GPS World

Tag: ION GNSS+ 2022

  • Research roundup: Autonomous applications in transportation

    Research roundup: Autonomous applications in transportation

    Image: gorodenkoff/iStock/Getty Images Plus/Getty Images
    Image: gorodenkoff/iStock/Getty Images Plus/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 autonomous applications in transportation. The papers are available here.

    Addressing integrity monitoring of autonomous navigation

    There are critical issues for the integrity monitoring of autonomous navigation applications, which include an adequate uncertainty budget in the observation domain, redundancy for the determination of the navigational states, and the capability of fault detection and exclusion.

    Several aspects are addressed in the paper, including how to: determine interval bounds to handle GNSS multipath effects in urban environments, realize fault detection and exclusion based on constraint satisfaction and set membership, and improve the detector using weighting models.

    The authors of the paper aim to contribute to the alternative integrity approach based on interval and set representations for bounding and propagating system uncertainty. Simulated and real-world experiments are carried out to demonstrate the feasibility of the authors’ proposed methods.

    The authors note that statistical evaluation of integrity will not always suffice due to the presence of remaining systematic uncertainty, but state the alternative integrity approach will contribute to future autonomous navigation applications.

    Su, Jingyao; Schön, Steffen; “Advances in Deterministic Approaches for Bounding Uncertainty and Integrity Monitoring of Autonomous Navigation.”

    Estimation and reference systems in automation

    For a high level of automation, estimation is crucial, and to achieve a full and reliable navigation evaluation, a trustable reference system needs to be developed.

    Although the presence of a reference system and of an inertial measurement unit with GNSS through the multi-sensor fusion scheme was integrated, in GNSS-denied or challenging environment the navigation solution could not be accurately estimated and still needs to be fixed.

    The authors of the paper propose new strategies to better estimate the lidar-based position uncertainty and to update the reference system.

    The first strategy proposed involves determining the appropriate position error covariance matrix, based on the Hessian matrix and the scale of covariance obtained from a normal distribution transform (NDT) scan matching technique and the geometric dilution of precision computed from the distribution of point cloud segments in each scan.

    In the second strategy proposed in the paper, the updated reference system was post-processed according to the loosely coupled INS/GNSS/NDT integration scheme with a forward and backward smoothing process.
    The results of the proposed strategies indicated that the updated reference system provides more reliable navigation estimation compared to an existing reference system from commercial software and can be used for accurate evaluation of positioning, navigation and timing with automated vehicle applications.

    Srinara, Surachet; Chiu, Yu-Ting; “Adaptive Covariance Estimation of Lidar-Based Positioning Error for Multi-Sensor Fusion Scheme with Autonomous Vehicular Navigation System.”

    Evaluating TerraStar-X

    GNSS performance using typical, low-cost GNSS devices in vehicles is not enough to achieve the positioning and availability needed for lane-level accuracy on autonomous vehicles. The antenna and receiver hardware available in standard vehicles limits the position accuracy and convergence performance. These limitations make the positioning more susceptible to error sources such as receiver multipath, noise, carrier tracking and stability.

    GNSS correction services with additional design considerations and sophisticated algorithms are needed to work within the constraints of automotive-grade GNSS devices to achieve the performance required for lane-level positioning.

    TerraStar X technology from NovAtel enables these applications. It includes an orbit and clock determination system (OCDS), which produces a set of corrections, precise satellite orbits and clocks, and satellite-specific biases for individual signals augmented by the computation of additional regional corrections.

    The authors of the paper outline the design and performance of the combined OCDS and regional correction system. They demonstrate the performance of the TerraStar X technology across a variety of applications.
    The addition of regional corrections enables automotive and mass-market applications to achieve in-lane positioning in seconds, using any dual-frequency, dual-constellation GNSS hardware. The result is software that provides a continuous stream of multi-constellation, multi-frequency GNSS corrections — enabling a correction service that makes the affordable GNSS device ecosystem possible.

    Regional corrections also improve the performance of survey-grade GNSS receivers.

    Mervart, Leos; Lukes, Zdenek; Alves, Paul; “TerraStar X Technology: Design of GNSS Corrections for Instantaneous Lane-Level Accuracy on Large Scale Connected Vehicles and Devices.”

    Solving the localization problem in autonomous driving

    The localization problem in autonomous driving imposes two criteria on the navigation solution: accuracy and reliability or integrity. According to the authors of this paper, solving the localization problem is a key requirement to enabling the development of autonomous platforms.

