC) and electromagnetic spectrum.

    “We consider thermal vacuum the gold standard for testing any satellite before it goes into operations,” Col. Steve Whitney, director, GPS Directorate, wrote in GPS World in December. “It really is putting the craft through the paces. When it goes through the testing, the satellite is on. It is working. It is exposing it to the heat and the cold and the zero pressure while the satellite is functional. The entire thermal vac testing from start to end is about 70 days. Test like you fly. From the time it launches and deployment sequence, we test it like it is real. Minus the shaking, the satellite thinks it is getting launched. Meanwhile, our people are looking at the data and its health. TVAC is a huge milestone for a satellite to go through and come out no issues.”

    To date, more than 90 percent of parts and materials for all 10 GPS III satellites have been received from more than 250 aerospace companies in 29 states.

    BRAIN OF THE BUNCH

    THE FIRST GPS III satellite was fully assembled and entered into SV single-line flow when Lockheed Martin technicians integrated its system module, propulsion core and antenna deck. (Photo: Lockheed Martin)
    THE FIRST GPS III satellite was fully assembled and entered into SV single-line flow when Lockheed Martin technicians integrated its system module, propulsion core and antenna deck. (Photo: Lockheed Martin)

    Harris Corporation is a subcontractor to Lockheed Martin for development and production of GPS III Mission Data Units (MDUs) and transmitters for the GPS space section. Six have been delivered.

    The Harris MDU, together with the Atomic Frequency Standards and the L-band transmitter equipment, make up the Navigation Payload Element. The MDU performs the primary mission of the GPS satellite: generation of the navigation signals and data on a continuous basis. The MDU controls the generation of the precise timing signals used for navigation signals while distributing the timing signals to other satellite components.

    This MDU is 70 percent digital. The next to come, aboard GPS IIIF satellites, will be fully digital.

    When asked about the advantages of an all-digital payload, Harris Corporation’s Jason Hendrix, PNT program director, told GPS World in April 2018, “The advantages and the 30 percent difference are the timekeeping system portion. We’re moving from manual, analog timing to digital to deliver to the Air Force more flexibility. It’s a nice option to have to be able to reprogram in orbit and maybe enhance capabilities desired in the future.”

    LIVING BETTER, LIVING LONGER

    Greater mission longevity is one of the key improvements GPS III delivers over those currently in service. Space Vehicles 1–10 have a planned mission life of 15 years, 25 percent longer than their predecessors. That begs the question, “How long should a satellite live in space, with technology innovation occurring almost annually?”

    Advanced payload technology provides a partial answer. Lockheed Martin and Harris point to new payload capabilities with built-in flexibility to adapt satellites in orbit to technology advances, as well as changes in missions. According to Harris, the fully digital navigation payload will provide the ability to change and upgrade the satellites incrementally over mission life.

    In late 2017, Lockheed announced a partnership with NEC Corporation to introduce artificial intelligence for computer learning in orbit. The company touted significant advances in processors and a move toward next-generation antennas, arrays and transmitters to drive more satellite flexibility, capability and resilience.

    FROM THE GROUND UP

    GPS IIIF’s M-Code can be broadcast from a high-gain directional antenna in a concentrated, high-powered spot beam, in addition to a wide-angle, full-Earth antenna. (Artist rendering: Lockheed Martin)
    GPS IIIF’s M-Code can be broadcast from a high-gain directional antenna in a concentrated, high-powered spot beam, in addition to a wide-angle, full-Earth antenna. (Artist rendering: Lockheed Martin)

    GPS III’s military upgrades require new ground control stations, a replacement effort called OCX that has suffered repeated delays and cost increases, due to the complexity of the programming and requirements modifications. The new jamming-resistant military signal will not be available until the new, highly complex ground control system is available, and that is not expected until 2022 or 2023. Delay and cost considerations were driven in part by full implementation of all Department of Defense 8500.2 “Defense in Depth” information assurance standards without waivers, giving it the highest level of cybersecurity protections of any DoD space system.

    Deliverables for GPS OCX are divided into three blocks. Block 0 delivery took place in fall 2017, enabling it to support the December launch. Block 1 delivery will take place in 2021, providing full operational capability to control both legacy and modernized satellites and signals. Block 2, delivered concurrently with Block 1, adds operational control of L1C and modernized M-code.

    In 2018, wrote Col. Whitney of the GPS Directorate, “We have actively utilized the [Block 0] system in a variety of exercises, training events, compatibility tests and launch readiness events. We also completed a comprehensive security review of the system to demonstrate our readiness to start operations. The system is ready to go. We continue to work the development of the OCX Block 1 system and are wrapping up the initial coding of the system early in 2019, leading into our integration and test campaign.”

    Given delays in OCX, “the Directorate is actively working two major upgrades to bridge the gap,” Whitney continued. “The first is GPS III Contingency Operations (COps) modification which will allow the 2nd Space Operations Squadron (2SOPS) to command and control the GPS III family of vehicles in a mission state matching today’s legacy signals for all users world-wide. The second modification is M-code early use (MCUE), which enables 2 SOPS to operationalize the Modernized GPS military (M-code) navigation signals for the warfighter.”

    Before December’s launch, OCX underwent rigorous cybersecurity vulnerability assessments that tested the system’s ability to defend against both internal and external cyber threats. GPS OCX prevented the broadcast of corrupt navigation and timing data in all tests, bolstering the program’s readiness for GPS III.

    “We’ve built a layered defense and implemented all information assurance requirements for the program into this system,” said Dave Wajsgras, president of Raytheon Intelligence, Information and Services. “The cyber threat will always change, so we’ve built OCX to evolve and to make sure it’s always operating at this level of protection.”

