GPS World

Author: Maddie Saines

  • Satellite imagery released in response to Libya flooding

    Satellite imagery released in response to Libya flooding

    Image: Maxar Technologies
    Image: Maxar Technologies

    On Sept. 10, floodwaters overpowered dams and wiped out entire neighborhoods in eastern Libya, taking the lives of thousands of people and displacing more than 40,000 people, reported the Associated Press.

    Maxar Technologies has responded by publicly releasing satellite imagery data that maps the affected areas to support emergency response efforts as a part of its Open Data Program.

    The Maxar imagery or data distributed through the program can be quickly integrated into first responder workflows with organizations such as Team Rubicon, the Red Cross and other nonprofits.

    Derna and other parts of eastern Libya were hit with extreme flash flooding the night of Sunday, Sept. 10 — an effect of the Mediterranean storm, Daniel.

    The National Meteorological Center of Libya had issued early warnings for Daniel 72 hours before it occurred and notified all governmental authorities by e-mail and through media urging them to take preventive measures, reported the Associated Press.

  • New Pentagon plan calls for UAV swarms to counter China, but is that enough?

    New Pentagon plan calls for UAV swarms to counter China, but is that enough?

    Image: Navy Petty Officer 1st Class Devin M. Langer
    Image: Navy Petty Officer 1st Class Devin M. Langer

    The U.S. Department of Defense has called for thousands of UAVs to be built as a part of its Replicator initiative that aims to hasten military innovation to “leverage platforms that are small, smart, cheap and many,” said Deputy Defense Secretary Kathleen Hicks in a recent speech. This was cited in a Wall Street Journal editorial published on Sept. 13.

    The United States plans to build thousands of UAVs over a 24-month period to counter China and the current military threat against U.S. forces in the Pacific Ocean. The UAV swarms could help the United States jam or distract enemy radars and surface-to-air missiles to stop China from pushing U.S. forces out of the Pacific.

    The Wall Street Journal article stated that this idea by the Pentagon is not a real substitute for a bigger navy. While the Pentagon’s idea of UAV swarms for reconnaissance in the Pacific is technologically innovative, the article stated that the United States will still need technology breakthroughs and plentiful stocks of materials ranging from aircraft to munitions.

    Furthermore, Deputy Hicks said that the Replicator initiative is not asking for new money in the next fiscal year budget, citing “not all problems need new money; we are problem-solvers, and we intend to self-solve,” reported the Wall Street Journal.

    A new swarm of UAVs will give significant support to the U.S. military to counter China. However, the Pentagon’s quick plan for an unmanned technological “revolution” will need more investment to compensate for the failures that will inevitably accompany the new technology, the editorial argued, and to build “two Virginia-class submarines a year and fielding thousands of long-range weapons so U.S. forces don’t run out of their best firepower after a week in the Taiwan Strait.”.

  • Breaking down the F-35 jet “mishap”

    Breaking down the F-35 jet “mishap”

    Image: Lance Cpl. Kayla Rainbolt, Marine Corps Air Station Beaufort
    Image: Lance Cpl. Kayla Rainbolt, Marine Corps Air Station Beaufort

    On Sept. 18, 2nd Marine Aircraft Wing Cpl. Christian Cortez, a pilot, set out on a training mission from the Marine Corps Air Station in Beaufort, South Carolina, only to eject from his Lockheed Martin F-35B Lightening II fighter jet over North Carolina. The U.S. military then lost the expensive, highly automated, lethal jet that was still in flight, as it was set on autopilot when the pilot ejected.

    During the mishap, the U.S. Air Force Joint Base Charleston made a highly usual plea to the public to call with information regarding the lost plane. It is also still unclear why the pilot had to bail out of the jet and those details are actively under investigation.

    The U.S. Marine Corps confirmed on Sept. 19, that debris had been found in South Carolina in Williamsburg County, north of Charleston, reported The New York Times. Joint Base Charleston stated the jet debris is located about two hours north of the base and it is urging residents to avoid the area as the recovery team secures the scene.

    The jet search team consisted of the Second Marine Aircraft Wing, Navy regional authorities in the southeast, the Civil Air Patrol, the Federal Aviation Administration, and local law enforcement teams.