    This paper presents AUTO, a real-time integrated navigation system that tightly integrates INS, GNSS-RTK, odometer, and multiple radars sensors with high-definition maps to achieve a high-rate, accurate, continuous, and reliable navigation solution. It also shows how AUTO leverages a tight integration of imaging radars with other traditional sensors to provide a robust navigation solution with corresponding estimates of the uncertainty.

    The AUTO solution was tested in a variety of environments and locations, including a range of conditions such as winter weather, to assure the robustness and reliability required by autonomous applications.

    The results demonstrate the lane level accuracy of the solution in a variety of challenging urban and downtown environments. Additionally, the tight integration enables the determination of protection levels to describe upper bounds on the uncertainty.

    The results in the paper are illustrated using a Stanford Diagram, along with a user-defined alert limit to describe the solution integrity and availability. The proposed algorithm uses a map matching technique between the imaging radar data and a globally referenced high-definition map to better estimate the solution uncertainty and protection levels.

    AUTO’s tightly integrated approach to integrity monitoring means uncertainties and protection levels can be determined even in areas where the system may experience extended periods of GNSS unavailability.

    Krupity, Dylan; Chan, Billy; Ali, Abdelrahman; Salib, Abanob; Georgy, Jacques; Goodall, Christopher; “Integrity Monitoring and Uncertainty Estimation with AUTO’s Non-linear Integration of Multiple Imaging Radars and INS/GNSS for Autonomous Vehicles and Robots.”

  • Research Roundup: Atmospheric effects on GNSS

    Research Roundup: Atmospheric effects on GNSS

    Photo: buradaki/iStock/Getty Images Plus/Getty Images
    Photo: buradaki/iStock/Getty Images Plus/Getty Images

    GNSS researchers presented hundreds of papers at the 2022 Institute of Navigation (ION) GNSS+ conference, which took place Sept. 19–23 in Denver, Colorado, and virtually. The following five papers focused on atmospheric effects on GNSS signals. The papers are available at www.ion.org/publications/browse.cfm. 

    Addressing Scintillation Error

    Mitigating the scintillation effect at low latitude is a complex matter: several kinds of experimental data must be collected, realistic models must be developed, and, most importantly, useful real-time indices and alerts must be made available.

    The authors introduce a prototype based on a patent owned by SpacEarth Technology to address scintillation error detection and mitigation, supporting precision GNSS-based services at low latitudes in any season and space weather conditions. The patent relates to a method of total electron content (TEC) and scintillation empirical forecasting, in particular short-term forecasting (seconds to minutes). The output of the method is necessary to feed mitigation algorithms aiming at improving accuracy on GNSS precise positioning techniques (RTK, NRTK, and PPP) under ionospheric harsh conditions.

    The prototype is designed with a Central Elaborating Facility, which collects the data provided by a network of GNSS monitoring stations detecting scintillation events, and broadcasts foreseen scintillation parameters. Users with a rover mitigation device can apply the parameters from the central facility for scintillation error mitigation. 

    Vincenzo Romano, INGV and SpacEarth Technology; Claudio Cesaroni, INGV; Luca Spogli, Alessandro Fiorini, INGV and SpacEarth Technology; Marco Fermi, Gter; Lorenzo Benvenuto, Gter and University of Genoa; Tiziano Cosso, Gter; Marcin Grzesiak, SRC/PAS; Joao Francisco Galera Monico, Italo Tsuchiya, UNESP; Gabriel Oliveira, Marcos Guandalini; “Ionospheric Scintillation Mitigation at Low Latitude to Improve Navigation Quality.”

    Ring of Fire GUARDIAN 

    Commonly, natural hazards release energy into the Earth’s atmosphere in the form of acoustic-gravity waves, which propagate up to the ionosphere. The resulting traveling ionospheric disturbances (TIDs) can be detected using GNSS signals, through the computation of the integrated total electron content (TEC) along the lines of sight between GNSS receivers and satellites. The global distribution of ground-based GNSS receivers constantly tracking multiple GNSS constellations (GPS, Galileo, GLONASS, BeiDou, and others) provides excellent spatio-temporal coverage around the world, including in areas of limited coverage by existing warning systems.