    The new Harris navigation payload offers a smooth transition to use of OCX. The payload for the first 10 GPS III satellites has been verified for OCX compatibility so the same OCX commands will seamlessly port to the Harris fully digital design, minimizing integration risks and associated costs.

    According the the GAO, “Full M-code capability —which includes both the ability to broadcast a signal via satellites and a ground system and user equipment to receive the signal — will take at least a decade once the services are able to deploy military GPS user equipment (MGUE) receivers in sufficient numbers.” The April 2019 issue of GPS World will review M-code implementation across U.S. DoD platforms.

    THE FUTURE’S NOT OVER YET

    In spring 2018, Lockheed Martin submitted a proposal for the GPS III Follow On (GPS IIIF) program, which will add enhanced capabilities to the satellites. New hardware — a high-gain directional antenna — aims signals in a spot beam at a limited area, but blasts the signal at high power for strategic use by the military.

    Inter-Satellite Links. Block IIIF satellites will carry laser retro-reflectors to enable orbit tracking independently of the satellites’ radio signals, which in turn will allow satellite clock errors to be disentangled from ephemeris errors. A standard feature of GLONASS, this is included in the Galileo positioning system, and was flown as an experiment on two older GPS satellites, 35 and 36.

    In September 2018, the Air Force selected Lockheed Martin to build up to 22 additional satellites under the GPS IIIF program.

  • Orolia acquires simulation company Skydel Solutions

    Orolia acquires simulation company Skydel Solutions

    Acquisition Expands Orolia’s Global Footprint into Canada.

    Orolia has acquired Skydel Solutions, a GPS/GNSS signal simulation company based in Montreal, Canada.

    Orolia made the announcement at the Association of the U.S. Army’s Global Force Exhibition in Huntsville, Alabama.

    Orolia is a resilient positioning, navigation and timing (PNT) solutions company and a partner of U.S., NATO and allied forces. The company provides end-to-end resilient PNT solutions, including scalable, modular and cost-effective technology to support PNT-reliant and critical defense and commercial applications.

    Skydel’s capabilities allows Orolia to offer customers more diverse resilient PNT solutions with sophisticated testing and simulation protocols, additional customized signals, and superior vulnerability assessments for military and commercial applications where GNSS failure is not an option.

    According to Orolia, as the latest addition to the Orolia portfolio, Skydel brand solutions bring a new paradigm to the GNSS simulator scene by combining innovative algorithms and off-the-shelf hardware to help protect the world’s most critical GNSS-reliant systems operating through GPS, Galileo and other GNSS.

    Skydel technology also supports secure communications signals such as SAASM, M-code, PRS and other alternative signals with approved partners to provide real-world PNT vulnerability testing for critical infrastructure applications worldwide.

    “The need for continuous, reliable GNSS signals is growing exponentially worldwide, particularly for military and commercial systems that depend on accurate PNT data,” said Orolia CEO Jean-Yves Courtois. “The threats to these systems are growing too, whether it’s through signal jamming, spoofing or meaconing. With Skydel’s unique industry expertise, Orolia now offers even more rigorous, broad spectrum testing and simulation solutions to ensure continuous signals, even in GNSS-denied environments.”

    By combining graphics processing unit (GPU) accelerated computing and software-defined radios (SDR), Skydel-powered simulation solutions generate signals in real time, with uncompromising performance for demanding use cases. They are available as complete turnkey systems suitable for all GNSS simulation needs, including everything from compact test benches to complete CRPA test systems.

    “Since our inception in 2014, Skydel has enjoyed exponential growth,” said Stéphane Hamel, CEO of Skydel. “This strategic move with Orolia will allow us to keep our focus on disruptive innovation and accelerate our global reach.”

    Above: A montage of screenshots showing the various updates, from a February 2019 story about Skydel updating its SDX GNSS simulator to version 19.1 with Galileo Alt-BOC and more. (Image: Skydel)

  • GPS III finally aloft, benefits on the way

    SpaceX’s Falcon 9 rocket orbited the first GPS III satellite on Dec. 23, 2018. (Photo: SpaceX)
    SpaceX’s Falcon 9 rocket orbited the first GPS III satellite on Dec. 23, 2018. (Photo: SpaceX)

    On December 23, the first GPS III satellite entered an orbit around Earth, after a five-day delay. This first of a new breed of GPS satellite also experienced a four-year delay, with its original launch scheduled for 2014.

    While the system has experienced more than its share of problems, at the start of a new year I want to focus on the benefits to come.

    Few of us realized how much our lives would change when the first GPS satellite was launched in 1978. GPS III could bring about a similar trajectory of changes. Civilians can expect a more reliable and accurate service. The smartphone message “searching for signal” could become a dim memory.

    GPS III signals will be three times more accurate than the current GPS Block II models. The navigation payload has more than three times reduction in range error and up to eight times increase in power — its signals should be much easier to pick up under tree canopy, within urban canyons and inside buildings.

    GPS III also has four civilian signals. The L1C signal is interoperable with international GNSS, meaning users can receive signals from any country’s satellites. Also, using two civilian signals means GPS III can directly detect and correct ionospheric errors.

    In addition to a standard wide-angle antenna for broad coverage, the GPS III satellites include a high-gain directional antenna that will operate with 100 times (+20 dB) the power of the wide-angle antenna, and will be exclusively for use with M-code (military) transmissions. This directional antenna’s spot beam covers an area 120 miles at high power— boosting the power of military GPS signals by 100 times in specific regions, making military GPS even harder to jam.

    These advantages may not reach the battlefield for a decade. The new constellation will take time to build. The GPS III constellation is projected to be fully capable in June 2023, when 10 Block IIIA satellites are expected to be in orbit. Ten follow-on satellites are planned to be placed into orbit from 2026 to 2034.

