Mätfokus - Maetfokus

A roundup of recent products in the GNSS and inertial positioning industry from the May 2022 issue of GPS World magazine.

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SURVEYING

Measurement Workflows

Field-to-office inspection with survey-grade accuracy

Trimble Access field software now connects with Infotech’s Appia service to streamline the workflow from survey to construction. Aimed at the inspection process for civil infrastructure projects, the software provides high-accuracy measurement workflows for daily work reports and inspection reporting for engineering, construction and public agencies. By streamlining the connection between data collected by Trimble GNSS rovers and simultaneously syncing Trimble Access, Infotech Mobile Inspector and Infotech Appia, inspectors can now complete their daily work reports more efficiently in the field and reduce errors. With manual processes removed, inspectors can more accurately represent infrastructure assets.

Trimble Geospatial, geospatial.trimble.com; Infotech, infotechinc.com

GNSS Receiver

For surveying, mapping and construction professionals

The i83 GNSS receiver is powered by a multi-band GNSS receiver, iStar technology, and a calibration-free, high-end inertial measurement unit (IMU) for faster and reliable field GNSS surveying. The third-generation high-gain antenna with advanced CHCNAV iStar algorithm improves GNSS satellite signal tracking efficiency by more than 30%. The i83 GNSS receiver features 1,408 GNSS channels for high performance across GPS, GLONASS, BeiDou, Galileo and QZSS constellations. Its onboard GNSS technology delivers centimeter-level positioning, maintains reliable fixed real-time kinematic (RTK) accuracy, and collects points faster than previous models, even in demanding conditions. The i83 receiver’s built-in IMU automatically compensates for pole tilt. In less than 5 seconds, the 200-Hz inertial module is initialized to ensure survey-grade accuracy over a pole-tilt range of up to 30 degrees. Productivity is dramatically increased, RTK usability greatly improved, and potential human error reduced, whether you are an engineer, site foreman or surveyor.

CHC Navigation, chcnav.com

Survey Software

Simplifies surveying with both GPS and total station

SurvPC Hybrid+ is a module for SurvCE version 6 software that enables surveying with mixed brands of GNSS receivers and total stations. SurvCE is a data-collection software package from Carlson Software. SurvPC Hybrid+ provides driver support for numerous devices, allowing the surveyor to interface with both types. Features include Follow Me, Smart Lock, Smart Staking, Cross Check, Backup Tracking, Hybrid-Resection, Auto-Localize, and Easy Setup Wizard.

Carlson Software, carlsonsw.com

Data-Collection Software

Runs on Android devices

SurPad 4.2 is designed to help surveyors work efficiently at all types of land surveying and road engineering projects in the field. It runs on eSurvey handhelds, Android smartphones and tablets, and third-party Android devices. It integrates with professional receiver control, point collection, stakeout, geographic information system (GIS) data collection, road measurement, road design, cross-section measurement and railway stakeout. SurPad 4.2 provides multiple operation and communication systems, has mapping and CAD functions, and has a coordinate system. It also includes a survey mode encompassing topo, control, quick point and COGO civil engineering programs.

eSurvey, esurvey-gnss.com

Total-Station Pole

Provides tilt-compensation for surveyors

The Leica AP20 AutoPole provides tilt compensation, automatic pole-height readings and unique target identification for automated total stations. It combines an intelligent sensor module with the AP Reflector Pole and operates with existing Leica Geosystems’ automated total stations to create a solution for autonomous workflows. Tilt compensation decreases measurement time and increases flexibility and safety on site by enabling measurement of points in inaccessible or risky locations. By updating the pole height automatically in the field software, the system ensures that the height on record is always correct.

Leica Geosystems, leica-geosystems.com

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MAPPING

Data Management Platform

Provides validation in the cloud

INSITE Data Reviewer moves geospatial data validation to the cloud, giving key stakeholders the ability to collaborate in real time. The third module in the INSITE Lifecycle suite of products, INSITE Data Reviewer provides reviewers real-time access to aerial imagery, lidar data and geographic information system (GIS) layers via the cloud to standardize quality control. This increases data validation speed and reduces costs of geospatial projects. The INSITE Lifecycle suite combines Project Tracker, Data Delivery and Data Reviewer modules through which users can see their projects executed on a map, from data acquisition through processing.