    The authors present the operational GNSS-based Upper Atmospheric Real-time Disaster Information and Alert Network (GUARDIAN). Based on dual-frequency GNSS data from the Global Differential GPS (GDGPS) network of the Jet Propulsion Laboratory, the GUARDIAN architecture computes slant TEC time series in near real time.

    As part of the GDGPS network, 78 stations around the Pacific ring of fire monitor the four GNSS constellations: GPS, Galileo, GLONASS and BeiDou. Cycle slips are corrected and the time series are filtered, both in real time. The resulting data stream is output live to a user-friendly public website, benefitting the general public and the scientific community. 

    The current GUARDIAN focuses on the Pacific region. However, the architecture can readily be extended to a worldwide coverage.

    Léo Martire, S. Krishnamoorthy, L. J. Romans, B. Szilágyi, P. Vergados, A. W. Moore, A. Komjáthy, Y. E. Bar-Sever, A. B. Craddock, NASA Jet Propulsion Laboratory, California Institute of Technology; “GUARDIAN: A Near Real-Time Ionospheric Monitoring System for Natural Hazards Early Warnings.”

    Civil Aviation Interference

    The authors provide a survey on GNSS receiver architectures with emphasis on new carrier-tracking techniques for mitigating the adverse effect of ionospheric scintillation within the context of civil aviation. The survey is complemented by results gathered from simulations on the impact of ionospheric scintillation in conventional receiver architectures. A review on scintillation mitigation techniques is carried out, covering several “technique families,” highlighting their potential for performance improvement, as well as their shortcomings and challenges in implementation.

    A semi-analytical simulation campaign is carried out for different modulations: L1, L5 for GPS, and E1, E5a for Galileo. Here, the performance of a standard receiver tracking a set of GPS and Galileo satellites affected by ionospheric scintillation is analyzed to pinpoint existing vulnerabilities to this effect.

    The simulation results show that ionospheric scintillations are responsible for large variations in carrier-to-noise ratio, which in turn can be responsible for losses of lock and large phase variations, increasing phase RMSE and in some cases leading to cycle slips of the phase estimation. Thus, the adopted solution must be robust to signal power fluctuations and the occurrence of cycle slips and able to maintain phase lock.

    António Negrinho, GMV-PT Pedro Boto, GMV-PT Marta Cueto, GMV-ES Mikael Mabilleau, EUSPA Claudia Paparini, EUSPA Ettore Canestri, EUSPA; “Survey on Signal Processing Techniques for GNSS Ionospheric Scintillation Mitigation.”

    Tonga Eruption Data Analyzed

    Extreme natural disasters, such as volcanic eruptions, can create visible pressure waves in the atmosphere and trigger observable ionospheric wave responses that can travel hundreds of kilometers in the ionosphere. The acoustic and gravity waves generated can cause ionospheric TEC perturbations and variations. The TEC determines the GNSS ionospheric delay and can cause significant positioning errors, which may affect the performance of GNSS-based applications.

    The researchers processed GNSS data collected from the Hong Kong Satellite Positioning Reference Station Network to analyze the ionospheric activity and positioning performance responding to the Tonga volcanic eruption on Jan. 15, 2022. To detect and repair cycle-slip jumps, the researchers applied theTEC rate and Melbourne Wubbena Wide Lane (MWWL) linear combinations. A Savitzky-Golay low-pass filter with a 30s window was used to improve the TEC accuracy.

    The team investigated the changes in TEC, Rate of TEC index (ROTI) and positioning errors in the eastward, northward and upward directions after the anomalous ionospheric propagation to Hong Kong between 11:30 and 14:30. The team found the ionospheric anomaly could generate large changes in the three parameters, with peaks up to three times the calm period. Their prompt research contributes to a better understanding of the coupling of extreme ionospheric activities and dynamics caused by volcanic eruptions. 

    Xiaojia Chang, Kai Guo, Zhipeng Wang, Kun Fang, Hongxia Wang, Beihang University; Hailong Chen, China Academy of Aerospace Electronics Technology; “Ionospheric Anomaly and GNSS Positioning Responses to the January 2022 Tonga Volcanic Eruption.” 

    Toolbox for Monitor Network

    The MONITORtoolbox is a set of Python-coded software tools to perform automatized large-scale processing of data from the Monitor network of the European Space Agency (ESA). The Monitor network aims to continuously monitor ionospheric scintillation events from multiple ground stations strategically located around the globe. It accommodates a repository with a large number of GNSS measurements containing scintillation events for users to analyze scintillation data or for research purposes.

