“Seen & Heard” is a monthly feature of GPS World magazine, traveling the world to capture interesting and unusual news stories involving the GNSS/PNT industry.
Photo: Drazen Zigic/iStock/Getty Images/Getty Images Plus
Where’s the Beef?
A new mapping app is helping Los Angeles County residents find more than 2,000 food resources, during and after the COVID-19 pandemic. Sponsored by the non-profit 211 LA County, the LA FoodFinder is powered by Slingshot Earth, which aggregates food resources and service data from multiple public and private sources. The app enables residents to find resources for child nutrition, meal services, groceries/food pantries, senior food needs and government food benefits programs. Since the COVID-19 outbreak, 211 LA County has experienced a 10-fold increase in website traffic for food needs.
Photo: Symbiont/iStock/Getty Images Plus
Use that app in Germany? No Waze!
The German government has amended its road traffic regulations to outlaw apps that alert drivers to speed cameras. The law makes it clear that any app used for traffic-monitoring alerts is forbidden, whether it runs on a phone, tablet or a GPS navigation system. Violating the traffic laws and using speed camera apps inside a car could result in a fine of up to €75 (about $83). Both Garmin and TomTom have emailed registered users alerting them to the news.
Photo: Geoffrey Blewitt/Debra Vigil
Making the most of GPS data
University of Nevada 2020 Outstanding Researcher Geoffrey Blewitt has made the most of GPS data to study changes in Earth’s crust, from the Ice Age to today. Nevada Today outlines his significant discoveries, including that GPS data may hold a key to detecting dark matter. Other discoveries: Nevada is the fastest growing state, geologically speaking, as it spreads apart. Drought in the western U.S. is causing the Sierra Nevada to lift, and the melting of ice sheets in Greenland is changing the shape of Earth.
Photo: iStock/Getty Images Plus/Getty Images
Koala care
Drones equipped with FLIR thermal-imaging cameras helped save koalas injured in this summer’s Australia bushfires. In a search-and-rescue operation, Victoria wildlife experts and police used DJI Mavic 2 Enterprise Dual drones to scan the forest for injured koalas, many found clinging to scorched eucalyptus trees. The images were relayed to a ground station in a nearby van for closer inspection. When a koala was located, the experts stepped in to assess the animal, and if needed, provide healthcare and relocate it. The team used cherry pickers to retrieve the little animals.
Septentrio’s mosaic-T is built specifically for resilient and precise time and frequency synchronization under challenging conditions. (Photo: Septentrio)
Septentrio has launched the mosaic-T GPS/GNSS receiver module, built specifically for resilient and precise time and frequency synchronization under challenging conditions.
According to the company, its multi-frequency, multi-constellation GNSS technology — together with AIM+ Advanced Interference Mitigation algorithms — allows mosaic-T to achieve maximal availability even in the presence of GNSS jamming or spoofing. This compact surface-mount module is designed for automated assembly and high-volume production.
“We are excited to expand our mosaic GNSS module family with mosaic-T, which will provide critical infrastructure and mission-critical PNT applications with accurate, reliable and resilient timing solutions,” said Francois Freulon, head of product management at Septentrio.
Septentrio mosaic-T delivers timing with nanosecond-level accuracy and has additional inputs for an external high-accuracy clock, the company added.
Septentrio, headquartered in Leuven, Belgium, designs and manufactures multi-frequency multi-constellation GPS/GNSS positioning technology for demanding applications.
Mitch Narins is the principal consultant and owner of Strategic Synergies LLC, a technical and management consulting firm that he formed after retiring following over four decades of U.S. government service. He worked at the Federal Communications Commission as an acquisition engineer for the Field Operation Bureau; supported the U.S. Navy and U.S. Marine Corps as branch chief for Data Terminal Systems and Electronic Warfare Systems; and served more than 26 years at the Federal Aviation Administration as a program manager, systems engineer, and finally as the chief systems engineer for navigation.
At the FAA, he was integrated into all aspects of aviation sector position, navigation and time systems engineering, standards development, and enterprise architecture efforts in support of the National Airspace System and the Next Generation Air Transportation System (NextGen).
Narins is a recognized position, navigation, and timing (PNT) expert, who has published numerous articles and delivered many papers at conferences and seminars worldwide. He is a Certified Information Systems Security Professional (CISSP), a Fellow of the Royal Institute of Navigation, an active member of the Institute of Navigation (ION), and a member of RTCA, RTCM, and SAE Standards Committees. He is a recipient of ION’s Norman P. Hays Award and the International Loran Association’s President’s Award and Medal of Merit.
