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Mobile mapping is helping accelerate the progression of some of the most difficult engineering challenges on the planet, including those around autonomous driving and advanced surveying techniques, such as lidar.

The complexity of those challenges means that the outputs from a mobile mapping inertial navigation system (INS) must be as accurate as possible. A high-performing INS will make the most of any available GNSS signals, with the aim of providing centimeter-level accuracy even in areas where GNSS performs poorly, for instance in urban canyons. It also offers important data on pitch, roll and heading, which maintains the integrity of survey data even as the vehicle moves across large areas.

With such a wide variety of INS devices on the market, it can be difficult to narrow down the best option. It is important to establish criteria that will aid in evaluating the different INS propositions out there for mobile mapping projects.

1) How tightly integrated are the inertial measurement unit (IMU) and GNSS data?

INS is an essential element in providing accurate location data in as many environments as possible. Therefore, it is important to know how effectively the data from the IMU supports the GNSS data. In technical terms, this means evaluating whether the sensors are tightly integrated at all, and if so, how well.

The reason GNSS struggles in urban canyons and under tree canopies is that it is unable to get the six satellite signals necessary for a real-time kinematic (RTK) lock. In this situation, the GNSS will give readings that may be incorrect, as it is essentially trying to solve an equation without having all the numbers.

A tightly integrated GNSS and INS data stream will select the most reliable signals and use those to determine the position of the vehicle. If the data streams are not tightly integrated, then the INS’ ability to counteract GNSS issues is limited. Without accurate positioning, data scans will lose accuracy and even become completely incoherent the longer the user scans — making them unreliable at best, and unusable at worst.

2) Trading off accuracy and cost

Although accuracy is vital in mobile mapping, some INS devices will provide data that is far more accurate than the given job requires. Because greater accuracy equals greater cost, users may be paying more than necessary.

With that being said, the scale of accuracy and cost is not linear. An INS half the price of the most expensive one on the market will not be half as accurate. Look at each offering carefully to see what it includes and decide what level of accuracy and features are vital to the task. Eliminating unnecessary levels of precision or additional software features that are not needed is an effective way to make some savings.

3) How rugged is the device?

Mobile mapping vehicles will likely be out in the dry, wet, hot, cold, mud and snow. These vehicles will almost certainly be used consistently for long periods of time. Thus, it is essential to know that none of these conditions will stop the INS from working at peak effectiveness. Look for the IP rating (IP65 is essential for being weatherproof and protecting against shocks and dust) and ask what the average lifespan of the product is.

4) Can the device be properly calibrated?

Any INS is only as good as its calibration. Without calibration, the sensors in any INS can become misaligned and therefore provide inaccurate readings. Talk to vendors about their calibration processes — do they work to a nationally recognized standard of calibration like ISO 17025? Do their calibrations account for variations in temperature or humidity?

It is also worth considering how often sensors need recalibration. Recalibration is a chargeable service from most vendors, meaning the more the device needs recalibrating, the more the user will have to pay. This could also lead to delays if the user must send units abroad to have them recalibrated.

On Feb. 6, the United Nations Satellite Center (UNOSAT) announced via Twitter that it had activated emergency mapping services of Turkey and northern Syria after the magnitude 7.8 earthquake hit earlier that day. The satellite images provide an overview of the damage, which can be used for humanitarian efforts and disaster relief, reported Space.com.

UNOSAT provides emergency mapping services, upon request, to provide satellite imagery analysis during emergencies and disasters. The maps show infrastructure that has been damaged during an emergency, which can then be used to provide relief by disaster response groups.

The earthquake caused massive destruction throughout Turkey and Northern Syria, causing an estimated death toll of more than 19,000 as of Feb. 9. Several historical structures dating back thousands of years have also been severely damaged.

UNOSAT started in 2001 and is hosted by the European Organization for Nuclear Research. It does not operate its own satellites, but coordinates with United Nations member states to gather imagery from government agencies and privately owned satellites. United Nations offices, government agencies and relief organizations can request access to imagery collected by UNOSAT.