    Back here on Earth, equipment makers will need time to develop and supply warfighters with military GPS user equipment (MGUE) that can take advantage of all that GPS III has to offer.

  • Directions 2019: GPS program looks toward GPS III launch

    Directions 2019: GPS program looks toward GPS III launch

    Col. Steve Whitney stands beside a statue of General Schriever at Los Angeles Air Force Base, home of the GPS Directorate. (Photo: U.S. Air Force/Joseph Juarez, Sr.)
    Col. Steve Whitney stands beside a statue of General Schriever at Los Angeles Air Force Base, home of the GPS Directorate. (Photo: U.S. Air Force/Joseph Juarez, Sr.)

    By Col. Steven Whitney
    Director, Global Positioning Systems Directorate

    Navigating across the world’s roads with GPS is easy. Navigating through the shifting construction zones, detours, and forks of the GPS Enterprise is not always so straightforward.

    For that reason, the GPS Directorate has placed more emphasis on illustrating, both figuratively and literally, the roadmaps leading to the integration of the GPS Enterprise.

    Before linking everything together, let’s start with an update on each major program effort. This way you can zoom out to see the path ahead; hopefully minimizing any “route recalculating” along the way.

    Program Updates

    The journey to build the new GPS III satellites has been full of twists and turns but we are now close to our destination – in this case the GPS orbit of 12,550 miles above the Earth.

    We not only have 10 GPS III Space Vehicles simultaneously in production at Lockheed Martin’s manufacturing facility in Waterton, Colorado, but are also going full swing on preparations to launch our first vehicle in December 2018 on a SpaceX Falcon 9 rocket – more on this later. The GPS III satellites provide signals designed to improve the user’s ability to navigate.

    In addition to the increased power and greater accuracy, GPS III adds a civil new signal, L1C, designed for compatibility with the international Global Navigation Satellite Systems (GNSS) community.

    GPS IIIF. In September 2018, the Air Force awarded the GPS III Follow-on contract to Lockheed Martin. This $7.2B contract for 22 satellites was the result of a competitive process for a production effort. Based on the GPS III technical baseline, the GPS IIIF family of satellites embraces modernization and capability improvements in multiple areas.

    First, a Regional Military Protection capability will provide increased anti-jam capabilities. Furthermore, a new Search-and-Rescue (SAR/GPS) payload will provide improved timeliness of global search-and-rescue operations. Additionally, a Laser Retro-reflector Array (LRA) payload will enable precise ranging measurements and the program will implement a Unified S-Band capability to address consolidation of telemetry, tracking, and commanding frequencies.

    Finally, the program will host a redesigned Nuclear Detonation (NUDET) Detection System (NDS) solution that has a lower overall size and weight. We look forward to the continued partnership with Lockheed Martin and will be looking collaboratively at opportunities to add additional capabilities incrementally over the life of the 22 GPS IIIF satellite production line.

    OCX, the Next Generation Operational Control Segment. Last year Raytheon delivered the initial system, known as OCX Block 0, to support the launch and on-orbit check-out of the GPS III satellites. This past year, we have actively utilized the system in a variety of exercises, training events, compatibility tests, and launch readiness events.

    We also completed a comprehensive security review of the system to demonstrate our readiness to start operations. The system is ready to go. We continue to work the development of the OCX Block 1 system and are wrapping up the initial coding of the system early in 2019, leading into our integration and test campaign.

    The journey over the past few years has been challenging, but we have emerged stronger, armed with better metrics, and a culture of integrated development (often called DevOps) which puts us on a path to success. There will be challenges and risks in the path ahead but rather than mountains to climb, I see these more as standard blocking and tackling of a software intensive program.

    Col. Whitney next to an artist's depiction of a GPS III satellite in orbit. (Photo: U.S. Air Force/Van Ha)
    Col. Whitney next to an artist’s depiction of a GPS III satellite in orbit. (Photo: U.S. Air Force/Van Ha)

    Legacy Ground Sustainment. Running in parallel to these modernization efforts is the all-important work to sustain our existing GPS infrastructure of our current Operational Control System (OCS). These sustainment efforts ensure GPS continues to be the gold standard in positioning, navigation, and timing but also are a crucial “on-ramp” to facilitate a smooth merge onto the modernized GPS capabilities.

    Since 2014, the GPS program office has incrementally implemented several upgrades that not only maintain our satellite constellation delivery of GPS signal-in-space accuracy of 50 cm, but also significantly increases the cybersecurity posture of the legacy OCS.

    These upgrades culminated with a deployment of the latest modification in October 2018, which finished a worldwide modernization of our entire control system hardware and software. This latest upgrade, known as Version 7.5, virtualized the network, implemented two-factor authentication, and improved encryption for mission data.

    Legacy Ground Improvements. Given the delays in OCX, the Directorate is actively working two major upgrades to OCS to bridge the gap. The first is GPS III Contingency Operations (COps) modification which will allow the 2nd Space Operations Squadron (2SOPS) to command and control the GPS III family of vehicles in a mission state matching today’s legacy signals for all users world-wide. The second modification is M-Code Early Use, which enables 2SOPS to operationalize the Modernized GPS military signals (M-Code) navigation signals for the warfighter.

    User Equipment. As I write this article, soldiers, sailors, marines and airmen are testing and integrating mature, next-generation GPS receiver cards providing more accurate and reliable position, navigation, and timing (PNT) solutions. In 2019, the first increment of Military GPS User Equipment (MGUE) is on track to complete card-level testing to inform Service procurement strategies.

