“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.
The Mayflower autonomous ship. (Photo: Tom Barnes for IBM)
No pilgrims needed aboard
The autonomous Mayflower trimaran launched Sept. 16 from Plymouth, England, on a mission to traverse oceans and gather vital environmental data, guided by Veripos GNSS and inertial measurement units from iXBlue and Silicon Sensing. Ocean research non-profit ProMare joined with IBM on the Mayflower Autonomous Ship — an artificial intelligence and solar-powered marine research vessel, two years in the making. Designed to provide a safe, flexible and cost-effective way of gathering data about the ocean, the Mayflower works in tandem with scientists and other autonomous vessels to help understand critical issues such as global warming, micro-plastic pollution and marine mammal conservation.
Photo: nycshooter/E+/Getty Images
A Guardian on the Bus
A school bus app aims to help monitor students’ exposure to others. App developer CalAmp’s Bus Guardian uses the same technology from its Here Comes the Bus app with an added layer of contact tracing. With Bus Guardian, parents can opt-in and invite their student to check on and off the bus. It uses telematics to convert a school bus into a contact tracing solution. Schools can deliver instant and actionable reports of ridership based on contact tracing — important if a student or driver becomes ill.
The Erta Ale volcano. (Photo: guenterguni/E+/Getty Image)
Rift splits Africa in two…eventually
GPS data is refining predictions of when Africa will split into two continents. In 5 to 10 million years , the Gulf of Aden and the Red Sea will flood the Afar region and the East African Rift Valley, creating a new ocean and continent. GPS data is precisely measuring ground movement as three tectonic plates peel away from each other at a triple junction, said Ken Macdonald, professor emeritus, University of California, Santa Barbara. “With GPS measurements, you can measure rates of movement down to a few millimeters per year,” Macdonald said. “As we get more and more measurements from GPS, we can get a much greater sense of what’s going on.”
Image: Rosie Bisset
Dangerous Retreat
In a first for mapping glacier retreat in the Peruvian Andes, the CASCADA UK + Peru glacier project used a drone fitted with a FLIR Vue Pro R 640 thermal-imaging camera for insight. A thicker layer acts as insulation. Researcher Rosie Bisset, Edinburgh University, is building a mosaic of the images to better understand how surface cover is affecting the melt rate. The glaciers have shrunk by about 30% in the past few decades, and pose a serious threat to the water supply of in the Ancash region.
A roundup of recent products in the GNSS and inertial positioning industry from the October 2020 issue of GPS World magazine.
OEM
GNSS antennas
Active and passive
Photo: 2J Antennas
A new range of high-precision GNSS antennas is designed for superior accuracy and reliability, with both active external antennas and passive internal ceramic antennas. The antennas provide precision, high bandwidth, and an advanced signal design for GPS, GLONASS, BeiDou, Galileo, IRNSS and SBAS navigation. They are designed for demanding GPS applications that require centimeter-level accuracy by combining precise point positioning (PPP) of L1 and L2 or by combining L1 and L5 bands with real-time kinematic (RTK) satellite navigation. Applications include aviation safety, UAVs, transportation, autonomous vehicles, agriculture and land and hydrographic surveys.
The HC976 housed and HC976E embedded helical antennas are light and compact, suitable for applications ranging from autonomous navigation to GNSS timing. Both models support GPS/QZSS-L1/L2/L6, GLONASS-G1/G2, Galileo-E1/E6, and BeiDou-B1/B3 frequency bands as well as regional augmentation systems and high-precision L-band correction services. The HC976 and HC976E support QZSS-L6, Galileo-E6 and BeiDou-B3. The HC976 is 44 x 62 millimeters and weighs 42 grams. It features a precision-tuned helical element that provides an excellent axial ratio and operates without the requirement of a ground plane, making it suitable for a wide variety of high-precision applications.
The mosaic-T GPS/GNSS receiver module is built for resilient and precise time and frequency synchronization under challenging conditions. Its multi-frequency, multi-constellation GNSS technology with AIM+ Advanced Interference Mitigation algorithms allows mosaic-T to achieve maximal availability even in the presence of GNSS jamming or spoofing. The compact surface-mount module is designed for automated assembly and high-volume production. Mosaic-T delivers timing and has additional inputs for an external high-accuracy clock.
