GPS World

Tag: jamming

  • Make it real: Developing a test framework for PNT systems and devices

    Make it real: Developing a test framework for PNT systems and devices

    Tests of the robustness of commercial GNSS devices against threats show that different receivers behave differently in the presence of the same threat vectors. A risk-assessment framework for PNT systems can gauge real-world threat vectors, then the most appropriate and cost-effective mitigation can be selected.

    Vulnerabilities of GNSS positioning, navigation and timing are a consequence of the signals’ very low received power. These vulnerabilities include RF interference, atmospheric effects, jamming and spoofing. All cases should be tested for all GNSS equipment, not solely those whose applications or cargoes might draw criminal or terrorist attention, because jamming or spoofing directed at another target can still affect any receiver in the vicinity.

    GNSS Jamming. Potential severe disruptions can be encountered by critical infrastructure in many scenarios, highlighting the need to understand the behavior of multiple systems that rely on positioning, and/or timing aspects of GNSS systems, when subject to real-world GNSS threat vectors.

    GNSS Spoofing. This can no longer be regarded as difficult to conduct or requiring a high degree of expertise and GNSS knowledge. In 2015, two engineers with no expertise in GNSS found it easy to construct a low-cost signal emulator using commercial off-the-shelf software–defined radio and RF transmission equipment, successfully spoofing a car’s built-in GPS receiver, two well-known brands of smartphone and a drone so that it would fly in a restricted area.

    In December 2015 the Department of Homeland Security revealed that drug traffickers have been attempting to spoof (as well as jam) border drones. This demonstrates that GNSS spoofing is now accessible enough that it should begin to be considered seriously as a valid attack vector in any GNSS vulnerability risk assessment.

    More recently, the release of the Pokémon Go game triggered a rapid development of spoofing techniques. This has led to spoofing at the application layer: jailbreaking the smartphone and installing an application designed to feed faked location information to other applications. It has also led to the use of spoofers at the RF level (record and playback or “meaconing”) and even the use of a programmed SDR to generate replica GPS signals — and all of this was accomplished in a matter of weeks.

    GNSS Segment Errors. Whilst not common, GNSS segment errors can create severe problems for users. Events affecting GLONASS during April 2014 are well known: corrupted ephemeris information was uploaded to the satellite vehicles and caused problems to many worldwide GLONASS users for almost 12 hours. Recently GPS was affected. On January 26, 2016, a glitch in the GPS ground software led to the wrong UTC correction value being broadcast. This bug started to cause problems when satellite SVN23 was withdrawn from service. A number of GPS satellites, while declaring themselves “healthy,” broadcast a wrong UTC correction parameter.

    Atmospheric Effects. Single frequency PNT systems generally compensate for the normal behavior of the ionosphere through the implementation of a model such as the Klobuchar Ionospheric Model.

    Space weather disturbs the ionosphere to an extent where the model no longer works and large pseudorange errors, which can affect position and timing, are generated. This typically happens when a severe solar storm causes the Total Electron Count (TEC) to increase to significantly higher than normal levels.

    Dual-frequency GNSS receivers can provide much higher levels of mitigation against solar weather effects. However, this is not always the case; during scintillation events dual frequency diversity is more likely to only partially mitigate the effects of scintillation.

    Solar weather events occur on an 11-year cycle; the sun has just peaked at solar maximum, so we will find solar activity decreasing to a minimum during the next 5 years of the cycle. However that does not mean that the effects of solar weather on PNT systems should be ignored for the next few years where safety or critical infrastructure systems are involved.

    TEST FRAMEWORK

    Characterization of receiver performance, to specific segments within the real world, can save either development time and cost or prevent poor performance in real deployments. Figure 1 shows the concept of a robust PNT test framework that uses real-world threat vectors to test GNSS-dependent systems and devices.

    We have deployed detectors — some on a permanent basis, some temporary — and have collected extensive information on real-world RFI that affects GNSS receivers, systems and applications.

    For example, all of the detected interference waveforms in Figure 2 have potential to cause unexpected behavior of any receiver that was picking up the repeated signal. A spectrogram is included with the first detected waveform for reference as it is quite an unusual looking waveform, which is most likely to have originated from a badly tuned, cheap jammer. The events in the figure, captured at the same European sports event, are thought to have been caused by a GPS repeater or a deliberate jammer. A repeater could be being used to rebroadcast GPS signals inside an enclosure to allow testing of a GPS system located indoors where it does not have a view of the sky.