All maps of Turkey and northern Syria from UNOSAT can be found here. A live interactive map can be found here.

The Emergency Mapping service is activated over #Syria for the #earthquake west of Gaziantep – M7.8
➡️https://t.co/eoHKIGJEaS@IFRC @UNEnvoySyria @UNHCRinSYRIA @UNinSyria pic.twitter.com/HkyceJLOLQ

— UNOSAT (@UNOSAT) February 6, 2023

Advanced Navigation’s Certus Evo enabled Nextcore to fly at 100 metres AGL, exceeding their goal. Nextcore required a MEMS INS that would enable their UAV-LiDAR to fly at 80 metres above ground level (AGL).

Discover Certus Evo.

This video is sponsored content by Advanced Navigation. 

Cepton has secured a multi-million-dollar contract from the United States Highway Tolling System Operator to use its Sora series lidar sensors. The sensors will be deployed on several major tollways in the tri-state area in Northern California.

The Sora lidars provide detailed and accurate 3D profiling of vehicles passing at highway speeds. The lidar sensors have been used to modernize global tolling infrastructure by facilitating electronic toll collection, reducing traffic congestion and toll leakage.

“In addition to superior performance, our Sora lidars were designed using the same auto-grade building blocks that have been validated by OEMs through our flagship automotive lidar program, and are reliable, embeddable, scalable and energy efficient, which are key advantages for tolling applications,” said Jun Pei, co-founder and CEO of Cepton.

The contract is expected to be the largest commercial lidar deployment in the tolling sector, with potential to scale outside the United States in the future.

UAV Navigation-Grupo Oesía has released the GHU-100 ground control hub unit that helps platform manufacturers connect multiple ground devices to form a single network segment.

The GHU-100 enables multi-UAV and multi-ground control system (GCS) operation and is also designed to fulfill all requirements of maritime operations. This includes control of NMEA inputs, real-time kinematic corrections, and more. The ground control station hub unit also increases UAV flight safety, as it is independent from the computer OS and its potential PC crashes.

The GHU-100 is designed to increase a system’s robustness while maintaining a high flexibility with its extensive input/output capabilities, which makes it easy to integrate into complex and advanced GCS architectures. It also implements critical functionalities on a self-developed real-time operating system to ensure secure missions in all environments.

Indiana state legislators have filed multiple bills that would make tracking someone with a GPS-based device without their knowledge a crime, reported WTHR of Indianapolis. The bills are in response to the growing number of criminal cases involving Apple AirTags and other GPS-based tracking devices.

Tracking someone secretly is not currently a crime in Indiana; however, laws vary from state to state. Under one proposed bill, the penalty would be increased from a Class C misdemeanor to a Class A misdemeanor if the person tracked is under a protective order. The penalty could be enhanced for someone convicted of using tracking devices when committing a felony.

Similar incidents are on the rise around the United State regarding the use of AirTags and other tracking devices for criminal purposes. In December 2022, two women in California filed a class-action lawsuit against Apple for privacy concerns after being stalked by ex-partners using AirTags.

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

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SURVEYING & MAPPING

Dual-Frequency Receiver

Receives all GNSS constellations plus SBAS

The Walker RTK is a dual-frequency GNSS receiver (L1, L2) for high-precision coordinate surveying in real-time kinematic (RTK) mode. It comes with a helical antenna, a bracket for attaching a smartphone, and the Geometer SCOUT mobile app. A classic geodesic antenna can be connected through the SMA connector. The Walker RTK has a rugged aluminum alloy casing with a shock-resistant coating, yet weighs only 250 grams. GNSS signals processed by the Walker RTK GNSS receiver include GPS (L1C/A, L2C), GLONASS (L1OF, L2OF), Galileo (E1B/C, E5b), BeiDou (B1I, B2I), QZSS (L1C/A, L1S, L2C) and SBAS (L1C/A). A built-in rechargeable battery provides 24 hours of continuous operation without recharging.

