Crowded cities with stacked road systems and reflective architecture may offer impressive skylines, but for GNSS receivers, they create some of the harshest conditions on Earth. For technologies that depend on stable, trustworthy positioning, real-world testing in these challenging environments is essential. Here, Jez Ellis-Gray, product manager at Focal Point Positioning, a provider of GNSS positioning software, examines what recent field deployments reveal about the future of reliable GNSS.
Urban environments present unique constraints that no laboratory or simulation can perfectly replicate. A lab test may miss the thousands of variables that influence signal behaviour in a living, breathing city or a dense forest road. This matters most for automotive applications, where positioning must remain stable and trustworthy to support driver assistance and higher levels of automation. That is why we conducted field trials across Germany and Japan, evaluating FocalPoint’s S-GNSS Auto software running on STMicroelectronics’ Teseo GNSS receivers in challenging real-world conditions.
This testing demonstrated that GNSS performance in the real world is often determined not by peak accuracy under ideal conditions, but by the system’s reliability when satellite signals are distorted, reflected or partially obstructed.
This distinction — between accuracy and reliability — is becoming increasingly important for sectors where positioning plays a safety-critical role, including automotive.
Understanding the complexity of real environments
Germany’s combination of modern architecture and medieval street layouts made it a good place to test GNSS upgrades against standard technology. A city like Frankfurt offers a nice mix of glass facades, narrow streets and tall buildings – conditions that tend to create multipath interference.
During our recent field testing, conventional GNSS receivers frequently suffered from severe degradation of position accuracy when compared to a state-of-the-art ground truthing system. The standard receiver positions will often drift away from the travelled path, often through buildings or even onto parallel roads.
As accuracy deteriorates, the receiver can usually tell that the input information is poor, and output a warning for a larger estimate of error. This is a useful warning flag for AVs and allows for safe handover back to the human driver. However, in some cases, the reflected signals cause the miscalculation to be assumed correct. This “confident but wrong” GNSS is a much greater threat to autonomous driving, as the vehicle may make a dangerous decision based on this false information.
In contrast, the S-GNSS Auto enhanced receiver was able to maintain lane-level accuracy far longer, even in areas where intense reflections would normally overwhelm the satellite data. In multipath-heavy environments, S-GNSS on Teseo receivers showed an accuracy improvement of up to 4x. These findings reinforced our belief that, as automation increases, consistency and reliability will be more valuable than peak accuracy.
A navigation system that performs well on open motorways but struggles on urban roads will not scale safely to higher levels of vehicular automation. This is particularly relevant as the industry transitions from Level 2 to Level 3 autonomy, marking the point at which a vehicle takes full responsibility for the driving task in defined conditions, allowing the driver to disengage temporarily while the system manages safety-critical decisions.
This shift is expected to unlock significant commercial value. A 2023 report by McKinsey predicted that advanced driver assistance and autonomous driving features could generate between $300 billion and $400 billion in annual revenue by 2035, driven by software services and subscription-based functionality that depend heavily on reliable positioning. Unlocking this potential will depend on the next generation of vehicles having robust positioning systems, as users are unlikely to pay ongoing subscriptions to systems that repeatedly require human intervention or where safety concerns linger.
Japan: one of the world’s most challenging environments
If Germany represents a demanding test bed, Japan pushes GNSS to the extreme. Tokyo offers some of the toughest conditions anywhere in the world due to its towering buildings, multilevel road networks and narrow corridors that create intense multipath environments, so it was a natural choice for our next field test.
The results showed that in particularly dense districts such as Shinjuku, standard GNSS receivers often struggled to maintain a coherent position solution. Reflections from glass towers, elevated highways and rail lines produced non-line-of-sight signals that overwhelmed conventional algorithms.
S-GNSS Auto, integrated onto STMicroelectronics’ Teseo receivers, demonstrating improvements in vehicle positioning accuracy. (Data from Shinjuku, Tokyo)
However, receivers equipped with S-GNSS’s advanced signal-processing techniques demonstrated significantly improved performance. These upgraded devices maintained a stable positioning where traditional systems faltered, avoiding errors that would cause an automated system to disengage or provide dangerously erroneous positions
This improved reliability has direct implications for safety and user experience, which vehicle OEMs will no doubt welcome. In driverless vehicles, GNSS problems that trigger sudden driver handovers or interruptions to hands-free modes, are likely to erode trust and reduce the likelihood of subscription renewals, as the end user will judge the product less by its peak performance and more by its dependability in everyday situations.
Field testing and the future of positioning technology
As cities evolve, buildings grow taller and mobility systems become more congested, the challenges facing GNSS will only increase. As such, automotive OEMs are rightly starting to demand real world results, not just in ideal conditions (static, open sky) but in the worst conditions.
Manufacturers increasingly recognise that positioning is now a foundational technology that underpins safety, automation and customer experience. Investments in more reliable GNSS systems are therefore not marginal enhancements but essential enablers of future services. For companies developing navigation and sensing technology, real-world testing offers a unique opportunity to understand how systems react to chaotic, imperfect environments. It provides granular insight into where and why positioning fails, and how these software-based enhancements can bridge the gap. By validating these solutions in the world’s toughest GNSS environments, developers can offer manufacturers greater confidence in deploying advanced features across global markets.
You can request an evaluation kit here or download the full results report of our latest testing here.
STMicroelectronics has partnered with Segway to enhance its latest range of robotic lawnmowers. The collaboration integrates precision positioning and extended satellite-signal coverage, designed to improve operational efficiency and safety.
Reliable satellite navigation is essential for robotic lawnmowers that operate without boundary wires. These devices must autonomously navigate safely, even in areas where tall buildings or trees obstruct satellite signals. Uninterrupted satellite signal coverage is critical for functioning at the edge of stairs or steep slopes.
STMicroelectronics’ Teseo satellite navigation chips — with automotive-grade quality and reliability — are well-suited for robotic lawnmowers. These chips enable decimeter-level location accuracy, ensuring the mower remains within its designated field perimeter.
Segway’s recently launched Navimow X3 robotic lawnmowers incorporate ST’s Teseo V single-chip triple-band GNSS receivers. These receivers track multiple satellite constellations simultaneously, delivering superior performance in challenging environments. The real-time kinematic (RTK) technique further corrects satellite signal errors, ensuring stable operation in complex layouts such as properties with narrow passageways or multiple mowing zones. The company said that compared to earlier models, Segway reports a 20 to 30% increase in satellite signal coverage with ST’s technology.
Technical specifications include ST’s STA8135GA GNSS receiver from the Teseo V family. This automotive-qualified chip integrates triple-band positioning measurement and dead-reckoning features within a compact package. On-chip voltage regulators simplify power supply selection, further enhancing design efficiency.
Point One Navigation has joined the STMicroelectronics Partner Program. The program aims to deliver reliable navigation and positioning solutions to a diverse spectrum of ST customers in the U.S. and Western Europe.