Stuart Riley
Stuart Riley is vice president of GNSS technology responsible for GNSS signal processing and products for several Trimble business areas. In this role, he is responsible for the core GNSS technology from signal reception through to the measurement engine that is used in all Trimble GNSS precision products. He oversees GNSS product development for Trimble’s GNSS Real-time Networks, Geospatial, Heavy Civil Construction and InTech OEM Divisions.
Beginning his career at Trimble in 1995, Stuart has worked on GNSS receiver development in various engineering roles, in addition to holding several management roles. He holds several patents filed and pending in the field of GNSS and is often a guest speaker at international conferences.
His research interests include improving GNSS performance in harsh environments, and taking measurements from additional sensors along with optimizing the GNSS receiver architecture, especially for the newer GNSS signals BeiDou, Galileo, IRNSS, QZSS and next-generation GPS and GLONASS signals.
Riley has an electronic engineering Ph.D. in the field of GNSS from the University of Leeds in England. After he graduated, he was a research fellow at the university on a European Space Agency-funded project to develop a prototype GNSS receiver for space applications.
Altitude Angel and Inmarsat are collaborating to develop and deliver advanced flight tracking and management capability for UAVs.
According to the companies, they will build on Altitude Angel’s GuardianUTM platform to jointly develop a “pop-up UTM” capability that can be deployed anywhere it is required to manage beyond visual line of sight UAV flights, without the need for ground-based communications infrastructure. By utilizing Inmarsat’s global network of satellites and leveraging its experience in air traffic management communications, Altitude Angel’s pop-up UTM can be accessed rapidly and deployed worldwide, the companies added.
The pop-up UTM will be developed initially to address the unmanned traffic management needs of blue light emergency services and first responders who need aerial surveillance rapidly with little notice. The companies plan to release a commercial, industry-focused product soon after. Through this technology, emergency services will be able to remotely manage UAVs, increasing their range of safe operations in mixed airspace of manned and unmanned vehicles.
“The ability to almost instantly ‘pop-up’ safe, secure and fully operational UTM platforms in any environment, at any time, will give first responders, blue light services and aid organizations a valuable tool that could save countless lives,” said Phil Binks, head of air traffic management at Altitude Angel. “Altitude Angel and Inmarsat, in developing ‘pop-up UTM,’ will be able to bring connectivity, clarity and automated air traffic control services for UAVs in even the most challenging of circumstances.”
Altitude Angel is an aviation technology company delivering solutions which enable the safer integration and use of fully automated drones into airspace. Inmarsat is a British satellite telecommunications company, offering global mobile services.
Testing the full operational performance of GPS/inertial systems usually requires expensive and time-consuming field testing on an appropriate moving vehicle platform. Spirent’s SimINERTIAL system emulates inertial sensor outputs while simultaneously simulating GPS RF signals. This enables controlled, repeatable testing of integrated GPS and inertial units, reducing the need for field trials.
SimINERTIAL is housed in a PC platform equipped with the appropriate data interface card. The simulated motion data is streamed from Spirent’s state-of-the art SimGEN application via Ethernet to SimINERTIAL, which translates this simulated motion data into representative real-time data streams at the data rate and with the data format appropriate to the unit being tested.
SimINERTIAL is equipped with fully user-configurable sensor error modeling and supports a range of popular inertial formats. SimINERTIAL architecture is also available in configurations to support transfer alignment and multiple sensor architectures. SimINERTIAL solutions can also be equipped to deliver a barometric altitude output via a MIL-STD-1553B card installed in the SimINERTIAL controller PC.
Honeywell, under a contract with Lockheed Martin, will supply guidance and navigation systems for NASA’s upcoming Artemis missions, which will fly humans to the moon for the first time since 1972.
The companies are supplying key components to NASA’s Orion spacecraft fleet for the Artemis missions. Components include the barometric altimeter, the inertial measurement system, and the GPS receiver.
Honeywell will provide 14 product types for Artemis missions III through V, including both hardware and software solutions, to support NASA’s lunar missions. NASA awarded Lockheed Martin a long-term, multibillion-dollar production contract for the Orion spacecraft, aimed to meet the space agency’s anticipated needs into the 2030s.