Geometer International, gpsgeometer.com

Base station receiver

Creates high-quality measurements

The AsteRx SB3 ProBase creates high-quality measurements for real-time kinematic (RTK) and differential corrections. The IP68-housed GNSS base station receiver features the latest quad-constellation GNSS technology and complements the SB3 receiver family: the AsteRx SB3 Pro rover receiver, the AsteRx SB3 Pro+ rover and base receiver, and the AsteRx SB3 CLAS for the Japanese market. The SB3 ProBase is easy to configure, the company says. It comes with Septentrio’s GNSS+ technologies, including anti-jam and anti-spoofing technology (AIM+) for robustness and reliability. AsteRx SB3 products are pin-to-pin compatible with the AsteRx SB ProDirect receiver and the recently released AsteRx SBi3 GNSS/INS system.

Septentrio, septentrio.com

Rugged Tablet

Equipped with Multi-Band GNSS

The Algiz 10XR is a rugged 10-inch Windows tablet that combines durability with a GNSS receiver and 5G communications. It was developed for challenging environments in logistics, mining, public transport, public safety, waste management or geographic information systems (GIS). The 10xR is customizable and has a dedicated multiband GNSS u-blox NEO-M8U receiver for accurate positioning as well as untethered dead-reckoning technology. The high-resolution, sunlight-readable 10-inch touchscreen has super-hardened glass and rain-and-glove mode. The tablet also has 4G/LTE high-speed data, Wi-Fi and Bluetooth.

Handheld Group, handheldgroup.com

Laser Scanner

Integrated GNSS receiver helps speed workflows

The VZ-600i terrestrial laser scanner has a 3D position accuracy of 3 mm and less than 30 seconds of scan time for high-resolution scans with 6 mm point spacing at 10 m. This enables more than 60 scan positions per hour with real-time registration. Weighing less than 6 kg (13 pounds), the VZ-600i has a 2.2-MHZ pulse repetition rate, three internal cameras and an integrated GNSS receiver. It also includes key features to speed up workflows in indoor and outdoor applications such as architecture, engineering, construction, building information modeling, as-built surveying, forensic and crash scene investigation, archaeology and cultural heritage documentation and forestry.

Riegl, riegl.com

Data Processing

For UAV lidar and photogrammetry

The LP360 Drone software system provides a geospatial-data workflow for UAV lidar and photogrammetry data processing. It provides powerful point cloud visualizations with multiple, synchronized windows. It can transform lidar and imagery data into survey-grade deliverables including visualization, quality checks, classification, analysis and 3D editing. For users of larger datasets, LP360 Geospatial can process captured lidar data or images from any aircraft or mobile sensor and analyze and extract values.

LP360, lp360.com

Mapping Databases

Free library offers data on healthcare, business, traffic

The extensive Maptitude library of free mapping databases has been updated for 2022 and is available for download, supporting insightful business development analysis. The data is available free to users of the latest version of the Maptitude mapping software. The data are also available as shapefile, KML, KMZ or GeoJSON for a fee. Maptitude includes business-critical data such as demographics, boundaries, streets, and the most ZIP Code/postal boundaries. Also available is a catalog of free premium datasets that can be used in other GIS applications, on the web, or in corporate databases.

Caliper, caliper.com 

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TRANSPORTATION

Asset Tracking Solution

Indoor and outdoor tracking of low-power, small IoT devices

Traxmate is integrating Nestwave GNSS location technology into its asset-tracking platform for seamless indoor and outdoor positioning, tracking and routing of small, low-power and battery-powered devices for the internet of things (IoT). Nestwave’s NestCore IP and NestCloud cloud services enable power-efficient geolocation solutions, while Traxmate (pictured) is a comprehensive data-processing hub that simplifies setup of tracking environments and provides real-time visualization of device location. The resulting geolocation solution is suitable for applications ranging from carrier tracking to tracking individual parcels and packets. Traxmate is simple to use and set up, requires no coding, and provides an out-of-the-box feature set that includes dashboards, alerts and processing rules for taking actions on incoming data. Nestwave’s trackers include ThinTrack, an ultra-low-profile, compact GPS tracking solution that integrates an LTE-M/NB-IoT modem, antenna, battery and SIM into a device that measures 82 mm x 35 mm x  3 mm and weighs 15 g. 

