GPS World

Tag: VIAVI

  • Launchpad: Mapping applications, new IOT platform and more

    Launchpad: Mapping applications, new IOT platform and more

    A roundup of recent products in the GNSS and inertial positioning industry from the March-April 2026 issue of GPS World magazine.

    Surveying & Mapping

    Mapping Application: High-precision GNSS for IOS and Android smartphones

    Digital Mapping Group

    Image: Fastxy
    Image: Fastxy

    FastXY can transform standard mobile devices into professional-grade data collection tools for geospatial information systems (GIS) and architecture, engineering and construction (AEC) professionals. FastXY offers professionals the ability to collect point, line and polygon data, and delivers advanced capabilities including 3D basemaps, construction staking, topographic surveying, on-the-fly datum transformations and survey-grade elevations. A built-in Bluetooth data parser allows users to configure the app to collect data from virtually any instrument supporting BLE Bluetooth or RS-232 — including echosounders, radiation sensors, laser rangefinders, barcode scanners and more — and marry that data instantly with precise GNSS coordinates. Available in free and premium versions.

    Handheld scanner: Designed for BIM, indoor scanning and reality capture

    CHC Navigation

    Credit: CHC Navigation
    Credit: CHC Navigation

    The RS7 handheld SLAM (simultaneous localization and mapping) scanning solution was built for BIM documentation, indoor surveying, renovation planning and complex spatial analysis. It is designed to help professionals capture high-density 3D data efficiently and convert it into practical deliverables through CHCNAV’s software and cloud ecosystem. The RS7 integrates a next-generation lidar scanner capable of measuring up to 1.15 million points per second. Its wide field of view (360° x 189°) supports comprehensive coverage of floors, walls and ceilings, helping reduce the need for repeated passes and complex capture maneuvers in tight or cluttered spaces. The scanner also includes a high-precision inertial measurement unit with bias stability better than 0.5°/h. By combining lidar and inertial data, the system is designed to maintain stable motion estimation and consistent point-cloud quality in environments that challenge many mobile workflows, including long corridors, repetitive structures, and feature-limited interiors.

    Mobile scanner: All-in-one system offers SLAM, LIDAR, RTK and 360 degree imagery

    Emesent

    Credit: Emesent
    Credit: Emesent

    The GX1 is an integrated, highly accurate all-in-one mobile scanning system combining simultaneous localization and mapping (SLAM), lidar, real-time kinematic (RTK) georeferencing, cameras and software. It supports a seamless workflow, from capture to deliverable, and can reduce the time required to survey a site by up to 95%. The independently validated global accuracy of 5 mm to 10 mm
    delivers the precision needed for topographic and road surveying, scan to building information models, construction progress tracking, and more. These capabilities are supported by integrated RTK georeferencing with real-time quality monitoring, four 20MP cameras for 360° panoramic imagery, and a proven SLAM algorithm. The GX1 has four deployment modes — backpack, survey pole, vehicle mount and supported handheld.

    Quad-band GNSS rover: With support for Galileo high accuracy service

    SparkFun Electronics

    Image: SparkFun
    Image: SparkFun

    The SparkPNT TX2 quad-band GNSS rover combines an IP67-rated aluminum enclosure with support for Galileo’s High Accuracy Service (HAS) and standard RTK correction workflows. The receiver is built around the Quectel LG290P quad-band GNSS engine and supports multi-constellation tracking. Galileo HAS support provides sub-20 cm accuracy globally without subscription-based correction services, while RTK workflows via NTRIP or u-blox PointPerfect can achieve centimeter-level positioning. Battery life is rated at 50-plus hours, positioning the TX2 for multi-day field campaigns without recharging. The unit connects to iOS and Android devices via Bluetooth and WiFi, with compatibility reported for common GIS and data-collection applications. A notable design choice is the open-source firmware, which gives users visibility into how positioning data is processed and allows for customization and third-party integration. SparkFun has positioned this as an alternative to closed GNSS ecosystems where firmware and processing pipelines are not user-accessible.

    Mobile

    GNSS platform: Provides ultra-low power GNSS for all environments

    u-blox

    Image: u-blox
    Image: u-blox

    The u-blox F11 platform provides L1/L5 dual-band standardprecision GNSS to improve positioning accuracy while reducing power consumption to as low as 7 mW in typical configurations. It combines ultra-low power operation with intelligent signal management to meet the evolving demands of tracking, wearables, telematics and mobility applications — including micromobility solutions and drones. The platform enables device manufacturers to achieve longer battery life, faster and more reliable position fixes, and greater design flexibility. Its situationally aware GNSS architecture, with integrated geofencing and indoor detections, dynamically balance accuracy and power consumption. By selectively using dual band L1/L5 operation only when it helps maintain positioning performance, the platform reduces energy use while providing resilience and maintaining confidence in location data.

    IOT platform: Combines GNSS, SBD and LTE-M

    Iridium Communications

    Image: Iridium
    Image: Iridium

    The Iridium 9604 is a compact, threein-one internet of things (IoT) module that integrates Iridium short burst data satellite service, LTE-M cellular connectivity, and GNSS positioning into a single platform. The Iridium 9604 seeks to make dual-mode IoT connectivity viable for price-sensitive, high-volume deployments. Built on the u blox SARA-R5 platform, the module comes in a compact 16 mm x 26 mm x 2.4 mm form factor, suitable for dual-mode IoT deployments across industrial, infrastructure and mobility applications.

    L1+L5 GNSS modules: For trackers and high-precision IOT

    Telit Cinterion

    Image: Telit Cinterion
    Image: Telit Cinterion

    Two dual-band positioning modules built on Airoha’s AG3335 chipset series are available: the ultracompact SE873K5-D and the high-end SE869eK5-DRK. Both support space- and power-constrained IOT devices and use cases that require continuous, ultraprecise positioning. The modules provide a scalable path to adopt dual-band L1 + L5 GNSS.