The HGuide n380 inertial navigation system (INS) communicates an object’s position, orientation and velocity when GNSS signals are unavailable. It is built to withstand harsh environments in the air, on land or at sea. It is designed to meet the need for a small, high-performance INS for 3D mapping, surveying and other applications where space is at a premium. It is composed of Honeywell’s HGuide i300 inertial measurement unit (IMU), a GNSS receiver and Honeywell’s proprietary sensor-fusion software, which is based on the algorithms used for navigation on millions of aircraft every day.
The LC29D eMobility module is a sub-meter-level GNSS module that integrates dead-reckoning and multi-band (L1/L5) real-time kinematic (RTK) algorithm technologies with fast convergence times and reliable performance. The module supports dual-band GNSS raw data output and integrates a 6-axis IMU sensor to deliver high-accuracy positioning performance in seconds. Based on the Broadcom BCM47758 GNSS chip, the LC29D can concurrently receive signals from up to six constellations (GPS, GLONASS, Galileo, IRNSS, BeiDou and QZSS), which maximizes the availability of sub-meter level accuracy. It offers a position update rate of up to 30 Hz (fusion output), enabling dynamic applications like shared emobility, delivery robots and precision agriculture to receive position information with lower latency.
The AlphaUni 300/900/1300 lidar series provides light, versatile long-range laser scanner systems for the high-end market. The series provides optimized data sets powered by advanced GNSS/inertial navigation system (INS) sensors and long-range Riegl scanners. AlphaUni’s design adapts to a variety of applications and can be installed on a variety of platforms, including multi-rotor UAV, fixed-wing vertical-takeoff-and-landing (VTOL) UAV, vehicles, rail trolleys, backpacks, boats and more.
The F100 GNSS receiver, an upgrade to the F90, is designed to meet surveyors’ demands for high field performance, flexibility and cost-effectiveness. It tracks multiple constellations (GPS, GLONASS, Galileo, BeiDou) and can maximize the acquisition and tracking process with all-in-view GNSS frequencies. The 1.45-inch color LCD display is a multi-touch capacitive screen. The F100 has 32GB of internal memory. Its integrated second-generation web user interface control is compatible with all devices and browsers.
Eos Tools Pro for Windows 10 implements powerful new features that enable users to exploit all four global GNSS constellations and a state-of-the-art NTRIP client to access real-time kinematic (RTK) bases and RTK networks all over the world via NTRIP, Direct IP and wireless radios. It provides the latest support for Windows Geolocation and other features by Microsoft to allow customers to use high-accuracy locations directly in their apps, such as RTK network/RTK base connectivity, support for all new Beidou and Galileo satellites, and SafeRTK functionality for areas with marginal cellular coverage. Features for app developers are also available.
The BB4 UAV high-end multi-rotor drone is optimized for the AlphaUni 300/900/1300 lidar series. Its modular design simplifies deployment in just a few minutes. Its 7-kg payload breaks the capacity barrier, and its more than 45 minutes of flight time increases the airborne lidar survey ability. The redundant CHCNAV and DJI inertial measurement unit (IMU) and GNSS unit provide reliable centimeter real-time kinematic (RTK) positioning, meeting the demand for high accuracy in the geospatial and mapping industries.
The ADNET autonomous delivery network is a technical solution to transport medical samples and quarantine materials in cities. It uses an RA3 drone, unmanned vehicle RG1 and RH1 hub station to deliver medical supplies without relying on manpower, alleviating time spent in traffic and the cost of traditional delivery. Supplies retrieved by the RG1 vehicle are delivered to the RH1 hub for sorting and redirecting, while the drone transfers the supplies between hubs. The RG1 then delivers goods on the receiving end. The system was demonstrated during China’s COVID-19 epidemic prevention and control period, reducing contact between samples and personnel.
The VECTOR-400 is a compact autopilot designed specifically for unmanned aerial vehicles. It features a robust enclosure and a military-grade connector for harsh environments (MIL-STD 810 and MIL-STD 461). Features enable sea-skimming (extremely low-level flight) and the capability to navigate without GNSS. The VECTOR-400 is able to continue a mission in case of individual sensor failure and when subject to jamming, maintaining accurate estimations of attitude and position. Advanced algorithms provide stall prevention and the ability to carry out an efficient gliding maneuver in case of engine failure. Its air data attitude and heading reference system and inertial navigation system provide high-precision attitude information and reliable navigation under demanding circumstances.