    The greatest problem with GPS repeaters is that the signal can “spill” outside of the test location and interfere with another receiver. This could cause the receiver to report the static position of the repeater, rather than its true position. The problem is how to reliably and repeatedly assess the resilience of GPS equipment to these kinds of interference waveforms. The key to this is the design of test cases, or scenarios, that are able to extract benchmark information from equipment. To complement the benchmarking test scenarios, it is also advisable to set up application specific scenarios to assess the likely impact of interference in specific environmental settings and use cases.

    TEST METHODOLOGY

    A benchmarking scenario was set up in the laboratory using a simulator to generate L1 GPS signals against some generic interference waveforms with the objective of developing a candidate benchmark scenario that could form part of a standard methodology for the assessment of receiver performance when subject to interference.

    Considering the requirements for a benchmark test, it was decided to implement a scenario where a GPS receiver tracking GPS L1 signals is moved slowly toward a fixed interference source as shown in Figure 3.

    The simulation is first run for 60 seconds with the “vehicle” static, and the receiver is cold started at the same time to let the receiver initialise properly. The static position is 1000m south of where the jammer will be. At t = 60s the “vehicle” starts driving due north at 5 m/s. At the same time a jamming source is turned on, located at 0.00 N 0.00 E. The “vehicle” drives straight through the jamming source, and then continues 1000m north of 0.00N 0.00E, for a total distance covered of 2000m. This method is used for all tests except the interference type comparison where there is no initialization period, the vehicle starts moving north as the receiver is turned on.

    The advantages of this simple and very repeatable scenario are that it shows how close a receiver could approach a fixed jammer without any ill effects, and measures the receiver’s recovery time after it has passed the interference source. We have anonymized the receivers used in the study, but they are representative user receivers that are in wide use today across a variety of applications. Isotropic antenna patterns were used for receivers and jammers in the test. The test system automatically models the power level changes as the vehicle moves relative to the jammer, based on a free-space path loss model.

    RESULTS

    Figure 4 shows a comparison of GPS receiver accuracy performance when subject to L1 CHIRP interference. This is representative of many PPD (personal protection device)-type jammers.
    Figure 5 shows the relative performance of Receiver A when subject to different jammer types — in this case AM, coherent CW and swept CW.

    Finally in Figure 6 the accuracy performance of Receiver A is tested to examine the change that a 10dB increase in signal power could make to the behavior of the receiver against jamming — a swept CW signal was used in this instance.

    Discussion. In the first set of results (the comparison of receivers against L1 CHIRP interference), it is interesting to note that all receivers tested lost lock at a very similar distance away from this particular interference source but all exhibited different recovery performance.

    The second test focused on the performance of Receiver A against various types of jammers — the aim of this experiment was to determine how much the receiver response against interference could be expected to vary with jammer type. It can be seen that for Receiver A there were marked differences in response to jammer type. Finally, the third test concentrated on determining how much a 10dB alteration in jammer power might change receiver responses. Receiver A was used again and a swept CW signal was used as the interferer. It can be seen that the increase of 10dB in the signal power does have the noticeable effect one would expect to see on the receiver response in this scenario with this receiver.

    Having developed a benchmark test bed for the evaluation of GNSS interference on receiver behavior, there is a great deal of opportunity to conduct further experimental work to assess the behavior of GNSS receivers subject to interference. Examples of areas for further work include:

    • Evaluation of other performance metrics important for assessing resilience to interference
    • Automation of test scenarios used for benchmarking
    • Evaluation of the effectiveness of different mitigation approaches, including improved antenna performance, RAIM, multi-frequency, multi-constellation
    • Performance of systems that include GNSS plus augmentation systems such as intertial, SBAS, GBAS

    CONCLUSIONS

    A simple candidate benchmark test for assessing receiver accuracy when subjected to RF interference has been presented by the authors.

    Different receivers perform quite differently when subjected to the same GNSS + RFI test conditions. Understanding how a receiver performs, and how this performance affects the PNT system or application performance, is an important element in system design and should be considered as part of a GNSS robustness risk assessment.

    Other GNSS threats are also important to consider: solar weather, scintillation, spoofing and segment errors.

    One of the biggest advantages of the automated test bench set-up used here is that it allows a system or device response to be tested against a wide range of of real world GNSS threats in a matter of hours, whereas previously it could have taken many weeks or months (or not even been possible) to test against such a wide range of threats.

    Whilst there is (rightly) a lot of material in which the potential impacts of GNSS threat vectors are debated, it should also be remembered that there are many mitigation actions that can be taken today which enable protection against current and some predictable future scenarios.

    Carrying out risk assessments including testing against the latest real-world threat baseline is the first vital step towards improving the security of GNSS dependent systems and devices.