    Timing

    Cesium-less clock: An alternative to cesium-accuracy holdover clocks

    Viavi Solutions

    Credit: Viavi
    Credit: Viavi

    The patent-pending Cesium-less ePRTC360+ holdover solution is designed to safeguard atrisk infrastructure against the increased threat of GNSS timing disruptions. It is the only alternative to Cesium clocks to meet ITU-T G.8272.1 standards. It can protect critical power grids; transportation, aviation and public safety systems; 5G mobile networks; and AI data centers. It meets the international ITU-T G.8272.1 standard and has been successfully tested across a range of livesky defense and commercial jamming/spoofing environments. It has been integrated into VIAVI’s SecurePNT 6200 product series and can maintain 100 ns accuracy during GNSS-denied threats through the resilient altGNSS GEO-L service with no time limit.

    Transportation

    MEMS IMU module: For vehicles, ships and drones

    Micro-Magic

    Credit: Micro-Magic
    Credit: Micro-Magic

    The U4930 series is a reliable and cost-effective six-axis microelectromechanical system (MEMS) and inertial measurement unit (IMU) module for navigation, control and measurement of vehicles, ships and drones. Applications include vehicle/ship
    attitude measurement, UAV attitude reference and trajectory control, mobile mapping, track inspection and underwater highprecision navigation. The U4930 series integrates high-performance MEMS gyroscopes and accelerometers within an independent structure. The three-axis MEMS gyroscopes sense the angular motion of the carrier, and the three-axis MEMS accelerometers sense the linear acceleration of the carrier. The system internally performs compensation for zero bias, scale factor, non-orthogonal error and acceleration-related terms across all temperature parameters, maintaining high measurement accuracy over a long period of time. The module supports custom communication protocols and provides synchronization for GPS/GNSS time data and pulse per second (PPS) signals.

    Underground navigation: For navigating mines and unmapped environments

    Advanced Navigation

    Image: Advanced Navigation
    Image: Advanced Navigation

    Chimera Land is a 3D laser velocity sensor (LVS) designed to solve the primary challenge for underground mining: maintaining precise vehicle positioning in deep,
    dark and unmapped environments where GPS cannot reach. When fused with an Advanced Navigation inertial navigation system (INS), Chimera Land allows underground vehicles to maintain stable navigation over extended distances and time. Instead of needing to query an external beacon or satellite for its location, the sensor uses specialized lasers to measure a vehicle’s ground-relative 3D velocity with high accuracy. By feeding this precise data into the vehicle’s INS, the sensor eliminates the drift that typically comes with standalone INS. Using AdNav Intelligence, the result is a resilient, high-performance, infrastructure-light positioning solution that excels in the highdust, zero-light conditions typical of underground mines.

    Simulators

    GNSS test tool: Provides real-world testing with signals from the field

    Spirent Communications

    Image: Spirent
    Image: Spirent

    The SimXTRACT GNSS test tool bridges the gap between field and laboratory. It enables signals captured in field environments to be comprehensively decomposed into individual, discrete signals and applied to lab simulation for realism at every stage of the development test cycle. Developers usually rely on either RF record-and-playback or lab simulation for testing and validation of PNT systems and devices. SimXTRACT takes real signals captured in field environments and performs complex signal decomposition, breaking down each received signal into discrete line-of-sight and multipath ray paths, along with metadata such as Doppler offset, code error, power level and angle of arrival. This decomposed environment is then automatically converted into fully controllable simulation scenarios for Spirent GNSS simulators.

    Autonomous

    Inertial measurement unit: For unmanned air, land and sea

    Honeywell Aerospace

    Image: Honeywell
    Image: Honeywell

    Honeywell launched the HGuide i700, an inertial measurement unit (IMU) that delivers high-accuracy performance for unmanned air, land and sea vehicles. By pairing near navigation-grade capability with a nolicense-required (NLR) classification, the HGuide i700 provides integrators worldwide with a new option for critical sensing and navigation. The HGuide i700 uses high reliability sensors and electronic architecture found in Honeywell’s HG3900 inertial measurement unit (IMU). Compact and low power, the HGuide i700 delivers near-navigationgrade accuracy and reliability while being optimized to support longer range navigation in GNSS-denied environments. The HGuide i700 offers strong GNSS-denied performance for by limiting maximum acceleration and spin rates in a license-free package. The latest in Honeywell’s HGuide suite of no-license inertial solutions, the HGuide i700 allows customers to streamline development cycles, simplify system architecture and transition to field deployment quickly. The HGuide i700’s rugged design, compact size and low-power profile make it suitable for diverse commercial, industrial and defense applications, including autonomous vehicles, mapping and surveying.

    Anti-jam antenna system: Provides multi-constellation, multi-frequency GNSS signal protection

    Hexagon | NovAtel

    Image: Hexagon
    Image: Hexagon

    The GAJT-AE3 protects all major GNSS constellations from jamming with full multiconstellation, multi-frequency coverage, ensuring reliable PNT in demanding airborne environments. Its antenna electronics mitigate interference by creating up to seven nulls per band in the direction of jammers, providing significant anti-jam protection even in dynamic multi-jammer scenarios. The output is a protected radio frequency signal, free from jamming and suitable for input to modern and legacy GNSS receivers. The GAJT-AE3 protects and supports all GNSS frequencies, including L-band corrections and Iridium PNT.

    OEM

    GNSS board: All-band multifrequency reception and HAS-ready

    Syslogic

    Credit: Syslogic
    Credit: Syslogic

    Syslogic’s new all-band GNSS expansion board for rugged embedded computers is powered by the u-blox X20 receiver. It supports all major GNSS constellations and frequencies, including L1, L2, L5, L6 and L-band, and enables the use of the Galileo High Accuracy Service (HAS). It provides centimeter-level positioning, opening up new applications across industries such as autonomous field management, operation of construction machinery in remote areas, or navigation of automated guided vehicles and autonomous mobile robots. The GNSS board is designed for worldwide use. The integrated u-blox receiver supports modern correction techniques such as RTK, PPP-RTK and PPP. For the first time, it has been fully optimized for PointPerfect Global, u-blox’s proprietary high-precision GNSS correction service, delivering centimeter-level positioning anywhere in the world. This is particularly useful in remote areas without cellular coverage.