NV5 Geospatial, nv5geospatial.com

Android Mapping

Asset locations can be captured from a distance

Eos Laser Mapping for ArcGIS is now available on Android devices. It allows mobile crews to capture high-accuracy laser offsets directly into ArcGIS Field Maps with Arrow Series GNSS receivers. The solution combines technology from geographic information system (GIS) provider Esri, laser rangefinders from Laser Tech, and Eos’ own Arrow Series GNSS receivers. The release supports three workflows: standard laser offset (range-azimuth), range-range (range-intersect) and range-backsight (a total station-like method).

Eos Positioning Systems, eos-gnss.com

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OEM

Accelerometer

For navigation systems on land and at sea

The MV60 micro-electromechanical system (MEMS) accelerometer delivers high performance and reliability in a small, rugged and low-cost package. The MV60 measures the acceleration experienced by an object during movement and is designed for use in inertial measurement units and navigation systems deployed on land, air and sea vehicles to measure velocity. It has a compact footprint of 1.2 square inches and shock survivability of up to 5,000 g. It also offers bandwidth of greater than 300 Hz — important for environmentally demanding missions.

Honeywell, honeywell.com

CLAS Support

Receivers support Japan’s cm-level augmentation service

Three multi-frequency GNSS receivers now support the Centimeter-Level Augmentation Service (CLAS), receiving the L6 signal that transmits high-accuracy corrections from Japan’s QZSS constellation. The mosaic-CLAS receiver is in a small form-factor suitable for high-volume industrial applications. The AsteRx-m3 CLAS OEM board combines PPP-RTK CLAS with dual-antenna heading functionality. The AsteRx SB3 CLAS features a ruggedized IP68 enclosure to protect it in harsh environments.

Septentrio, septentrio.com

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UAV

Long-Endurance Prototype

Designed to check basic aircraft systems

The S1-V300 medium-altitude long-endurance (MALE) unmanned aerial system (UAS) prototype is based on the Saker MALE UAS design that achieved operational capability in 2020. The prototype features a new design and a more powerful heavy fuel engine with 260 HP, offering greater speed, payload and endurance of 28 hours with a range of 4,020 km. The aircraft features unique UAVOS avionics solutions and a redundant flight control system that will enable complex missions, including overland and maritime intelligence, surveillance and reconnaissance (ISR) missions. The improved S1-V300 prototype is equipped with both line-of-sight and beyond-visual-line-of-sight (BVLOS) datalink systems for over-the-horizon operations. It can be integrated with multiple ISR sensors, including electro-optical infrared cameras and a synthetic aperture radar that offers all-weather, day/night performance for a wide-area search capability.

UAVOS, uavos.com

Professional UAVs

Dragonfish Lite and Pro now available in United States

The rugged Dragonfish UAVs are capable of vertical takeoff and landing (VTOL) with both multi-rotor and winged flight, with an endurance of up to 180 minutes. They are suitable for professional applications such as energy, mining, defense and surveillance. Maximum winged flight speed is 30 m/s (108 km/h, 67 mph), and maximum video transmission range is 30 km (18.6 miles) with a base station. The aircraft can make a smart decision to either land or return to base in case of issues such as loss of GPS signal, loss of operator communications, or low battery power. The tilt-rotor system will automatically transition to multi-rotor mode if adverse conditions cause fixed-winged flight to stall or become unsustainable. The Dragonfish battery, barometer, positioning system, compass and inertial measurement unit all have backup modules to ensure flight safety.

Autel Robotics, autelrobotics.com

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TRANSPORTATION

Video Telematics

Enhanced experience for fleet operators

The SureCam connected dash camera system now features a method for capturing video footage from SureCam cameras using Geotab’s telematics device and rule-based system. This results in 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 also uses G-force triggered alerts that detect unsafe driving behaviors and automatically captures video footage that can be reviewed later. A new Video Request feature in GeoTab enables fleet managers to preview and download additional SureCam video, enabling them to investigate call-ins and other minor incidents that may not have been triggered by an event-based rule.

Geotab, geotab.com; SureCam, surecam.com

Asset Tracker

Module enables NB-IoT on-the-fly

Momentum IoT’s long-life Eagle 1 tracker works without external power for more than six months after a single charge. The device switches on-the-fly between narrowband internet of things (NB-IoT) and LTE Cat-M. The Eagle 1 leverages Telit’s dual-mode ME310G1 module, which delivers low power consumption in a small footprint. The Eagle 1 detects movement with a built-in accelerometer. Using movement and signals from its GPS receiver to determine vehicle trip starts and stops, the device can go into hibernation mode during periods when the vehicle is not in use, further reducing power consumption. Applications include garbage and storage bins, portable toilets, roll-off containers, message-boards, coolers, and other equipment typically stationed in non-powered, remote places for extended periods.

