Fact-checked by Grok 2 weeks ago

GNSS applications

Global Navigation Satellite Systems (GNSS) applications refer to the diverse implementations of satellite constellations—such as the ' GPS, Russia's , Europe's Galileo, and China's —that deliver autonomous global positioning, navigation, and timing (PNT) services through receivers processing orbital signals. These systems achieve positioning accuracies from meters to centimeters, depending on augmentation techniques like differential GNSS or real-time kinematic processing, enabling widespread utility beyond military origins to civilian sectors. In transportation, GNSS underpins en-route guidance, vessel tracking, and road , supporting enhancements like automatic dependent surveillance-broadcast (ADS-B) and reducing collision risks via precise location data. leverages high-precision GNSS for variable-rate application of fertilizers and pesticides, optimizing yields while minimizing environmental impact through site-specific crop management. and applications utilize GNSS for centimeter-level mapping in , deformation monitoring of , and coastline delineation, surpassing traditional methods in efficiency and coverage. Timing applications synchronize global networks, providing sub-microsecond accuracy for , power grid stability, and financial transaction timestamps, where disruptions could cascade into widespread outages or economic losses. Defining achievements include enabling autonomous development and precision farming that has documented input reductions of up to 20% in empirical field trials, though vulnerabilities to and spoofing highlight ongoing challenges in and multi-constellation resilience.

Navigation

Consumer and Personal Navigation

Consumer and personal navigation utilizes GNSS signals in portable devices like smartphones, smartwatches, and handheld receivers to provide positioning, turn-by-turn directions, and -based services for individuals. These applications enable users to determine their precise on with accuracies typically ranging from 1 to 5 meters under open-sky conditions, improving with multi-constellation systems combining GPS, , Galileo, and . The origins of civilian GNSS access trace to September 1, 1983, when Soviet forces shot down after it strayed into prohibited airspace due to navigational deviation, prompting President to announce GPS availability to non-military users as a safety measure. Full civilian utility expanded in May 2000 with the discontinuation of Selective Availability, which had intentionally degraded public GPS accuracy to about 100 meters. Adoption surged in the mid-2000s with GNSS chip integration into ; by 2007, devices like the incorporated assisted GPS for faster fixes in urban environments. Popular apps such as and leverage GNSS for route optimization, delivering real-time traffic-aware guidance that reduces average commute times by avoiding congestion hotspots. Empirical analyses indicate these tools yield fuel savings of approximately 8.2% on selected trips through eco-routing algorithms prioritizing shorter or less congested paths over shortest-distance options. In personal fitness and outdoor activities, GNSS supports tracking applications in wearables, enabling accurate measurement of distance, speed, and elevation for runners and cyclists, with studies confirming meter-level precision sufficient for performance monitoring outside controlled tracks. Location-sharing features further enhance safety, allowing users to broadcast positions via apps integrated with cellular networks for response or coordination.