    GNSS L1/L5 breakout: For meter-level positioning in embedded applications

    SparkFun Electronics

    Photo: SparkFun
    Photo: SparkFun

    The SparkFun GNSS L1/L5 Breakout – NEO-F10N (SMA) is a compact GNSS module designed for meter-level positioning accuracy in embedded applications. It uses dual-frequency L1 and L5 bands, with the L5 signal offering improved performance in urban environments due to reduced RF interference within the protected ARNS spectrum.


    The board supports concurrent reception of GPS, Galileo and BeiDou, and uses u blox dual-band multipath mitigation to enhance accuracy in challenging conditions. It features a single UART interface, with an onboard CH340 USB-to-serial converter for easy connection to a computer, and standard pin headers for integration with external systems.

    The module includes an SMA connector for secure antenna attachment and is configurable using u-blox u-center software.

  • VIAVI partners with Ground Control to enable assured maritime vessel tracking

    VIAVI partners with Ground Control to enable assured maritime vessel tracking

    VIAVI Solutions is partnering with satellite communications and positioning solutions provider Ground Control to integrate its Secure µPNT STL-1000 into the RockFLEET Assured asset tracking and assured navigation solution.

    Viavi’s Secure µPNT STL-1000 is a compact software-defined receiver designed to operate with the Viavi SecureTime altGNSS LEO services. Delivering precise timing with holdover capability, it enables tracking, authentication and assured navigation in denied, degraded and disrupted space operational environment, also known as D3SOE.

    “With jamming and spoofing now a core element of cyber warfare, resilient PNT solutions are no longer optional,” said Doug Russell, senior vice president and general manager, Aerospace and Defense, Viavi. “The Secure µPNT STL-1000 enables assured, uninterrupted operations, especially in contested environments. Its compact size and low power consumption makes it ideal for applications that require an extremely small, low-power, secure, resilient embedded PNT receiver.”

    “As the frequency of jamming and spoofing continues to rise, reliance on GPS/GNSS signals alone increasingly exposes both commercial and military operations to risk,” said Alastair MacLeod, CEO of Ground Control. “Integrating Viavi’s Secure µPNT STL-1000 into RockFLEET Assured delivers a trusted secondary position source, strengthening resilience for mission‑critical operations across defense, maritime and critical infrastructure environments.”

    RockFLEET Assured is a marine-grade assured position, navigation and timing (A-PNT) solution designed to support maritime vessel navigation and oversight in GNSS-denied environments.

  • Viavi launches ePRTC360+ clock alternative to Cesium-accuracy holdover clock

    Viavi launches ePRTC360+ clock alternative to Cesium-accuracy holdover clock

     Viavi Solutions Inc. has launched the patent-pending Cesium-less ePRTC360+ holdover solution to safeguard at-risk critical power grids, transportation, aviation and public safety systems, 5G mobile networks and AI data center infrastructure against the increased threat of GNSS timing disruptions. It is the only alternative to Cesium clocks to meet ITU-T G.8272.1 standards.

    The international ITU-T G.8272.1 standard stipulates that Enhanced Primary Reference Time Clock (ePRTC) holdover must have short-term drift of less than 30 ns when entering into holdover and a long-term drift of less than 100 ns over 14 days, all traceable to UTC. Previously achieved only by Cesium atomic clocks, VIAVI’s ePRTC360+ now also meets this standard.

    ePRTC360+ Enhanced Primary Reference Time Clock

    The ePRTC360+ has been successfully tested across a range of live-sky defense and commercial jamming/spoofing environments, and has been integrated into VIAVI’s SecurePNT 6200 product series. The technology can maintain 100 ns accuracy during GNSS-denied threats through the resilient altGNSS GEO-L service with no time limit.

    It also combines an augmented VIAVI SecureTime GEO anti-jamming antenna and an enhanced GNSS anti-spoofing antenna that also receive eGNSS GEO service with GPS/GNSS-NMA authentication for spoofing detection and mitigation.

    Unlike conventional GNSS omni-directional signals, which can be drowned out by low-power interference, VIAVI’s GNSS-independent GEO-L service leverages encrypted and highly directional L-band signals transmitted from geostationary satellites. Coupled with the augmented VIAVI SecureTime GEO antenna, the altGNSS GEO-L service provides enhanced anti-jamming protection and a resilient timing reference for the ePRTC360+’s internal Rubidium holdover oscillator and enables smooth multi-orbit source switchover, even when primary GNSS frequencies are jammed, spoofed or subject to sophisticated meaconing attacks.

    The affordability of ePRTC360+ clocks compared to Cesium clocks enable operators to deploy them beyond the core and across the network. They also complement non-RF Cesium clocks at the core. This boosts end-to-end sync network robustness and holdover reliability through meshed network PTP feeds as backup between the clocks, especially in case of local or regional jamming and/or spoofing threats.

    In addition, the ePRTC360+ addresses constraints posed by the use of Cesium clocks for holdover timing. These include sensitivity to shock, delicate and multi-stage startup procedures that take days to complete, the need for ECCN 3A001.i licenses for export, long GNSS learning period of up to 40 days, as well as strict shipping and storage protocols. In addition, Cesium tubes need to be replaced approximately every seven years, and the dismantling and disposal of Cesium clocks are classified as a hazard due to their material content.

    The ePRTC360+ eliminates these hurdles and has been designed for rapid and easy integration into any vendor’s grandmaster clock system. It enables operators to meet stringent ePRTC requirements while reducing total cost of ownership.