Working in collaboration with the Orion team over the next decade, Honeywell will support Lockheed Martin and its partners through the development and production of essential guidance and navigation systems, command data handling, and display and control products. The focus of the missions is to conduct science and learn lessons that will help take humans to Mars.
Honeywell will supply the following types of technology for the Artemis missions:
First Orion Spacecraft: In this March 30 photo, Orion I is moved to the Final Assembly and Systems Test cell at Kennedy Space Center. The spacecraft returned from Ohio after a successful series of environmental tests at Glenn Research Center’s Plum Brook Station. (Photo: NASA)
• Guidance and Navigation Systems. Key navigation and guidance solutions, including the barometric altimeter, which tracks the altitude of the Orion capsule in Earth’s atmosphere, as well as the inertial measurement system (INS) and GPS receiver, which track the position and movements of the capsule.
• Command Data Handling. Several data-handling products, including the vehicle management computer, which acts as the central computing platform supporting flight and vehicle control, as well as spacecraft communication functions.
• Displays and Controls. Three display units and struts, seven control panels, and two hand controllers used inside the spacecraft to help astronauts in the Orion capsule monitor and control the vehicle.
• Core Flight Software. Includes the integrated modular avionics software, a key system responsible for supporting maintenance functions sharing flight data information.
The contract to supply key components of the Orion crew module and service module is being managed and performed out of Honeywell’s facility in Clearwater, Florida. Work is also being conducted at the company’s facilities in Glendale, Arizona, and Puerto Rico.
Honeywell was part of NASA’s previous crewed space missions, including those that took humans to the moon.
The basic ArduSimple RTK kit includes Sapcorda SAPA. (Image: ArduSimple)
ArduSimple has integrated Sapcorda’s SAPA Premium Service into its new simpleRTK2B+SSR GNSS receiver. The user-friendly integration based on SSR technology allows plug-and-play real-time kinematic (RTK) without the need for a base station. Users can connect the receiver to their PC or tablet to achieve centimeter-level accuracy.
Based in Berlin, ArduSimple develops user-friendly, affordable RTK receivers and tools for evaluation of multi-band GNSS technology.
The simpleSSR basic starter kit includes a multi-band RTK receiver, SSR receiver, one year unlimited data package and one year SAPA Premium license. Accurate position is available via USB, UART and I2C, as well as via Bluetooth, Wi-Fi or RS232 with the corresponding accessory.
“ArduSimple’s vision is to make RTK technology affordable and accessible to everyone. Removing the hassle of the base station is a key step towards it,” said Josep Olivart, Senior Consultant at ArduSimple. “The decision to select Sapcorda was clear: best in class service performance at affordable mass market price, supported by a highly skilled and committed team.”
Sapcorda provides GNSS augmentation services for the internet of things (IoT), automotive, and industrial applications across the United States and Europe including up to 20 kilometers off coastlines, delivered with low-bandwidth data over internet and satellite, and providing uniform, high-integrity instantaneous sub-decimeter positioning on a continental scale with enterprise-level service availability.
“Sapcorda aims to establish GNSS precise positioning in mass-market applications and ArduSimple is an ideal partner for the integration of our services into a high precision GNSS hardware,” said Botho Graf zu Eulenburg, managing director at Sapcorda. “The combination of our advanced services with ArduSimple’s new platform provides an easy to use and affordable high precision solution to everyone.”
In early February, TopXGun Robotics — based in Shanghai, China — started to use 10L drones for spraying disinfectant to help fight COVID-19. Six volunteers provided free disinfectant spraying service to more than 10 large companies, factories and universities, covering about 800,000 square meters in the Shanghai area.
TopXGun outlined the advantage drones have over manual spraying.
Safety. Using a UAV means no wokers inhale disinfectant. Pilots stay distant, and no one enters a sprayed building until it is safe.
Effectiveness. By spraying from above, drones can reach difficult locations, such as a landfill or a roof. Reportedly, the spray can kill the virus in the air.
Cost-savings. Only one pilot and one assistant are required to operate, reducing labor costs.
The 10L drones are equipped with Septentrio’s high-precision GNSS, which provides robust anti-spoofing and anti-jamming capabilities, important in urban areas.