    The Marine Corp released a statement on Sept. 18, stating that its acting commander, Gen. Eric M. Smith, had directed all Marine Corps aviation units to conduct a two-day pause in operations to discuss aviation safety matters and best practices. The statement said that the directive came after three Class-A aviation mishaps occurred during the last six weeks.

    During the pause of operations, aviation commanders plan to review the service’s flight practices, procedures, and policies.

    The jet

    Lockheed Martin’s website states, “with stealth technology, advanced sensors, supersonic speed, weapons capacity and superior range, the F-35 is the most lethal, survivable and connected aircraft in the world. More than a fighter jet, the F-35’s ability to collect, analyze and share data, is a powerful force multiplier that enhances all airborne, surface and ground-based assets in the battlespace enabling men and women in uniform to execute their mission and return home safely.”

    The F-35 program is the most expensive U.S. weapons program of all time and is expected to cost more than $400 billion in development and acquisition and $1.2 trillion to operate and maintain the fleet over 60 years. Each jet costs more than $160 million, depending on the variant.

    Notable program advancements

    Lockheed Martin reached a $4 billion deal with the Pentagon in 2014 to bring in the new fleet of F-35 jets.

    In late 2019, Lockheed Martin received a $25 million initial contract for engineering and manufacturing development for the GPS Spatial Temporal Anti-Jam Receiver (GSTAR) system that was integrated into the F-35 as part of its modernization phase, also known as Block 4. The GSTAR provides protection against enemy jamming and spoofing by utilizing critical GPS capabilities that can quickly adapt to meet specific platform requirements.

    Several unanswered questions

    Several details of this story have left many wondering exactly how this U.S. fighter jet just went missing in U.S. airspace without anyone being able to locate it or know its heading. It is an expensive, highly automated, weaponized aircraft that can create catastrophic damage to its surroundings. 

    As this investigation is ongoing, further details about this incident have not been reported.   

  • Launchpad: New receivers, GIS platform and delivery UAV

    Launchpad: New receivers, GIS platform and delivery UAV

    A roundup of recent products in the GNSS and inertial positioning industry from the September 2023 issue of GPS World magazine.

    MOBILE

    Image: Fairview Microwave

    Commercial RF antennas
    Marine grade for ships/boats

    The Fairview commercial RF antennas provide accurate positioning with L1 band and multiband capabilities and offer a 28 dBi gain for reliable positioning. The antennas offer full-spectrum connectivity and operate within the universal marine frequency range of 156 MHz to 163 MHz and CB-27 MHz, 10m-HAM, ensuring unbroken connections at sea. The antennas are also weatherproof, rated IP67 for water ingress. They are offered with three types of mounts, making it easier to integrate into any vessel. All antennas are crafted from robust stainless steel or fiberglass for durability and reliable performance. Various antenna lengths are available for users to select based on their signal performance needs..
    Fairview Microwave, fairviewmicrowave.com

    SURVEYING & MAPPING

    Image: Advanced Navigation

    Inertial Measurement Units
    Features ultra-high accuracy DFOG range and more

    The Boreas A90 and A70 are strategic-grade inertial measurement units (IMU) that deliver acceleration and orientation with accuracy, stability and reliability under all conditions with no reliance on GNSS. They also feature automatic gyrocompassing. The IMUs contain ultra-high accuracy digital fiber-optic gyroscope (DFOG) range and high performance closed-loop accelerometers. The Boreas A90 and A70 are both suitable for surveying, mapping and navigation across subsea, marine, land and air applications. The Boreas A90 and A70 also offer an optional license to add inertial navigation system capabilities and enable integration with external GNSS receivers using Advanced Navigation’s range of interfaces and communication protocols.
    Advanced Navigation, advancednavigation.com

    Photo: ComNav Technology

    GNSS Receiver
    Suitable for surveying, mapping, and geographic information system applications