Momentum IoT, momentumiot.com; Telit, telit.com

The largest source of error in GNSS positioning is the delay suffered by the signals as they pass through the ionosphere traveling from the satellites in orbit to receivers on or near Earth’s surface. That is because the ionosphere is full of free electrons stripped from atoms and molecules by ionization and this plasma refracts the signals, changing their speed. Normally, models compensate for this. However, geomagnetic storms wreak havoc on the free electrons in the ionosphere, making it difficult to accurately determine the signal delay.

That is why space weather matters for GNSS and for the myriad human activities that have come to depend on it.

So, here’s the good news. “On a scale of one to five, the geomagnetic storm on April 14 was a three,” Bill Murtagh told me. Murtagh is the Program Coordinator and Space Weather Forecaster at the Space Weather Prediction Center (SWPC) of the National Oceanic and Atmospheric Administration (NOAA). He was referring to the third rung of NOAA’s space weather scales, which were introduced to communicate to the public the current and future space weather conditions and their possible effects on people and systems.

NOAA has three space weather scales, one each for geomagnetic storms (G scale), solar radiation storms (S scale), and radio blackouts (R scale). The steps on the scales, ranging from “minor” to “extreme,” are analogous to those NOAA uses to classify hurricanes, tornadoes and earthquakes. They describe the environmental disturbances for each of these events and list their possible effects at each level.

Solar activity runs in 11-year cycles. A G5 event happens two or three times per cycle, and the last one was in October 2003, Murtagh told me. “I can only remember a handful of occasions over the past 20 years when ionospheric activity has significantly impacted users,” told me Gavin Schrock, PLS, manager of the Washington State Reference Network, a regional cooperative of GPS reference stations and data. According to Rick Hamilton, the GPS Information Analysis Team Lead at the U.S. Coast Guard Navigation Center, it “did not receive any reports of interference related to the geostorm” and “there was no significant increase in reports that we might attribute to geomagnetic activity.”

Now, the bad news. We are heading for a maximum in solar activity, expected to occur in 2025. The Sun is “already quite active,” Murtagh pointed out, and recently there has been an increase in the number of R1 and R2 storms. Solar coronal mass ejections (CMEs), which launch plasma and magnetic fields into space, also have become more frequent. When a CME hits the Earth, its collision with the Earth’s magnetic field causes a geomagnetic storm.

So, the GNSS constellations and the GNSS industry should be preparing now. Fortunately, improvements in GNSS software and receiver technology, plus corrections and integrity information and the much larger number of satellites, make us better prepared than we were during the last cycle. On the other hand, the stakes also are much larger, due to our ever-greater reliance on GNSS.

As a sailor, I rely on NOAA nautical charts and marine weather forecasts. GNSS users can thank NOAA for its space weather forecasts.

Contract to provide geospatial intelligence, infrastructure support and training for the Air Force Distributed Common Ground System

Raytheon Intelligence & Space (RI&S), a Raytheon Technologies business, has been awarded a five-year indefinite delivery, indefinite quantity contract to continue geospatial intelligence (GEOINT) system mission support and training for the U.S. Air Force’s Distributed Common Ground System (DCGS).

Under the DCGS GEOINT Field Support contract, RI&S will provide mission support and engineering services for the current DCGS weapon-system baseline as well as partnering with the Air Force to facilitate the transition to an open architecture.

Open architecture will enable DCGS to more readily integrate data from the intelligence community and commercial providers, with the goal of using artificial intelligence to create multi-intelligence analysis.

DCGS draws in data from airborne sensors aboard the RQ-4 Global Hawk, Mq-1 Predator, MQ-9 Reaper and other intelligence, surveillance and reconnaissance platforms all over the globe.

Under the contract, RI&S will leverage its mission domain knowledge to ensure high mission availability to support end-to-end operations, from mission planning for an airborne sensor to data collection, processing and data discoverability for the DCGS Analysis Exploitation Teams in support of theater and National Command Authority.