Before spraying, TopXGun used a XC-05 vertical-takeoff-and-landing (VTOL) drone to survey the area. With reliable real-time kinematic (RTK) technology from the Septentrio receiver, the survey drone accurately generated a map of the operation area, marking the flight route. In this way, the spraying drone could fly and spray automatically in most cases. If the operation area is in an irregular shape or has obstacles in the middle — such as poles or trees — the mapping pilot can use markers to indicate these obstacles so the spraying drone will avoid it.
An international survey and analysis on GNSS interference detection and localization systems reveal the path forward for transportation and other critical infrastructure.
By José Luis Madrid-Cobos and Ana Bodero-Alonso, ENAIRE
Ignacio Fernández-Hernández and Eric Châtre, EC
Andriy Konovaltsev, DLR, and Christopher Hegarty, MITRE
An ENAIRE GNSS RFI monitor close to the Madrid-Barajas Airport in Madrid, Spain. (Photo: ENAIRE)
The received power of GPS and Galileo navigation signals at the antenna output of a user receiver is typically extremely small, from approximately –165 up to –150 dBW, which makes them inherently vulnerable to radio-frequency interference (RFI) caused by the emissions of other radio systems. This interference is often unintentional, such as from malfunctioning or spurious emission from a transmitter in the vicinity of the GNSS receiver.
However, we have seen numerous reports about the deliberate jamming of GNSS signals. The most frequent examples of such interference reports are caused by so-called personal privacy devices (PPDs) — low-power GNSS jammers used to locally disable the operation of GNSS receivers. Although the use of PPDs is illegal, they can be easily acquired on the internet. A $10 jammer with 100 mW of transmitter power is enough to degrade performance or disrupt GNSS receivers in a range of 10–100 meters. In the past decade, more complex and powerful jammers have also become available, along with spoofers — devices that create GNSS-like signals that fool receivers to provide false location or time solutions. A $100 software-defined radio bought online can be used as a spoofer.
ENAIRE (the Spanish air navigation service provider) conducted an international survey and associated analysis of GNSS RFI detection and localization systems. The survey was part of the EU–U.S. Working Group C Sept. 2017–Sept. 2019 Work Plan, with contributions of the European Commission (DG DEFIS), the German Aerospace Center (DLR), the U.S. Federal Aviation Administration (FAA), Eurocontrol, the MITRE Corporation and Stanford University. Working Group C promotes cooperation between the U.S. and EU on design and development of the next generation of civil satellite-based navigation and timing systems. The survey was conducted within the Resilience Subgroup focused on counteractions required in view of growing concerns over jamming and spoofing threats.
Manufacturers and Users
The survey was provided in two versions: one targeted to manufacturers and another to the users of interference detection systems. The two surveys were implemented online July 12–Oct. 26, 2018. There were 23 responses: 11 from manufacturers and 12 from users (see Acknowledgments below for companies that participated). Regarding the manufacturers’ responses, the nine surveyed companies represent about 50% of the market of RFI monitoring products available in 2018.
RFI Equipment Used
We present here the aggregated results of the RFI equipment manufactured and used by the participating entities.
Frequency Bands and Signals. The L1/E1 band is covered by all of the manufacturers’ and users’ surveyed products. L5/E5a and other bands are monitored in only 42% of the cases, or even less. Most RFI systems demodulate or analyze the GPS L1 C/A signal. Only 8% and 17% of users analyze GPS L5 and Galileo E5a, respectively.
Capabilities. 55% of the industry, and 25% of the users’ surveyed products, provide RFI localization capabilities, while 45% of the industry, and only 33% of the users’ surveyed products, detect some type of spoofing.
Power and Antenna Gain. Most of the systems achieve a sensitivity better than or equal to –120 dBm, meeting the International Civil Aviation Organization requirement for GPS and SBAS L1 airborne receivers to withstand interference (–120.5 dBm CW, in-band) after steady-state navigation has been established. The gain of antennas used in RFI detection systems ranges from 2 dBi up to 45 dBi.
Real-Time Bandwidth. The maximum real-time monitored bandwidth of the surveyed products ranges from 16 MHz up to 60 MHz in L1. Most of the products monitor a 20-MHz bandwidth (similar to the GPS L1 C/A reference bandwidth for pre-GPS III satellites, which is 20.46 MHz).
Spectrum Refresh Time. The time needed by the RFI detector to capture and process a plot of the RF spectrum in a specific band to look for interference signals ranges from 1 microsecond to 2 seconds.