    ACKNOWLEDGMENTS

    The authors would like to thank all of the staff at Spirent Communications, Nottingham Scientific Ltd and Qascom who have contributed to this paper. In particular, thanks are due to Kimon Voutsis and Joshua Stubbs from Spirent’s Professional Services team for their expert contributions to the interference benchmark tests.

    MANUFACTURERS

    The benchmarking scenario described here was set up in the laboratory using a Spirent GSS6700 GNSS simulator.

  • Canada, US workshops focus on PNT threats

    Canada, US workshops focus on PNT threats

    Two workshops convened in recent weeks in the U.S. and Canadian capitals, respectively, sought to bring into focus looming threats to the nations’ positioning, navigation and timing capabilities and critical infrastructures. Some of the threats are pervasive — jamming and spoofing — and formed the general topic of the Canadian workshop. Some threats are specific — powerful terrestrial transmitters overwhelming GPS/GNSS receivers — and occasioned the U.S. gathering.

    Canada. In a first for Canada, the October 21 GNSS Vulnerabilities Innovation Policy (VIP) Workshop brought together 19 federal government departments as well as  provincial and municipal agencies and private sector companies.  U.S. State Dept. and Homeland Security gave presentations, as did the European Space Agency, Bell Canada, NovAtel and Spirent Communications.

    Integrity challenge for automotive positioning, presented by NovAtel
    Integrity challenge for automotive positioning, presented by NovAtel

    The workshop was sponsored by the the Federal Global Navigation Satellite Systems Coordination Board (FGCB), a government board with representations from various government departments and agencies. The GNSS Coordination Office (which organized the workshop) is hosted at Canada’s Ministry of Innovation, Science and Economic Development and sponsored by the FGCB members.

    Presentations covered such topics as Demonstration of the Geolocation of GPS Jammers, GNSS & the Telecom Sector, Detecting and Protecting Against GPS Cyberthreats, and Safety Critical, High Precision, GNSS Positioning for Autonomous Vehicles.

    United States. The U.S. Department of Transportation (DOT) hosted its fifth workshop on the GPS Adjacent-Band Compatibility Assessment effort on October 14. This lengthy, thorny and occasionally acrimonious process started out benignly enough in 2010 with the statement, “Demand for commercial spectrum to support broadband wireless communications has led the government to consider repurposing various radio frequencies, including the satellite communications bands next to GPS.”

    The workshop discussed the results from testing of various categories of GPS/GNSS receivers including aviation (non-certified), cellular, general location/navigation, high precision and networks, timing, and space-based receivers. The workshop also included a discussion on the development of use-case scenarios for these categories — which is where the going got heavy and differences of opinion truly emerged.

    DOT has posted all presentations from the workshop.  Scroll down to “October 2016 Workshop.”

    The furor stems from a renewed effort by Ligado, formerly known as LightSquared and now re-emergent from a 2-year bankruptcy process, to convert relatively inexpensive satellite-to-earth spectrum into very valuable terrestrial spectrum. The company stands to gain billions of dollars and secured rights from the process.

    Members of the DoT team presented the first results from the GPS Adjacent-Band Compatibility (ABC) Assessment, an effort to determine the power limits by frequency, or interference tolerance masks (ITM), needed to protect both existing and future GPS receivers. Test results indicated a need to limit interfering signals at different levels depending on the type of receiver being used. 80 receivers in six categories were tested: cellular, general location/navigation, general aviation, timing, high precision and space receivers. Certified and military receivers are undergoing separate tests.

    The tests of current receivers took place April 25–29 at White Sands Missile Range, New Mexico, using a 100 x 70 x 40 anechoic chamber. The signals used in the test included GPS L1 C/A-code, GPS L1 P-code, GPS L1C, GPS L1 M-code, GPS L2 P-code, SBAS L1, GLONASS L1 C, GLONASS L1 P, BeiDou B1I and Galileo E1 B/C. Tests were conducted within 100 megahertz on either side of the GPS L1 center frequency of 1575.42 using a 10-megahertz LTE signal and a narrow bandwidth 1-megahertz bandpass white noise signal.

    The tests were conducted for GPS and GNSS receivers processing signals in the 1559–1610 MHz Radionavigation Satellite Service (RNSS) frequency band, as well as receivers that process Mobile Satellite Service (MSS) signals in the 1525–1559 MHz band to receive differential GNSS corrections.

    The tests determined the power levels at which each device experienced a one-decibel degradation in the carrier-to-noise density ratio (CNR) at a particular frequency. The DoT team graphed results for each device. The recommended power limits were the lowest in frequencies closest to the GPS bands.