Aviation Navigation

Global Navigation Satellite Systems (GNSS) serve as the cornerstone of performance-based navigation (PBN) in , encompassing (RNAV) for flexible routing independent of ground-based aids and (RNP) which mandates onboard performance monitoring and alerting to ensure accuracy within specified tolerances, such as RNP 0.3 for approaches. These standards, formalized by the (ICAO) under its PBN framework, allow aircraft to fly direct paths en route, reducing reliance on traditional navaids like VOR and enabling precision in terminal areas and approaches. GNSS integration has progressed since the U.S. (GPS) achieved full operational capability on July 17, 1995, with ICAO endorsing RNAV specifications in the that evolved into comprehensive RNP requirements by the early . In approach procedures, GNSS supports (LPV) minima, providing angular guidance comparable to (ILS) Category I precision, down to decision altitudes as low as 200 feet, though classified as an approach with vertical guidance (APV) rather than true precision due to lack of ground-based ranging. (WAAS), a U.S. satellite-based augmentation system (SBAS), enhances GNSS accuracy to meet LPV requirements, enabling over 4,000 such approaches at U.S. airports as of 2025. Ground-Based Augmentation Systems (GBAS) offer airport-specific corrections, supporting Cat I-III operations with reduced infrastructure compared to ILS, thereby increasing capacity and yielding fuel savings through minimized holding patterns. Overall, PBN via GNSS shortens flight times, cuts fuel consumption, and lowers operating costs by obviating extensive ground infrastructure maintenance. Automatic Dependent Surveillance-Broadcast (ADS-B) leverages GNSS-derived positions to broadcast real-time aircraft data, including , , altitude, and , every second via 1090 MHz or 978 MHz frequencies, facilitating and collision avoidance without dependency. Mandated in U.S. since January 1, 2020, ADS-B enhances but inherits GNSS vulnerabilities, prompting integration with inertial reference systems for short-term continuity during outages. Multi-constellation GNSS, combining GPS with Galileo, , and , boosts satellite visibility—often exceeding 30 in view—improving geometric dilution of precision and enabling (RAIM) for fault detection, thus enhancing reliability in equatorial regions or urban canyons where single-system geometry falters. This redundancy mitigates single-constellation outages, as seen in the Galileo service disruption of July 2019, supporting 's continuity requirements. Despite benefits, GNSS signals' low power renders them susceptible to jamming and spoofing, with incidents surging in and the since 2022 due to geopolitical conflicts, occasionally forcing diversions or inertial backups. overwhelms receivers, while spoofing injects falsified positions, potentially disrupting ADS-B broadcasts and approach . Mitigations include SBAS alerts from WAAS, GBAS for localized , and alternative positioning, , and timing (A-PNT) like enhanced long-range (eLORAN), ensuring safe operations per ICAO resilience guidelines. These backups underscore GNSS's role as primary but not sole means, preserving causal links between signal availability and flight safety.

Maritime Navigation

GNSS enables precise positioning for maritime vessels, supporting navigation in open oceans, coastal waters, and congested ports by providing real-time , , speed, and heading data with accuracies typically under 10 meters under standard conditions. The (IMO) has integrated GNSS as a core input for Electronic Chart Display and Information Systems (ECDIS), with SOLAS amendments mandating ECDIS carriage for new passenger ships over 500 from July 1, 2012, and phasing in requirements for all applicable cargo ships by 2018 to replace paper charts and enhance . This system overlays GNSS-derived positions on digital vector charts, alerting operators to hazards like shallow waters or traffic separation schemes, thereby reducing grounding and collision risks empirically demonstrated in post-implementation studies showing decreased navigational incidents. Integration of GNSS with the Automatic Identification System (AIS) facilitates real-time vessel tracking and collision avoidance, as AIS transponders broadcast GNSS positions every 2-10 seconds depending on speed, enabling automated radar plotting aids (ARPA) and electronic chart systems to predict closest points of approach (CPA) and time to CPA (TCPA) for evasive maneuvers. In port operations, GNSS supports berthing and maneuvering with sub-meter precision when augmented by differential GNSS (DGNSS), which uses coastal reference stations to broadcast pseudorange corrections via medium-frequency radio, correcting common errors like ionospheric delays and satellite clock biases to achieve 1-5 meter accuracies. However, multipath errors—signal reflections off ship superstructures, docks, or water surfaces—can degrade accuracy to tens of meters in harbors, prompting mitigation through multi-frequency GNSS receivers and antenna placement optimizations that discriminate direct from reflected signals based on carrier-to-noise ratio variations. Beyond core navigation, GNSS underpins specialized applications such as oil exploration, where systems on rigs maintain station-keeping within 1-2 meters using DGNSS and inertial aids to align with subsea wells despite currents and winds. Fishing fleets leverage GNSS for vessel monitoring systems (), enabling through mandatory position reporting and optimizing operations by mapping productive grounds with historical track data, as evidenced by global deployments reducing illegal fishing via satellite-verified logs. Emerging multi-constellation use, including China's , enhances reliability on routes by increasing visible satellites—up to 30 versus 8-12 from GPS alone—improving geometry and redundancy amid geopolitical expansions like China's interests, though vulnerabilities to jamming persist in contested areas. Overall, these capabilities yield safer via predictive routing algorithms, cutting fuel use by 5-10% through optimized paths, but demand vigilant monitoring of to counter spoofing or outages.