The F700 DroneHunter UAS is a radar-based autonomous interceptor drone for tracking and stopping dangerous drones. Its flexible undercarriage offers interchangeable counter measures for single, multiple or swarm-based threats, while its lightweight carbon-fiber frame enables quick speed and response. The F700 can carry multiple types of anti-drone countermeasures and deploy them in real time, based on which dynamic threat is detected miles beyond the protected area. The pogo pins and payload snaps of the undercarriage are integrated with artificial intelligence for firing and flight software.
Drones equipped with cost-intensive cameras and sensors need protection in the event of a flight-system failure. A parachute system for the DJI M210 drone is now available. Both commercial and emergency response operations are using the M210; its design and flexibility allow for a variety of industry-specific applications. The DRS-M210 parachute system is designed to ensure high pendulum and wind stability, allowing a damaged drone to land safely with minimal impact.
Altitude indicator (AI) or directional gyro (DG) replacement
Photo: uAvionix
The AV-30-C aircraft panel display adds a suite of in-flight information for pilots, including GPS navigational data, a probeless angle of attack indicator, baro-corrected altitude, indicated/vertical/true airspeed, non-slaved heading, bus voltage and G load. It is designed to fit into any aircraft with a 3 1/8-inch round instrument slot without cutting or modifying the panel. It is authorized for FAR Part 23 Class 1 and Class 2 aircraft listed on the AV-30-C Approved Model List (AML), containing 635 aircraft models including Cessna, Piper, Beechcraft, American Champion, Maule, Boeing, Swift, Mooney, Aviat and others.
The R3S series of rugged, EN-50155-certified fanless vehicle/rail computers is equipped with a u-blox NEO-M8N module, which receives GPS, Galileo, GLONASS and BeiDou with the default set for GPS + GLONASS dual band. The series offers power-efficient performance for consolidating in-vehicle workloads such as video surveillance, control/monitoring, passenger information and Wi-Fi hotspot sharing. For edge-to-cloud connectivity, R3S uses its internal GPS/GLONASS chipsets for GPS tracking and has two M.2 slots with up to 4x SIM card readers for failover LTE connection. To ensure proper operations in moving vehicles, the series is certified with EN50155, EN50121-3-2, EN50121-4, EN50125-3, EN45545 and E13 standards and has passed MIL-STD-810G shock and vibration resistance certifications. The series can operate under a wide temperature range and offers excellent reliability in harsh railway settings. It has one external removable 2.5-inch HDD/SSD drive bay for recorded footage storage. For consolidating in-vehicle workloads such as in-vehicle control/monitoring and passenger information, the R3S features a variety of I/O support, including 2x HDMI, DI/DO, 3x COM/CAN BUS and 4xUSB ports.
The aborted launch of the fourth GPS III satellite has sparked an investigation into the SpaceX Falcon 9’s Merlin engine. With only two seconds before launch, SpaceX stopped the scheduled launch of the fourth GPS III satellite on Oct. 2.
Tim Dunn of NASA’s Launch Services Program said at an Oct. 16 briefing that the engines had undergone significant testing since the GPS III launch scrub, including taking the Merlin engines from that rocket back to SpaceX’s McGregor, Texas, test site for further study, reports SpaceNews.com. That investigation has involved NASA and Space Force personnel working with SpaceX.
While the GPS III launch has not been rescheduled, Dunn said that the NASA and SpaceX personnel have learned much, with implications involving the rocket hardware.
GPS III SV04 rests atop a Falcon 9 rocket, waiting to be sent into orbit. (Photo: SpaceX)
A new white paper sponsored by the Resilient Navigation and Timing Foundation (RNT Foundation) discusses the need and implementation of a reliable and resilient national timing architecture that will include space-based assets. This system-of-systems architecture — GNSS, terrestrial eLoran broadcasts and fiber — is essential to underpin today’s technology and support development of tomorrow’s systems, according to the executive summary of A Resilient National Timing Architecture.
“Everyone in the developed world needs precise time, all the time, whether they know it or not,” said Marc Weiss, one of the paper’s authors and an internationally recognized expert on timing and synchronization. “It is a foundation of every networked technology, digital broadcast, and most navigation systems, to name just a few critical uses.”