Because of Point One’s navigation software and real-time kinematic (RTK) network, developers using ST Teseo GNSS solutions now have a more efficient path to create precise navigation solutions in industries such as agriculture, construction, last-mile delivery, and autonomous vehicles.
Point One’s Polaris Cloud is a GNSS correction network that enables GPS based localization, while allowing users to choose the performance and price point that best fits their application. With coverage across the U.S. and most of Western Europe, Polaris Cloud provides a readily available solution for precise localization.
FusionEngine software, developed by Point One, further enhances precision navigation by integrating additional sensors like IMUs and wheel speed sensors. This allows users to achieve a desired level of accuracy, even in situations where satellite signals are absent or in challenging urban environments. The software also offers automatic calibration, fault detection and compatibility with a range of host processors.
A roundup of recent products in the GNSS and inertial positioning industry from the June 2023 issue of GPS World magazine.
SURVEYING
Survey Software Georeference raw lidar data
Georeferencer 2.5 featuring anyNAV software is suitable for survey applications. Users of Georeferencer 2.5 with the anyNAV feature enabled can boresight payloads and georeference lidar data using the user’s navigation data. The anyNAV software enables lidar surveyors to create accurate point clouds quickly. Georeferencer 2.5 now takes navigation data from third-party inertial navigation systems, which enables users to use that data to georeference raw lidar data from multiple sensor families. The resulting data can then be viewed in many point cloud viewer software packages. OxTS, oxts.com
Inertial Navigation Solution Designed to deliver accuracy in challenging environments
Ekinox Micro combines a high-performance MEMS tactical inertial sensor with a quad-constellation, dual-antenna GNSS receiver, making it suitable for mission-critical applications. The device includes pre-configured motion profiles for land, air and marine applications, enabling the sensor and algorithms to be tuned for maximum performance in any condition. The device is designed for ease of use and integration, with simple connectors, a web configuration interface, datalogger, Ethernet connectivity, a PTP server, a REST API for configuration, and multiple input and output formats. Ekinox Micro is compatible with real-time kinematic (RTK) solutions and based on a tactical 0.8°/h class inertial measurement unit calibrated across the entire operating temperature range. It features accuracy roll/pitch of 0.015°, accuracy heading of 0.035°, and accuracy position of 1.2 m without any corrections or 1 cm in RTK. The device also meets the MIL-STD-461, MIL-STD-1275, and MIL-STD-810 standards. SBG Systems, sbg-systems.com
Lidar Sensor High-performance airborne bathymetric solution for deep water surveying
The HawkEye-5 increases survey efficiency by up to 25% compared to previous generations. The technology expands the capabilities of the Chiroptera-5 bathymetric lidar system, enhancing the productivity of applications such as nautical charting, environmental monitoring, and maritime surveillance in deep waters. The technology is designed to fit the Leica PAV100 gyro-stabilized mount, which isolates the sensor from unwanted aircraft movements — resulting in consistent data density and more efficient area coverage. The HawkEye-5 combined with the Chiroptera-5 features three lidar sensors, one four-band camera, and a QC camera to collect data from the seabed to land. Leica Geosystems, leica-geosystems.com
GNSS Receiver Complete with network RTK rover
The Sfaira One GNSS receiver is small and centimeter accurate. It provides users with an entry-level network real time kinematic (RTK) rover. Sfaira One is equipped with a GNSS module with 1,408 channels for GPS, BDS, GLONASS, Galileo and QZSS tracking — providing centimeter positioning in harsh environments. It also features advanced RTK and an anti-interference algorithm. The GNSS receiver connects via Bluetooth and can be configured to conduct surveying tasks on a smartphone. Additionally, Sfaira One supports SingularPad and SingularSurv software and is also compatible with mainstream field survey or GIS software. Sfaira One is IP65 dustproof and waterproof, which makes the receiver suitable for all weather conditions. It has a 4,800 mAh battery life with 16 hours working time and type-C interface that can be charged on-the-go with a power bank. SingularXYZ, singularxyz.com
MAPPING
Mobile Mapping Solution Built for large-scale infrastructure measurement and digital twin creation
The Pegasus TRK100 is small and light, making it easy to mount on any vehicle. The mobile mapping system features the same modular hardware approach that enables users to add more cameras to expand the range of use cases. With its advanced mapping capabilities, the Pegasus TRK100 enables GIS professionals to visualize and understand the location of assets to help make the right decisions, improve asset management, and support infrastructure building and maintenance. The Pegasus TRK100 combines artificial intelligence and a learning algorithm to enhance and optimize the clarity of points in post-processing for improved accuracy. The versatility of the Pegasus TRK100 suits a variety of applications in diverse industries, including telecommunications, utilities and road maintenance. Leica Geosystems, leica-geosystems.com
OEM
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Helix Antenna Series Suitable for unmanned system applications
HX-CUX012A is designed with an extremely low profile, making it suitable for integration into UAVs, surveying and monitoring devices. It reduces the overall weight of applications, enables multipath mitigation and more. HX-CUX005A is a solution for integrated helix antenna applications. It is designed with the integration of a GNSS antenna and Bluetooth/Wi-Fi antenna, enabling communication and navigation without mutual interference. HX-CH7609A is a low profile and small size housed helix antenna. It has comprehensive GNSS support including GPS, GLONASS, Galileo, BeiDou, as well as L-band correction services. HX-CH7609A features centimeter phase center repeatability and high gain at a low elevation. With signal filtering and multipath rejection, it provides reliable and stable GNSS signals. HX-CHX600A is a high-performance helix antenna that receives GPS, Galileo, BeiDou, GLONASS, as well as L-band signals. With 4.2 dBi high gain, it provides suitable tracking performance at a low elevation angle. Its low noise figure design reduces transmission interference and improves signal quality. Harxon, en.harxon.com
Helical Antenna Suitable for UAV applications
The HC990XF helical antenna is designed for precise positioning, covering the GPS/QZSS L1/L2/L5, QZSS L6, GLONASS G1/G2/G3, Galileo E1/E5a/E5b/E6, BeiDou B1/B2a/B2b/B3, and NavIC L5 frequency bands. This includes the satellite-based augmentation system (SBAS) available in the region of operation as well as L-band correction services. The HC990XF has a base diameter of 64 mm, is 37 mm tall and weighs 45 g. Its precision-tuned helical element provides full GNSS band coverage, suitable gain and axial ratio, and a tight phase center. The antenna base has an SMA (male) connector, three screw holes for secure attachment and an O-ring to waterproof the antenna connector. The HC990XF helical design does not require a ground plane, making it a suitable antenna for UAV applications. Tallysman Wireless, tallysman.com
Inertial Module For automotive uses
The ASM330LHB automotive-qualified MEMS inertial-sensing module provides accurate measurements for a wide variety of vehicle functions. With the dedicated software provided, ASM330LHB also addresses functional-safety applications up to ASIL B1. ASM330LHB contains a 3-axis digital accelerometer and 3-axis digital gyroscope that provides a six-channel synchronized output. The module’s high-accuracy inertial measurements are used to improve the precise positioning of a vehicle. The accelerometer and gyroscope maintain high stability over time and temperature, and have very low noise for an overall bias instability of 3°/hour. Specified over the extended temperature range, -40°C to 105°C, the ASM330LHB has multiple operating modes that let designers optimize the data-update rate and power consumption.