Jamming Detection Techniques. The most widespread jamming detection technique is RF power monitoring (45% industry, 92% users), followed by digital beamforming (CRPAs), carrier-to-noise-density ratio (C/N0) monitoring and spectral analysis/transforms (see Figure 1). Note that RF power monitoring and automatic gain control (AGC) monitoring are in essence the same detection technique: AGC voltage levels — after calibration with a reference RF generator — can be converted into RF input power levels.
Figure 1a. Jamming detection techniques used by industry. (Chart: RFI survey)Figure 1b. Jamming detection techniques of users. (Chart: RFI survey)
Spoofing Detection Techniques. The most widespread spoofing detection techniques are PVTF consistency monitoring (industry products, 27%) and correlation peak monitoring (users, 25%), followed by digital beamforming (CRPAs), C/N0 monitoring and spectral analysis/transforms (see Figure 2).
Figure 2a. Spoofing detection techniques used by industry. (Chart: RFI survey)Figure 2b. Spoofing detection techniques of users.(Chart: RFI survey)
Localization. The most widespread RFI localization technique is direction/angle of arrival (DOA/AOA): 55% in industry products and 25% in users’ systems. AOA techniques used are correlative interferometer (phase-difference), Watson-Watt (amplitude-difference) and array signal processing. The AOA accuracy of surveyed products ranges from ±3° to ±10°.
Event Recording. For an interference event, most products record the time stamp, received power, central frequency, frequency spectrum, the spectrogram (frequency versus time plot) and the jammer type. Only 8% of surveyed users perform spoofing event recording (see Figure 3). 92% of users record RFI/spoofing events; half also report them to their national spectrum administration. Users have from one to 11 jammer detectors. Only four users have been registered with spoofing detectors, each using one.
Figure 3a. RFI events recording/database used by industry. Jammer classifications: Class I — continuous wave signal; Class II — chirp signal with one saw-tooth function; Class III — chirp signal with multi saw-tooth functions; Class IV — chirp signal with frequency bursts. (Chart: RFI survey)Figure 3b. RFI events recording/database of users. Jammer classifications: Class I — continuous wave signal; Class II — chirp signal with one saw-tooth function; Class III — chirp signal with multi saw-tooth functions; Class IV — chirp signal with frequency bursts. (Chart: RFI survey)
Event Sharing. 75% of surveyed users are willing to collaborate in the creation of an international RFI and spoofing events common database, but the remaining 25% explicitly do not want to share their databases.
Future RFI Monitoring Equipment
Based on the analysis of the aggregated results from the survey, we identified some recommendations for improving RFI monitoring:
L5/E5a band. To be ready for introduction of the L5/E5a band into aviation operational use (expected by 2025), it is suggested that aviation organizations increase efforts to monitor and analyze the RFI situation in the L5/E5a band.
Spoofing detection. National organizations in charge of critical infrastructures should increase their efforts to detect spoofing (at least at the same level as jamming detection). Multi-constellation and dual-frequency spoofing detection should be promoted (not only L1/E1 spoofing).
GNSS RFI monitoring with enough bandwidth: The maximum real-time monitored bandwidth of the surveyed products ranges from 16 MHz to 60 MHz, while most of the products monitor only a 20-MHz bandwidth. The receiver reference bandwidth for E1 is 24.552 MHz, while for L1 GPS III it is 30.69 MHz. U.S.-EU GNSS RFI detection systems for critical infrastructures should be designed to monitor at least 31 MHz of bandwidth in the L1/E1 band, with 50 MHz recommended to cope with typical –3 dB bandwidth of pre-low-noise-amplifier (LNA) GNSS L1/E1 receiver filter. The same rule should be applied to other GNSS bands. Even more bandwidth for monitoring could be needed to cope with rare interferers, such as a high-power source, whether intentional or unintentional, radiating in near-band L1/E1 but not in the passband frequencies, bypassing the rejection of the receiver’s filters and degrading the GNSS signal reception.
Air Navigation
In the EU, performance-based navigation (PBN) will become the norm in all flight phases, and GNSS (with or without SBAS) will be the main position source, by June 2030. A similar scenario is being developed in the U.S. Conventional procedures and ground-based navigation aids will be used only in contingency situations. GNSS RFI can degrade the current GBAS CAT I (GAST-C) service in airports and could jeopardize safe operation of upcoming GBAS CAT II-III (GAST-D) service. GNSS also is the key enabler for ADS-B.