Three Paths to Precise Time
“Precise time is so important that everyone needs at least three independent methods of getting it. So, if one, or even two, fail it is not a national disaster,” said Pat Diamond, co-author of the paper. “Our proposed architecture calls for precise time via GNSS, terrestrial eLoran broadcasts and fiber.” Diamond is a long-time network designer, developer, and entrepreneur. He is also a member of the U.S. National Space-Based Positioning, Navigation, and Timing Advisory Board.
Diamond also pointed out that these three methods should be the backbone for timing distribution in the U.S., but won’t be the only methods. “What we are describing is a baseline architecture that will be added to,” he said. “It is a starting point. We envision in the paper additional distribution methods like time from other satellites, user clocks, and so on, all being part of the mix.”
Government Leadership
The U.S. federal government has a leadership interest and responsibility in all of this, according to the paper. Nations have long recognized the military and commercial advantages of determining and distributing precise time. Great Britain’s Longitude Act of 1714 was really about developing a chronometer to support safe navigation of Royal Navy and British merchant fleet. In the United States, the U.S. Naval Observatory has been keeping and distributing a national time scale time since 1845.
“Just because the feds have an important leadership role, doesn’t mean they have to build and own a bunch of systems,” said Dana A. Goward, the paper’s third co-author and executive director of the RNT Foundation. “There are a variety of ways these systems can be established. Public-private-partnerships, subscription contracts like the FAA did with their air traffic ADS-B system, and cooperative agreements are all examples. As we move forward with 5G telecommunications and perhaps even timing and navigation, it will be increasingly important to have a rock solid timing infrastructure to support it all.”
The National Timing Resilience and Security Act of 2018 requires the U.S. Department of Transportation to establish a terrestrial system to backup GPS timing services by December of this year. While the department does not appear to be on track to meet that goal, it completed a technology demonstration program for GPS backup technologies earlier this year. Two companies demonstrated timing distribution by fiber. Another two demonstrated eLoran.
Many Pieces Already in Place
One of the benefits of the proposed architecture is that much of what is called for is already in place, according to the paper. “We already have fiber networks, NAPs (network access points). eLoran is mature and has been deployed by the Brits. And the U.S. government owns enough former Loran-C sites to establish a nationwide eLoran network,” Diamond said. “All we need is a bit of money and some engineering work to put this all together.”
On Oct. 16, Rodrigo da Costa took up his duties as executive director of the European GNSS Agency (GSA), soon to become the EU Space Programme Agency.
He was elected by the GSA Administrative Board on Sept. 15 and met with the ITRE Committee of the European Parliament on Oct. 12.
Da Costa, a Portuguese national who has worked in a number of EU countries, joined the GSA as the Galileo Services Programme manager in March 2017. In this position he was responsible for leading Galileo, the European Union GNSS, in its service provision phase.
He has previously held several senior project management, business development, and institutional account management positions in space industry, in the areas of human space flight, exploration, launchers and research and development.
Da Costa will now be working on transforming the GSA into the EU Space Programme Agency (EUSPA). He will ensure that its existing activities continue to be successfully delivered while also performing new ones required to undertake with the Agency’s new mandate.
Since its creation in 2004, the GSA has made an unparalleled contribution to the EU flagship satellite systems Galileo and EGNOS, which have significantly contributed to the union’s independence and economic growth.
Staffed with highly skilled and dedicated personnel, the agency has boosted innovation, fostered entrepreneurship, led the provision of services, and stimulated the EU economy, in particular through ensuring Galileo and EGNOS uptake across a wide range of market segments thanks to high-quality and secure satellite services.
Rodrigo da Costa, executive director of the European GNSS Agency. (Photo: GSA)
With eyes fixed on the future, EUSPA will further build on the work of the GSA, and will take on additional new responsibilities for further components to the EU Space Programme, including activities in Copernicus (the European Earth observation programme), GOVSATCOM (the EU secure satellite communication system).
Commenting on his new duties da Costa said: “Becoming Executive Director of the Agency means, above all, to lead a team of excellent, dedicated professionals. I’m immensely excited by the opportunity we have to build a successful EUSPA, a key contributor of the EU Space Programme. I’m looking forward to working with all our stakeholders. The task is vast, but I am confident we will be able to play our part, demonstrating to EU citizens what we can do together in EU space activities as GSA/EUSPA.’’