    This paper shows the potential of the MONITORtoolbox for providing access to a large amount of data that otherwise, without a systematic processing, becomes practically useless. The software developed implements the means to collect data and store it in a local database for quick offline access. It detects the presence of scintillation events based on certain conditions and criteria defined by the user and identifies its properties in terms of duration, time of occurrence, intensity and satellite location. It implements the tools to compute relevant statistics, providing insights on ionospheric scintillation phenomena.

    Sergi Locubiche-Serra, Alejandro Pérez-Conesa, Diego Fraile-Parra, Gonzalo Seco-Granados, José A. López-Salcedo, Universitat Autònoma de Barcelona, IEEC-CERES; Juan M. Parro-Jiménez, Raúl Orús-Pérez, ESTEC, European Space Agency; “MONITORtoolbox — Software Tool for the Analysis of Ionospheric Scintillation Data from the ESA Monitor Network.” 

  • WORK Microwave showcases self-configurable Xidus GNSS simulator

    WORK Microwave showcases self-configurable Xidus GNSS simulator

     

    Xidus-648 (Photo: Work Microwave)
    Xidus-648 (Photo: Work Microwave)

    WORK Microwave demonstrated its Xidus GNSS Simulator at the ION GNSS+ 2022 conference, which took place last week in Denver.

    The Xidus GNSS simulator provides high-fidelity, reliable RF signals with automated calibration, making it suitable for validating the performance of GNSS receivers for a wide range of applications, including spacecraft, aviation, unmanned aerial vehicles, digitalized agriculture, autonomous driving, and military drones and vehicles.

    The Xidus GNSS simulator enables users to perform rigorous and extensive testing of GNSS systems. Through advanced customization and configurable capabilities, Xidus provides pure, perfectly synchronized and reliable benchmark signals distributed over one or many RF outputs. The wide, dynamic power range is a key differentiator, allowing users to perform real tests without attenuation artifacts. With the Xidus system, users can easily and effectively generate long-term, complex and reproducible yet variable scenarios at higher update rates without leaving the laboratory.

    Xidus simulates multi-constellation, multi-frequency and multi-RF signals out of the box — for any position on Earth and in space. The simulator includes APIs and remote control for flexible system integration and automated testing. Modular signal-generation hardware allows simple plug-and-play module insertion, enabling easy and robust field upgrades whenever necessary, the company said.

    WORK Microwave’s Xidus GNSS simulator series includes:

    Xidus-Studio Software — This powerful and intuitive graphical user interface for the Xidus GNSS simulator simplifies the configuration of any scenario, providing access to a wide variety of parameters: different vehicle models with 6DOF, multiple vehicle simulation, spoofing and meaconing, multiple TX antenna patterns, multiple RX antenna patterns, industry standard error models, runtime distortions on individual channels, and more. Xidus-Studio also allows the design of bespoke satellite orbits ranging from LEO to GEO. The software runs on both Windows and Linux platforms.

    Xidus-424 GNSS simulator — Offering a compact chassis with two RF outputs, it runs any scenario over multi-constellation/frequency even with the entry configuration. This chassis supports up to 128 LOS channels and 512 multipaths that can be seamlessly distributed over the two RF outputs.

    Xidus-648 GNSS simulator — This is a bigger chassis designed to support the most demanding scenarios, up to 256 LOS channels and 1,024 multipaths, dispatched seamlessly over four RF outputs. The chassis can easily be cascaded if needed. The tool is suitable for test campaigns on receivers with multiple antennas.

  • Next-gen Unicore GNSS hardware available through Rx Networks 

    Next-gen Unicore GNSS hardware available through Rx Networks 

    Photo: Unicore
    Photo: Unicore

    Rx Networks is offering for both the North and South American markets the next-generation high-precision GNSS modules from Unicore Communications, based in China.

    Based on the new NebulasIV systems-on-chip (SOC), the UM960, UM980 and UM982 modules offer all-constellation, multi-frequency, high-precision real-time kinematic (RTK) positioning and heading capabilities.  

    Rx Networks is exhibiting at  ION-GNSS+ taking place this week in Denver, at Booth 108, and will exhibit at  Intergeo in Essen, Germany, Oct. 18-20, at Booth F2.033.