    The receivers most affected by the test transmissions were identified as high-precision receivers. They experienced interference at power levels as low as –90 to –95dBm at around 1550 MHz and –90 dBm at roughly 1610 MHz.

    highprecision-gps-l1-receiver-category

    The strictest limit for both the general aviation, general navigation/location, and timing receivers was a little below –80 dBm at about 1550 MHz, while space-based receivers were equally sensitive on both sides of the RNSS band with the toughest limit being about –85 dBm.

    FAA. The Federal Aviation Administration (FAA) has authority to set power and out-of-band emissions limits to meet aviation safety standards, and it had been thought that these limits might  address interference with other types of receivers as well. But the test results showed that “protecting the FAA-certified mask does not necessarily protect the rest of the receiver categories,” according to Hadi Wassaf, technical lead for GPS interference analysis at DoT’s Volpe Center.

    Use Cases. Ligado has proposed that position error as experienced by the user is a better guide to interference levels than degradation in the carrier-to-noise density ratio. The GPS community generally opposes this approach. The next step is the development of use cases. According to the test plan, use cases define the regions of operations for a receiver, and they identify applications that “that are vital to economic, public safety, scientific, and/or national security needs and any other factors supporting why this particular receiver model is important to be tested (e.g., quantity in use, economic impact, etc.).”

  • Are you experienced? Tell us about jamming, spoofing, RF interference encounters

    We talk a lot about — and publish a lot of technical articles about — GPS/GNSS jamming, spoofing and unintentional RF interference in GPS World magazine and on this website. Clearly it is an emerging and potentially huge problem. How much of it goes on right now?  Tell us very briefly (10 seconds it will take) if You are experienced with these incidents.

    One week only! Final results will be collected on October 18 and published in the November issue of the magazine.

    Answer now, and you’ll be entered in a drawing to win a $50 gift card. Go to env-gpsworld-integration.kinsta.cloud/septpoll now!

  • Expert Opinions: OEM R&D budget for mitigation of jamming

    Q: What percent of a GNSS designer or manufacturer’s R&D budget should be devoted to mitigation of jamming?

    MIchael Ritter, President & CEO, Novatel Inc.
    MIchael Ritter, President & CEO, Novatel Inc.

    A: Solving for jamming, intentional or unintentional, in the design of any GNSS technology platform is no longer an option. How much any one company spends is largely a function of how much is spent on engineering overall and of how much has already been invested upfront on jamming mitigation. The required level of jamming resistance of any PNT solution also depends very much on the particular application, which in turn influences the budget allocated.

    Jeff Martin, Director, GPS/GNSS Sales, Spirent Federal
    Jeff Martin, Director GPS/GNSS Sales,
    Spirent Federal

    A: GNSS jamming is a growing concern, and an assessment of risks and an element of testing against the most applicable real world threats should be included as part of every developer’s engineering process. Spirent has decades of experience in providing test equipment and services to engineers working to understand and mitigate jamming threats. We have seen increased investment by designers and integrators of PNT systems that are driven to provide robust/resilient solutions to their customers.

    Andrey Soloviev, Principal, Qunav
    Andrey Soloviev, Principal, Qunav

    A: While some receivers already incorporate jamming protection (e.g., CW excision), more sophisticated methods (for example, against broad-band jamming and spoofing) should be incorporated into perspective products. The percentage of R&D budget depends on a line of business. For manufactures pursuing applications such as military and critical infrastructure, the number can be as high as 50 percent. For many civilian applications a potential impact of jamming is less damaging. Yet, from 10 percent to 20 percent should be still allocated.

  • FAA issues GPS interference flight advisory

    FAA issues GPS interference flight advisory

    [[Editor’s note: After this story was posted, and after the Navigate! enewsletter containing it was sent out to 27,128 subscribers, GPS World received notice that in fact the U.S. Navy  canceled plans to jam GPS signals in the vicinity of the China Lake, California, Naval Air Weapons Station. The Aircraft Owners and Pilots Association (AOPA) had raised concerns about the impact on civilian air traffic and the size of the affected area. The Navy did not reveal the cause of the cancellation, other than to say the reason was “internal.”]]

    According to a June 4 Federal Aviation Administration advisory, GPS testing is scheduled several days this month that may affect GPS reception on the West Coast of the U.S. with an unreliable or unavailable GPS signal.

    The time periods discussed in this advisory may be reduced or cancelled with little or no notice. Pilots are advised to check NOTAMs frequently for possible changes prior to operations in the area. NOTAMs will be published at least 24 hours in advance of any GPS tests.