GNSS augmentation solution targets North America and Europe with safe and precise centimeter-level accuracy performance from two geostationary satellites.
Sapcorda Services GmbH is now testing its GNSS augmentation services for the L-band signal in North America and Europe. The testing lays the foundation for a Dec. 1 launch of what Sapcorda said will be the strongest, most reliable GNSS augmentation signal for safety-critical navigation in autonomous vehicles and machinery.
Available in areas without GSM coverage or mobile internet signal, the new Sapcorda L-band beam solutions from two geostationary satellites provide PPP-RTK data-feed redundancy in real-time by swapping to a second data feed when internet connectivity is not available. This automated swapping significantly improves reliability for life-critical applications such as autonomous cars.
“To use GNSS in mass-market safety-critical applications, manufacturers need GNSS augmentation services that provide correction data with safety-critical positioning,” said Botho zu Eulenburg, CEO, Sapcorda. “By expanding our SAPA services with L-band transmission, we enable a high-power correction data stream for homogeneous performance and end-to-end data security with continental coverage in the United States and Europe — thus improving accuracy, reducing convergence time, and enabling the use of lower-cost receivers and antennae.”
The Sapcorda L-band signal will be transmitted in the open SPARTN format, a format specifically developed for IP-based and geostationary satellite distributions. It will be invaluable for safety-critical applications in automotive (such as V2X and autonomous driving, AD/ADAS) and maritime, as well as a wide variety of uses across sectors such as industrial, robotics and drones.
The L-band satellite beam coverage will be available on December 1, 2020. Sapcorda’s safe and precise augmentation (SAPA) service will broadcast SAPA Basic and SAPA Premium correction data streams.
These data streams feature:
99.9% service availability with fast convergence and an accuracy of less than 10 cm, delivering the precision required for safety- and life-critical applications
Redundancy through dual data streams when internet connectivity isn’t available, ensuring uninterrupted broadcast streaming
Demodulation by any L-band demodulator on the market, simplifying hardware design and reducing bill of materials
Availability of service coverage areas in North America and Europe, allowing manufacturers to use a single GNSS augmentation services’ solution for major global regions
Distributed in the same open format as IP-delivery channels (SPARTN)
Sapcorda’s SAPA services are supported by experienced engineering teams dedicated to systems integrators and enterprise business customers. The Basic and Premium SAPA services for L-band signal operation begins in both regions on Dec. 1.
UAVOS Inc. has performed a series of successful flight trials with High Altitude Pseudo Satellite (HAPS) ApusDuo, testing its unique control system.
The test flights confirmed that UAVOS’s control system allows aircraft with a large-wing elongation to fly in unstable atmospheric conditions. The ApusDuo aircraft successfully copes with turbulence, actively changing the bend of the wings.
The total flight time of UAVOS solar-powered test aircraft is more than 1,000 hours. Test flights took place at an altitude of up to 62,000 feet (19,000 meters).
UAVOS’s control system does not require the installation of wing mechanization. This reduces the aircraft’s weight by 30% or more, improves reliability and simplifies wing production for lower manufacturing costs.
The ApusDuo drone weighs about 95 lbs (43 kg) and has a wingspan of 49.2 ft. It is launched by a winch. The aircraft is built on the tandem principle, where two of the wings are located one after another with a small elevation difference.
ApusDuo is controlled by changing the geometry of the aircraft. It is designed to linger at an altitude of about 60,000 feet (18,000 m) for months at a time for surveillance or to provide a temporary boost to communications.
Additional test flights are planned for this year, said Aliaksei Stratsilatau, UAVOS CEO and lead developer.
Robotic Research LLC has added Retrotraverse to its AutoDrive-M autonomy kit. The autonomy kit is equipped on the U.S. Army’s Palettized Load System (PLS) logistics trucks.
Robotic Research demonstrated the Retrotraverse capabilities with three of the U.S. Army’s PLS trucks, each towing trailers. “This is a major step forward for our company and has broad application both in autonomy and platooning. The capability solves the potentially life-threatening problem of an autonomous platoon of military vehicles being unable to navigate out of a dangerous situation,” said Alberto Lacaze, president of Robotic Research. “This automated platooning capability will ultimately extend the reach of soldiers without putting them in harm’s way.”