ASM330LHB can support advanced driver assistance systems or vehicle-to-everything communication, as well as help stabilize sensing systems such as radar, lidar and visual cameras, and assist semi-automated driving applications up to L2+. Additionally, ASM330LHB can be used to enable a variety of functionalities in the body of a vehicle. ASM330LHB was developed with the automotive functional-safety standard ISO 26262 — the ASIL B compatible software library has been certified independently by TÜV SÜD. By implementing dedicated safety mechanisms, including data integrity and accuracy, the library ensures compliance with ASIL B automotive systems.
With the companion software engine, the ASM330LHB supports the growing adoption of automotive systems that require safety integrity up to level B. The combination of two ASM330LHB sensor modules for fail-safe redundancy delivers resilient contextual data for driver-assistance applications such as lane centering, emergency braking, cruise assistance and semi-automated driving. ASM330LHB is AEC-Q100 qualified and in production now in a 2.5 mm x 3.0 mm 14-lead VFLGA package. STMicroelectronics, st.com
INS Built for automation applications
The AV200 is designed to give precise location data. It includes quad-constellation, dual-antenna, real-time kinematic (RTK) GNSS to provide users with position data as well as its temperature-calibrated, multi-core inertial measurement unit. These technologies give the AV200 position accuracy within 0.05 m, heading accuracy of 0.2°, and velocity accuracy of 0.2 km/h. The AV200 is built using the same technology that is commonly used for NCAP test validation, which has become the preferred technology for OEMs globally to test vehicles in both test-track and real-world scenarios. OxTS, oxts.com
Reference System For attitude and heading
AHRS-II-P is an enhanced, high-performance strapdown system that determines absolute orientation (heading, pitch and roll) for any mounted device. The AHRS-II-P can determine orientation for both motionless and dynamic applications. The AHRS-II-P contains a tactical-grade inertial measurement unit (IMU) consisting of three high-precision MEMS accelerometers, three advanced MEMS gyroscopes and a high-precision, gyro-compensated, embedded fluxgate compass. It also uses 8 mm fluxgate magnetometers. This device is suitable for a variety of devices such as UAVs, antennas, ships and robotic devices.
Inertial Labs, inertiallabs.com
GNSS Receiver For accurate positioning and heading
As a high-precision integrated GNSS positioning and heading receiver, the A200 can track all existing and planned constellations — including GPS, BSD, GLONASS, Galileo, QZSS and SBAS — providing high-precision positioning and heading data for users. A200 is designed specifically for precision agriculture, machine control, fleet management, robot and other industries. The A200 is equipped with a K823 GNSS module. It also features 1,226 channels. The A200’s third generation IMU delivers fast initialization and ensures the output of heading during temporary GNSS signal loss. The built-in data link has low power consumption and a long working range. It also can be upgraded to a super-long-range data link module. ComNav Technology, comnavtech.com
A roundup of recent products in the GNSS and inertial positioning industry from the April 2023 issue of GPS World magazine.
TIMING
Image: Furuno
Global Timing Module Supports L1 and L5 GNSS signals
GT-100 is compatible with all GNSS constellations. The GT-100 realizes high robustness and standard of time accuracy and stability. The GT-100 features advanced multipath mitigation, anti-jamming and anti-spoofing as well as short-term holdover, ensuring superior performance even if L1 or L5 are jammed. The module delivers nanosecond precision for 5G wireless systems, radio communications systems, smart power grids and grand master clocks. Along with the GT-100, GT-9001 and GT-90 achieve a level of time stability of 4.5ns (1σ) and offer superior features and performance. Furuno, furuno.com
Image: UTStarcom
PTP Grandmaster Designed for mobile networks
The SyncRing XGM30E precision time protocol (PTP) grandmaster is designed for mobile networks and other applications requiring accurate time and frequency synchronization. It is an addition to the SyncRing line of network synchronization equipment. The SyncRing XGM30E is an indoor PTP grandmaster offering echo time accuracy of more than ±40 ns, which can meet the stringent timing requirements of demanding applications, including 4G and 5G networks. The clock complies with the PTP IEEE 1588-2008 standard, supporting major ITU-T frequency and phase and time profiles. SyncRing XGM30E supports synchronous Ethernet (SyncE) output on all service interfaces for accurate frequency synchronization, and SyncE input for enhanced time holdover operation during GNSS outages. The grandmaster includes an indoor rack-mount design and power supply redundancy with AC or DC built-in options and has flexible management options. The SyncRing XGM30E is available now.
UTStarcom, utstar.com
Image: Huber+Suhner
Copper-Free Data System For precise timing synchronization for high-performance networks
The GNSS and Power over Fiber GPSoF System receives, transmits and expands GNSS timing signals for the purpose of timing synchronization in data centers, central offices, distributed antenna systems or enterprise applications. It enables greater distances between the radio frequency source and the receiver system. It is also immune to RFI, EMI and EMP, contains remote control and monitoring via a web interface, and supports infrastructure installation due to direct GNSS signal evaluation.
Huber+Suhner, hubersuhner.com
Image: ADVA
M-Code Device With advanced timing for military applications
The OSA 5422 grandmaster clock meets key requirements of military networks by providing advanced positioning, navigation and timing (PNT) capabilities and improved resilience. The OSA 5422 grandmaster clock is integrated with a highly reliable M-code receiver, which meets stringent frequency and phase synchronization needs. The device is equipped with multi-band, multi-constellation GNSS receivers for when M-code is not available. The OSA 5422 also has long holdover and precision time protocol backup, which enables it to maintain accurate timing even in the event of M-code disruption. The OSA 5422 supports legacy interfaces such as BITS and IRIG and features eight field-upgradable 10G bit/s ports and 1G bit/s interfaces. The device is suitable for most demanding military edge applications.