    This exciting work is the culmination of nearly two decades of modernization efforts throughout the GPS Enterprise. In the near term, we are utilizing M-Code capable lead platforms ­— USAF B-2 Bomber, USMC Joint Light Tactical Vehicle, USN Arleigh-Burke Class Guided Missile Destroyer, and Army Stryker combat vehicle — to prove out those capabilities.

    The second increment of MGUE focuses on requirements for precision guided munitions, a joint common modular handheld unit, as well as circuit cards and components for low size, weight and power needs. With MGUE, the DoD and services are poised to have enduring PNT solutions the warfighter can leverage for years to come.

    Integration Roadmaps

    The delivery of individual programs is the stepping stone in the capability deliveries to the warfighter and our civilian users. However, it is our ability to unite a diverse collection of programs and stakeholders, across the GPS Enterprise, which defines our success as the GPS Green Monsters. We have done this by linking cross-program enterprise teams so the sum of the whole is greater than its parts.

    Enterprise Road to Launch (ERTL). The goal is pulling together a series of firsts (new satellite, new ground system, and new launch provider), which has not been done before in the modern GPS Era, to deliver the spacecraft safely on-orbit and under control. Our journey to this historic launch has taken time and effort, and we are enthusiastically awaiting the final steps.

    The first GPS III spacecraft is safely at Cape Canaveral and ready to go. The control system has been tested and run through its paces. The integrated launch team has conducted its exercises and reviews. All signs point to launch in December 2018.

    The launch itself is a significant milestone, and marks a beginning of the orbital phase of GPS III. The Road to Launch team is prepared to execute the launch, the check-out and the day-to-day on-orbit housekeeping until the ground updates are complete to transfer the new GPS III satellite into the active constellation later in 2019.

    Enterprise Road to Mission (ERM). The goal is bringing the GPS III satellites into the active constellation providing mission similar to today’s capabilities. A key enabler of the ERM IPT’s success is their development of the first-ever Enterprise “Integration Playbook”, which is the tangible, documented output of a significant dedicated planning effort.

    The Playbook captures how all the pieces and efforts from each stakeholder community tie together to achieve Operational Acceptance of the first GPS III satellite, the USNDS payload, and the COps modification to OCS. The “Playbook” describes in clear and concise terms how these deliveries integrate across the GPS Enterprise, as well as how tasks and milestones from various stakeholders converge to achieve clear end states.

    Enterprise Road to M-Code Mission, or ERM-M-Code. Shifting now to our military users, the purpose of the ERM-M-Code team is to lead the early delivery of a more robust, resilient, jamming/tampering-resistant PNT signal capability to warfighters.

    The rollout of the operational M-code capability depends on the success of the M-Code Early Use modification to OCS, installation of new M-code signal monitoring equipment at sites around the globe, modification of mission planning software, Military GPS User Equipment Increment 1 development, service lead platform integration efforts, and operationalization of space receivers.

    Our ultimate objective is to improve the ability of the Combined Space Operations Center (CSpOC) to respond to urgent PNT needs of the combatant commanders, as they engage more sophisticated adversaries. We remain closely aligned with our peers at USSTRATCOM, AFSPC and user communities.

    Conclusion

    It is an exciting time to be a GPS Green Monster! These roadmaps are by no means easy to create and execute. It is thanks to the remarkable people of your GPS Directorate that these multifaceted challenges are unraveled, aligned, and resolved. The team has worked incredibly hard this past year to position our systems for major, integrated deliveries over the next couple of years.

    It has been the highlight of my career to serve with these men and women and I can’t wait to see where we — and the GPS Enterprise — go next.

  • Lockheed preps ground system to support GPS III launches

    Lockheed preps ground system to support GPS III launches

    Once the next-generation GPS III satellites begin launching in December, a series of updates to the current ground control system from Lockheed Martin will help the U.S. Air Force gain early command and control of the new satellites for testing and operations.

    In 2016 and 2017, the Air Force placed Lockheed Martin under two contracts, called GPS III Contingency Operations (COps) and M-code Early Use (MCEU), which directed the company to upgrade the existing Architecture Evolution Plan (AEP) Operational Control System (OCS), which operates today’s GPS constellation.

    The fourth Lockheed Martin-built GPS Ill satellite is fully integrated. (Photo: Lockheed Martin)
    The fourth Lockheed Martin-built GPS Ill satellite is fully integrated. (Photo: Lockheed Martin)

    These upgrades to the AEP OCS are intended to serve as gap fillers prior to the entire GPS constellation’s operational transition to the next-generation Operational Control System (OCX) Block 1, now in development.

    In April, the Air Force approved Lockheed Martin’s critical design for MCEU, essentially providing a green light for the company to proceed with software development and systems engineering to deploy the M-code upgrade to the legacy AEP OCS.

    The Air Force gave a similar nod to COps in November 2016. COps is now on schedule for delivery in May 2019 and MCEU is scheduled for delivery in January 2020.

    “The Air Force declared the first GPS III satellite Available for Launch last year, and it’s expected to launch later this year. Nine more GPS III satellites are following close behind in production flow,” explained Johnathon Caldwell, Lockheed Martin’s program manager for Navigation Systems. “GPS III is coming soon, and as these satellites are launched, COps and MCEU will allow the Air Force the opportunity to integrate these satellites into the constellation and to start testing some of GPS III’s advanced capabilities even earlier.”

    MCEU Capabilities

    Part of the Air Force’s overall modernization plan for the GPS, M-code is a new, advanced signal designed to improve anti-jamming and anti-spoofing, as well as to increase secure access to military GPS signals for U.S. and allied armed forces.

    To accelerate M-code’s deployment to support testing and fielding of modernized user equipment in support of the warfighter, MCEU will upgrade the AEP OCS, allowing it to task, upload and monitor M-code within the GPS constellation.