The Retrotraverse feature allows a platoon of heavy-duty trucks with trailers to autonomously reverse. Several autonomous vehicle providers in the trucking industry are demonstrating platooning in benign conditions, where the weather is ideal and road surfaces are smooth and marked.
Robotic Research has been specifically focusing on addressing the edge cases, such as poor weather, dust and off-road conditions, to ensure a robust autonomous system that is necessary for operating in all conditions and during mission-critical operations for the military.
If a platoon drives into a dead end, or similar edge case where it cannot make a U-turn, the platoon of vehicles with trailers needs to be able to reverse out of the situation. Retrotraverse can make this happen.
“Anyone who has backed up a truck with a trailer knows how difficult it is to navigate,” said Joe Putney, director of commercial systems at Robotic Research. “The autonomous Retrotraverse feature was able to reverse a truck and trailer faster than even our most skilled drivers. This feature is not just lifesaving, it’s time-saving, and it has the ability to reduce one of the greatest pains truck drivers have.”
In 2018, Robotic Research was awarded a three-year, $49.7 million contract by the U.S. Army to provide its autonomy kit for large convoy resupply vehicles. Robotic Research has since delivered nearly 100 unmanned platooning trucks.
Javad GNSS introduced a new solution, Real-Time Post-processed Kinematics (RTPK), at Intergeo Digital 2020.
With the new option, the Javad Triumph-LS combines the strengths of RTK and PPK into a system that can post-process RTK data and verify its results in parallel and real time.
If RTK fails, RTPK is available in a fraction of a second, the company said.
Screenshot: Javad GNSS
“The RTPK feature is about as simple as any feature can get,” said Darren Clemons, PLS. “When you are on a point and stop the session, the LS automatically starts downloading the data for the time period matching that session from your base (or RTN) and then internally in the LS (no internet connection required) runs the post processing and gives you the PPK solution right there on your point in real time. […] It is a very nice and ingenious feature and, for us anyway, is a great check on our RTK results.”
Tallysman Wireless Inc. has added four new embedded VeroStar Mini products to its line of antennas. The ultra-compact and lightweight embedded VeroStar Mini models offer the same key features as the full-size VeroStar models but in a smaller, lighter package, with either a 90-mm (58 g) or 106-mm (69 g) integrated ground plane, both 32.4 mm in height.
The VSM6028, VSM6028L, VSM6328 and VSM6328L embedded VeroStar Mini antennas are designed and crafted for high-accuracy positioning. With an exceptionally low roll-off from zenith to the horizon, VeroStar antennas provide the excellent tracking of GNSS and L-band correction signals at low elevation angles.
The VSM6028 VeroStar antenna. (Photo: Tallysman Wireless)
Also, the optimized axial ratio at all elevation angles results in excellent multipath rejection, enabling accurate and precise code and phase tracking. Additionally, VeroStar antennas feature a robust pre-filter and high-IP3 LNA architecture, minimizing de-sensing from high-level out-of-band signals, including 700 MHz LTE, while still providing a noise figure of only 1.8 dB.
The light and compact wide-band spherical antenna element enables the VeroStar Mini to deliver a ±2 mm phase center variation (PCV), making it suitable for high-precision applications such as autonomous vehicle navigation (land, sea, and air), smart survey devices, and maritime positioning.
The VSM6028 supports the full GNSS spectrum (the VSM6028L includes support for L-band correction services), while the VSM6328 supports the GPS/QZSS-L1/L2/L5, GLONASS-G1/G2/G3, Galileo-E1/E5a/E5b, BeiDou-B1/B2/B2a, and NavIC-L5 signals and frequency bands (the VSM6328L includes support for L-band correction services).
The unique features of the VeroStar Mini antennas guarantee it can deliver a high signal-to-noise ratio (SNR), high accuracy, and high precision in the most challenging environments.
Rohde & Schwarz supports 5G LBS with assisted GPS and 5G NR FR2 mmW performance testing
Photo: Rohde & Schwarz
Simulator and test company Rohde & Schwarz has verified assisted GPS (AGPS) performance in a commercial mobile device, while simultaneously transferring data using 5G millimeter wave (mmW). This capability is now available with the Rohde & Schwarz TS-LBS (location-based services) test system.