Therefore, it is critical for air transportation to improve its capability to detect radio frequency interference to GNSS and mitigate its harmful effects, both on the ground and in the air.
Ground Detection and Localization. These systems should be installed at and around all airports. ENAIRE has recently deployed an AOA RFI detection and localization system around the Madrid airport called DYLEMA. It consists of nine AOA RFI and spoofing detectors, two spoofing-only detectors, an IP communication network and a GNSS monitoring center operated 24/7. From this center, ENAIRE will report RFI events to the Spanish spectrum agency. Similar systems will be deployed in other large Spanish airports in the next years. In small airports, ENAIRE is deploying single-unit RFI detectors (one detector per airport, currently without the AOA feature). These systems are complemented by handheld and airborne spectrum analyzers equipped with directional antennas and RFI AOA features, used if an RFI event of high power or duration takes place.
Airborne Detection and Localization. Several initiatives are under study or initial design for airborne detection and localization systems, using current avionics receivers with no hardware modification or new hardware such as additional antennas in the aircraft. Future airborne RFI detection systems should include indoor coverage to detect jammers and spoofers in the airplane itself. EUROCONTROL is leading one of these initiatives using ADS-B. Given a reliable ADS-B data feed with suitable coverage information, a search algorithm could scan for outages. If the data is dense enough, it is possible to locate the source, even if the GNSS airborne antenna is omnidirectional with no AOA features. Another commercial initiative, GATEMAN, uses new GNSS antennas and components to provide AOA detection and localization features.
UAV-Embedded Detection and Localization. Detection and localization systems embedded in UAVs are not widely commercially available, but they will be useful to complement fixed or ground RFI monitoring systems, especially to detect fast moving mobile jammers and spoofers. A jammer moving at high speed could be found by a fixed detector, trigger the UAV take-off (collocated with the detector or close to it), and start tracking the target. If equipped with a camera, it could identify the vehicle carrying the jammer or spoofer. Such a system has to function in GNSS-denied scenarios, and needs to use sensors other than GNSS. Stanford University has recently developed a prototype of such a system.
Other Sectors
Shipping. RFI detection systems should be installed at and around harbors, where positioning requirements are the most stringent. Mobile AOA detectors can be installed in vessels. A DLR experiment integrated its GALANT GNSS RFI detector on a ship sailing from Spain to South Korea and back.
Railroads. Detection and localization systems should be installed at train stations and main railway junctions or switches. It is possible to install mobile detectors in trains to detect jammers inside the train apart from outdoor coverage to detect jammers outside the train.
Roads. Most PPD jammers in use are on roadways. Jammers not only jeopardize aviation and timing systems; they can jeopardize the safety of the coming autonomous road vehicles. We strongly recommend that police and road surveillance systems include jammers and spoofers as a daily target, to detect, localize and punish their users.
Supporting proposals include installing fixed detectors at tollbooths, road gantries or other points near roads; and using mobile detectors — for example, on police vehicles for locating a car that carries a jammer. Public transport services with enough vehicles (such as taxis or busses) could also detect RFI.
Smartphone Platforms. Initiatives are using smartphone crowdsourcing platforms to detect interference based on C/N0 or AGC measurements. At this time, only prototype apps for Android phones are available. The Apple iOS does not allow access to GNSS raw data. Android applications can include localization capabilities based on Time Difference Of Arrival (TDOA) or Power Difference Of Arrival (PDOA). Having a detection system in a mass-market product would create millions of detectors around the world. Reward programs by national or local administrations would encourage use of the app. User consent to obtain the data will be needed.
Space-Based Detection. Space-based detection is feasible to find medium- to high-power jammers and spoofers. Several projects have performed simulations, such as the ground to space threat simulator from Qascom and Spirent Communications. In this project, simulations achieved an error of less than 1.5 km using a medium-Earth-orbit (MEO) satellite as the RFI sensor and a 20-dBm static jammer on Earth, with 15 minutes of observation time. Also, an experimental program from the International Space Station has demonstrated that RFI can be detected from low Earth orbit.
The main issue of such detection systems is the cost to deploy all the satellites needed to have a global coverage with a low response time (2 hours or less to detect RFI). The performance of a space-based RFI system is better when using a LEO constellation (as, compared to an MEO system, it detects RFI with a lower transmitted power). One such system by HawkEye 360 was deployed in 2019. The company plans to operate a fleet of 30 satellites in LEO orbit, enabling it to gather new signals from any point on the planet within 30 to 45 minutes.