    GPS Interference testing this June on the West Coast of the United States.
    GPS Interference testing this June on the West Coast of the United States.

    Location: The location is centered at 360822N1173846W or the BTY VOR 214 degree radial at 059 NM.

    Dates and times

    7 JUN 16 1630Z – 2230Z
    9 JUN 16 1630Z – 2230Z
    21 JUN 16 1630Z – 2230Z
    23 JUN 16 1630Z – 2230Z
    28 JUN 16 1630Z – 2230Z
    30 JUN 16 1630Z – 2230Z

    Duration: Each event may last the entire requested period.

    NOTAM INFO:

    NAV (CHLK GPS 16-08) GPS (including WAAS, GBAS and ADS-B) may not be available within a  476 nautical mile radius centered at 360822N1173846W (BTY 214059) FL400-UNL DECREASING IN AREA WITH A DECREASE IN ALT DEFINED AS:
    432NM RADIUS AT FL250
    375NM RADIUS AT 10000FT
    340NM RADIUS AT 4000FT AGL
    253NM RADIUS AT 50FT AGL

    THIS NOTAM APPLIES TO ALL AIRCRAFT RELYING ON GPS. ADDITIONALLY, DUE TO GPS INTERFERENCE IMPACTS POTENTIALLY AFFECTING EMBRAER PHENOM 300 AIRCRAFT FLIGHT STABILITY CONTROLS, FAA RECOMMENDS EMB PHENOM PILOTS AVOID THE ABOVE TESTING AREA AND CLOSELY MONITOR FLIGHT CONTROL SYSTEMS DUE TO POTENTIAL LOSS OF GPS SIGNAL.

    Affected Centers: Pilots are encouraged to report anomalies only when ATC assistance is required.

  • GNSS jam-proof test range ready for customer testing

    Locatalite transceiver installation in the White Sands Missile Range Ultra High-Accuracy Reference System, provided by the U.S. Air Force for testing equipment under conditions of GPS jamming.
    Locatalite transceiver installation in the White Sands Missile Range Ultra High-Accuracy Reference System, provided by the U.S. Air Force for testing equipment under conditions of GPS jamming.

    A new dimension in real-world PNT testing has arrived. One of the most critical things to predict for chips, receivers and devices using alternative or back-up PNT technologies is how they will actually perform without GPS.

    Filling this need, the U.S. Air Force 746th Test Squadron has declared Initial Operational Capability (IOC) for its new truth reference, the Ultra High-Accuracy Reference System (UHARS) at the White Sands Missile Range in New Mexico. Even when GPS — or any other GNSS system — is being completely jammed, UHARS provides extremely accurate positioning, navigation and time (PNT) over the large area that the system was designed to cover.

    “Initial testing shows that UHARS delivers accurate independent PNT as good as, or better than, the Air Force’s current Central Inertial and GPS Test Facility (CIGTF) Reference System (CRS), so it is perfectly able to support current customer requirements,” said Dr. Jim Brewer, Chief Scientist of the 746th Test Squadron. “However, more data are required to tune the UHARS filter and optimize its accuracy to meet even tighter PNT requirements, which is our objective. When this is achieved, UHARS will deliver truth accuracy for next-generation military capabilities, and we will declare UHARS Full Operational Capability.”

    “UHARS is a rack-mounted, tightly integrated system of improved navigation sensors, a data acquisition system (DAS) and a new post-mission Kalman filter, all of which need to work together,” explained John Cao, Technical Director of the 746th Test Squadron. “It’s working very well, but once we completely measure and characterize the individual components and then tune and validate the filter, the complete system will provide a significantly more accurate reference solution for future airborne and land-based test vehicles in navigation warfare environments where modernized and legacy GPS signals are jammed from friendly or hostile systems.”

    To achieve these accurate reference solutions, UHARS requires a core Non-GPS Based Positioning System (NGBPS) component capable of operating and providing sub-meter position accuracy in a GPS-denied (jamming) environment. The NGBPS subsystem of the UHARS program employs a network of ground-based LocataLite transceivers and test vehicle receivers manufactured by the Locata Corporation. The Locata network deliver centimeter-level positioning and navigation as well as nanosecond-level synchronization, which may be useful for military applications requiring precise time transfer in GPS-denied environments.

    White Sands Missile Range (WSMR) is a United States Army rocket range of almost 3,200 sq mi (8,300 sq km) in parts of five counties in southern New Mexico. It is the largest military installation in the United States.