    The Mars Laser RTK features a datalink modem that transmits and receives across the full frequency range from 410 MHz to 470 MHz. With adjustable transmit power of 0.5 w to 2 w and a maximum distance of 15 km, it meets the measurement demands of complex environments. It can also switch roles between a rover and a base, enabling more flexibility in demanding applications. The Mars Laser RTK is equipped with a Wi-Fi/4G modem and Bluetooth capabilities, facilitating reliable communication across various platforms. The Mars Laser RTK also features five LEDs on the front panel for satellite tracking, RTK corrections data and more. Powered by the SinoGNSS K8 high precision module, the device supports full-constellation and multi-frequency tracking, including GPS, GLONASS, BDS, QZSS, IRNSS, and Galileo, and supports precise-point positioning service. Additionally, the device tracks more than 60 satellites and has 1,590 channels. The Mars Laser RTK’s third-generation inertial measurement unit (IMU) supports 60° tilt with 2.5 cm accuracy. The IMU can be set to both traditional mode with range pole and to laser mode.
    ComNav Technology, comnavtech.com

    Image: Trimble Geospatial

    Desktop Solution
    An Esri ArcGIS Pro add-in for field data collection software

    With a streamlined user interface, the Terra Office add-in for ArcGIS Pro enables users to connect TerraFlex workflows directly to the ArcGIS platform from within ArcGIS Pro — Esri’s desktop GIS application. ArcGIS Pro users can now create and manage TerraFlex geospatial data collection projects without leaving ArcGIS. Organizations that collect data in TerraFlex and bring it into ArcGIS through the add-in can also use the Trimble Offline GNSS Corrections service for situations where real-time correction services are intermittent or unavailable. With this service, all data from the field is automatically processed in the cloud without user intervention, and the most accurate real-time or post-processed position is stored for each feature and made available for download through the Terra Office add-in for ArcGIS Pro.
    Trimble Geospatial, geospatial.trimble.com

    Image: 1Spatial

    Data Capture App
    A customizable mobile application for GIS data collection

    1Capture is a mobile GIS editing application that is multi-use and configurable. It provides accurate and reliable data collection and editing in the field for a multitude of asset, job, and survey types. Customizable rules and actions work to improve data quality at the point of capture. This ensures that good quality data is captured at the source, minimizing re-surveys. The built-in rules engine automatically validates and corrects the GIS and non-GIS data collected, whether working online or offline. 1Capture connects with a variety of GIS environments, including Esri ArcGIS and open-source technologies such as PostGIS and Geoserver.
    1Spatial, 1spatial.com/us/

    AUTONOMOUS

    Heavy-Lift Delivery UAV
    An off-the-shelf, ready-to-fly delivery aircraft for last mile delivery

    The RDST Longtail features a RDS2 drone winch, enabling payloads to be deposited safely from altitude so that spinning rotors are kept far from people and property. The UAV can deliver or retrieve payloads up to 5 kg and over a distance of 11 km, making it suitable for various applications such as local parcel or food delivery, emergency medical deliveries, water sampling programs, offshore logistics, search and rescue operations and more. The UAV can also auto-release packages without the need for a recipient to be present at the delivery location. This is made possible by the all-new bag auto-release mechanism, allowing for easy pickups and auto-releasing of bags during deliveries. Designed to meet FAA regulations, the RDST Longtail is remote ID compliant with a factory-integrated remote ID beacon. The Premium edition of the drone can fly in inclement weather and features a quick-release battery system for minimal downtime.
    A2Z Drone Delivery, a2zdronedelivery.com

    Image: Anello Photonics

    GNSS INS
    Suitable for multiple applications

    The ANELLO GNSS inertial navigation system (INS) is designed for reliable long-term GPS-denied navigation and localization. Powered by optical gyroscope technology and artificial intelligence-based sensor fusion engine, the ANELLO GNSS INS delivers robust, high-accuracy positioning and orientation for applications such as agriculture, construction, trucking, and autonomous vehicles. It comes equipped with unaided heading drift of less than 0.5°/hr, dual multi-band real-time kinematic-capable GNSS engines, ASIL-D-ready automotive qualified CPU, automotive 2-wire Ethernet, and dual high-speed CAN FD interfaces. It also features dual RS-232 interfaces, hardware precision time protocol, IEEE 802.1AS. The ANELLO GNSS INS is IP68 waterproof, as well as resistant to dust, salt spray and chemicals.
    ANELLO Photonics, anellophotonics.com