Traxmate, traxmate.io; Nestwave, nestwave.com

Auto Navigation

Provides guidance even without an internet connection

The Sygic GPS Navigation app uses a smartphone’s camera and augmented reality to display navigation instructions over the view ahead on the windshield. The head-up display is especially useful at night, enabling recognition of critical speed limit, road work or traffic restriction signs. Cockpit is a powerful tool that shows the real-time performance of the car, measuring the G force and actual speed to help users drive economically. The Dashcam feature records the road ahead and automatically saves the video in case of an accident. An Electric Vehicle Mode locates nearby charging stations.

Sygic, sygic.com

Video Telematics

Enhanced data-based rule implementation for fleets

An enhanced SureCam video telematics integration provides fleet managers with access to new capabilities to keep drivers safe and maximize fleet efficiency. The solution features a method for capturing video footage from SureCam cameras using Geotab’s powerful telematics device and rule-based system. The result is a seamless display of video within the MyGeotab platform. The enhanced SureCam fleet video solution leverages Geotab’s numerous data-based rules, such as improper seat belt usage and speeding. It uses G-force triggered alerts that detect unsafe driving behaviors and automatically captures video footage that can be reviewed later on the MyGeotab platform and alert managers to incidents when necessary. Camera configuration and customized triggers are managed directly within MyGeotab.

Geotab, geotab.com; SureCam, surecam.com

Autonomous Driving Solution

Can navigate heavy traffic safely and efficiently

Driver 2.0 is a Level 4 production-ready autonomous driving solution that can operate in complex and challenging traffic environments. Demonstrations with Driver 2.0 showed an autonomous vehicle could maneuver around double-parked cars, e-scooters and pedestrians, negotiate oncoming vehicles to calculate the right timing and trajectory to pass busy intersections, and make multiple lane changes and unprotected left turns. In the case of long tail scenarios, the system will alert the remote monitoring center to intervene or take other safety measures. Driver 2.0 includes five solid-state lidar units, eight cameras and other sensors, and a computing platform integrated with a proprietary inference engine. The perception algorithm with sensor fusion can achieve precise object detection up to nearly 220 yards. The planning and control algorithm based on game theory can choose optimal routes and make decisions based on real-time situations when negotiating with oncoming vehicles and other road agents.

DeepRoute.ai, DeepRoute.ai

Antenna compounds

Provide improved signal gain for automotive antennas

Two new compounds could improve signal-gain performance compared to ceramics in second-generation automotive GNSS antennas. The new compounds — LNP Thermocomp ZKC0CXXD and LNP Thermocomp ZKC0DXXD — help enable the design and molding of antenna substrates with more complex pattern markings that add effective surface area, a critical factor in enhancing signal capture. They also provide flexibility to produce smaller parts with the same performance as ceramic, or equal-size parts with better performance. The LNP Thermocomp compounds feature electroplating capability, good thermal resistance for reliability, and the design freedom and production efficiency of thermoplastics. Both are well-suited for shark-fin-style and new conformal antenna designs.

SABIC, sabic.com 

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AUTONOMOUS

Robotic Surveyor

Precisely marks thousands of coordinates per day

The CivDot unmanned ground vehicle (UGV) is designed for civil engineering and infrastructure projects such as solar farms, roadways, data centers, power plants and more. The autonomous surveying robot is designed to increase efficiency, productivity and safety on the job. Augmenting the surveyor’s work, CivDot marks thousands of coordinates per day precisely and efficiently, while delivering layouts faster than traditional methods. Civ Robotics uses Trimble’s high-precision GNSS positioning technology and surveying software.