    MCEU will provide command and control of M-Code capability to eight GPS IIR-M and 12 GPS IIF satellites currently on orbit, as well as future GPS III satellites.

    COps Capabilities

    Following launch and check out, each future GPS III satellite will take its place in the GPS constellation. The COps modifications will allow the AEP OCS to support these more powerful GPS III satellites, enabling them to perform their positioning, navigation and timing missions for more than one billion civil, commercial and military users who depend on GPS every day.

    Besides the addition of GPS III, COps will also continue to support all the GPS IIR, IIR-M and IIF satellites in the legacy constellation.

    Lockheed Martin has a long history of supporting ground systems, providing operations, sustainment and logistics support for nearly 60 Department of Defense satellites, including GPS, often allowing them to double their on-orbit operational design life.

    GPS III Satellites

    Lockheed Martin also is under contract to develop and build 10 GPS III satellites, which will deliver three times better accuracy and provide up to eight times improved anti-jamming capabilities compared to current GPS satellites.

    GPS III’s new L1C civil signal also will make it the first GPS satellite to be interoperable with other international global navigation satellite systems.

  • Spirent Federal presents GSS9000 GNSS simulator at Xponential 2018

    Spirent Federal Systems’ Kalani Needham discusses the company’s GSS9000 GNSS/GPS simulator at Xponential 2018. Needham also discusses the company’s partnership with Rockwell Collins to develop software that will support M-Code using the Modernized Navstar Security Algorithm.

  • GPS OCX software ready for 2018 GPS III launch

    Raytheon Company’s GPS OCX program is ready for the U.S. Air Force’s launch of the first modernized GPS satellite later this year.

    Raytheon’s GPS Next-Generation Operational Control System, known as GPS OCX, is in its final software development phase. This phase focuses on increasing automation and building controls for both L1C, a civilian GPS signal aimed at increasing international access, and M-code, a military GPS signal with better anti-jam capability.

    Once complete, the team will begin integration and testing to keep the program on track for full system delivery in June 2021.

    The GPS Operational Control System’s launch and checkout system will control launch and early orbit operations and the on-orbit checkout of all GPS III satellites. (Image: Raytheon)

    “Our team has two primary goals this year,” said Dave Wajsgras, president of Raytheon intelligence, information and services. “We will support the U.S. Air Force’s GPS III launch this fall and complete the software build for the full operational system by year’s end.”

    GPS OCX is the enhanced ground control segment of a U.S. Air Force-led effort to modernize America’s GPS system. The program is implementing 100 percent of DODI 8500.2 “Defense in Depth” information assurance standards without waivers, giving it the highest level of cybersecurity protections of any DoD space system, Raytheon said.

    For protection against future cyber threats, the system’s open architecture allows it to integrate new capabilities and signals as they become available.

    Because GPS OCX can manage nearly twice the satellites of the current system, it will increase signal strength in hard-to-reach areas like dense cities and mountainous terrain.

    Also, advanced automation will free crews to focus on mission-critical tasks such as updating satellite positions more often.

    Learn more about the program’s progress here.

  • The promises of M-code and quantum

    November has certainly been a busy month, and I’ve been lucky enough to be involved in a number of standout events where defense PNT was discussed.

    The National Space-Based Positioning, Navigation, and Timing (PNT) Advisory Board met in California; GPS World hosted a webinar on military PNT technology; and the International Navigation Conference took place in the U.K. Check out a brief roundup of what’s been taking place.

    Next-generation GPS takes steps in the right direction

    The December issue of GPS World magazine has an excellent update from Col. Steven Whitney. GPS itself is often referred to as the “gold standard” by which other GNSS and PNT solutions are benchmarked. And GPS is undergoing a fairly monumental modernization program, in order to stay current and provide the right services to the military. There are broadly three aspects to this: the next-generation ground segment, the space segment, and the user equipment.

    It’s fair to say that the ride hasn’t been a particularly smooth one, and the Next Generation Operational Control System (OCX) has been plagued by delays and challenges. Following a Nunn-McCurdy breach in 2016, the future of the OCX development program looked to be hanging on a knife edge, but the program was recertified and continued.

    At the PNT Advisory Board meeting on Nov. 15, Col. Gerry Gleckel (deputy director, GPS Directorate, Space & Missile Systems Center) gave an upbeat presentation on the status of GPS modernization. Describing the current status of OCX as “working through program challenges,” he described how the first integrated launch rehearsal between GPS III and OCX Block 0 had been completed in August.

    The GPS III satellites themselves are in full production flow, with five satellites at various stages of assembly.

    Figure 1. Five GPS III satellites are in production flow. (Credit: Gerry Gleckel, Nov. 15, 2017).

    The next-generation military receivers, known as Military GPS User Equipment (MGUE), are also under development by a range of vendors, of which L-3 Technologies was the first vendor to receive security certification in 2016. A number of equipment form factors are being developed to address land, sea and air platforms, and great progress is being made.

    Figure 2. Military GPS User Equipment (MGUE) will address a range of platforms. (Credit: Gerry Gleckel, Nov. 15, 2017)

    The U.S. Air Force recently completed a number of successful test flights of a prototype M-code receiver on board a B-2 stealth bomber, which marks an important milestone for the GPS modernization effort. Let’s remind ourselves what M-code is, and what it does for us.

    The promise of M-code

    Until now, the military has relied on the encrypted P(Y) code to provide advantage on the battlefield. Compared to the civilian C/A code, the P(Y) offered improved accuracy, ionospheric correction, resistance to spoofing and a marginal level of jamming resistance.