    Image: Turf Tank

    GPS-Guided Robot
    Designed specifically for painting athletic fields

    The Turf Tank Two features dual motor drives for enhanced torque and optimized wheels for traction. On its own and controlled through a tablet, the Turf Tank Two can paint a regulation soccer field for two teams of 11 players each in less than 24 minutes, a baseball or softball field in less than 11 minutes, a lacrosse field in less than 26 minutes, and a full 100-yard football field in less than 3.5 hours. It can also paint logos and numbers. The Turf Tank Two is 43 in x 33 in x 22.5 in. It weighs 123 lbs, without paint or the battery installed, and it can hold 5.5 gallons of paint. Enhanced features of the Turf Tank Two also include a revamped sprayer module and advanced control features — including a redesigned front panel that has convenient pause/resume options with LED indicators displaying the robot’s status and a start/stop sprayer button. An LED indicator also comes on the battery. Its batteries are rechargeable. Because of the robot’s precision and accuracy, it uses significantly less paint and eliminates the overspray that is common with either painting by hand or using many of the older paint machines and sprayers on the market. The GNSS-guided Turf Tank Two uses a base station to enhance its accuracy, while its onboard GNSS receiver acts as a rover.
    Turf Tank, turftank.com

    DEFENSE

    Photo: BAE Systems

    Solar-Electric HAPS UAS
    Provides an alternative to conventional sensing and communications systems

    PHASA-35 is an ultra-light weight, solar-electric high altitude pseudo satellite (HAPS) unmanned aerial system (UAS) designed as an alternative to conventional systems such as satellites or conventionally powered aircraft for cost-effective imagery and communications. PHASA-35 uses photo-voltaic arrays to provide energy during the day, which is stored in rechargeable cells to maintain flight overnight. The UAS is designed to provide a persistent, stable platform for monitoring, surveillance, communications, and security applications. When connected to other solutions, it provides military and commercial customers with capabilities that are not currently available from existing air and space platforms. PHASA-35 can also be used to deliver communications networks including 5G, as well as provide other services, such as disaster relief and border protection. The UAS also has a flexible payload design that enables a large and varied range of sensor capabilities to be carried and updated. The PHASA-35 is suitable for military communications, military surveillance, commercial communications, maritime surveillance, border security, agricultural monitoring, and environmental monitoring.
    BAE Systems, baesystems.com

    Photo:

    GPS Receiver
    A-PNT device featuring M-code GPS technology

    NavGuide is a field-installable replacement to the defense advanced GPS receiver (DAGR), designed for quick integration into current DAGR mounts and accessories without mission interruption. NavGuide features a 3 in, full-color, graphical user interface for dismounted soldiers, and easily integrates with existing mounted platforms and systems. The device leverages the advanced M-code GPS signal with enhanced jamming and spoofing protection. NavGuide is portable, versatile, and precise, and enables vehicular, handheld, sensor, and gun laying applications that enable the military to defeat adversaries in a variety of challenging threat environments.
    BAE Systems, baesystems.com

    OEM

    Image: NextNav

    Vertical Location Device
    For a variety of applications that rely on precise PNT

    Pinnacle delivers precise, floor-level, vertical positioning for geolocation applications. It offers altitude measurements that meet the Federal Communications Commission mandate of 3 m accuracy. Pinnacle works with existing barometric pressure sensors in devices to improve quality and accuracy. Pinnacle technology provides z-axis data and has been demonstrated in independent testing to deliver 94% accuracy. Pinnacle data is derived from a proprietary network built for public safety, operated and maintained by NextNav, for wide availability. SDK, API, and Unity plug-in options make it easy to integrate 3D geolocation technology into existing applications.
    The device also offers consistent vertical location abilities available throughout large urban areas. Pinnacle is available across the United States, is currently being deployed across Japan, and is being tested in France for local emergency repsonse agencies.
    NextNav, nextnav.com