Civ Robotics, civrobotics.com

Enterprise Drones

Designed for business, government, public safety

The compact DJI Mavic 3E and 3T drones have been designed for an array of commercial missions. Flight time is 45 minutes. Both models have a real-time kinematic (RTK) module that enables surveying professionals to achieve centimeter-level accuracy with support for network RTK, custom network RTK services, and the D-RTK 2 Mobile Station. The D-RTK 2 Mobile Station is DJI’s upgraded high-precision GNSS receiver that supports all major GNSS, providing real-time differential corrections. The DJI Mavic 3E enables efficient mapping and surveying missions without the need for ground control points. The DJI Mavic 3T is engineered for aerial operations in firefighting, search and rescue, inspections and night missions.

DJI, dji.com  

AlphaRTK has signed agreements with Rutgers University, West Chester University and Warren County Community College to provide free access to its GNSS correction network for students and faculty.

The AlphaRTK network — an affordable RTK subscription network that supports four constellations — launched in 2021 and is available for use in New Jersey as well as both the New York City and Philadelphia metropolitan areas.

All institutions perform geospatial research and instruction. Having access to the AlphaRTK network is a powerful resource and will enhance the performance of modern geospatial data collection, the company said.

Warren County Community College specializes in precision agriculture using drones. The AlphaRTK network will provide its fleet with centimeter-level accuracy, advancing analytical capabilities. Rutgers University plans to advance turf farm research, and West Chester University aims to use the network for a geophysics course, among more geospatial research.

AlphaRTK records raw RINEX data that can be used for post-processing workflows, such as with post-processed kinematic drones. Additionally, in southern New Jersey where wireless coverage is weak, Alpha RTK has added ultra-high frequency radio transmitters to broadcast real-time data wirelessly.

The United States Department of Defense (DOD) will provide a new package of security assistance for Ukraine to aid with ongoing Russian aerial attacks. The package includes defense tools such as GPS-guided rockets and counter-UAV equipment.

The presidential drawdown package includes:

• additional ammunition for High Mobility Artillery Rocket Systems
• additional 155 mm artillery rounds
• additional 120 mm mortar rounds
• 190 heavy machine guns with thermal imagery sights and associated ammunition to counter unmanned aerial systems
• 181 Mine Resistant Ambush Protected vehicles
• 250 Javelin anti-armor systems
• 2,000 anti-armor rockets
• Claymore anti-personnel munitions
• demolitions munitions
• cold weather gear, helmets and other field equipment.

Under the Ukraine Security Assistance Initiative (USAI), DOD will provide Ukraine with:

• two HAWK air defense firing units
• anti-aircraft guns and ammunition
• equipment to integrate Western air defense launchers, missiles and radars with Ukraine’s air defense systems
• equipment to sustain Ukraine’s existing air defense capabilities
• air defense generators
• counter-unmanned aerial systems
• four air surveillance radars
• 20 counter-mortar radars
• spare parts for counter-artillery radars
• Puma unmanned aerial systems
• precision-guided rockets
• secure communications equipment
• medical supplies
• funding for training, maintenance and sustainment.

Ukraine has been able to intercept Russian UAVs and missiles; however, having additional air defense will help combat efforts.

Ever since it came on-line in February 2022, the website GPSJam.org has shown what appears to be regular interference with GPS signals in Texas near San Antonio and Del Rio, and locations north and south of Oklahoma City, Oklahoma.

Only on normal workdays, however. Not on weekends or holidays. Furthermore, whatever was happening also took time off between the Christmas and New Year holidays GPSJam.org also shows similar, though less regular, activity in New Mexico. Experts say this is easily explained as White Sands Missile Range is often the site of electronic warfare training and tests. These are always announced in advance in FAA Notices to Air Missions (NOTAMs) when any interference with GPS reception is anticipated.