    Available in a small footprint with low-power consumption, the Unicore modules are suited for use in reference stations, surveying and mapping, precision agriculture, heading applications, machine control, drones and robotics, vehicle navigation, precision timing, and more.

    Photo: Unicore
    Photo: Unicore

    Rx Networks is a key supplier of high-accuracy services and assistance data to a growing list of GNSS hardware manufacturers. As high-precision GNSS becomes ubiquitous, those seeking precise positioning solutions can now have Unicore GNSS hardware enlightened with Rx Networks data services.

    “We are pleased to be bringing this new leading GNSS Technology into the Americas,”  said Cameron Baird, head of Business Development, GNSS Hardware. “With further product miniaturization coupled with added performance, features and functionality, Unicore GNSS technology is well suited for all precision GNSS applications.”

    Email [email protected] for details.

  • Orolia’s new GNSS simulator GSG-7 packed with features

    Orolia’s new GNSS simulator GSG-7 packed with features

    GSG-7 delivers the highest standard of GNSS signal testing in a cost-effective, easy-to-use, turnkey form factor supporting navigation and timing systems

    Photo: Orolia
    Photo: Orolia

    Orolia has released the GSG-7, its latest GNSS signal testing solution.

    Orolia made the announcement at the ION GNSS+ conference, taking place this week in Denver.

    Offered through the Orolia family of Skydel-based simulators, the GSG-7 features a small form factor, an internal RF combiner, high-end performance with a 1,000-Hz simulation iteration rate, real-time synchronization, hardware-in-the-loop (HIL) integration, powerful automation, and multi-constellation and multi-frequency simulations.

    “The GSG-7 is redefining the essential and high capabilities in GNSS simulation with its ease of use, advanced simulation capabilities, reduced size, and competitive price,” said Lisa Perdue, simulation product line director. “Leveraging the powerful Skydel software and commercial-off-the-shelf (COTS) hardware, GSG-7 can accommodate almost any configuration to conduct system testing and simulation. The use of SDRs [software-defined receivers] means that maintenance and customization are not only easier, but more cost-effective than other options on the market.”

    Powered by Orolia’s Skydel simulation engine, the GSG-7 can be programmed to simulate operations with all current GNSS signals, as well as future ones. Skydel’s architecture makes the GSG-7 future-proof by allowing new, incoming signals and updates to be implemented through software updates.

    The GSG-7 simulator is suitable for development and integration projects that require high performance, all-in-view satellite signals, and an increased number of GNSS constellations.

    “Capable of handling complex simulation scenarios, the GSG-7 has a simple, yet powerful application program interface (API) ensuring easy automation and integration into your test environment,” Perdue added. “Users can also benefit from advanced HIL capabilities that include zero-effective latency and built-in performance monitoring tools.”

    GSG-7 Webinar

    Orolia will host a product webinar on Oct. 6 to discuss the new GSG-7 in great detail. Topics will include:

    • What is the architectural difference?
    • What are the applications?
    • What are the use cases?
    • What resources are available to users?

    Register here.

  • Research Roundup: Mitigating GNSS interference

    Research Roundup: Mitigating GNSS interference

    Photo: traveler1116/iStock/Getty Images Plus/Getty Images
    Photo: traveler1116/iStock/Getty Images Plus/Getty Images

    GNSS researchers are presenting hundreds of papers at the 2022 Institute of Navigation (ION) GNSS+ conference, taking place Sept. 19–23 in Denver, Colorado, and virtually. The following five papers focus on GNSS receiver technology and interference mitigation. The papers will be available at www.ion.org/publications/browse.cfm.

    FINDING INTERFERENCE WITH ADS-B

    Conference Presentation: Sept. 23, 1:50 p.m.; Session F6

    The growing dependence of critical and safety-of-life systems on GNSS makes the ability to rapidly detect and localize the presence of GNSS interference events increasingly important. Ground-based GNSS jammer detection can be used to detect local interference sources. However, this approach is limited by line of sight, hence applying it to large areas is costly in both time and money.

    A complementary technique is to use the airborne GNSS receiver data provided by Automatic Dependent Surveillance—Broadcast (ADS-B). As these receivers are at altitude, their lines of sight can cover a wide area. The drawback is that ADS-B was not designed for this purpose, and the messages contain limited information for the assessment of interference.

    The authors have developed and will demonstrate an algorithm for real-time detection and localization of GNSS interference sources using ADS-B transmissions on the 1090 MHz (Mode S ES) radio frequency channel. They demonstrate this capability using recorded ADS-B transmissions from known interference events.