    The ePRTC360+ will be demonstrated at VIAVI’s Stand 5B18 at Mobile World Congress (MWC) Barcelona 2026, March 2-5, in Barcelona, Spain. 

  • Inertial Labs launches IRINS LEO-aided inertial navigation system

    Inertial Labs launches IRINS LEO-aided inertial navigation system

    Inertial Labs, a Viavi Solutions Inc. company, has announced IRINS, a low Earth orbit (LEO)-aided inertial navigation system (INS) designed to allow full operation across land, air and sea in GNSS-denied, -degraded and -disrupted space operating environment .

    Combining the capabilities of an INS, an altitude and heading reference system (AHRS) and a LEO PNT receiver, this platform marks a major milestone in Viavi’s portfolio for assured positioning, navigation and timing by bringing together the INS capabilities of inertial labs and the timing expertise of Jackson Labs.

    The IRINS embedded system has been developed to counter the exponentially rising number of spoofing and jamming attacks that have affected military and critical infrastructure. Now, resilient LEO-based PNT and inertial navigation are available within a fully integrated system from a single vendor.

    The system combines an INS, an AHRS and the GNSS-independent STL-2600 LEO Iridium receiver module. These capabilities enable the system to calculate altitude, position, velocity and time data, as well as minimize bias from causing drift. To help detect and eliminate attack signals, the device additionally integrates a GNSS receiver with a controlled reception pattern antenna (CRPA) port.

    “The IRINS is the first fruit borne of VIAVI’s visionary strategy to mitigate vulnerabilities in positioning, navigation and timing, bringing together resilient satellite-based timing with tactical-grade IMUs to deliver the most precise PNT for GNSS-denied environments,” said Jamie Marraccini, vice president, Inertial Labs Products, Viavi. “By tightly coupling inertial sensing, LEO-based timing and navigation and anti-jam GNSS technologies into a single platform, the IRINS provides unmatched continuity, accuracy and trust for operations in contested and denied environments.”

    “Assured access to PNT is critical for operations in contested environments,” said Maynard Porter, Director, Government PNT Business, Iridium. “Integrating Iridium PNT alongside VIAVI’s INS and AHRS provides users with an exceptionally resilient source of time and location data to maintain operational effectiveness when GNSS signals are disrupted.”

    The IRINS is certified for IP67 and MIL-STD-810G environmental requirements. It is based on the company’s fully calibrated tactical-grade MEMS 3-axis accelerometer, gyroscope and clock. These are combined with embedded barometers, magnetometers and an optional onboard air-data computer as part of its AHRS.

    Satellite communication is provided through the company’s STL-2600 receiver, which links to the Iridium LEO constellation. All capabilities are housed within a compact 126.5 × 49.3 × 53.3 mm enclosure. 

  • VIAVI wins US DOT award to advance complementary PNT for critical infrastructure

    VIAVI wins US DOT award to advance complementary PNT for critical infrastructure

    VIAVI Solutions has received an award from the U.S. Department of Transportation (DOT) through its Complementary Positioning, Navigation and Timing (CPNT) Action Plan Rapid Phase II.

    VIAVI will integrate and test its SecureTime altGNSS GEO-L service and SecurePNT 6200 resilient timing solution at the VIAVI Automated Lab-as-a-Service for Open RAN (VALOR) and the Open RAN Center for Integration and Deployment labs. VALOR and ORCID are funded by the National Telecommunications and Information Administration Public Wireless Supply Chain Innovation Fund.

    Incidents of GNSS signal interference, such as jamming and spoofing, have increased significantly in recent years, emphasizing the need for a resilient PNT ecosystem that can function in denied, degraded and disrupted space operational environments (D3SOE). Complementary to GPS and GNSS, VIAVI’s SecureTime GEO-L service and SecurePNT-6260 switch to a completely GPS-independent, GEO-L satellite-based time service and a precision holdover clock in the event of jamming or spoofing with no interruption perceived by the critical infrastructure system.

    The DOT action plan aims to test systems that augment or replace GPS and GNSS, providing accurate timing services to critical infrastructure ranging from data centers and financial systems to power grids and cellular networks. Data from the VALOR, ORCID and field trials will be used to support widespread adoption of complementary positioning, navigation and timing services to protect the nation’s critical infrastructure.

    “Integration and testing at the VALOR and ORCID labs demonstrate the technology’s readiness in an operational critical infrastructure environment. We look forward to partnering with DOT and NTIA to improve resilience for critical infrastructure and providing vital data to support widespread CPNT adoption,” said Doug Russell, senior vice president and general manager of aerospace and defense at VIAVI.

    In addition to integration and testing at the VALOR and ORCID labs, the VIAVI GEO-L service and user equipment will be tested at an upcoming government field test event that provides live-sky jamming and spoofing of GPS/GNSS.

  • Implementing assured PNT for static and dynamic applications

    Implementing assured PNT for static and dynamic applications

    Position, navigation and timing (PNT) services, derived primarily from GNSS constellations, have become a critical element underpinning the global economy, with a vast range of sectors depending on these signals.

    This includes coordinating financial transactions, stabilizing power grids as well as navigation, with supply chains set to become more reliant on the technology as autonomous vehicles become prevalent. However, GNSS is a vulnerable technology, with faint signals from medium-Earth orbit (MEO) satellites being susceptible to disruption.

    In this article we’ll look at how both static and dynamic applications can achieve resilient PNT, with strategies and sensor fusion techniques that allow operational capability when GNSS is denied.

    Seven hundred. That’s the number of GPS interference events such as jamming and spoofing that take place every single day, according to the U.S. government. And this number is increasing across North America and Western Europe, with it being especially prevalent in or near war zones.