    Image: u-blox

    LTE-M/NB-IoT Module
    For small asset trackers

    The LEXI-R4 module is customized for size-constrained application requirements. The device is suitable for small asset trackers, such as pet and personal trackers, micro-mobility devices, and luggage tags. The LEXI-R4 module supports all LTE-M and NB-internet of things (IoT) bands, with an RF output power of 23 dBm. It is natively designed to support GNSS AT commands, and its dedicated port enables easy integration with any u-blox M10-based GNSS module, such as the MIA-M10. Additionally, the module can connect to additional positioning services, such as AssistNow and CellLocate. The compact size of the module, measuring 16 mm x 16 mm, results from a 40% footprint reduction in dimensions compared to the previous u-blox SARA-R4. Due to its small size, it leaves room for larger antennas, which can improve RF performance, or for larger batteries. Another feature of the LEXI-R4 is its 2G fallback capability. Whenever LTE-M/NB-IoT coverage conditions are not optimal, it continues to function by falling back onto a 2G network. The company said this feature could be helpful in countries where LTE-M/NB-IoT networks have yet to be fully deployed.
    u-blox, u-blox.com

  • Tallysman introduces smart GNSS antenna

    Tallysman introduces smart GNSS antenna

    Image: Tallysman Wireless
    Image: Tallysman Wireless

    Tallysman Wireless has added the HCS885XF/HCS885EXF embedded smart helical GNSS antenna to its line of Smart GNSS Antennas. This antenna is suitable for UAV, land survey devices, automotive positioning, and other precise positioning/heading applications.

    The HCS885XF/HCS885EXF combines the performance and light weight of the Tallysman dual-band (GPS/QZSS L1/L5, GLONASS G1/G3, Galileo E1/E5a/b, BeiDou B1/B2/B2a) HC885SXF antenna with the low power consumption and GNSS augmentation capabilities of the u-blox NEO-F9P GNSS receiver.

    Instead of using L2 signals, HCS885XF/HCS885EXF employs L5 signals (1160-1217 MHz), which transmits stronger signal power and a higher bandwidth chipping rate to offer high performance when challenged with strong multipath signals. It also employs Tallysman’s eXtended Filtering system, which mitigates near-band and out-of-band interference, such as LTE signals and their harmonics, and the planned Ligado service in North America, enabling operation in the most challenging deployments.

    The HCS885XF/HCS885EXF integrated receiver can monitor four constellations simultaneously, provides support for base/rover RTK configurations (<1 cm), and makes use of u-blox PointPerfect PPP-RTK augmented services over a terrestrial control network (3-6 cm). A moving-base precise heading configuration is available with base/rover antenna pairs.

  • DOT releases Complementary PNT Action Plan

    DOT releases Complementary PNT Action Plan

    Image: DOT
    Image: DOT

    The U.S. Department of Transportation (DOT) has unveiled its Complementary Positioning Navigation and Timing (CPNT) Action Plan, which contains steps the department is taking to drive CPNT adoption across the United States transportation system and within other critical infrastructure areas. This plan was mentioned by Robert Hampshire — Deputy Assistant Secretary for Research and Technology and Chief Science Officer, U.S. DOT — during his keynote address at the annual Civil GPS Service Interface Committee (CGSIC) meeting on September 12, at ION GNSS+, which GPS World’s Editor-in-Chief, Matteo Luccio, is attending.

    In 2020, the U.S. DOT Volpe National Transportation Systems Center conducted field demonstrations of various PNT technologies that could offer complementary service if GPS is disrupted. The department was able to gather information on PNT technologies at a high technology readiness level that can work in the absence of GPS.

    The U.S. DOT have selected 11 candidate technologies to demonstrate positioning or timing functions:

    • Two vendors demonstrated low-Earth orbit satellite PNT technologies — one L-band and one S-band; 
    • two vendors demonstrated fiber-optic timing systems, both based on the White Rabbit Precision Time Protocol; 
    • one vendor demonstrated localized database map matching database, inertial measurement unit, and ultra-wideband technologies; and, 
    • six vendors demonstrated terrestrial radio frequency PNT technologies across low frequency, medium frequency, ultra-high frequency, and Wi-Fi/802.11 spectrum bands.   