    Zixi Liu, Sherman Lo, Todd Walter, Juan Blanch, Stanford University; “Real-time Detection and Localization of GNSS Interference Source.”

    TESTING A GNSS MONITORING SYSTEM

    Conference Presentation: Sept. 23, 4:04 p.m.; Session F6

    Even interference at low levels can be catastrophic to systems that depend on GNSS. It can prevent GNSS signals from reaching the user (interference or jamming) or give false signals, resulting in an incorrect position and time solution (spoofing). The capability to confidently detect and localize interference quickly could help mitigate this threat. Furthermore, if the system could also provide information characterizing the interference, it could help law enforcement not only interdict, but also prosecute the threat.

    Building a consumer-level commercial-off-the-shelf (COTS) GNSS monitor would also make it cost effective for widespread utilization. This paper describes the development and field testing of a system to provide this capability.
    The monitor uses the u-blox F9, an inexpensive commercial receiver offering multi-constellation and dual-frequency position and time solutions, as well as powerful interference-detection metrics. Initial analysis of the receiver’s measurement capabilities determined that it provides many features useful for assessing the operational environment across a geographical region. Performance and output of the receiver is characterized under different jamming and spoofing scenarios.

    Different receivers and antennas may react differently based on both hardware and software configurations and offer the user varying interference rejection techniques and detection metrics. As a result, it is important to gain a good understanding of the receiver’s behavior. Another way to test behavior is to examine its performance in nominal conditions in various scenarios and locations, as presented in this paper.

    Benon Gattis, Dennis Akos, University of Colorado Boulder; Yu-Hsuan Chen, Sherman Lo, Todd Walter, Stanford University; “Test and Measurements from a Global Navigation Satellite System (GNSS) Monitoring System.”

    GEOLOCATING INTERFERENCE WITH SMARTPHONES

    Conference Presentation: Virtual; Session F6

    With the availability of RAW GNSS measurements on Android smartphones, detecting GNSS interference using modern handsets has become a realistic crowdsourcing possibility, especially with the inclusion of automatic gain control (AGC) in Android 8 (Oreo).

    While crowdsourcing jamming detection — and knowing whether your smartphone is subject to jamming or spoofing  — is valuable, locating the interference source may be even more important. This work explores the feasibility of crowdsourcing interference source localization with modern Android smartphones.

    The work has three goals:

    • To examine localization of a civilian-type GPS L1 jammer using a network of smartphones
    • To investigate how best to approach current obstacles regarding such localization
    • To estimate how accurate this type of positioning can be.

    An important part of this work is to investigate differences in GNSS data reported by various Android smartphones. The smartphones in this study were specifically selected by the manufacturer of the GNSS chipset to enable the authors to examine how their GNSS receivers perform under the same circumstances. Three parameters were specifically investigated as measures of received jamming power: carrier-to-noise ratio (C/N0), AGC and the number of tracked satellites.

    The selected smartphones were put through a series of tests to examine how these three parameters vary with changing conditions. These tests include subjecting the smartphones to an actual jammer in a controlled lab setup and an investigation of the impact of smartphone (GNSS antenna) position and orientation on C/N0 and AGC. Using the data collected in these tests, several interference geolocation strategies will be discussed.

    The authors also consider whether interference localization from consumer-off-the-shelf (COTS) smartphones is currently accurate enough for this use. The shortcomings of smartphone GNSS hardware may be resolved using more clever positioning strategies such as using a larger number of handsets. Alternatively, it may require upgraded hardware and standardization.

    Søren Skaarup Larsen, Daniel Haugård Olesen, Anna B. O. Jensen, Lars Stenseng, Technical University of Denmark, DTU Space; “Assessment of RFI Geolocation Using Modern Android Smartphones.”

    MITIGATING MULTIPATH IN AN L5 CHANNEL

    Conference Presentation: Sep. 21, 4 p.m.; Session F2

    Multipath mitigation with machine learning relies on offline training with an exhaustive number of labeled observations. Current super-resolution correlation methods, which include MUltiple SIgnal Classification (MUSIC), operate online by testing and choosing from a high number of candidate signal hypotheses.

    A new method of MUSIC is presented that reduces numerical complexity and is applied to processing L5 correlation vectors to reduce multipath by identifying the earliest path. The rank of this estimator is examined in static and dynamic conditions in various signal environments. Higher rank allows more signal paths to be identified.