    Indeed, in August, the navigation system of a plane carrying the EU President, Ursula von de Leyen, was reportedly targeted by a GPS jamming attack as it was due to land in Bulgaria — forcing pilots to rely on paper maps. And GPS interference has been linked to the crash of Azerbaijan Airlines flight J2-8243, which was shot down on Christmas Day, 2024.

    Relying on a single source for PNT is no longer a viable strategy and developing a resilient PNT ecosystem that can function in D3SOE (denied, degraded, and disrupted space operational environments) has become essential.

    While navigation is the most commonly understood application of PNT, the timing component is critical in so many of the static systems we rely on — not just finance and power (as listed above) but for AI data centers, asset tracking systems and communication networks — which require precise and stable time references to ensure data integrity, and need these to be synchronized across global networks.

    For such systems, the consequences of getting timing off by even the smallest amount can be seen in the 2016 decommissioning of the SVN23 GPS satellite. During this, a software error created a 13.7 microsecond anomaly across the entire constellation that, according to a UK government report caused issues with digital radio broadcasts and communication networks. The event is also seen by some as a warning for the financial sector and in particular for high-frequency trading (HFT), where trades take place in millionths and studies have suggested that a 1 ms advantage in trading applications could be worth $100 million a year to a major brokerage firm.

    By subtly altering timing signals used by trading systems, malicious actors can effectively see and use market data “from the future” and enact transfers worth billions of dollars.

    Similarly, a timing attack on the phasor measurement units (PMUs) used to measure real-time stress in power grids could trigger major blackouts. The effect of such an attack can be seen in 2003’s (pre-PMU) Northeast Blackout, in which a sagging power line touched tree and caused a series of cascading outages that affected 55 million people across the U.S. and Canada. 

    And further putting the importance of protecting PNT in context, in 2020 the U.S. defined 16 critical infrastructure sectors as part of its Executive Order 13905. Of these 14 (88%) of these are reliant on PNT for their safe operation. Going beyond the energy and finance examples above, this includes sectors like communications, transportation, and agriculture. In short, PNT resilience is essential across virtually the entire economy.

    Detecting a Compromised GNSS Signal

    Of course, the first stage in protecting a PNT signal is in the identification of an attack, and several techniques can be used to identify inconsistencies that point to jamming or spoofing.

    These range from the analysis of the signal’s Doppler shift (transmissions from nearby terrestrial spoofer will have a near-zero Doppler shift) to techniques like RAIM (receiver autonomous integrity monitoring), which continually recalculates position while excluding one satellite each time to see if the results are consistent.

    Cryptographic methods, such as Galileo’s Open Service Navigation Message Authentication (OSNMA), are also available to verify a satellite’s digital signature and confirm the data’s authenticity.

    However, relying on cryptographic authentication alone still comes with risks. Notably, authenticated signals are susceptible to meaconing attacks, where a legitimate signal is recorded and replayed later to mislead a receiver. It is, however, possible to counter these attacks using a secure, out-of-band verification layer for all GNSS constellations. This involves the independent delivery of authentication data with hash authentication transmitted via encrypted L-band correction signals from geostationary (GEO) satellites.

    This approach can also be retrofitted to older equipment using PNT by using an RSR transcoding device (see below).

    For dynamic systems, an additional level of validation can be gained by inertial sensors, comparing their output against PNT data to detect both sudden large jumps in position and continual slight deviations that can be characteristic of a sophisticated spoofing attack.

    Timing in Static Applications

    The timing architecture of such systems must go beyond simply identifying a threat and validate incoming data. This requires the integration of alternative PNT sources through an intelligent sensor fusion framework. To achieve this level of resilience in a fixed location, a multi-source, zero-trust approach is necessary. This involves augmenting or replacing GNSS with a layered defense of terrestrial and alternative space-based signals that can be authenticated and trusted.

    Modern PTP grandmasters utilize the latest sub-microsecond accuracy Precision Time Protocol (PTP) and the more common millisecond-range Network Time Protocol (NTP) to ensure compatibility with nearly all standard IT equipment.

    High-speed 25G PTP Ethernet connections are also being implemented to support high-performance AI data centers and financial exchanges without creating data bottlenecks. To ensure continuous operation during extended GNSS outages, these systems can draw synchronization from terrestrial sources like a network PTP feed or an optional atomic caesium clock.

    Furthermore, it is also possible to use encrypted L-Band signals from geostationary (GEO) satellites, such as those from Inmarsat, which create an enhanced timing service with built-in GNSS authentication and anti-spoofing features to deliver timing accuracy of sub-5 ns.

    Figure 1: VIAVI’s Inertial Labs division has developed a Visual-Inertial Navigation System (VINS) that combines 3D vision aided mapping with inertial accelerometers to enable positioning in D3SOE environments – shown in prototyping stage
    Figure 1: VIAVI’s Inertial Labs division has developed a Visual-Inertial Navigation System (VINS) that combines 3D vision aided mapping with inertial accelerometers to enable positioning in D3SOE environments — shown in prototyping stage.

    Navigation Without a North Star

    While static applications can utilize fixed terrestrial infrastructure for backup, dynamic systems do not have this luxury.

    The inherent weakness of RF signals makes them easy to overpower through deliberate jamming by hostile actors. As such, navigation systems onboard UAVs and autonomous vehicles, as well as manned commercial and military vehicles require self-contained navigation capabilities that can function reliably when GNSS signals are compromised. This has driven significant advances in inertial navigation.

    Sensors like accelerometers and gyroscopes have become a critical source for orientation and direction data that remains available at all times. The development of micro-electromechanical systems (MEMS) has been crucial, enabling the integration of inertial navigation into even the smallest systems.

    These sensors aren’t an alternative to PNT satellites. By their very nature they will accumulate errors over time, with sensor bias causing drift and random-walk deviations allowing random noise in each measurement to accumulate. However, recent years have seen significant gains in their accuracy, allowing navigation to continue for short periods after GNSS data is compromised.