ADVA, adva.com; Brandywine Communications, brandywinecomm.com
AUTONOMOUS
Image: CHC Navigation
GNSS RTK Steering System Suitable for agriculture applications
The NX510 SE Auto-Steer is an automated steering system that retrofits several types of new and old farm tractors and other vehicles. It can be connected to local real-time kinematic (RTK) networks or GNSS RTK base stations. NX510 SE is a guidance controller powered by multiple corrections sources and five satellite constellations: GPS, GLONASS, Galileo, BeiDou and QZSS. It has a built-in 4G and UHF modem that connects to all industry-standard differential GPS and RTK corrections to achieve centimeter-accuracy steering. NX510 SE contains GNSS and inertial navigation system terrain compensation technology, which maintains high accuracy in challenging environments and terrain. This makes NX510 SE suitable for ditching, planting and harvesting applications. In addition, AgNav multilingual software, operating on a 10.1 in industrial display, supports multiple guideline patterns that include AB line, A+ line, circle line, irregular curve and headland turn. CHC Navigation, chcnav.com
Image: Trimble
Module for Rail Monitoring For automated and semi-automated rail monitoring
The T4D Rail Module enables simple data collection and reduces office work required to automate movement detection for rail monitoring projects. The T4D software offers four main elements for automated monitoring: sensor management and data integration for GNSS; total station, geotechnical, vibration and environmental sensors; geodetic processing and adjustments for accurate results; analysis and visualization through several tools that provide real-time updates to support in-depth analysis and data presentation; and alarming and reporting. The T4D Rail module enables integration of rail as-builts collected with the Trimble GEDO system or with a track measuring bar paired with the Trimble Access Gauge Survey app. It also can automate calculations for track geometry parameters, generate analysis charts, and trigger alarms. The T4D software is offered in five editions to fit various project requirements. The editions include T4D Access, T4D Field, T4D Intermediate, T4D Geotechnical and T4D Advanced. T4D Access and T4D Advanced are the two editions that support the add-on Rail Module. Trimble Geospatial, geospatial.trimble.com
Image: Airobotics
C-UAV Device Anti-UAV protection device
The Iron Drone system is an advanced counter-UAV device, designed to defend against hostile drones in complex environments with minimal damage. Iron Drone is an automated intercepting system designed to eliminate small drones without using GPS or radio frequency jamming. The Iron Drone system is launched from a designated pod and flies autonomously towards targets under radar guidance. It identifies the target using computer vision capabilities. The intercepting UAV follows the target then uses a net and a parachute to incapacitate it, capture it and lower it to the ground.
Airobotics, airoboticsdrones.com
Image: Rohde & Schwarz
Drone-based analyzer For UAV inspections
EVSD1000 VHF/UHF nav/drone analyzer provides highly accurate UAV inspection of terrestrial navigation and communications systems. The EVSD1000 VHF/UHF nav/drone analyzer is a signal-level and modulation analyzer for medium-sized UAVs. It features measurements of instrument landing systems, ground-based augmentation systems and VHF omnirange ground stations. The mechanical and electrical design is optimized for UAV-based, real-time measurements of terrestrial navigation systems with up to 100 measurement data sets per second. The analyzer provides high-precision signal analysis in the frequency range from 70 MHz to 410 MHz. This also includes the needed measurement repeatability to ensure that results from UAV measurements can be compared to flight and to ground inspections in line with ICAO standards. The EVSD1000 VHF/UHF nav/drone analyzer reduces runway blocking times, provides necessary measurement repeatability and offers measurement precision and GNSS time and location stamps. While streaming measurement data during a drone flight via the data link to a PC on the ground, the analyzer can also buffer data internally to ensure no results are lost if the data link is lost. Rohde & Schwarz, rohde-schwarz.com
SURVEYING & MAPPING
Image: SiLC
Coherent Vision Solution Suitable for advanced products
The Eyeonic Vision System is a frequency-modulated continuous wave lidar solution, which delivers high levels of vision perception to identify and avoid objects with low latency. At the core of the system is a fully integrated silicon photonics chip. It provides more definition and precision than legacy lidar solutions, with roughly 10 milli-degree of angular resolution coupled with millimeter-level precision. These features enable this solution to measure the shape and distance of objects with high-precision and at a large distance. The system combines the Eyeonic Vision Sensor and a digital processing solution based on a powerful field-programmable gate array. The flexible architecture enables synchronization of multiple vision sensors for unlimited points per second. The compact, powerful, vision solution is suitable for autonomous vehicles, smart cameras, robotics and other advanced products. It is available now. Pricing varies depending on configuration.
SiLC Technologies, silc.com
Image: SBG Systems
GNSS-Aided INS Easily integrated with lidar or other third-party sensors
Quanta Plus is a GNSS-aided inertial navigation system (INS). The device combines a MEMS inertial measurement unit (IMU) with a resilient GNSS receiver to get reliable position and attitude, as well as providing real-time kinematic (RTK) fixes. Quanta Plus includes motion profiles, which enable users to optimize the sensor parameters to suit different use cases. The built-in precise time protocol server ensures sub-microsecond synchronization with external devices such as lidar. The device also has a built-in datalogger, Ethernet interface for easy integration, and a web configuration interface for simple setup and control. The INS can be integrated with Qinertia, SBG System’s post-processing software. Qinertia improves the performance of acquired data during a mission using reliable RTK corrections from a wide range of continuously operating reference station networks, or by importing base-station data during the process. Quanta Plus also improves the accuracy of the position and attitude using forward and backward processing and by integrating a tight coupling between GNSS and IMU data. SBG Systems, sbg-systems.com
Image: Inertial Labs
Survey Laser Suitable for remote-sensing applications
The Resepi Hesai XT32 laser is designed for accurate remote-sensing applications. It can be used with commercially available lidar scanners, including Velodyne, Quanergy, Ouster, RIEGL, LIVOX and Hesai, as well as with UAVs. Resepi is completely modular, so users have full control for customization. The remote-sensing device uses a GPS-aided inertial navigation system with a NovAtel RTK/PPK single- or dual-antenna GNSS receiver, integrated with a Linux-based processing platform. It also comes with a 2 TB USB memory drive and has an embedded Wi-Fi cellular modem. Resepi has 3 cm to 5 cm point-cloud accuracy and can reach heights of more than 200 m above ground level. It is compatible with most UAV models; however, it is typically used with DJI M300, DJI M210 or DJI M600 models. The device is suitable for scanning and mapping, precision agriculture with lidar, simultaneous localization and mapping algorithm development, utility inspection and construction site monitoring. Resepi-supported software includes Hexagon NovAtel, PCPainter and PCMaster. Inertial Labs, inertiallabs.com
Image: CHC Navigation
IMU-RTK GNSS Receiver Provides robust and accurate positioning
The i90 GNSS receiver combines a GNSS real-time kinematic (RTK) engine, a high-end inertial measurement unit (IMU) sensor and advanced GNSS tracking capabilities to increase RTK availability and reliability. The embedded 624-channel GNSS receiver is compatible with GPS, GLONASS, Galileo and BeiDou signals. The i90 GNSS combines high-end connectivity modules: Bluetooth, Wi-Fi, NFC, 4G and a UHF radio modem. The internal UHF radio modem allows long-distance base-to-rover surveying up to 5 km. The built-in IMU ensures interference-free and automatic pole-tilt compensation in real time. An accuracy of 3 cm is achieved with pole-tilt range of up to 30°. The i90 GNSS receiver is suitable for construction and land surveying projects. CHC Navigation, chcnav.com
Image: CHCNAV
Field Application For Android devices
LandStar8 is designed to be flexible and user-friendly for surveying and mapping tasks. It is versatile, modular and customizable for topographic tasks such as surveying, stake out, cadastral, mapping and geographic information systems (GIS). Building on the legacy of LandStar7, the LandStar8 provides features such as a refined user interface, streamlined workflows, faster operation, and integrated cloud services. Cloud connectivity is built in for backup, data storage or remote technical support. LandStar8 has a simple and intuitive layout with large map windows and sharp graphics. Users can hide features they rarely use and display only those they need. They also can copy coordinate settings, control and staking points from another handheld controller by scanning a QR code. Projects can be edited and sorted by history and attributes. Custom coordinate systems, geoid models and coding libraries can be updated at any time by using resource packages. LandStar8 also features a terrain calibration wizard designed for non-expert users. CHCNAV, chcnav.com
Image: Position Partners
Survey Rover For accurate, survey-grade aerial mapping and photogrammetry
SmartSurveyor facilitates accurate, survey-grade aerial mapping and photogrammetry without the need for a connection between a camera shutter and a GNSS receiver. The fully compact, handheld aerial mapping survey rover is compatible with DJI Mavix 2 and 3 series and Phantom 4 Pro UAVs. The design is dissimilar from other UAV mapping systems in that it works from a UAV or smartphone and with two or more ground control points (GCPs) while using an ultra-matching technique. Once SmartSurveyor captures data, all photos and the GNSS file are uploaded to a PC and analyzed through the Agisoft UltraMatch workflow to confirm their accuracy before they are exported. Data can be managed in the cloud or on a local PC using software designed by MapSender. Additionally, this mapping tool works in tandem with the AllDayRTK subscription GNSS network service so that collected data can be uploaded to Tokara to remotely manage a project.