This month our UAV and GNSS news ranges from a drone diving into the Boston subway to a GNSS receiver designed for Moon orbit. We also look at the types of drones heading to Ukraine to help fight the Russian invasion and rescue citizens from demolished buildings.

Boston cleanup

Bostonians’ morning commutes were disrupted at the end of March after 100 tons of demolition debris fell nine stories onto ground directly above subway tunnels, and the Massachusetts Bay Transport Authority (MBTA) closed the Orange and Green lines as a precaution.

The bad news got worse. A construction worker was killed when part of a parking garage under demolition collapsed. Apparently his jackhammer-construction vehicle — in the midst of demolition work — fell nine stories when the floor near the edge of the building buckled and crumbled away.

MBTA was concerned that damage could have occurred to the subway under the building from the huge amount of debris that fell on the ground above a tunnel. The agency closed the line passing through that section of the system. Hundreds of morning commuters were turned away from the subway at nearby station entrances and were directed to buses hastily brought on as temporary shuttles around the closed subway sections.

MBTA wanted to immediately, but carefully, inspect the tunnel for damage, but was concerned for the safety of its inspection personnel. As news of the disaster circulated, the Massachusetts Department of Transportation (MassDOT) Aeronautics Division became aware of the subway issue, and proposed a rapid solution to the dilemma — to fly a drone through the tunnel. The drone would transmit high-resolution video and gather data on the status of both tracks and tunnel structure.

Soon after, Bostonians were able to watch a 29-second video collected by the drone that was sent into the subway tunnel.

“As we work to safely restore service following the Gov Center Garage accident, we teamed with @MassDOT Aeronautics to scan Orange & Green Line tunnels with a drone. This allowed us to safely assess tunnel conditions before sending engineers in for in-depth structural inspections.” pic.twitter.com/LHGUfiou9r

— MBTA (@MBTA) March 29, 2022

MBTA was then able to gauge that live inspections would be safe. The tunnel was ultimately assessed as being sound and, following test trains being run, service was restored.

It has been difficult to establish which drone was used for these initial visual tunnel inspections, but in 2021 the Aeronautics Division was operating multiple drones, including the DJI Matrice, Inspire, Phantom and Mavic, as well as a few fixed-wing and multi-rotor models manufactured by Yuneec, SenseFly and Delair.

Flyability provides the Elios 2 drone, specifically built for indoor inspection, for such places as inside underground tunnels. Similar “caged” inspection drones include Droneball 360 by Imaze, the Skycopter Cobra drone, the Asio Caged Inspection Drone and several others.

Lunar Pathfinder

Turning our attention to space, the European Space Agency (ESA) will conduct a mission to place a refrigerator-sized satellite in orbit around the Moon. Of course, there have been many successful efforts to put things in lunar orbit since Russia first achieved the feat with Lunar 10 in 1966. NASA’s Lunar Reconnaissance Orbiter followed in 2009, along with India’s Chandrayaan-2 orbiter and its failed lander.

ESA has contracted Surrey Satellite Technology Ltd. (SSTL) in Guildford, UK, to develop the Lunar Pathfinder communications relay satellite — the first part of a project to provide communications and navigation for the Moon. This capability will enable assets on the lunar surface to communicate directly with the Pathfinder via S-band and UHF, which will then relay their signals onwards to Earth using X-band.

The satellite will also carry a laser retro-reflector and a space-weather payload designed to assess the radiation environment in orbit. This should help support landers carrying astronauts, such as the NASA Artemis, by broadcasting radiation intensity to the surface.

The Lunar Pathfinder satellite. (Image: SSTL)The Pathfinder satellite will carry a few passenger payloads, but the most interesting to us might be the highly sensitive GNSS receiver, which will attempt to make position fixes from lunar orbit using GPS and Galileo satellites in Earth orbit.

The NaviMoon receiver designed by SpacePNT in Switzerland was implemented and tested by European Engineering & Consultancy, which added a special low-noise amplifier of its own design — essential for detecting minute satnav signals at 20 times the distance they usually travel to Earth’s surface from Earth orbit. In addition, antennas on GNSS satellites are designed for transmissions towards the Earth’s surface, not out toward space, further decreasing the signal strength in the vicinity of the Moon.

As you might expect, the view of the various constellations of GNSS satellites from orbit around the Moon is extremely limited. To give the NaviMoon receiver any sort of chance of picking up signals when they are in view, an onboard dynamic force model provides the receiver with its anticipated location along its orbit, and also derives the apparent direction from which signals should be observed. Even detecting a single satnav signal could assist the receiver in creating a position fix. SSTL will also reorient the Lunar Pathfinder satellite from time to time to enable the receiver to gain access to GNSS signals from Earth.