    The importance and uniqueness of the WSMR as GPS test facility spring from the fact that it is illegal to jam GPS elsewhere without a special permit. Thus it is extremely difficult to create a real-world test scenario for various GPS and other PNT devices, to see how they perform under denied or restricted circumstances. This is of critical importance for flight testing (UAVs and other avionics) for which the UHARS was primarily designed and optimized.

    The LocataNet truth reference system can also provide a 2D solution to support ground vehicle testing.  Reportedly, the 2D solution, while also very good, has not yet been fully characterized. Once the filter has been fully tuned in this respect, WSMR could serve as a test facility for autonomous driving. There are many miles of paved highway on the WSMR, possibly in the hundreds of miles.

    History of UHARS Development. Based on successful results of the original technical demonstration at WSMR in a real-world end-to-end environment, the USAF proceeded to the NGBPS production and fielding phase in 2012. The Locata Corporation was contracted to provide production ground transceivers and receivers, navigation algorithms required for data analysis and subject matter expertise. The TMC Design Corporation, the integrating contractor for this program, was tasked to develop the production hardware to house the Locata hardware, develop the command and control hardware and software, and field the production hardware at WSMR. The Locata network was fielded in September 2014, and its NGBPS capability is now core to the UHARS that is replacing the CRS.

    “Our team is thrilled to be part of this historic USAF capability,” said Nunzio Gambale, CEO and co-founder of Locata Corporation. “Locata products developed and fielded by important commercial partners like Hexagon and Perrone Robotics routinely prove our technology is a game-changer for positioning over industrial-sized areas. However, leveraging Locata technology as the core non-GPS-based PNT solution over a vast military area when GPS is jammed instantly elevates our achievements into a completely new league. Clearly, we are witnessing the arrival of one of the most important technology developments for the future of the entire PNT industry.”

    Customers wishing to leverage UHARS into their test programs should contact the 746th Test Squadron at (575) 679-2123 or [email protected] for scheduling information.

  • Air Force jam-proof reference system ready to support testing

    The U.S. Air Force 746th Test Squadron has declared Initial Operational Capability (IOC) for its new truth reference, the Ultra High-Accuracy Reference System (UHARS), which employs LocataLite transceivers.

    Even when GPS is being completely jammed, UHARS provides extremely accurate positioning, navigation and time (PNT) over the large area of White Sands Missile Range (WSMR) in New Mexico that the system was designed to cover.

    To achieve these accurate reference solutions, UHARS requires a core Non-GPS Based Positioning System (NGBPS) component capable of operating and providing sub-meter position accuracy in a GPS-denied (jamming) environment. The NGBPS subsystem of the UHARS program employs a network of ground-based LocataLite transceivers and test vehicle receivers manufactured by the Locata Corporation.

    Further details on the White Sands UHARS appear in the GNSS Design & Test e-newsletter from GPS World. For a free subscription, visit env-gpsworld-integration.kinsta.cloud/subscribe.

  • AF Space Command holds wargame focused on resilience

    Air Force Space Command began its 10th Schriever Wargame May 19 at Maxwell AFB, Montgomery, Ala.

    The Schriever Wargame (SW 16), set in the year 2026, explores critical space issues and investigates the integration activities of multiple agencies associated with space systems and services.

    The objectives of SW 16 center on identifying ways to increase the resilience of space that includes our intelligence community, civil, commercial and Allied partners; exploring how to provide optimized effects to the warfighter in support of coalition operations; and examining how to apply future capabilities to protect the space enterprise in a multi-domain conflict.

    The Air Force announcement did not include specific mention of GPS jamming and spoofing, but these and related cyberthreats could reasonably be expected to appear in the pantheon of cyberspace competition.

    The SW 16 scenario depicts a peer space and cyberspace competitor seeking to achieve strategic goals by exploiting those domains. Scenarios will focus on the European Command Area of Responsibility. They will also include a full spectrum of threats across diverse operating environments to challenge civilian and military leaders, planners and space system operators, as well as the capabilities they employ.

    The Schriever Wargame team will conduct SW 16 on behalf of Air Force Space Command, headquartered in Colorado Springs, Colorado. Approximately 200 military and civilian experts from more than 27 commands and agencies around the country will participate in the Wargame.

    U.S. commands and agencies participating in SW 2016 include: Air Force Space Command, Army Space and Missile Defense Command, Naval Fleet Cyber Command, the National Reconnaissance Office, Executive Agent for Space Staff, Air Combat Command, Office of the Secretary of Defense, U.S. European Command, U.S. Strategic Command, Defense Information Systems Agency, the Intelligence Community, National Aeronautics and Space Administration, Office of Homeland Security, Department of Transportation, Department of State and Department of Commerce.