NB-IoT Industrial Module Complete with GNSS geo-location capabilities
Image: STMicroelectronics
The ST87M01 is a fully programmable, certified LTE Cat NB2 NB-IoT industrial module that covers worldwide cellular frequency bands and integrates advanced security features. The ST87M01 is an integrated native GNSS receiver with multi-constellation access, which ensures enhanced and accurate localization. The module has a diminutive 10.6 mm x 12.8 mm land grid array footprint, making it suitable for applications where a small form factor is key. The STM8701 offers flexibility for product developers, presenting a fully programmable internet of things (IoT) platform enabling users to embed their own code into the module for simple applications. A variety of protocol stacks are available to handle popular IoT use cases. It targets wide-ranging IoT applications that require ultra-reliable low-power wide-area network connectivity and has ultra-low power consumption with less than 2 µA in low-power mode and transmit output power up to +23 dBm. Suitable applications for the module include smart metering, smart grid, smart building, smart city and smart infrastructure applications, as well as industrial condition monitoring and factory automation, smart agriculture and environmental monitoring. The module also can be combined with a separate host microcontroller, permitting many more use cases. STMicroelectronics, st.com
Image: Quectel
GNSS Module Designed for battery-operated, ultra-low power GNSS devices
The LC76G module is a compact, single-band, ultra-low power GNSS module that features fast and accurate location performance. The module can concurrently receive and process signals from the GPS, GLONASS, BeiDou, Galileo and QZSS constellations. The LC76G has an internal surface acoustic wave filter and integrated low-noise amplifier, which can be connected directly to a passive patch antenna and provides filtering against unwanted interference. With a compact size of 10.1 mm × 9.7 mm × 2.4 mm, the footprint of the LC76G is compatible with other industry solutions, as well as Quectel’s legacy L76 and L76-LB modules. The LC67G is designed for battery-operated, ultra-low power GNSS devices, such as wearable personal trackers, wildlife and livestock tracking, toll tags, portable container trackers, as well as several traditional markets such as shared mobility and low-cost asset trackers. Quectel Wireless Solutions, quectel.com
The INS-DH-OEM. (Photo: Inertial Labs)
Inertial Navigation System Incorporates NovAtel and Honeywell technology
The INS-DH-OEM utilizes a dual-antenna NovAtel GNSS receiver and a Honeywell HG4930-CA51 inertial measurement unit (IMU). The INS-DH-OEM contains Inertial Labs’ on-board sensor-fusion filter, navigation and guidance algorithms, and calibration software. The INS-DH-OEM has three axes, a full operational temperature range, advanced MEMS accelerometers and new-generation tactical-grade MEMS gyroscopes to provide accurate position, velocity, heading, pitch and roll. It is small and lightweight, measuring 85.5 mm x 67.5 mm x 52.0 mm and weighing 280 g. The dual-antenna NovAtel GNSS receiver is operational with GPS, GLONASS, Galileo, BeiDou and QZSS constellations. The INS-DH-OEM is compatible with most commercially available lidars including Velodyne, Riegl and Faro. The algorithms are suitable for different dynamic motions of vessels, ships, helicopters, UAVs, gimbals and land vehicles. Inertial Labs, inertiallabs.com
Image: MSO
Speed Sensor Multi-use sensor for workflow
The Speed Wedge MKII is a true-ground speed sensor and active motion detector for moving objects, based on radar doppler technology. This sensor is suitable for use in indoor and off-highway vehicles, conveyor belts, material flow and open channel water surface flow. The sensor contains a dead-reckoning system component for inertial measurement units and integrated management systems (IMS) in GPS/GNSS-denied environments such as in tunnels and underground mining operations. It also features sensor fusion with GNSS and IMS improving positioning accuracy, quality and reliability. Speed Wedge MKII deploys a radar front-end with planar antennas continuously emitting electro-magnetic waves at 24 GHz. It is designed for contactless measurement of speed and distance travelled independent on wheel/drive slip. For demanding applications Speed Wedge MKII is sealed and potted in a rugged encasing. Speed Wedge MKII is available in variants with pulse, serial RS232 and CAN-Bus output. High-speed up to 200 km/h is available.
MSO, mso-technik.de/home-en.html
Image: Orolia
GNSS Simulations Software For simulation and testing needs
Skydel GNSS simulation software can now generate more than 500 simulated satellite signals. This platform is suitable for GNSS users, experts and manufacturers, as well as users needing a low-Earth-orbit-capable simulation system. Skydel contains a feature that includes multi-constellation and multi-frequency signal generation, remote control from user-defined scripts, and integrated interference generation. In addition to generating a high channel and satellite count, Skydel also can produce navigation warfare signals without any additional hardware. Orolia, orolia.com
Image: Mikroe
Compact Add-On Board Provides access to L-band GNSS corrections
LBand RTK Click is a compact add-on featuring the NEO-D9S-00B, a professional-grade, satellite data receiver for L-band corrections from u-blox. Operating in a frequency range from 1,525 MHz to 1,559 MHz, the NEO-D9S-00B decodes the satellite transmission and outputs a correction stream. This enables a high-precision GNSS receiver to reach accuracies down to centimeter-level. An independent stream of correction data, delivered over L-band signals, ensures high availability of position output. LBand RTK Click also uses several mikroBUS pins. In addition, LBand RTK Click contains an SMA antenna for connecting a Mikroe-brand antenna. This antenna easily allows positioning in space, supporting GNSS L-band frequencies. LBand RTK Click implements advanced security features such as signature and anti-jamming mechanisms. It also can be integrated with other GNSS receivers from the u-blox F9 platform. Mikroe, mikroe.com
Quectel Wireless Solutions Co. Ltd., in association with STMicroelectronics, has released the LG69T module, an automotive-grade dual-band high-precision GNSS module that integrates dead-reckoning (DR) and real-time kinematic (RTK) technologies.