    Five of the selected technologies were demonstrated at Joint Base Cape Cod in Massachusetts, and six were demonstrated at NASA Langley Research Center in Virginia. The demonstrations were scenario-based implementations modeled on critical infrastructure use cases under different operating conditions.  

    Two central recommendations from the demonstration were made: the U.S. DOT should develop system requirements for PNT functions that support safety-critical services; and the U.S. DOT should develop standards, test procedures, and monitoring capabilities to ensure that PNT services, and the equipage that utilize them, meet the necessary levels of safety and resilience identified in recommendation one.   

    For the full U.S. CPNT Action Plan, click here. 

    Request for information

    The U.S. DOT has also released a request for information (RFI) as one of the steps in driving adoption of complementary PNT services to augment GPS. The department is planning a resiliency test, evaluation, and performance monitoring strategy for PNT-dependent transportation systems.  

    If any readers are interested in participating, click here for more information.  

  • Spirent to generate Xona PULSAR production signals via SimXona

    Spirent to generate Xona PULSAR production signals via SimXona

    Image: Spirent
    Image: Spirent

    Spirent has concluded a review of Xona Space Systems’ PULSAR production signals, and has deemed them feasibile for integration into the SimXona product line. Spirent will integrate the Xona production signals as an evolution of the SimXona platform.

    Support will become available to existing and new users throughout 2024.

    Xona is developing PULSAR, a high-performance positioning, navigation, and timing (PNT) service built on low-Earth orbit (LEO) small satellites. Xona’s high-powered smallsat signals aim to improve PNT resilience and accuracy by augmenting GNSS while operating with an independent navigation and timing system architecture.

  • M3 Systems launches project for reconfigurable GNSS payload in LEO

    M3 Systems launches project for reconfigurable GNSS payload in LEO

    M3 Systems has launched a disruptive project, co-financed by the Occitanie Region, aiming to provide new GNSS services.

    Image: M3 Systems
    Image: M3 Systems

    The IOD-full software-defined radio (SDR) GNSS project will enable new services through a reconfigurable SDR payload, enabling on-demand analysis of GNSS signals from space. Through space-based signal analysis, this project paves the way for reconfiguring GNSS signal processing and developing expertise in adaptable and scalable GNSS receivers to accommodate signals from future constellations.

    M3 Systems, Loft Orbital, and Space Co-Design play a key role by providing rapid access to space for the facilitated and accelerated deployment of the receiver in orbit. Co-financed by the Occitanie Region, the IOD-full-SDR-GNSS project was selected as part of the “Nanosatellites Plan – Acceleration of In-Orbit Validations (IoD/IoV)” call for projects, co-developed with the French government based on the needs expressed by regional companies under the ADER 4 Recovery Plan.

  • ComNav Technology launched Mars Pro Laser RTK

    ComNav Technology launched Mars Pro Laser RTK

    Image: ComNav Technology
    Image: ComNav Technology

    ComNav Technology Ltd. has introduced the Mars Pro Laser RTK, the latest addition to its Universe Series GNSS receiver lineup, which includes the Venus Laser RTK and Mars Laser RTK. This GNSS receiver is suitable for land surveying, GIS, and construction industries with its innovative features.

    The Mars Pro’s laser mode helps in signal-blocked, hard-to-reach or hazardous areas, where conventional GNSS receivers struggle. By switching to laser mode, users can effortlessly use the laser distance meter on the back of the Mars Pro to determine the distance between the receiver and the point. The effective distance of the laser is up to 10 m, ensuring signal-friendly accuracy even in GNSS-challenged places, such as in a garage, under a bridge, over the water, or in traffic.

    Additionally, the integrated inertial measurement unit sensor provides up to 60°tilt compensation, ensuring efficiency and accuracy in conventional mode and laser mode.

    The Mars Pro has full-constellation capabilities with 1,668 channels across GPS, GLONASS, Galileo, BDS, QZSS, and IRNSS. Support for precise-point positioning service ensures rapid fixing. Its OLED color screen also offers real-time data visualization, enhancing operational control.