  • Congress yanks funding for OCX

    The U.S. Senate Armed Services Committee withheld the full amount requested by the Pentagon for Fiscal Year (FY) 2017 for OCX, the Next-Generation Operational Control System (ground control) for GPS, heretofore deemed necessary to operate the next generation of satellites, GPS III. The Pentagon had asked for $394 million in the upcoming funding cycle, to enable Raytheon to continue work on the program.

    If allowed by Congress to continue, OCX may cost as much as $5.3 billion, and there is no certainty that the bill will not rise further.

    The Senate committee will not release the $394 million until the Defense Department complies with the requirements of the Nunn-McCurdy Act governing defense programs. Otherwise, Congress could act to terminate OCX.

    The terms of the Act now require the Secretary of Defense conduct an in-depth review and then state that the program is essential to the national security, is more important than other programs that will have to be cut to accommodate its cost overruns, and that there are no acceptable alternatives.

    From the Defense Department point of view, the new GPS III satellites are essential because of, among other things, their signals’ improved resistance to jamming and cyberattack, an oft-cited peril in the modern global security scenario.

    How GPS III could be launched — the first satellite is scheduled for sometime in 2017 — and operated without OCX is not entirely clear, although in February, Lockheed Martin received a $96 million contract to provide contingency control operations for the first GPS III satellites upon launch because OCX won’t be ready.

    Raytheon and the U.S. Air Force announced a month ago that OCX “successfully passed the first formal qualification test milestone” needed to check out the system and for the early monitoring of satellites in orbit. That “validates the maturity of the OCX launch and checkout system,” according to a statement by Bill Sullivan, Raytheon’s OCX program director.

    Raytheon  won the OCX contract in 2010 with a bid somewhat more than $1.5 billion. The Air Force recently made its FY 2017 budget request for $393 million as part of an overall anticipated program cost of $4.82 billion. However, a Bloomberg news report states that the total cost may have risen to $5.3 billion.

  • South Korea to build eLoran system after jamming incident

    South Korea will award a contract this month to secure technology required to build an eLoran system as an alternative to GPS, reports the Australian Broadcasting Company (ABC).

    The announcement follows South Korea pointing the finger at North Korea for jamming its GPS signal reception in late March.

    The South Korean eLoran plan envisions setting up coastal transmitters by the end of 2019, said Seo Ji-won, a government advisory panel member and professor at Yonsei University.

    “The need for us is especially high, because of the deliberate signal interference by North Korea,” a South Korean government official told Reuters, as reported by ABC.

    The latest jamming campaign from the North began on March 31. According to ABC, the jamming lasted nearly a week and affected signal reception of more than 1,000 aircraft and 700 ships, with the jamming originating from five locations along the border, South Korean officials said.

    GPS vulnerability poses security and commercial risks, especially for ships whose crews are not familiar with traditional navigation techniques or using paper charts. Vessels such as fishing boats lack backup electronic navigation systems.

    Air traffic was not usually affected because the GPS system is normally used as a backup in South Korea, not a primary navigation tool.

    GPS in the United States and Europe could also experience malicious jamming attacks, reinforcing the need for a backup alternative such as eLoran.

  • GNSS has bad days, too

    GNSS has bad days, too

    (courtesy Ursanav)
    (courtesy UrsaNav)

    “Even the best technology has a bad day,” Charles Schue told the New York Stock Exchange (NYSE), which relies very heavily on the best technology to keep the world’s financial edifice afloat. Vulnerabilities in the stock market were pointed up during a demonstration on April 19, showcasing how one positioning, navigation and timing (PNT) system can cover the chinks in another. Respectively, eLoran and GPS in this case.

    Schue is CEO of UrsaNav, a company that has been developing complementary PNT solutions, specifically the high-power, low-frequency (LF), ground-wave technology that is eLoran, which UrsaNav calls “the most reliable, scalable, and future-proof available.” Schue spoke at the NYSE along with representatives from the Department of Homeland Security (DHS), the U.S. Coast Guard, Juniper Networks and Harris Corporation.

    “2014 was a very bad year for GNSS,” Schue continued, citing the GLONASS full-system outage for 11 hours and Galileo’s wrong-orbit launch of two satellites. “This year, GPS, the gold standard, had an ‘oops’ and slipped from gold to silver, when one satellite kind of wigged out, a 13.7 microsecond error that contaminated 15 other satellites.” He ran a simulation that showed how, at one point, six GPS satellites were communicating bad timing to the Eastern seaboard, where the NYSE is located.