General Recommendations
Increased Effort Needed. Public administrations and transport service providers should increase their efforts to deploy GNSS RFI detection and localization systems. In parallel, governments should punish individuals or organizations using jammers or other types of illegal transmitters or emissions. Jamming and spoofing is illegal in the EU and the U.S. An increased RFI monitoring effort should be coordinated at the national or regional level to find synergies and avoid duplications.
Planned Interference. Government agencies, including national radiofrequency spectrum agencies, should coordinate nationally and internationally with air, rail, road, maritime and other critical infrastructure entities before any planned intentional interference is conducted, such as military exercises or protection of special events from potential terrorist attack. This coordination includes an analysis of the estimated area and airspace volume affected by the RFI, the associated notification to the GNSS users before and during the RFI radiation period (such as a NOTAM, Notice to Airmen), as well as the indication to use established alternative procedures (non-GNSS).
A Common Database. The creation of an international common database of GNSS RFI events could boost the fight against GNSS RFI. A specific action could define a standard of the RFI data format to be registered and shared in an international database, including a possible RFI classification (also defined and agreed to as part of the standard). One initiative related to the creation of an international GNSS RFI threats database was proposed by the EU-funded STRIKE 3 project in 2017.
Acknowledgments
The work presented in this report has been performed under the U.S.-EU Agreement on GPS-Galileo Cooperation, Working Group C, Resiliency Subgroup. The authors thank the participants of the Working Group and the Resiliency Subgroup — in particular, Eurocontrol and the FAA for distribution of the survey in the EU and the U.S., respectively. The authors also thank the organizations that participated in the survey: Spirent Communications, GMV, Centum Solutions, THALES, IDS AirNav, Chronos Technology, Innovationszentrum für Telekommunikationstechnik (IZT), Collins Aerospace, German Aerospace Center (DLR), Netherlands Aerospace Centre (NLR), Deutsche Flugsicherung (DFS), Direction des Services de la Navigation Aérienne (DSNA), Polish Air Navigation Services Agency (PANSA), Belgocontrol, ENAV and ENAIRE.
José Luis Madrid-Cobos is the technical manager of GNSS interference detection and localization systems at ENAIRE, the Air Navigation Service Provider in Spain. Ana Bodero-Alonso is the head of the Satellite Navigation Department at ENAIRE. Ignacio Fernández-Hernández is responsible for Galileo high accuracy and authentication at the European Commission. Eric Châtre is the head of the GNSS Exploitation and Evolutions Sector at the European Commission. Andriy Konovaltsev is a research assistant at Institute of Communications and Navigation of the German Aerospace Center (DLR). Christopher Hegarty is a technical fellow with The MITRE Corporation.
SBG Systems renews its popular line of miniature inertial sensors with high-end functionalities and dual frequency RTK
SBG Systems has announced the third generation of its Ellipse series of miniature inertial sensors. The renewed product line benefits from a 64-bit architecture, allowing high precision signal processing.
All of the INS/GNSS devices now embed a dual-frequency, quad constellations GNSS receiver for centimetric position and higher orientation accuracy.
SBG Systems manufactures miniature high-accuracy inertial navigation systems with inertial measurement unit (IMU) design, calibration and filtering. All improvements made in the high-end lines could naturally benefit the Ellipse miniature line.
The Ellipse series includes four models.
Ellipse-A is a motion sensor
Ellipse-E provides navigation with an external GNSS receiver
Ellipse-N is a single-antenna RTK GNSS/INS
Ellipse-D is a dual-antenna RTK GNSS/INS
With its new 64-bit architecture, the third-generation Ellipse series enables the use of high-precision algorithms and technology used in high-end inertial systems such as rejection filters and FIR filtering.
All Ellipse miniature INS are now RTK-enabled without extra cost, and output raw data for post-processing. All these features are made possible in a small, robust aluminum-enclosure box version, as well as in the 17-gram OEM version.
The 17-gram OEM version of the Ellipse-D can provide drones with high-end features. Its dual antennas gives UAVs robust instant heading for take-off. Dual antenna is achievable with a very short baseline, down to 50 centimeters. Integration is enabled with ROS and PX4 drivers, full API, and free phone and email technical support.
Ellipse-D
Ellipse-D is the smallest dual-frequency, dual-antenna RTK GNSS/INS device offered.