    M-code is quite a different picture. Rather than the traditional BPSK modulation schemes used by legacy signals, M-code utilizes a type of binary offset carrier (BOC) signal. In the case of M-code, the signal is a BOCsin(10,5) modulation, which has a power spectral density given by:

    This power spectral density can be seen in the figures below, along with legacy C/A and P(Y) codes (and also the new L2C signal on L2). The M-code BOC signal has a number of important properties; I won’t describe all of them, but I will pick out a couple.

    Firstly, the signal is able to support navigation warfare activities. Because the energy in the signal is spread in two lobes away from the center, it allows for the C/A code to be selectively jammed without affecting the military receivers. This is often referred to as “blue force jamming” or “blue on blue jamming,” where friendly forces might wish to perform jamming in an environment in which they are themselves operating. Currently, such blue force jamming is not possible with P(Y) code receivers, without also degrading the friendly force’s receiver.

    Another promise of M-code is the ability to use spot-beam transmissions from Block III satellites. This is where a high-gain antenna on the satellites aims the M-code signal at a specific region of the earth, with much greater received satellite power in that region. The received signal from the spot beam is expected to be around 20-dB more powerful than the conventional full-Earth coverage beam. This means that, in a given conflict region, military GPS receivers should be able to benefit from a large increase in jamming resistance.

    Figure 3a. M-code signal compared to traditional L1 GPS signal. (Image: Michael Jones)
    Figure 3b. M-code signal compared to traditional L2 GPS signal. (Image: Michael Jones)

    Shortly after the GPS Advisory Board meeting in California, on the other side of the Atlantic a range of defense PNT technologies was also discussed.

    International PNT experts gather in the UK

    The International Navigation Conference (INC 2017) is now in its third year, and has been steadily growing in prominence. This year’s event, which took place Nov. 27-30, focused on the themes of resilient PNT, autonomy, and sensor and data fusion. As usual, there was a substantial defense presence.

    I had the pleasure of chairing a few sessions, including a panel discussion on resilient PNT. The event began with a cross-government meeting, where representatives from across the UK government met to discuss PNT issues concerning defense and national security.

    What I loved about this conference is the sheer diversity of PNT topics that were discussed. In the military domain, it wasn’t just the traditional subjects of GNSS, inertial, visual and signals-of-opportunity that were discussed. Also considered was cognitive navigation — how does a soldier’s brain work when in an unfamiliar battlefield? And how will quantum technology benefit defense PNT in the medium to long term?

    The promise of quantum

    Quantum technology has for some time been touted as the future of PNT: clocks so accurate that you’ll never need to worry about timing again. Inertial measurement units that have so little drift, you’ll never need anything else for navigation.

    If you’re not familiar with quantum technology, let me explain. Quantum technology exploits science that cannot be explained by classical physics, such as Newtonian mechanics, thermodynamics and Maxwell’s electromagnetism.

    As atoms get colder, they have lower energy levels and move more slowly. Taking this argument all the way down to absolute zero, the atoms would stop moving. By using lasers to cool atoms to very near absolute zero, the atoms are essentially placed under precise control, and hence are sensitive to changes in the local magnetic and gravitational fields. What does this mean for navigation?

    An excellent INC 2017 session on quantum navigation revealed some of the answers. Dr. Tim Freegarde of the University of Southampton gave the keynote “Navigator’s Introduction to Quantum Technologies,” which was followed by sessions on quantum/classical combined navigation, and quantum technology for performing gravity gradient map matching.

    Quantum sensors rely on a phenomenon known as entanglement, where two physically separated systems are linked in such a way that a measurement of one affects the results of the other. Once atoms have been cooled, they can be made to travel in opposite directions around a loop, where the interference pattern generated allows rotation to be sensed.

    But the atoms can also be sensitive to gravitational and magnetic fields, and frequency. So, amongst many other things, quantum technology allows for more accurate atomic clocks, and rotational and gravitational sensors.

    A huge amount of money has been poured into quantum research in recent years and, whilst it’s clear there is still a long way to go, progress is certainly being made. At the UK National Quantum Technology Hub in Sensors and Metrology, the focus is on achieving sensors that are useful, and not necessarily to look for the highest possible precision. This is essential if quantum sensors for PNT are to be adopted by governments and industry.

    Cyber takes center stage

    At the end of the conference, I had the pleasure of chairing a lively panel discussion on resilient PNT, where I put a number of questions to both the panel and the audience.

    Coming back to satellite navigation, my first question was, “What is the greatest threat to GNSS over the next three years?” You may be forgiven for thinking that “jamming” or “spoofing” was the top answer because, no, the top answer was in fact “cyber attack”.

    Figure 4. At the International Navigation Conference, the audience voted “cyber attack” as the greatest threat to GNSS. (Photo: Michael Jones)

    But what exactly do we mean by “cyber attack”? The word “cyber” is a pretty loose word, which is often misused as a catch-all phrase to cover anything that’s not RF related. Let’s quote the NIST definition of cyber attack:

    “An attack, via cyberspace, targeting an enterprise’s use of cyberspace for the purpose of disrupting, disabling, destroying or maliciously controlling a computing environment/infrastructure; or destroying the integrity of the data or stealing controlled information.”

    How does this apply to military PNT? Well, a key theme from the conference was the trend towards more complex PNT systems. No longer do we have a simple GPS receiver, but an ever-increasing mix of different PNT sensors, and a system more comparable to a computer than a traditional GPS receiver.

    What this means is that modern and future military PNT will be susceptible to the full range of cyber attacks currently associated with computing environments. Guy Buesnel from Spirent Communications gave an excellent keynote presentation where he covered this topic. Describing the “attack surface” for GNSS, he noted how many GNSS receivers currently run embedded operating systems such as VxWorks or Linux, and many support standard protocols such as TCP/IP and USB, all of which leaves them vulnerable to cyber attacks.