    The Mars Pro supports communication via Wi-Fi, 4G, and Bluetooth, enabling easy data exchange and interaction. It’s compatibility with mainstream brands and multiple protocols makes it versatile and multifunctional. It can transition between roles as a rover and a base and collaborate seamlessly with users.

  • ANELLO Photonics releases new IMU

    ANELLO Photonics releases new IMU

     

    Image: ANELLO Photonics
    Image: ANELLO Photonics

    ANELLO Photonics has released the ANELLO IMU+ for robust and reliable autonomous navigation and positioning in GNSS-denied or GNSS-compromised environments.

    Powered by optical gyroscope technology, the ANELLO IMU+ delivers high precision and reliability in demanding conditions, including shock, vibration, electromagnetic interference and temperature. The ANELLO IMU+ is suitable for autonomous applications in the construction, robotics, mining, trucking and defense industries.

    The device delivers long-term dead reckoning in high-temperature and high-vibration environments.

    The ANELLO IMU+ features unaided heading drift of < 0.5°/hr, dual high-speed CAN FD interfaces, and dual RS-232 interfaces; has ASIL-D ready, automotive-qualified CPU and OS; and is IP68 waterproof, resistant to dust, salt spray and chemicals.

  • Join GPS World at ION GNSS+ 2023

    Join GPS World at ION GNSS+ 2023

    Image: ION website
    Image: ION website

    Institute of Navigation (ION) GNSS+ is the world’s largest technical meeting and showcase of GNSS technology, products and services. This year’s conference will bring together international leaders in GNSS and related positioning, navigation and timing fields to present new research, introduce new technologies, discuss current policy, demonstrate products and exchange ideas.

    ION GNSS+ 2023 is scheduled for September 11-15, at the Hyatt Regency in Denver, Colorado.

    GPS World, a proud media partner of ION GNSS+ 2023, will be attending the conference and will be located at booth 214 next to CAST Navigation.

    If you are attending the conference, feel free to stop by the GPS World booth.

    To view the full ION GNSS+ Technical Program click here.

  • Research roundup: GNSS in urban canyons

    Research roundup: GNSS in urban canyons

    Image: Predrag Vuckovic/E+/Getty Images
    Image: Predrag Vuckovic/E+/Getty Images

    GNSS researchers presented hundreds of papers at the 2022 Institute of Navigation (ION) GNSS+ conference, which took place Sept. 19-23, 2022, in Denver, Colorado, and virtually. The following four papers focused on the use of GNSS in urban environments. The papers are available here.

    GPS World will be attending this year’s ION conference in Denver, Colorado, on Sept. 11-15.

    FGO-based GNSS/INS integration improves performance in urban canyons in Hong Kong

    The integration of GNSS and inertial navigation systems (INS) has the potential to improve performance due to their complementariness. In this paper, the authors investigated positioning based on the integration of GNSS and INS using factor graph optimization (FGO). This ultimately showed improved performance in urban canyons in Hong Kong. The effectiveness of the proposed method was verified using challenging datasets collected using two automobile-level GNSS receivers in the urban canyons of Hong Kong.

    For the experiment conducted in this paper, only the GNSS pseudorange measurement was utilized in the existing FGO-based GNSS/INS integration. The overall potential of the Doppler frequency and carrier-phase measurements has yet to be explored by the authors. To fill this gap, the authors proposed a tightly coupled GNSS/INS integration, using FGO, by exploiting the potential of diverse raw GNSS measurements. The GNSS pseudorange, Doppler frequency, and time-differenced carrier-phase measurements were integrated with the INS, using FGO.

    The authors believe the improved performance using FGO-based GNSS/INS integration positioning was due to the global optimization property and the increased measurement redundancy of FGO, compared with the method based on extended Kalman filtering.

    Weisong, Hsu; “Factor Graph Optimization for Tightly-Coupled GNSS Pseudorange/Doppler/Carrier Phase/INS Integration: Performance in Urban Canyons of Hong Kong.”

    3D mapping in urban environments aided by surround mask GNSS/lidar SLAM

    Automatic driving with coupled GNSS/INS and lidar sensors has been implemented in many urban environments successfully over the years. However, this technology is still prone to errors. These potential errors are especially evident in challenging environments, such as urban canyons with several moving objects and building layouts that provide unexpected and abnormal features for lidar sensors and multi-path for GNSS signals.