Measurements from Earth using laser ranging, aimed at the laser retro-reflector on the satellite, will be used as “truth” against which the position fixes by the NaviMoon receiver will be verified.

UAVs for Ukraine

Meanwhile, as the war in Ukraine continues to rage on, AeroVironment has been contracted by the U.S. Army to supply its RQ-20 Puma AE for use in Ukraine for almost $20 million. The package includes reconnaissance/surveillance and target acquisition kits, spares, logistics support and training for operators in Ukraine.

The Puma has an endurance of about three hours, carries a gimbaled visual/IR camera and is equipped with dual GPS receivers.

U.S. drone manufacturers have donated hundreds of other recon drones to Ukraine. The AeroVironment Quantix Recon drone takes off and lands vertically, but flies rapidly as a fixed-wing observation platform. While its endurance is not as long as the Puma’s, it flies faster so it can return with information more quickly.

Brinc has also donated and sold its Lemur tactical drones to Ukraine for use in disaster recovery work in devastated buildings throughout the country. The rugged quadrotor drone has two-way voice communications, video and lidar, and has proven itself in difficult building-collapse search and recovery operations in confined spaces. Skydio has apparently donated and sold quadrotor drones to Ukraine with multi-view video from six 200-degree color cameras, also for use in collapsed building search and recovery.

Tony Murfin
GNSS Aerospace

News from the EU Agency for the Space Programme (EUSPA)

After a challenging Launch and Early Orbit Phase (LEOP) and testing campaign during the COVID-19 pandemic, Galileo satellite “Nikolina” (GSAT0223) entered service on May 5. The satellite will reinforce the performance and robustness of the Galileo satellite.

GSAT0223 was launched Dec. 5, 2021 with Galileo launch L11 after the usual design, acceptance, validation, launch and early orbit preparation and operations phases.

This was the first Early Orbit Operations phase conducted directly from the operational center in Germany, under the responsibility of EUSPA.

GSAT0223 and its launch companion GSAT0224 (Shriya) are the first pair of the third batch of Galileo First Generation satellites to reach space. GSAT0223 will fill the last empty slot in Galileo’s orbital plane B.

Shriya will soon complete its in-orbit validation and will then join the operational constellation. Ten additional satellites of the same batch are continuing assembly, acceptance and launch preparations.

Topcon Positioning Germany is one of 22 partners involved in CampusOS, a research project with the goal of developing a modular ecosystem for open 5G campus networks based on open radio technologies and interoperable network components.

As part of the German technology program “Campus networks based on 5G communication technologies,” innovative solutions for open 5G networks are being developed and tested in conjunction with the German Federal Ministry for Economic Affairs and Climate Protection. The program was launched at the beginning of 2022 and will run through 2025.

The use of artificial intelligence in the operation of autonomous plants and construction machinery requires the highest level of digital sovereignty. If Construction 4.0, including far-reaching automation, is to become a reality in Germany and the rest of the world, the processes of such data-driven solutions must run reliably, quickly and autonomously.

The German Federal Ministry for Economic Affairs and Climate Protection is providing €18.1 million in funding for the technology program over the next three years, which will cost €33 million total. The Fraunhofer Institutes FOKUS and HHI are coordinating the project. 22 partners from industry and research are involved, including Deutsche Telekom, Siemens, Robert Bosch and more.

“To enable companies to operate their own campus networks, certain requirements must be met; from standardized technology building blocks to network structures,” explained Ulrich Hermanski, chief marketing officer of the Topcon Positioning Group. “As the sole representative of the construction industry, Topcon will test the technologies on reference test sites and, therefore, will help shape the solutions for the future. We look forward to working with our research partners to take the digital construction site to the next level.”

With this research project, construction companies will one day be able to operate plants and machinery autonomously in open campus networks. This will allow the fluid and uninterrupted monitoring of construction sites in real time, as well as the networking of all sensors and construction machines in use on construction sites.

Autonomous from public networks, 5G technology guarantees seamless machine-to-machine communication and transmits data 10 times faster than 4G.

CACI International, a U.S. defense contractor, plans to demonstrate a supporting navigation technology for military use as part of its DemoSat launch in January 2023.