    Combining these inertial sensors with sensor fusion techniques also allows each element in a multi sensor system (using magnetometer; and accelerometers/ gyroscopes for roll, pitch and yaw…) to be continually verified by the others for further improvements in accuracy, reducing overall level of error. Data from these IMUs can also be fused with signals from alternative satellite constellations like those in LEO.

    LEO satellite signals are less accurate for timing than GNSS (around 80 ns vs. sub-15 ns) but are significantly stronger. For example, the Iridium LEO STL signal is c.1,000 times stronger than GNSS, making these signals both more resistant to jamming and harder to undertake a (successful) denial of service.

    More recently, techniques using downward-facing camera to track fixed identifiable landmarks have been developed as an alternative / additional data validation method for dynamic systems.

    These external sources provide absolute reference points that can be used to correct the inertial system’s calculations, dramatically improving accuracy and enabling reliable navigation for much longer periods.

    Figure 2: VIAVI’s SecureTime uses GEO and LEO constellations to provide positioning and timing signals that are resilient to attacks.
    Figure 2: VIAVI’s SecureTime uses GEO and LEO constellations to provide positioning and timing signals that are resilient to attacks.

    Sensor Fusion Gives Resilience

    The limitations of individual PNT sources — whether the vulnerability of GNSS or the inherent drift of inertial sensors — mean they cannot depend on a single technology. The most effective strategy is often a hybrid one, combining a high-accuracy inertial sensor unit with inputs from other sensors.

    As we touched on above, adding data sources improves the ability to detect and counter PNT attacks. For example, the EU has confirmed it will deploy additional LEO satellites to bolster its ability to detect GPS interference. And vision cameras can also be used as part of a Visual-Aided Inertial Navigation System (VINS), which provides a powerful method for maintaining an accurate position in the complete absence of GNSS signals.

    This technique was developed in 2025 by VIAVI’s Inertial Labs division, with VINS combining processing with multiple inertial sensors to maintain position. This is reinforced with, and calibrated by a 3D vision-based positioning algorithm that compares visual patterns captured by an onboard camera (either daylight or infrared) with pre-loaded, satellite-imagery-derived 3D maps to track against known landmarks. In a GNSS-denied environment, a VINS system can maintain a horizontal position within 35 m, a vertical position within 5 m, and a desired velocity within 0.9 m/s.

    Conclusion: Bridging the Legacy Gap

    While modern systems can be designed from the ground up with a multi-layered, sensor-fusion PNT architecture, there is still the problem of the huge number of legacy systems that are very much prone to attack.

    These legacy PNT systems are still widely used, including in military conflicts where D3SOE attacks are prevalent. To address this vulnerability, resilient signal retransmission technology has been developed to cost-effectively upgrade these older systems. This approach uses RSR transcoders (constellation simulators) to take a trusted PNT signal, derived from multiple assured inputs, and convert it into the standard GPS format that legacy equipment is designed to receive. This set up – in which the GNSS aerial is replaced with the input from the RSR transcoder – allows the existing systems to operate with state-of-the-art resilience without requiring replacement.

    But, as we’ve seen in the above, a single, invulnerable replacement for GPS is simply not possible, so integrating multiple trusted sources is therefore essential. The path to assured PNT relies on a multi-layered ecosystem of diverse signals and sensors and applying this approach to both modern designs and legacy-system upgrades ensures all assets can maintain uninterrupted PNT access.

    viavisolutions.com

  • Launchpad: dual-band antennas, mobile clocks, UAV upgrades and more

    Launchpad: dual-band antennas, mobile clocks, UAV upgrades and more

    Read a roundup of recent products in the GNSS and inertial positioning industry from the June 2025 issue of GPS World magazine.

    MOBILE

    Photo: SiTime

    Mobile Clock Generators
    With an integrated MEMS resonator

    SiTime’s Symphonic is a mobile clock generator built around the SiT30100, which integrates a MEMS resonator and a temperature sensor in a compact 2.22 mm² chip. Designed for 5G and GNSS chipsets, Symphonic delivers precise, resilient clock signals while supporting efficient power consumption in mobile and IoT devices, including smartphones, tablets, laptops and asset trackers.

    The integrated temperature sensor feeds data to compensation algorithms, providing frequency stability as low as ±0.5 parts per million to enhance GPS accuracy and shorten lock times, which is critical for reliable performance in challenging environments. The device operates across a -30°C to 90°C temperature range and is engineered for dynamic stability and power optimization, helping to mitigate electromagnetic interference. Symphonic features four configurable clock outputs, each capable of delivering 76.8 MHz, 38.4 MHz or 19.2 MHz, suitable for baseband, radio frequency and GNSS applications. The single-chip design eliminates the need for external resonators.

    SiTime, sitime.com

    Photo: Calian GNSS

    Dual-Band L1/L5 Antenna
    For critical positioning and timing applications

    The TW3885TL is a dual-band GNSS antenna engineered to deliver reliable, interference-free signal reception for critical positioning and timing applications. Supporting both L1 and L5 frequency bands, the antenna is compatible with a wide range of global navigation satellite systems, including GPS, QZSS, Galileo, BeiDou, GLONASS and NavIC, as well as regional satellite-based augmentation systems.
    The TW3885TL incorporates advanced filtering technology designed to reduce interference from crowded radio frequency environments. It features a low-noise preamplifier, with a typical noise figure of less than 2.5 dB, and offers high gain, typically around 40 dB. The antenna maintains a low axial ratio, under 2.0 dB, and exhibits tight phase center variation, which contributes to precise timing and superior signal quality. Constructed with a weatherproof enclosure rated to IP69K, the TW3885TL is suitable for permanent outdoor installations and can be mounted through-hole, with optional accessories available to support various mounting configurations.