    2016 has also seen renewed GPS jamming from North Korea.

    The stock exchange, along with other global financial markets, relies on microsecond timing to properly execute all transactions. The U.S. air traffic management system likewise relies on high-precision aspects of GPS that are vulnerable to interference, jamming, and even occasional system failure. Many other industries, telecommunications principally among them, are also building infrastructures and applications that rely on GPS for precise timing, thus making them vulnerable as well.

    One Back-Up Transmitter in Place

    An eLoran transmitter in Wildwood, New Jersey, relies on three primary reference standards, three atomic clocks, just as each GPS satellite carries three or four atomic clocks. “The signals coming from space, the signals coming from ground, they’re very similar.” ELoran also has monitoring and control sites on the ground, just like the satellite system; it has differential reference stations, and of course eLoran receivers, playing the same role as GPS receivers.

    Schue asserted that the cost of launching one GPS satellite into space would fund an eLoran system for the continental United States for 20 years. Also, that a lot of industries in addition to the financial community are building infrastructures and applications that rely on GPS for precise timing, and so are equally vulnerable.

    The eLoran demonstration showed how the Wildwood station sent a timing signal 130 miles to the NYSE, deep within several urban canyons and enveloped in several layers of concrete, steel and glass. A GPS receiver in the room did not pick up anything. The eLoran receiver showed precise time, to the standard of NYSE requirements.

    Equipment utilized included a Spectracom SecureSync providing time to the network, once it received it from eLoran.

    On a screen display showing plus or minus 500 nanoseconds relative to Coordinated Universal Time, “that red line is us receiving eLoran timing at that antenna, 130 miles away, through the urban canyons, inside this building, right now at minus 14 nanoseconds.” The eLoran equipment transmitted and received two signals, with a data channel on one of the signals. “We could put the data channel on both signals, and we could put multiple data channels on both on there as well.”

    Photo: UrsaNav Photo: UrsaNav

    Schue said another demo inside a downtown Boston hotel, 305 miles from the New Jersey transmitter, obtained 83-nanosecond accuracy. A 2015 test to an outdoor receiver in Bangor, Maine, 500 miles from the transmitter, logged 68-nanosecond accuracy.

    Plus or minus 100 nanoseconds is the typical GPS performance. “We can do far better, and GPS often does far better than that.”

    Initial operating capability for a wide-area eLoran service providing precise time for the continental United States would require four transmitter sites across the middle of the country. The corporate and government partners hope to use some repurposed Loran-C assets and turn them into eLoran stations. Wildwood is transmitting at 360 kilowatts; if transmitting at 1 million watts, or 1 megawatt, the signal could penetrate even further inside buildings. The cost difference between the two powers of transmitter is not significant.

    Bringing six more continental eLoran transmitter sites online, for a total of ten, would add a back-up positioning capability in addition to timing. “This is very important, because with positioning, you get mobile time — a co-primary solution for position, navigation, and timing.”

    Using a differential receiver would yield even better local-area accuracy for about 35 miles around a selected site, for high-priority locations. Such a higher-precision system for the nation’s top 50 metropolitan areas, top 50 airports, and top 50 harbors could be accomplished with 71 differential sites.

    Concurrence from Government and Other Industry Partners

    Spokespersons from the DHS, Coast Guard, Juniper Networks and Harris Corporation preceded Schue at the NYSE presentation, all giving similar perspectives on U.S. vulnerability in many aspects, due to reliance on GPS as a sole, unsupported source of precision PNT.  “Of the 16 critical infrastructure / key resource sectors in the United States, 15 use GPS for timing. GPS timing is deemed essential for 11 of these sectors,” stressed DHS.

  • State Department issues notice on North Korean jamming

    On April 7, the U.S. Department of State issued a notice about the recent jamming experienced in South Korea.

    Korean Peninsula GPS Jamming Notice

    A continuing series of incidents have been reported in the general location of Incheon, Republic of Korea and the surrounding Gyeonggi and Gangwon provinces out to approximately 100 nautical miles beginning on or about 0000Z31March16.

    The nature of the events appear to be Global Positioning System (GPS) jamming emanating from the Democratic People’s Republic of Korea causing signal disruptions to airplanes, ships, and buoys in the area.

    Exercise caution when transiting this area. If appropriate, further information may be forthcoming. Vessels experiencing disruptions in the area are urged to report them to the point of contact (POC) below.

    The notice was forwarded by the U.S. Coast Guard Navigation Center’s Civil GPS Service Interface Committee (CGSIC).