The new Quectel module, announced at 2019 Apsara Conference in Hangzhou, is designed to facilitate open-sky positioning performance with an accuracy of up to 10 centimeters, which is currently the industry’s most advanced positioning technology for the automotive market. LG69T will support next-generation precision positioning capabilities for smart vehicles and autonomous driving scenarios.
The Quectel LG69T GNSS module is based on ST’s STA8100GA, the latest Automotive-grade dual frequency positioning chip with 80 tracking channels and four rapid-acquisition channels that are compatible with many constellations: GPS, BeiDou, Galileo, NAVIC/IRNSS and QZSS.
It is an AEC-Q100-qualified dual-band (L1 + L5) GNSS module that integrates multi-band RTK technology for centimeter-level accuracy.
The LG69T module’s dead-reckoning capabilities feature an integrated inertial measurement unit (IMU) that provides continuous high-precision positioning. The LG69T supports corrections input for standard Radio Technical Commission for Maritime Services (RTCM) and centimeter-level navigation by using RTCM data from a third — local base stations. The module performs well under the highly challenging conditions of urban canyon environments.
“We are thrilled to collaborate with STMicroelectronics on our newest generation of high-precision positioning module,” said Min Wang, Quectel’s automotive product line general manager. “With this highly-integrated LG69T module, automakers and Tier 1 suppliers will no longer have to spend time selecting components, integrating hardware, adapting interfaces and conducting tests and verifications, which will greatly cut their time-to-market and costs, and help them accelerate the deployment of autonomous driving to seize early opportunities.”
“ST has strong experience and is the Global Automotive High Precise Positioning Technology and Market Leader. We are very proud to cooperate with leading Chinese smart driving high technology company,” said MH TEY, Greater China, South Asia and Korea automotive marketing and application head of department, STMicroelectronics. “Today, there is growing dependency on high-performance GNSS in automotive applications such as navigation, safety and autonomous driving. With this cooperation, we are very confident to become the market leader by providing cost-effective and unique best-in-class solution for autonomous vehicle.”
Engineering samples of Quectel’s LG69T module will be offered to automakers and Tier 1 suppliers by the end of 2019, and the product will be commercially available around mid-2020 and is expected to be deployed in mass produced models as early as 2021.
GNSS chip manufacturers and positioning systems developers are working on bespoke devices for autonomous driving. This month, we look at a development with embedded functional safety.
By Fabio Pisoni, Domenico Di Grazia, Giuseppe Avellone, Luis Serrano, Brett Kruger, Laura Norman and Natasha Wong Ken
INNOVATION INSIGHTS by Richard Langley
I DRIVE A 10-YEAR OLD KIA SPORTAGE. It is still quite roadworthy despite having to contend with New Brunswick winters. However, it lacks some of the safety features that are present in newer cars. There is no back-up camera, no forward-collision warning, no automatic emergency braking, and no blind-spot warning, for example. These are just some of the safety systems that come as standard or optional on most new cars these days. Still, the driver is responsible for the safety and operation of the car at all times. True, help might be provided for parallel parking and cruise control, but that’s about it for automated operation with most vehicles.
But things are changing and changing fast. Real automation is coming to automobiles. Already partial automation is available in some high-end vehicles that can take over steering, braking and acceleration in certain circumstances. The driver is still responsible for other aspects of the vehicle’s operation including paying attention to road conditions. Soon, we will have conditional automation where the car can drive itself but the driver must stay alert and be prepared to take over immediately at any time. Next will come high automation where a computer fully drives the car at certain times on certain routes such as a highway. Multiple systems, including back-up systems, will maintain a required safety level and the car will determine if it is safe to operate autonomously. If not, it could pull over to the side of the road and shut down. And finally, we may have full automation of cars. They will be able to drive on any road under virtually any conditions and won’t need any controls such as steering wheels or accelerator or brake pedals.
Augmented GNSS guidance will play a major role in the automation of vehicles. As with any navigation or guidance system, there are four important requirements: accuracy, availability, continuity and integrity. Perhaps the most obvious requirement, accuracy describes how well a measured value agrees with a reference value, typically the true value. How well a system accounts for various errors or biases determines the accuracy of corrected measurements and, ultimately, the accuracy of a derived position. A navigation system’s availability refers to its ability to provide the required function and performance within the specified coverage area at the start of an intended operation. In many cases, system availability implies signal availability. Environmental factors such as signal attenuation or blockage or the presence of interfering signals might affect availability. Ideally, any navigation system should be continuously available to users. But, because of scheduled maintenance or unpredictable outages, a particular system may be unavailable at a certain time. Continuity, accordingly, is the ability of a navigation system to function without interruption during an intended period of operation.
While accuracy, availability and continuity of a guidance system are all important, it is the integrity or trustworthiness of the system that is paramount. It is why the automotive industry has already developed integrity standards for the automation of vehicles. And it is why GNSS chip manufacturers and positioning systems developers are working on bespoke devices for autonomous driving, whatever the level of automation. In the Innovation column this time around, we’ll learn about one such development — one with embedded functional safety.
Autonomous driving applications are raising the requirements for onboard GNSS receivers to new highs. Position accuracy, protection levels, high availability, robustness of operation and integrity are the priorities shaping a new class of automotive components and architectures. Autonomous driving deals with life-critical issues: the expectation of reliability and safety for this new generation of receivers, as well as for other sensors and systems, is very high.
The International Organization for Standardization (known by the language-independent short form ISO) has issued documents codifying functional safety (FuSa) for automotive applications: ISO 26262: part 1 to part 11. ISO 26262 complements the well-known automotive reliability standard published by the Automotive Electronics Council, AEC-Q100. With respect to FuSa, a system can be defined as functionally safe if it always operates correctly and predictably. More importantly, in the event of failures, the system must remain safe for people. Lastly, as security is becoming paramount, a new standard for cybersecurity in automotive applications — ISO/SAE 21434 — is in development by ISO and SAE International (initially called the Society of Automotive Engineers) that will require a GNSS receiver to be robust against jamming, spoofing and meaconing attacks.