With its dual-frequency RTK GNSS receiver, the Ellipse-D provides a centimeter positioning. Dual frequency provides more robust heading and position computation than single-frequency receivers. It also allows high performance in attitude (0.05°) and in heading (0.2°).
With its dual-antenna capability, Ellipse-D provides precise heading in a few seconds, in all dynamic conditions, and even in challenging GNSS conditions. It is also immune to magnetic disturbances. Ellipse-D is a quad-constellation receiver, simultaneously using signals from GPS, GLONASS, BeiDou and Galileo to enable navigation in challenging conditions.
Designed with high quality industrial-grade components, Ellipse inertial sensors are highly tested and calibrated in dynamic and temperature for consistent, repeatable behavior in all conditions.
Septentrio has unveiled the AsteRx-m2 Sx OEM board, which provides a GPS/GNSS receiver with always-on sub-decimeter accuracy without the need for additional correction service subscriptions.
With the AsteRx-m2 Sx, Septentrio is pioneering a novel approach to high-accuracy positioning. Its latest core GNSS technology is integrated with a sub-decimeter correction service enabling simple plug-and-play positioning solutions.
High-accuracy positioning is available directly out of the box as GNSS corrections are automatically streamed to the receiver. This significantly simplifies the receiver set-up process and eliminates the hassle of corrections service subscription and maintenance.
“This product marks a new step for GNSS technology towards convenience and ease-of-use,” said Danilo Sabbatini, product manager at Septentrio. “By integrating the correction service directly into the GNSS receiver, we are removing the hassle of positioning service set-up and maintenance from the user. This means faster set-up times for our customers and worry-free, always-on high-accuracy positioning throughout the receiver lifetime.”
The AsteRx-m2 Sx is an efficient positioning solution for small robots, aerial drones and automation applications. Its optimized size, weight and power (SWaP) means longer operation on a single battery charge and better value in the field, according to Septentrio.
Advanced anti-jamming technology AIM+ ensures robust and reliable operation in challenging environments, even in the presence of RF interference.
Septentrio is offering a free GNSS corrections webinar on July 8 at 5 p.m. CEST/ 8 p.m. PST.
HoverGames Challenge 2: Help Drones Help Others is the second installment of NXP’s challenge-based, interactive coding competition. It encourages developers to create drone and rover solutions for frontline support during pandemics.
A carbon-fiber quadcopter frame is included in the developer’s kit. (Photo: NXP)
Participants will leverage NXP’s broad portfolio of automotive, industrial and IoT technologies for system control, networking, security and motor control to create solutions that can make a difference in pandemic response.
The first HoverGames took place in the summer of 2019, and was centered around firefighter response. Read about it here.
The collateral effects of pandemics leave citizens with difficult challenges to overcome. A lack of mobility, social isolation and lack of access to goods and services can be physically and psychologically devastating.
HoverGames Challenge 2 will inspire participants to develop pioneering ways to use drones to help healthcare and frontline workers overcome these barriers. The competition encourages contestants to consider the full scope of the difficulties facing society during a pandemic, apply new learning, and work cooperatively through the development of open-source code and community-tested projects to create solutions that help society prepare for future challenges.
Deadline for application is July 31. The competition closes Nov. 30, and winners will be announced in December.
Drone Developer Kit. The hardware and software of this year’s developer kit remains open, flexible and modular. The flight management unit (RDDRONE-FMUK44FMU) includes professional, automotive and industrial-grade components enabled by the PX4 flight stack. PX4 is a large commercially deployed open source flight stack and supports contemporary airframe architectures including vertical-takeoff-and-landing (VTOL) aircraft, multicopter and rover profile.
The kit also includes a strong, rigid, lightweight carbon-fiber quadcopter frame with platform, mounting rails, landing gear, motor controllers, motors and props as well as telemetry radio and remote-control radio.
This year’s kit will contain a bonus extension component, the NavQ, an i.MX8M Mini Vision development board.
Projects and lessons learned are transferable to real-world enterprise and commercial applications thanks to Auterion, the company that builds the enterprise distribution of PX4 for the commercial drone market.
“The current pandemic has exposed our vulnerability to disease and the general structural breakdown that can occur during a crisis,” said Iain Galloway, drone program lead, Systems Innovation, NXP. “But we don’t have to feel powerless in its wake. We can harness technology to make a difference. We invite you to leverage a complete functional system of hardware and software for drone and rover development and to share your creative solutions.”