    To address these error challenges in urban environments, the authors of this paper proposed a surround mask that explores error sources from surrounding environments, which could subsequently improve the performance of an integrated mapping system. The surround mask in this experiment extracted a two-layer factor, including non-line-of-sight detection and static objects detection, to collectively compensate for the specific drawbacks of the lidar-based SLAM and the navigation system.

    The authors explain that the surround mask eliminated the need to apply complex post-processing to eliminate the accumulated error for each observing unit.

    The experimental results demonstrated that the proposed surround mask detected the represented error sources in the local coordinate and provided environment-awareness information for the integrated mapping system.

    Ai, Luo, El-Sheimy; “Surround Mask Aiding GNSS/LiDAR SLAM for 3D Mapping in the Dense Urban Environment.”

    Novel process noise model helps GNSS Kalman filter degradation in busy cities

    Improving the accuracy of GNSS positioning in urban environments is difficult, especially when using low-cost GNSS receivers. In this paper, the authors showed that if the process noise covariance is turned up in a “naïve” manner for poor satellite geometry, the estimation-error covariance could become unintentionally large in a certain direction.

    The unintentional inflation of estimation-error covariance could cause the degradation of accuracy. The authors also proposed a fictitious process noise covariance based on an extension of a novel process noise model, which was proposed in their previous work.

    The authors stated that in Kalman filter for GNSS positioning, the process noise covariance is often bumped up to avoid the filter divergence in the presence of unknown model errors, by assuming there is a fictitious process noise in addition to the nominal process noise. In this study, the fictitious noise covariance is determined based on the observation matrix, step-by-step, and it reduced the estimation errors without causing the unintentional inflation of estimation-error covariance.

    The effectiveness of the derived process noise model is demonstrated for the data sets that simulate GNSS signals from the antenna that moves from open sky areas to urban areas. The estimation errors with the derived process noise model were significantly reduced, compared to the ones with other two process noise models.

    Takayama, Yoji, Urakubo, Takateru, Tamaki, Hisashi; “Avoiding GNSS Kalman Filter Degradation in Urban Canyons with a Novel Process Noise Model.”

    3D lidar-aided GNSS RTK positioning for increased accuracy mapping in urban canyons

    The GNSS real-time kinematic (RTK) positioning technique has shown centimeter-level absolute results in open-sky areas; however, it can suffer from polluted GNSS measurements and poor satellite geometry in urban environments. This is due to the non-line-of-sight (NLOS) and multipath reception caused by signal blockage and reflection.

    In this paper, the authors stated that lidar sensors integrated with odometry systems that include an inertial measurement unit (IMU) provided a precise environment description and short-term accurate relative positioning capabilities that could be utilized for aiding GNSS-RTK to obtain better performance.

    While 3D lidar-aided GNSS RTK positioning methods detect the GNSS NLOS receptions via an incrementally built map and improve the satellite geometry using the low-lying virtual satellite from lidar features, the high-elevation angle NLOS receptions cannot be fully detected, and the multipath signals cannot be effectively mitigated.

    In response to this, the authors proposed a 3D lidar-aided GNSS RTK positioning method with iterated coarse to fine batch optimization by a global 3D NLOS exclusion aided by a point cloud map, which enables the detection of high-elevation angle NLOS receptions. Additionally, the authors proposed iterated batch optimization based on a devised, tightly coupled, factor graph that fully exploited the global consistency among the constraints of lidar, IMU and GNSS RTK to exclude potential multipath signals.

    The proposed method aimed to achieve lifelong accurate positioning performance in deeply urbanized areas. The effectiveness of the proposed method has been proved by the evaluation conducted on the author’s open-source challenging dataset, UrbanNav, which contains various sequences collected by automobile-level low-cost GNSS receivers in urban canyons of Hong Kong.

    Liu, Wen, Hsu; “3D LiDAR Aided GNSS Real-time Kinematic Positioning via Coarse-to-fine Batch Optimization for High Accuracy Mapping in Dense Urban Canyons.”