CACI will launch two demonstration payloads on a York Space Systems satellite scheduled to fly to low Earth orbit in January aboard the SpaceX Transporter 7 rideshare.

The payload will contain an alternative positioning, navigation and timing solution that will work in a contested space domain. It is designed to support rather than replace GPS.

The technology is two-way time transfer and clock modeling technology. Two-way time transfer has been used for years on the ground. Two-way time transfer in space means the satellite sends a timing signal and a receiver on the ground or aboard an aircraft sends a signal simultaneously back to the satellite. The low size, weight and power (SWaP) space-based PNT is expected to significantly improve multi-platform remote sensing.

If the experiment is successful, CACI plans to offer the two-way time transfer PNT service to the military and other government agencies.

CACI has completed the critical design review for the DemoSat. CACI and its partner York Space Systems will also demonstrate a tactical intelligence, surveillance and reconnaissance (TacISR) payload. The TacISR payload identifies and captures key signals of interest and operates with CACI’s Beast ground receiver to demonstrate real-time radiofrequency geolocation for deployed U.S. forces.

“CACI expertise, systems, and technology help our customers maintain dominance in the increasingly contested space environment,” said Mike Hale, executive vice president of CACI’s Advanced Solutions Group. “We are very proud that CACI is launching a DemoSat payload into orbit – distinguishing our mission technology and transformative solutions for customer success.”

Tersus GNSS has released a white paper on ExtremeRTK Technology. According to the company, the white paper demonstrates how ExtremeRTK Technology delivers excellent performance in all manner of surveying scenarios and describes its impressive compensated results when performing tilt surveys — even tilt at angles greater than 90°.

As a professional real-time kinematic (RTK) developer and manufacturer, Tersus believes the stability and accuracy of RTK are the cornerstones of RTK measurement.

According to the paper, “ExtremeRTK integrates the receiver’s hardware, high-precision baseband IC [integrated circuit], RTK engine, GNSS/INS coupling algorithm, etc. It enables unprecedented performance stability in challenging environments and prevents occurrences of occasional RTK positioning outliers.”

Tersus starts from scratch — engineering each element from its foundation in the physics of GNSS. From signal capture and baseband tracking engine to position-velocity-time (PVT) results and the overall algorithm of RTK, Tersus completes all algorithm logic independently.

The white paper discusses:

• signal tracking and multipath mitigation capabilities
• fix speed in open-sky and challenging environments
• accuracy when performing RTK control/detail point/continuous point surveys
• GNSS/INS tilt compensation.

Test results described indicate the remarkable performance of ExtremeRTK technology in RTK initialization, accuracy and tilt compensation. Based on ExtremeRTK, Tersus will continue to invest in the further development of RTK receivers by adding photogrammetry, laser scanning and more.

Meanwhile, Tersus will also focus research and development on professional industry software, the integration of resources in data management, and big-data applications so it can provide users with additional professional services.

To download the white paper, visit the Tersus GNSS site.

We asked Dean Kemp, Ph.D., director of Marketing, Aerospace and Defense for Hexagon’s Autonomy & Positioning division, a few questions.

How do jamming and spoofing threats change?

Jamming and spoofing methods change as new interference-causing technologies become available. As such, it’s vital for us to continuously evaluate potential sources of threats and provide the highest possible level of resiliency to interference in our solutions.

Have new threats emerged in the past six weeks in connection with Russia’s invasion of Ukraine?

Evidence is emerging that electronic-warfare systems capable of high-power jamming and spoofing across wide areas are being used within Ukraine. Fortunately, there have been no known impacts on allied forces. However, knowing that the technology is in place and in use highlights the importance of assured positioning, navigation and timing (APNT) and our contribution to building resiliency in allied forces’ equipment against the potentially destabilizing effects of jamming and spoofing.

How do you define APNT?

We use APNT to describe measurements that are always accurate, available and reliable. Our anti-jamming, anti-spoofing and other resilience-building capabilities provide trusted and available PNT information at the level of accuracy requested.

When did you introduce GPS Anti-Jam Technology (GAJT)? How do you define it?

GAJT was introduced in 2011 and is our leading APNT solution. GAJT units are utilized worldwide across land, sea and air, with rapid deployment supported by commercial off-the-shelf solutions and short lead times. GAJT provides jamming protection of satellite-based navigation and precise timing receivers from intentional jamming and unintentional interference whatever your application. Product variants provide features to best support anti-jamming capabilities for the warfighter, national infrastructure, low-SWaP platforms and other mission-critical applications.