    Calian GNSS, calian.com

    UAV

    Photo: AgEagle Aerial Systems

    Software Upgrades
    Enable positioning in GNSS-denied environments

    eBee VISION application software now includes a suite of updates for UAV navigation in environments where GNSS signals are compromised or unavailable. The latest software enables autonomous position updates with map referencing, allowing for precise navigation even when satellite signals are jammed, spoofed or blocked. This product is suitable for defense personnel, public safety agencies, and industrial teams working in high-stakes environments where GNSS signals are unavailable (densely populated urban areas, near critical infrastructure, or in contested zones with active interference). The update introduces optical flow stabilization for target lock, which uses visual cues to keep the camera centered on a point of interest during zoom-ins or drone movement. The software allows for adaptive behavior after GNSS recovery or visual repositioning. Additional enhancements include real-time mission duration and return-to-home estimates, optimized cruise speed in windy conditions, high-precision landings using lidar-based altitude calibration, a gimbal auto-recovery mechanism to clear obstructions mid-flight, and smart motor speed reduction to prevent overheating during extreme conditions.

    AgEagle Aerial Systems, ageagle.com

    Photo: Inertial Labs

    IMU
    For unmanned commercial and defense applications

    The IMU-H100 is a micro-electromechanical systems inertial measurement unit (IMU) designed to improve tactical guidance and navigation for UAVs, short-range missiles, precision-guided munitions, and a range of commercial applications.
    The tactical-grade unit features accelerometers and gyroscopes on all three axes. It offers a gyro bias of 1° per hour and an accelerometer bias of 1 mg. The unit measures 5 in³ and weighs 160 g. The IMU-H100 surpasses comparable products in data rate, measurement range, stability and repeatability, even under challenging conditions such as vibration, shock, high acceleration, spinning, temperature changes and acoustic noise.

    Inertial Labs, a VIAVI Solutions company, inertiallabs.com

  • Inertial Labs unveils visual-aided inertial navigation system for GPS-denied environments

    Inertial Labs unveils visual-aided inertial navigation system for GPS-denied environments

    Inertial Labs, a VIAVI Solutions company, has introduced its Visual-Aided Inertial Navigation System (VINS), designed to help aircraft maintain accurate flight paths in environments where GPS/GNSS signals are unreliable.

    The launch follows a report from the U.S. Department of Transportation noting a rise in GPS jamming and spoofing incidents across North America and much of Western Europe. These disruptions, which now reach up to 700 cases worldwide each day, impact both commercial and military operations. War zones have seen the highest concentration of interference, with Lithuanian airspace alone recording more than 800 cases in the last three months of 2024. Communications and emergency services, which depend on precise timing and geolocation, are also affected.

    VINS is engineered for unmanned aerial vehicles to complete long-range missions in GNSS-challenged environments. The system leverages Maxar Raptor 3D vision-based positioning software, which estimates a vehicle’s absolute 3D position by comparing onboard camera imagery — day or infrared —with Maxar Precision3D satellite-derived maps using Perspective and Point principles.

    In GNSS-denied conditions, VINS can maintain a horizontal position within 35 m, a vertical position within 5 m, and velocity within 0.9 m per second of true values. It also holds heading accuracy within 1° and pitch/roll within 0.1°. With GNSS enabled, the system achieves a horizontal position of 1 meter, vertical position under 2 m, velocity accuracy of 0.03 m per second, heading within 0.1 °, and pitch/roll within 0.03°.

    The modular system is designed for low-altitude operation and includes processing and sensor modules, a GNSS or CRPA antenna, an air-data computer, and a digital windspeed sensor for use with both fixed-wing and multi-rotor UAVs. Optional features include a commercial off-the-shelf radio for data and absolute positioning in GPS-denied environments, as well as Iridium low-earth orbit (LEO) GNSS and M-Code/SAASM GNSS receivers.

    Inertial Labs and VIAVI will demonstrate VINS and the second-generation RSR Transcoder with GPS full constellation simulator at the 2025 Joint Navigation Conference (JNC), held June 2-5 in the Greater Cincinnati area. The products will be on display at the Inertial Labs (booth 430) and VIAVI (booth 406) stands.

    VIAVI and its Inertial Labs division will also present three sessions at the conference:

    • “3D Vision-Based Positioning for Autonomous Aerial Platform Navigation and Human-in-the-Loop Reconnaissance Mission,” presented with Maxar, Monday, June 2 at 1:50 p.m. ET.
    • “Anti-Jam/Spoof Phased Array Antenna,” Wednesday, June 4 at 10:50 a.m. ET.
    • “Retrofitting At-Risk GPS Defense Equipment with a Multi-Orbit LEO and GEO Clock System for Resilient PNT Services,” Wednesday, June 4 at 11:30 a.m. ET.
  • VIAVI unveils second-generation RSR Transcoder for reliable PNT in GPS-denied environments

    VIAVI unveils second-generation RSR Transcoder for reliable PNT in GPS-denied environments

    VIAVI Solutions Inc. has introduced its second-generation RSR Transcoder, engineered to maintain operational capability in GPS/GNSS-denied, degraded or disrupted space operational environments.

    This development comes amid a global increase in GPS and GNSS jamming and spoofing, which have become standard tactics in electronic warfare. These hostile activities, while primarily aimed at military operations, also threaten sectors that depend on precise timing and geolocation, such as aviation, communications and emergency services.

    The new RSR Transcoder is designed to deliver assured positioning, navigation and timing (PNT) in a wide range of outputs to upgrade legacy systems. The device features a GPS full constellation simulator and employs a patented algorithm to rapidly convert assured inputs — including M-Code, SAASM, IMU/INS, and other signals of opportunity — into universal GPS L1 and L2 signals with both C/A-code and P-code outputs. This capability allows for the straightforward enhancement of older GPS systems, providing them with modern, resilient PNT functionality.

    The RSR Transcoder is housed in ruggedized IP68 enclosures suitable for deployment on land, sea and air platforms. It is capable of covert, lights-out operation and offers a 100 Hz output rate with an ICD-GPS-153 interface. The device is available with holdover oscillator options of 4, 8 and 24 hours, supporting continued operation during signal loss.