    But let’s not despair. The good news is that there is an awful lot to learn from the computing domain. After all, when computers first became vulnerable to cyber attacks, we quickly learned to make use of virus checkers, firewalls and other such mechanisms available to us. And now the domain of cyber security gives us an arsenal of defensive measures to combat cyber-space risks.

    I’ll finish by returning to the PNT Advisory Board meeting in California on Nov. 15, where Harold Martin, director of the National Coordination Office for Space-Based PNT, said “GPS is more computer than radio… GPS receivers lack cyber resilience. This is a national issue.”

    Don’t forget it.

    Equation figure: Michael Jones

  • GAO: Better coordination needed for GPS M-code adoption

    The Government Accountability Office (GAO) recommends the U.S. Department of Defense (DOD) assign responsibility to an organization to collect test data, lessons learned and design solutions in its effort to meet GPS modernization goals.

    According to the GAO, “The Secretary of Defense should ensure that the Under Secretary of Defense for Acquisition, Technology and Logistics, as part of M-code receiver card acquisition planning, assign an organization with responsibility for systematically collecting integration test data, lessons learned, and design solutions and making them available to all programs expected to integrate M-code receiver cards.”

    DOD concurred with the recommendation.

    The GAO presented its findings in a 53-page report issued Dec. 12, “Global Positioning System: Better Planning and Coordination Needed to Improve Prospects for Fielding Modernized Capability.”

    According to the GAO, “DOD has made some progress on initial testing of the receiver cards needed to utilize the M-code signal. However, additional development is necessary to make M-code work with over 700 weapon systems that require it.

    “DOD has begun initial planning for some weapon systems, but more remains to be done to understand the cost and schedule needed to transition to M-code receivers.

    “The preliminary estimate for integrating and testing a fraction of the weapon systems that need the receiver cards is over $2.5 billion through fiscal year 2021 with only 28 fully and 72 partially funded (see below figure). The cost will increase by billions when as yet unfunded weapon systems are included.”

    Status of weapon systems that have determined the cost needed to transition to M-code receivers through Fiscal Year 2021, as of February 2017.

    In its summary, the GAO wrote “DOD faces risks as it simultaneously develops satellites, a ground system to operate them, and receiver cards that allow use of GPS signals. It will need to install receiver cards on hundreds of systems and, without better coordination, risks paying repeatedly to solve similar problems across the systems.”

    The report also assesses the extent to which DOD faces acquisition challenges in sustaining the GPS constellation and developing a new ground control system. The GAO analyzed GPS quarterly acquisition reports and data, acquisition strategies, software and test plans, and other documents, and interviewed DOD and contractor officials.

  • New M-code GPS capability tested onboard B-2 bomber

    New M-code GPS capability tested onboard B-2 bomber

    M-code receiver enhances security, positioning, navigation and timing capabilities

    The U.S. Air Force recently completed a series of successful flight tests of its next-generation military-code GPS using a Raytheon Company receiver onboard a B-2 Spirit at Edwards Air Force Base, California.

    This first M-code test onboard the B-2 is an important milestone for the U.S. government-led GPS modernization effort to enhance security, positioning, navigation and timing capabilities for U.S. military and civilian applications.

    Military GPS user equipment (MGUE) M-code receivers will give military aircraft, ships and ground vehicles access to the modernized GPS network.

    “M-code receivers unlock the next-generation GPS network for military users,” said Rick Yuse, president of Raytheon Space and Airborne Systems. “This test demonstrated M-code capability onboard the B-2 for the first time, marking an early milestone for the overall GPS modernization effort.”

    The tests verified the integration of an MGUE-equipped risk reduction prototype of Raytheon’s miniaturized GPS airborne MAGR-2K-M receiver with B-2 systems in representative flight and mission profiles.

    Raytheon is developing M-code receivers under a contract with the USAF Global Positioning System Directorate GPS User Equipment Division. The company is also under contract with the USAF Joint Service Systems Management Office to qualify and certify the MAGR-2K-M and deliver production representative units to support platform integration and testing.

  • Directions 2018: Resiliency key to new GPS

    Col. Steve Whitney stands beside a statue of General Schriever at Los Angeles Air Force Base, home of the GPS Directorate. (Photo: U.S. Air Force/Joseph Juarez, Sr.)
    Col. Steve Whitney stands beside a statue of General Schriever at Los Angeles Air Force Base, home of the GPS Directorate. (Photo: U.S. Air Force/Joseph Juarez, Sr.)

    By Col. Steven Whitney
    Director, Global Positioning Systems Directorate

    The most discussed theme in the U.S. Air Force space community over the last year has been “resiliency.” But what does that actually mean, and how can the Air Force increase resiliency in space?

    The GPS Directorate took these questions to heart and thought long and hard about resiliency in our Positioning, Navigation, and Timing (PNT) service. I am pleased to report that we have made significant progress in the past year in our quest to bring a new generation of PNT technology to reality.

    More importantly, our investments in space, ground, and user equipment developments are bringing real, tangible benefits towards providing a more resilient PNT service worldwide. We stand on the cusp of delivering modernized civil and military GPS signals which provide critical pieces to the puzzle.

    Farther into the future, the Air Force is already exploring new, emerging technologies and capabilities to even further advance the robustness of the GPS enterprise, with the vision that GPS will always remain the “Gold Standard” for the worldwide PNT community.

    Resiliency Begins with Signals

    Modernized GPS signals will be the first piece of the puzzle for an overall resilient PNT solution. The community has long anticipated the beginning of the multi-GNSS era.

    The GPS Directorate has embraced this future with a new L1C signal, designed cooperatively from the ground up to be interoperable with international satellite navigation systems. The signal design will greatly improve GPS reception in cities and other challenging environments.