What are the key differences between the GAJT-710ML, the GAJT-710MS and the GAJT-410MS? 

The GAJT-710 is designed for land vehicles (ML variant) and marine vessel platforms (MS variant) with up to six simultaneous nulls to protect against jamming signals and interference. The next generation of GAJT-710 includes jammer direction-finding and a silent mode to reduce its thermal signature. The GAJT-410 maintains the high levels of interference-rejection performance in the 710 but in a lower size, weight and power (SWaP) design, with three simultaneous nulls, for both land and marine variants. It also utilizes a single RF cable to provide clean power, data and protected GPS signal. The GAJT-410 enables APNT while also reducing the need for platform modifications or armor penetration.  

The GAJT-AE extends jamming and interference protection to unmanned and autonomous applications. Using an external CRPA antenna, the GAJT-AE offers flexibility of integration into space-constrained platforms. 

Is the GAJT-AE-N Anti-Jam Antenna receiver-agnostic? 

We designed our GAJT product line to be receiver-agnostic and compatible with legacy and modern GNSS receivers. This flexibility results in GAJT being ideal for civil and military applications, including SAASM and M-code systems. 

How does your GNSS Resilience and Integrity Technology (GRIT, launched in 2020 November) relate to your GAJT antennas? 

GRIT is a firmware suite for our OEM7 receivers that expands their situational awareness and interference mitigation tools. GRIT includes our Interference Toolkit (ITK) along with spoofing detection to identify when your GNSS signal may be under threat. It also empowers the user to develop interference location algorithms through time-tagged snapshots of data samples to characterize the RF environment around your operations. GRIT, alongside GAJT, forms the foundation of our APNT strategy in providing accurate and always-available PNT. 

Do you have any recent contracts with the U.S. Department of Defense or the militaries of other NATO countries to supply GAJT antennas? 

Our GAJT product portfolio has been sold in large quantities to military and civil organizations for many years, successfully proving itself in the field. In 2020, we achieved a milestone of more than several thousand units shipped worldwide, making it one of Hexagon | NovAtel’s more successful years.  

Accurate and reliable time is just as important as accurate and reliable location for a wide range of military and civilian applications — and GNSS receivers cannot provide either one when they are jammed. For timing, one solution is to supplement GNSS receivers with a miniature atomic clock. We asked Microchip Technology a few questions about their chip-scale atomic clock (CSAC) and Stewart Hampton, the company’s senior product line manager, responded.

How long was your SA65 CSAC in development before you announced it in August 2021? Typically, how often do you launch a new CSAC?

CSAC development started in 2001 under a contract from DARPA with Draper and Sandia laboratories. CSAC was first introduced to the commercial marketplace in 2011, and in 2016 we released an improved product design with an operating temperature range of –10 C° to +70 C°. Last year we released our CSAC SA65 with a wider operating temperature range, faster warm-up and improved frequency stability aimed at the defense and industrial marketplace. So, it has been about five years between major CSAC releases, but that may not be indicative of future products because we have also introduced specialized CSAC versions, such as the Low Noise CSAC (LNCSAC) in 2014 and the only commercially available radiation-tolerant CSAC (Space CSAC) in 2018.

What is the CSAC SA65’s drift rate?

Its typical drift rate is specified at <9 × 10–10 per month. Another key specification, particularly for many portable military applications, is total sensitivity of frequency to temperature (tempco) over a specified range. For the CSAC SA65, that specification is ±3 × 10–10 over the entire operating temperature range of –40 C° to +80 C °.

What are a few specific military use cases?

CSAC is designed into multiple military programs and used in a wide variety of military applications, particularly in GNSS-denied environments — including assured positioning, navigation and timing (APNT) modules, underwater unmanned and autonomous vehicles, software-defined radios, man-portable transceiver-based military communications, vehicle management computers, airborne reconnaissance/UAVs and GNSS-disciplined oscillators. It is also used in command, control, communications, computers, cyber, intelligence, surveillance and reconnaissance (C5ISR). The space CSAC variant is commonly used on low-Earth-orbit space defense payloads supporting such applications as low-latency communications networks, RF geolocation (geointelligence, or GEOINT), optical time transfer, alternative PNT satellites and Earth observation.