    On Display at the Joint Navigation Conference

    The RSR Transcoder will be demonstrated at the 2025 Joint Navigation Conference, which is held June 2-5 in the Greater Cincinnati Area and jointly hosted by the Departments of Defense and Homeland Security. It will be on display at VIAVI’s booth #406. VIAVI’s Inertial Labs division will also demonstrate recent breakthroughs in D3SOE navigation at booth #430. 

    VIAVI and its Inertial Labs division will also give three presentations: 

    • “3D Vision-Based Positioning for Autonomous Aerial Platform Navigation and Human-in-the-Loop Reconnaissance Mission”: Monday, June 2 at 1:50 PM ET
    • “Anti-Jam/Spoof Phased Array Antenna”: Wednesday, June 4 at 10:50 AM ET
    • “Retrofitting At-Risk GPS Defense Equipment with a Multi-Orbit LEO and GEO Clock System for Resilient PNT Services”: Wednesday, June 4 at 11:30 AM ET
  • Inertial Labs, a VIAVI Solutions company, launches tactical-grade MEMS IMU

    Inertial Labs, a VIAVI Solutions company, launches tactical-grade MEMS IMU

    Inertial Labs, a VIAVI Solutions company, has released the IMU-H100, a micro-electromechanical systems inertial measurement unit (IMU) designed to improve tactical guidance and navigation for UAVs, short-range missiles, precision-guided munitions and a range of commercial applications.

    As technology for unmanned vehicles advances and safety considerations take precedence, both military and commercial sectors are increasing their adoption of IMUs, which are critical for navigation and control systems. An IMU can track angular velocity and linear acceleration using MEMS gyroscopes and accelerometers. These devices are now considered essential for guidance, navigation, orientation and stabilization, especially in short- and medium-range flight control systems. Their applications extend to autonomous vehicles operating on land, at sea and in aerospace and defense sectors.

    The IMU-H100 is a tactical-grade unit that features accelerometers and gyroscopes on all three axes. It offers a gyro bias of 1° per hour and an accelerometer bias of 1 mg. The unit measures 5 cubic inches and weighs 160 g. According to the company, the IMU-H100 surpasses comparable products in data rate, measurement range, stability and repeatability, even under challenging conditions such as vibration, shock, high acceleration, spinning, temperature changes and acoustic noise.

  • Inertial Labs launches anti-jamming solution

    Inertial Labs launches anti-jamming solution

    Inertial Labs, a VIAVI Solutions Inc. Company, has introduced the M-AJ-QUATRO anti-jamming antenna system, designed to ensure assured positioning, navigation and timing (A-PNT) in GNSS-challenged environments. The system incorporates advanced Controlled Reception Pattern Antenna (CRPA) technology and digital processing capabilities, making it suitable for applications ranging from military operations to commercial aviation.

    PNT services are increasingly critical for various sectors, including transportation, telecommunications, artificial intelligence, hyperscale data centers, energy, finance and defense. As GNSS jamming and spoofing threats grow, government agencies and industry leaders are working to address these challenges. For instance, the Federal Aviation Administration and Naval Air Warfare Center Aircraft Division are expediting approval processes for CRPA technology to enhance aviation safety and counter GPS interference.

    The M-AJ-QUATRO supports the L1, L2, and L5 GNSS bands and offers robust interference suppression capabilities. Its adaptive digital nulling feature automatically mitigates jamming signals with over 34dB+ suppression in the export-free version and over 45dB+ suppression in the export-controlled version. Additionally, the system can identify and locate sources of interference through its jammer direction-finding capability, improving situational awareness.

    It is compatible with multiple GNSS constellations to provide comprehensive global coverage. It employs dual FPGA-based encryption and anti-spoofing technologies for secure signal processing and data integrity. Built to meet stringent military standards like MIL-STD-810G and MIL-STD-461F, the M-AJ-QUATRO is engineered to withstand extreme conditions, making it an ideal solution for defense and aerospace applications.

  • VIAVI strengthens portfolio with acquisition of Inertial Labs

    VIAVI strengthens portfolio with acquisition of Inertial Labs

    VIAVI Solutions has signed an agreement to acquire Inertial Labs for $150 million. The acquisition, subject to certain regulatory approvals and customary closing conditions, is expected to close in the third quarter of fiscal 2025 and has a potential for up to $175 million in contingent payments throughout the next four years. 

    This acquisition is expected to significantly boost VIAVI’s financial performance, with projections indicating an increase of approximately $50 million to the company’s Network and Service Enablement (NSE) annual revenue in 2025. Inertial Labs brings to VIAVI a comprehensive portfolio, including inertial measurement units (IMU), inertial navigation systems (INS), assured positioning navigation and timing (APNT), GNSS tracking, lidar scanning, alternative navigation (ALTNAV) and visual navigation solutions. These offerings complement VIAVI’s existing PNT and other aerospace and defense solutions.

    According to VIAVI Solutions, the acquisition is designed to open up new opportunities for VIAVI in emerging markets. Inertial Labs’ expertise in utility inspection through lidar and photogrammetry algorithms, as well as smart system navigation for airborne and autonomous ground vehicles, is expected to accelerate VIAVI’s entry into industrial and autonomous delivery and transportation end markets.

    “With a highly complementary product portfolio focused on alternate navigation solutions, this transaction supports VIAVI’s strategy to expand our presence in domestic and international aerospace and defense segments and accelerates our entry into autonomous air, land and sea systems in the military and industrial end markets,” said Oleg Khaykin, president and CEO of VIAVI.

    “We are excited that our expertise, precision solutions and resources provide expansion opportunities for VIAVI in high growth markets and applications such as drone-based lidar and camera systems,” said Jamie Marraccini, president and CEO of Inertial Labs.