As wireless network operators roll out 5G NR in the millimeter wave spectrum, it is critical to ensure continued reliability of E911 calls and accurate determination of location in mobile devices.
5G NR utilizes frequencies in the FR1 frequency range (<7.125GHz) and in the FR2 mmW frequency range (>24GHz). FR2 creates unique challenges for mobile devices in terms of power consumption and heat. With FR2 becoming more common in North American mobile devices, performance of critical services such as E911 emergency calls cannot be allowed to degrade when utilizing this mmW spectrum.
When used together in the TS-LBS test system, the R&S CMX500 radio communication tester and R&S CMW500 wideband radio communication tester provide a seamless and comprehensive test platform capable of testing LTE, 5G NR FR1 and FR2, while the R&S SMBV100B vector signal generator simulates the GPS L1 & L5, GALILEO, GLONASS & BEIDOU satellite constellations for A-GNSS.
Other positioning technologies that use barometric pressure sensors, Wi-Fi and/or Bluetooth are also available in the same solution. Legacy technologies such as GSM, WCDMA and LTE are all supported using the same hardware.
“The addition of FR2 mmW to our TS-LBS test solution gives customers the latest capabilities needed to continue certifying their mobile devices to evolving 5G standards,” said Bryan Helmick, Rohde & Schwarz. “Customers can easily add 5G to existing LTE TS-LBS systems with the simple addition of an R&S CMX500. FR2 support only requires some hardware on the R&S CMX500 and an R&S CMQ500 mmW shield cube.”
5G NR in the sub 6 GHz frequency range (FR1) can be seen as a natural evolution of LTE to achieve higher bandwidth and more flexibility on the physical layer in order to realize all the new and additional use cases defined for a next-generation mobile network.
The real technical challenge, however, comes with 5G mmWave (FR2), which opens up a new level of complexity in device development. mmWave frequencies imply measurement challenges that call for new testing approaches.
An August 2020 paper published by the journal Sensors revealed China’s plans to expand coverage of its terrestrial Loran positioning, navigation and timing (PNT) system with three new transmitter sites in the western part of the country. The article indicates that this is a part of providing a backup system for GNSS.
According to the paper, “…the vulnerability of GNSS to unintentional and intentional interference signals can be found frequently nowadays. For national security and economic effectiveness, a reliable and complementary navigation system is needed desperately. The suitability of the Loran for a backup navigation system has been evaluated and reported.”
China has operated a Loran system for decades. While the system is capable of operating independently, its signals are also compatible with systems operated by South Korea and Russia. These are coordinated through the Far East Radio Navigation Service (FERNS) to ensure the systems are complementary and reinforce each other where coverage overlaps. The United States and Japan were also members of FERNS until they terminated Loran transmissions in 2010 and 2015, respectively.
Image: RNT Foundation
Little public information about China’s Loran system has been available and our queries have gone unanswered. One of the few documents available in the west is a 2014 paper about Loran-C from the Chinese Academy of Sciences in Shaanxi, China which can be accessed through the RNT Foundation website. It shows substantial Loran coverage in the eastern part of the nation, but only a broken circle indicating “projected coverage” in the west.
Graphic from 2014 Chinese Academy of Sciences paper on Loran showing projected coverage in the western part of the country with a dotted circle. (Image: RNT Foundation)
The single transmitter in that area projected by the 2014 paper could provide a strong, difficult to disrupt timing signal for fixed receivers with known locations.
Three new transmitters will be installed according to the August 2020 paper titled “High-Accuracy Positioning Based on Pseudo-Ranges: Integrated Difference and Performance Analysis of the Loran System.” The increased service in the western part of the country will provide “full coverage” positioning, navigation and timing usable by both fixed and mobile receivers.
The August 2020 paper is the first known documentation in over a decade of specific Chinese intentions regarding its Loran system.
Still, it is not a surprise to many observers. At 2019’s Stanford PNT Symposium, Xiaochun Lu of China’s National Time Service Center described the nation’s plan for a “comprehensive” PNT system. This system will include a wide variety of PNT sources including low earth orbit satellites, inertial systems, local positioning systems, and Loran.
Like Ms Lu, the authors of the August 2020 paper are employed at China’s National Time Service Center, which is part of the Chinese Academy of Sciences.