    This method is also complementary with various L5 signal-tracking methods such as open- and closed-loop tracking.

    Paul McBurney, Norman Krasner, Florean Curticapean, Miguel Ribot, Mahdi Maaref and Lionel Garin, OneNav; “Application of Super Resolution Correlation to Multipath Mitigation in an L5 Channel.”

    USING A VIRTUAL ANTENNA ARRAY

    Conference Presentation: Sep. 22, 11:03 a.m.: Session F3

    One of the simplest ways to increase GNSS anti-jamming and anti-spoofing (AJ/AS) performance is increasing the number of controlled reception pattern antenna (CRPA) array elements. However, this increases the size, cost, complexity and required processing power of the overall system. To counter this constraint, the researchers applied a new development in antenna hardware design to GNSS threat mitigation techniques. This resulted in better CRPA performance without increasing the footprint. The work improves AJ/AS performance without adding additional elements, and serves as proof of concept of the application of an adaptively spaced virtual array created with multimodal elements to GNSS AJ/AS.

    New breakthroughs in antenna-array research extend the case of non-uniform excitation of elements to the elements’ individual positions. By using multimodal antennas as elements, it has been shown that elements’ phase centers, or perceived locations, can be adjusted with purely electronic means. When applied to each element in an antenna array, this realizes a reconfigurable array.

    This research extends the concept of a virtual array with adaptive inter-element spacing into GNSS AJ/AJ methods. A new way to integrate a virtual array into a GNSS application is explored and incorporated into current space-time adaptive processing (STAP) algorithms.

    Gabriel Wiggins and Scott Martin, Auburn University; “Applications of a Virtual Antenna Array to GNSS Threat Mitigation: First Results.”

  • ION and Google host Smartphone Decimeter Challenge

    ION and Google host Smartphone Decimeter Challenge

    Photo: Google
    Photo: Google

    Winners will present their projects at ION GNSS+ 2022 in Denver

    The Institute of Navigation’s Satellite Division, in partnership with Google, will host the 2nd annual Smartphone Decimeter Challenge, with the winning teams presenting their methods at the ION GNSS+ 2022 meeting. ION GNSS+ 2022 takes place Sept. 19–23 at the Hyatt Regency Denver, adjacent to the Colorado Convention Centerx.

    The Smartphone Decimeter Challenge is designed to advance research in smartphone GNSS positioning accuracy using state-of-the-art algorithms and technologies such as advanced machine learning models and precision GNSS algorithms.

    While standard receivers using signals from GPS, other GNSS (Galileo, BeiDou, GLONASS) and regional systems (QZSS and IRNSS) provide accuracy between 3 and 10 meters (often worse in urban environments), better location can be obtained by processing carrier-phase measurements, inertial measurement unit (IMU) data, and base station corrections.

    Teams will use datasets collected using the GPS receivers and IMUs of Android smartphones to compute location down to an accuracy of decimeters. Mobile users will benefit from lane-level-accuracy-based services, enhanced experience in location-based gaming, and greater specificity in location of road safety issues.

    Winner selection is based on the accuracy of results from the test datasets compared to highly accurate ground truth. The top three winners will receive prizes valued at $15,000+ including a guaranteed speaking slot at the highly competitive ION GNSS+ 2022 conference (subject to technical paper and ION presentation requirements); a travel subsidy; and complimentary registration to attend ION GNSS+ 2022 in Denver.

    Entries must be received by July 29.

  • ION GNSS+ 2022 abstract deadline is March 4

    ION GNSS+ 2022 abstract deadline is March 4

    Photo: ION
    Photo: ION

    Abstracts for the ION GNSS+ 2022 show, “GNSS + Other Sensors in Today’s Marketplace,” are due March 4.

    The ION GNSS+ conference will take place September 19-23  at the Hyatt Regency Denver at Colorado Convention Center in Denver. The show will also include a virtual option.

    The 2022 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.

    The two tracks covered during the conference will be commercial and policy tracks and research tracks.

    The commercial and policy tracks will include high performance and safety critical applications, status and future trends in GNSS, and mass market and commercial applications. The research tracks will include multisensor and autonomous navigation, algorithms and methods, and advanced GNSS technologies.

    Interested parties may submit their abstracts at https://www.ion.org/gnss/call-for-abstracts.cfm.