    Another important GPS signal was introduced with our GPS IIF satellites. The L5 signal is designed specifically to meet the demanding requirements for safety-of-life transportation and other high-performance applications.

    This signal is broadcast in a radio-frequency band reserved exclusively for aviation safety services to ensure it has optimal spectrum protection. Together, these two new additions greater improve PNT resilience for civil users around the globe.

    “The need to improve cyber security and protection quite honestly cannot wait until delivery of the Next-Generation Operational Control System (OCX). To that end, the Directorate has focused on high payoff updates for the existing operational system.”

    Other measures already improve resiliency by leveraging existing signals. For example, the L2C signal, when combined with L1 C/A in a dual-frequency receiver, will enable ionospheric error correction and improve positioning and timing accuracy.

    For the military, the directorate has been focused on bring Military Code (M-code) into operations. The M-code signal features advanced anti-jam, anti-spoof, and encryption features that will ensure resilient and dependable PNT solutions for the United States and its allies.

    The rollout of an operational M-code capability involves all segments of the GPS enterprise, and while it has been a long time in coming, the GPS Directorate made big strides this year (see “2017 in Review”). I will touch on the progress we are making in each of our development programs.

    Resiliency in Space

    The GPS space segment is the next step towards a more resilient PNT architecture. Our constellation remains robust and healthy, albeit aging, with 31 operational satellites providing worldwide coverage at the time of this article. The GPS III satellites will bring additional robustness with increased power and accuracy over previous generations of satellites.

    We made big strides towards launching the first GPS III satellite in 2018, and just as importantly, production is in full swing on the rest of the ten satellites. I am incredibly proud of the entire government and contractor team that is meticulously acquiring, assembling, and testing these complex machines.

    GPS IIIF. Farther into the future, the directorate is preparing for the GPS III follow-on program. The Air Force will be adding important new resiliency capabilities, with added signal flexibility via a reprogrammable, digital payload and increased anti-jam support to theater with a Regional Military Protection capability. Over the coming years as the follow-on GPS III satellites join the constellation, they will revolutionize GNSS with the full complement of operational L1C, L2C, L5 and M-code signals.

    Resiliency in Control Segment

    As important as the satellites are, the control segment is just as integral to the overall resiliency of the GPS enterprise. The need to improve cyber security and protection quite honestly cannot wait until delivery of the Next-Generation Operational Control System (OCX).

    To that end, the directorate has focused on high payoff updates for the existing operational system.

    For example, we acquired and deployed software-based GPS monitor station receivers, known as Monitor Station Technology Improvement and Capability (MSTIC) receivers, to replace the aging fleet of existing monitor-station receivers.

    The functionality and expandability of the MSTIC receiver design will facilitate adding further capabilities such as M-code signal monitoring, and even civil L1C, L2C, and L5 signal monitoring.

    The GPS Directorate also deployed a new cybersecurity monitoring suite to enhance cyber defenses. This new suite is in operation today at the GPS Master Control Station (MCS).

    Beyond just improving our cyber protection, the Air Force has also stepped out on several OCX off-ramps to support the launch and operation of the GPS III satellites and mitigate risk of further OCX delays.

    The Contingency Operations (COps) program modifies the existing Operational Control System (OCS) to allow the first GPS III satellites to join the operational constellation. The Air Force also initiated a companion program, M-code Early Use (MCEU) to further update OCS to provide limited M-code operations.

    Together, these two programs provide critical interim steps towards fielding a more resilient constellation.

    See also by Col. Steven Whitney,

    Directions 2018: The GPS year in review

    The OCX program provides the ultimate cyber protection and assurance needed for the GPS enterprise. After emerging from program recertification this year, the program has focused heavily on improved software system engineering and embracing software industry best practices, such as adopting DevOps and greater software automation.

    The program has even leveraged Amazon Web Services’ Gov’t Cloud capability to provide more responsive development and test environments. While the program has a long ways to go, the government and prime contractor, Raytheon, are committed to delivery to ensure a robust and secure ground infrastructure.

    User Equipment: Final Piece

    The final piece of the resiliency puzzle for military customers is our user equipment segment. The directorate has made big strides in delivering the first set of modernized receiver cards for the Military GPS User Equipment (MGUE) Increment 1 program.

    These advanced cards will enable platforms across the U.S. Department of Defense to leverage the new M-code signal, providing a tremendous boost in both anti-jam and anti-spoof capability.

    They will also provide the latest in cryptography to ensure secure, robust protection for the United States and its allies.

    Down the road, the Department of Defense is evaluating additional capabilities and platforms for the MGUE Increment 2 program.

    Currently envisioned to address precision guided munitions, space receivers, and a modernized handheld unit, the Increment 2 program will be laying out an acquisition plan in this coming year to further adoption of M-code signals throughout the military.

    A consideration for the future of user equipment will be exploring processing multi-GNSS signals. While no decisions have been made, multi-GNSS could offer opportunities for even additional resiliency.

    Final Thoughts

    This is an exciting time for the GPS enterprise.

    We stand on the cusp of a new generation of capabilities that will usher in a huge increase in PNT resiliency and robustness. I am astounded at the quality of work that is presented at the many GNSS and PNT conferences around the world, and it is both exciting and humbling to see the community continuing to innovate ways to increase accuracy, integrity, availability, continuity, and performance.

    Likewise, I am honored to lead the men and women of the GPS Directorate as we strive to deliver on our commitments and find new, innovative ways to provide robust and resilient PNT to the world.

    This dedicated team is poised and ready to lead us into the future, and we look forward to working with the entire community to continue delivering the GPS “Gold Standard” in space-based PNT.