The regular patterns observed in Texas and Oklahoma and the lack of NOTAMs led some experts to speculate the source could be inadvertent interference from a commercial or government activity. Said one former official, “It’s just the kind of pattern you see from large organizations. They are off every weekend, federal holidays, and around Christmas.”

GPSJam.org is the brainchild of aviation analyst John Wiseman. The site uses crowdsourced ADS-B reports gathered by the ADS-B Exchange and displays it on a world map. Areas in yellow indicate that between two and ten percent of ADS-B reports for the day had low navigation accuracy. Areas in red had ten percent or more.

Information from the site has proved useful in identifying patterns of regular GPS jamming and spoofing in Russia and other conflict areas around the globe.
The workday patterns in Texas and Oklahoma have appeared on GPSJam.org displays since the site went live in February 2022.

GPS Interference and Aviation

Minor interference with GPS signals is fairly common. GPS jamming devices, while illegal to use, are inexpensive and easy to obtain from vendors on the internet.

Truck drivers wanting to defeat their company’s fleet tracking system, people concerned about being tracked by the government or others, even ministers trying to keep parishioners from texting during sermons – all have been known to use such devices.

Most GPS interference is unintentional. A two-year European Union study found hundreds of thousands of potentially harmful signals, but judged only about ten percent to be intentional. The rest were the inadvertent byproduct of poorly tuned electrical and electronic equipment.

While most GPS interference is unintentional and localized, spurious signals powerful enough to noticeably impact airborne operations are not unknown.

In two separate incidents last year strong interference near the Denver and Dallas airports impacted air traffic, each for more than a day. The Denver incident lasted for 33 hours before authorities found the source and shut it down. Air traffic was disrupted at Dallas for 44 hours according to government sources, though researchers found the actual interference only lasted for 24 hours. The source of the disruption was never identified.

In 2019 a passenger aircraft was almost lost due to GPS interference while on approach to Sun Valley, Idaho’s Friedman Memorial Airport. As the aircraft flew a GPS-based approach in smoke and haze, the interfering signal was just strong enough to lure it off course and toward a mountain. Fortunately, a sharp-eyed radar controller hundreds of miles away spotted the problem and intervened in time. The source of the interference was never identified.

As a result of the Sun Valley incident and input from numerous aviation groups, the International Civil Aviation Organization told its members there was an “urgent need to address harmful interferences” to satnav signals.

Texas and Oklahoma Mystery Solved

A researcher at Stanford University finally solved the puzzle of the strange recurring sequence of reports from Texas and Oklahoma.

While investigating last October’s GPS interference event near the Dallas airport, PhD candidate Zixi Liu noticed aircraft outside the main area of effect also reporting low Navigation Integrity Category (NIC) values. This began before and continued after complaints from commercial airlines about GPS not being available at Dallas-Fort Worth. These aircraft were in the same general area of Texas, but far enough away that there were large areas between them and Dallas that did not contain any reports with low NIC values.

At the same time MS Liu was also investigating anomalous ADS-B reports near San Antonio and Del Rio, Texas. She discovered in all three cases the reports of low NIC values were coming from military training aircraft regularly used for aerobatics. Other aircraft nearby reported good NIC values and showed no evidence interference.

In a recent presentation to the Institute of Navigation, she postulated that Interference with GPS signals was not the cause of the low navigation integrity reports. Rather, the rapid maneuvers and unusual aircraft attitudes of aerobatics caused the airplanes’ navigation receivers to intermittently lose lock on signals from GPS satellites. This caused their ADS-B equipment to report low navigation integrity.

Having solved that mystery, Ms. Liu continues to work on her original question – identifying the source of October’s 24-hour GPS disruption near the Dallas-Fort Worth airport.

Mr. Dana A. Goward is the President of the Resilient Navigation and Timing Foundation and a former US Coast Guard helicopter pilot.