The Automotive Safety Integrity Level (ASIL) is a key part of ISO 26262 compliance, and the standard specifically identifies the minimum testing requirements depending on the ASIL of the component. The ASIL of a component or system depends on the ASIL of the target application. The ASIL is determined at the beginning of a development process. It varies from ASIL-A to ASIL-D, where A is for less critical applications and D for the most critical ones such as steering and breaking systems. ASIL-rated lane-level positioning performance can be demonstrated today by combining an ASIL-B software positioning engine and TerraStar-X correction technology from Hexagon Positioning Intelligence with GNSS measurements from an ASIL-B-rated GNSS chipset.
To conjugate performance requirements with the demand of embedded functional safety, STMicroelectronics has developed TeseoAPP (STA9100), a next-generation GNSS component, designed to meet an ASIL-B level of safety. TeseoAPP is a multi-band GNSS measurement engine. It outputs all the observables, navigation and integrity data required by a safety-critical precise positioning algorithm, located on a host processor. TeseoAPP also computes a local L1 code-based standard position, velocity and time (PVT) solution (SPS) for monitoring and integrity purposes. Also part of the baseline features are autonomous satellite acquisition (cold start condition), real-time assistance, data decoding and storage on external non-volatile memory (NVM), accurate timing and pulse-per-second generation under vehicle dynamics.
RECEIVER ARCHITECTURE
The target architecture for a safety-critical platform is sketched in FIGURE 1, where a host microprocessor is in charge of collecting GNSS observables and sensor data from the TeseoAPP. The latter includes on the same chip die a first configurable RF chain for the L1 signal ensemble and the baseband part for processing all the signals in the served bands, while the second chip is an RF front end (code-named STA5635), configurable for receiving the other served bands (such as GPS L2 or L5, Galileo E5a or E5b or E6, and so forth). The two chips are clearly visible in the photograph of a TeseoAPP evaluation module of FIGURE 2.
FIGURE 1. Block diagram of the TeseoAPP platform for safety-critical applications, featuring surface-acoustic-wave (SAW) filters, a temperature-compensated crystal oscillator (TXCO), non-volatile memory (NVM) and both internal and external STA5635 tuners. (See text for other initialisms used.) Diagram: Authors)
FIGURE 2 The TeseoAPP Evaluation Module, including the STA9100 (TeseoAPP) and STA5635 (external tuner). Photo: Authors
The selected frequency plan and constellation configuration depend on the specific autonomous driving scenario and the target geographic area. The TeseoAPP supports a mix of frequencies and signals as shown in TABLE 1. The chipset baseband unit can track up to 80 channels. A tracking snapshot from a rooftop antenna (located at the ST office in Naples, Italy) is illustrated in FIGURE 3.
Both the TeseoAPP and the STA5635 have been designed for ASIL-B following the concept of “safety element out of context” (SEooC) described in ISO standard ISO 26262:2012. In this context, assumptions have been made for the application (such as on the mission profile), identifying the related safety goals from which functional and technical safety requirements have been derived.
TABLE 1. The TeseoAPP (STA5635) supported frequency plans and scenarios.
FIGURE 3. Screenshot of the L1-L5 TeseoAPP configuration, from the ST Teseo-Suite tool (using the Naples rooftop antenna). Image: Authors
Following the guidelines identified in the ISO 26262 flow for safety-relevant product development, several safety mechanisms have been identified at the hardware, firmware and system/boot level. The microcontroller unit (MCU) supports dual-core operation in a lock-step configuration to verify processor output errors together with a memory built-in self-test (executed at startup) and error correction code on a safety-related embedded random access memory. Other hardware redundancies have been introduced in safety relevant parts such as triple-voted registers for critical configuration parameters. For the real-time operating system (RTOS), an ASIL-D-level product — the highest level — was selected.Functional safety analysis of the GNSS sub-system has produced a dedicated technical safety concept, including aspects such as tuner operation, interference and jamming mitigation, signals and observables quality management (QM), reliable host communication (using generic end-to-end or E2E protocols for data integrity and resilient flow control), and reliable system software. A simplified overview of all these safety mechanisms is outlined in FIGURE 4, where the orange-colored blocks are specific for the GNSS sub-system.
FIGURE 4. Overview of the TeseoAPP safety mechanisms. (See text for acronyms and initialisms used.) Diagram: Authors
Safety Mechanisms. The technical safety concept of the GNSS sub-system is implemented by a security, integrity and safety (SIS) monitoring layer (see FIGURE 5). The SIS collects information and metrics from other receiver blocks embedded in the RF/baseband hardware and from different components of the GNSS firmware stack. The SIS internally computes integrity risk estimates, which are delivered to a central intelligence monitor (CIM) capable of switching the receiver into a safe state, within a fault-tolerant time interval, when the overall receiver integrity appears compromised. In its simplest form, the CIM can be represented by a weighted sum of integrity risk inputs, followed by some activation function. During this process, a first layer of logic (CIM-L1) combines a subset of signal quality metrics to decide a priori which observables shall be passed to the host or discarded (not delivered).
FIGURE 5 Safety information flow through the TeseoAPP security, integrity and safety layer. (IP = intellectual property; other short forms in text.) Diagram: Authors
The collected signal metrics include quality estimators (based on multi-correlation techniques for example) or classic linear combinations of observables (such as dual-frequency carrier-phase differences or code-minus-carrier). Receiver metrics, on the other hand, have a more global scope and include estimators for inter-frequency biases, system-time cross-checks among constellations, and so on. The fault collection and control unit (FCCU) conveys hardware status flags to the SIS. Typically, an FCCU exception indicates some critical hardware failure and takes a priority path when switching the safe state. For example, a fault in the MCU lock-step monitor will trigger an immediate firmware action, mediated by the FCCU.
POSITIONING PERFORMANCE
To demonstrate the performance that can be achieved using the ST TeseoAPP chipset, Hexagon Positioning Intelligence (PI) has combined measurements from the TeseoAPP with an automotive-grade antenna and Terrastar-X correction technology, and processed the data using Hexagon PI’s software positioning engine. Even with a modern receiver supporting dual-frequency, multi-constellation measurements, such as the TeseoAPP, corrections are necessary to deliver decimeter-level performance and safety information required by an autonomous vehicle.
In clear-sky environments, lane-level positioning accuracy is achieved, enabling GNSS as a key input to autonomous systems. FIGURE 6 shows the horizontal error performance of the combined ST+PI solution in the form of an error time series and an error cumulative distribution function (CDF). The error performance expected from today’s single frequency automotive-grade GNSS without corrections and processing is also shown for comparison.
FIGURE 6. Horizontal error time series and cumulative distribution function (CDF) of the TeseoAPP alone and of the TeseoAPP with Hexagon PI software positioning engine (SWPE) in an open-sky environment. (Image: Authors)
For guidance systems in autonomous applications, the GNSS position must be accompanied by safety information and integrity guarantees. The concept of protection levels (PLs) has been introduced to provide this. A horizontal protection level defines a circle or ellipse around the reported GNSS position, which will have some error, within which the actual position is guaranteed to fall. The Hexagon PI software positioning engine is ASIL-B rated, so its position and PL outputs are available for use in safety-related autonomous applications. The autonomous system using the GNSS position is assured that its actual position is within the protection level ellipse. To output ASIL-B-rated positions accompanied by PLs, ASIL-rated GNSS measurement inputs are required.
Using the inputs and techniques described above, the Hexagon PI software positioning engine calculates PLs for every GNSS position output. The Hexagon PI data from Figure 6 is shown again in FIGURE 7 with accompanying PL information. In this case, a PL with integrity risk of 10-7 is shown, meaning that the actual position error is expected to exceed the reported PL at a rate less than 10-7 per hour.
FIGURE 7. Horizontal error and protection level (PL) including cumulative distribution functions (CDFs) of the Hexagon PI software positioning engine (SWPE) in an open-sky environment. (Image: Authors)
The PLs shown in Figure 7 are typically much greater than the position error. This is because the protection level calculation must account for a large number of potential faults that are not generally present. For instance, undetectable GNSS satellite faults can occur at rates greater than 10-7 per hour, and so must be accounted for in the PL.
In non-clear-sky environments, the GNSS position calculation is complicated by frequent loss of “sight” of the GNSS satellites. This is mitigated by having additional constellations and frequencies. However, for added availability of a precise position in challenging environments, it is necessary to incorporate sensor fusion into the position calculation, typically by using a six degree-of-freedom inertial measurement unit (IMU) as input, which includes three accelerometers and three gyroscopes to measure 3D translational and rotational motion. The IMU can maintain position accuracy for short periods when GNSS is unavailable, such as when driving under an overpass on a highway. The IMU provides a relative positioning output, so the absolute error growth is unconstrained in the absence of GNSS inputs. Therefore, it is important to have the GNSS receiver as the primary sensor in the positioning solution to constrain IMU drift and to reacquire GNSS signals rapidly after emerging from a GNSS outage.
Position error results for a typical highway environment are shown in FIGURE 8 after adding input from an automotive-quality IMU to the Hexagon PI software positioning engine. Small spikes in position error are due to short GNSS outages along the test route. However, the error growth due to loss of GNSS is minimal due to the coupling of the IMU data with the GNSS measurements.
FIGURE 8. Horizontal error time series and cumulative distribution function (CDF) of the TeseoAPP alone, and of the TeseoAPP with Hexagon PI software positioning engine (SWPE) in a highway environment. (Image: Authors)
FIGURE 9 shows the Hexagon PI highway data with accompanying PLs. Though the errors are well-constrained through GNSS outages, the PLs typically increase significantly. This is due to the higher noise of low-cost IMUs, and the uncertainty associated with reacquiring GNSS signals. PLs must account for worst-case IMU performance, which can have errors orders of magnitude greater than the nominal performance. During GNSS signal reacquisition, minimizing receiver noise is critical for fast position reconvergence, reinforcing the need for high-quality GNSS in autonomous applications.
FIGURE 9. Horizontal error and protection level (PL) including cumulative distribution functions (CDFs) of the Hexagon PI software positioning engine (SWPE) in a highway environment. (Image: Authors)
CONCLUSION
The TeseoAPP is the first generation of multi-band GNSS chipsets designed by STMicroelectronics to meet the two main requirements of autonomous driving: accuracy and safety-critical operation. The execution of the ISO 26262 standard for TeseoAPP is still a work in progress and encompasses two main aspects: 1) a safety plan implementation, code quality metrics and processes management and 2) the technical safety concept. Both of these aspects presented specific challenges, mainly due to the inherent complexity of the product and the large amount of firmware involved.
To exploit the maximum benefit of the TeseoAPP in safety-critical automotive applications, a high-accuracy ASIL-B-rated position engine is required. Hexagon PI’s software positioning engine is designed to use measurements from an ASIL-rated GNSS receiver, along with GNSS corrections and IMU data, to generate ASIL-rated position outputs, with accompanying integrity guarantees. The Hexagon PI software positioning engine computes protection levels. The calculation and determination of PLs is required to meet the safety and integrity guarantees necessary in autonomous driving for functionally safe operation.The software positioning engine also outputs ASIL-rated velocity, attitude and absolute time data, although we have not discussed these in this article.
The required high performance and safety expectations suggested, since the early stages of the project, a system composition in which the TeseoAPP was configured as an ASIL-B measurement-engine whereas the ASIL-B software positioning engine algorithms (by Hexagon PI) run on a separate ASIL host processor. We believe this synergy of competencies will represent the key for a successful solution to enable safe and reliable positioning in autonomous driving applications.
ACKNOWLEDGMENTS
The TeseoAPP chipset has been developed with the support and in the framework of the European Safety Critical Applications Positioning Engine project, which is funded by the European GNSS Agency under the European Union’s Fundamental Elements research and development program.
FABIO PISONI leads the GNSS System Architecture and Software Team (Automotive and Discrete Group) at STMicroelectonics Italy in Milan, where he has worked since 2009. He has a degree in electronics from Politecnico di Milano and has previous experience as a GNSS and digital signal processing (DSP) engineer.
DOMENICO DI GRAZIA is a GNSS signal senior staff engineer at STMicroelectronics Italy in Naples, where he has worked since 2003. He has a degree in telecommunication engineering from the University of Naples Federico II, holds patents in the GNSS area, and has previous experience in digital communications.
GIUSEPPE AVELLONE is in the GNSS System Architecture and Software Team (Automotive and Discrete Group) at STMicroelectonics Italy in Catania, where he has worked since 1998. He has a degree in electronics from Università di Palermo and previous experience as a GNSS and DSP engineer.
LUIS SERRANO is a GNSS technical marketing manager with STMicroelectronics based in Munich. He holds a Ph.D. in GNSS from the Department of Geodesy and Geomatics Engineering, University of New Brunswick, Canada. He has been active in the GNSS precise positioning field since 2007, and holds a patent on GNSS.
BRETT KRUGER is a software engineer specializing in GNSS/INS integration in the Safety Critical Systems Group at the Hexagon Positioning Intelligence (PI) NovAtel brandin Calgary, Canada. He holds an M.A.Sc. in electrical engineering from the University of Toronto, Canada.
LAURA NORMAN is a geomatics engineer specializing in GNSS integrity and protection levels in Hexagon PI’s Safety Critical Systems Group. She obtained her M.Sc. from the Department of Geomatics Engineering at the University of Calgary, Canada.
NATASHA WONG KEN is the Safety Critical Systems product manager at Hexagon PI. She has worked at Hexagon PI since 2012 after obtaining a B.Sc. in geomatics engineering from the University of Calgary.