Land Vehicle Navigation

GNSS receivers in land provide positioning essential for , enabling accurate calculation and integration with digital maps for driver guidance. In automotive applications, these systems support -aware by combining satellite-derived location data with feeds, allowing dynamic adjustments to avoid and optimize travel times. This capability outperforms precomputed static routes, as GNSS-derived positions permit immediate response to changing conditions such as accidents or closures, grounded in the direct measurement of coordinates against known . Advanced driver assistance systems (ADAS), such as Tesla's introduced in vehicles produced after September 2014, incorporate GNSS for localization alongside cameras and inertial sensors to facilitate features like lane-keeping and highway navigation. While primary reliance is on vision-based perception, GNSS ensures robust positioning in scenarios with limited visual cues, contributing to safer autonomous driving precursors. Fleet telematics systems leverage GNSS for automatic vehicle location (AVL), enabling operators to monitor truck and delivery fleets in , which supports route optimization and reduces fuel consumption through minimized idling and detours. In , GNSS augments traditional signaling for (PTC) systems, which the U.S. mandated for full implementation on required lines by December 31, 2020. PTC uses GNSS to determine train positions precisely, preventing collisions, derailments, and incursions into work zones by enforcing speed limits and movement authorities automatically. This integration enhances safety on over 60,000 miles of track, where GNSS provides continuous location data superior to fixed trackside sensors in dynamic environments.

Surveying and Geospatial Applications

Geodetic and Land Surveying

Real-time kinematic (RTK) GNSS positioning, implemented practically since the early 1990s, delivers centimeter-level horizontal and vertical accuracy for establishing geodetic control points by correcting carrier-phase ambiguities using data from a fixed within 10-20 km. This precision supports boundary delineation in projects, where control networks define reference frameworks for infrastructure alignment and deformation monitoring. In , RTK enables legal boundary determinations compliant with standards requiring sub-decimeter accuracy, reducing reliance on labor-intensive terrestrial methods. Precise point positioning (PPP), conceptualized in the 1970s and advanced for use by the 2010s, achieves comparable centimeter-level accuracy globally without local base stations, by applying satellite orbit, clock, and atmospheric corrections from service providers. complements RTK in geodetic applications for sparse networks, such as tectonic plate monitoring, though initial convergence to high precision requires 10-30 minutes. Integration of GNSS with total stations in hybrid workflows allows seamless transitions: GNSS establishes wide-area control points, while optical total stations handle detailed measurements in obstructed urban or forested sites. U.S. Geological Survey practices demonstrate that GNSS reduces baseline survey effort substantially compared to traditional leveling or triangulation, enabling control point occupation in hours rather than days for networks spanning kilometers. RTK's dependence on base station proximity limits efficacy in remote areas, where atmospheric differentials and signal interruptions degrade fixes beyond 20 km baselines; adoption of multi-GNSS (integrating GPS, , Galileo, ) enhances robustness by increasing visible satellites and redundancy, improving initialization reliability by 20-50% in challenging geometries. Network RTK via continuously operating reference stations (CORS) mitigates single-base limitations for regional geodetic frameworks, as standardized by NOAA's National Geodetic Survey.

Mapping and Geographic Information Systems (GIS)

GNSS integration with Geographic Information Systems (GIS) enables the precise georeferencing and of and raster data layers, supporting applications in such as infrastructure siting and zoning, as well as including inventory and water basin delineation. By providing real-time or post-processed positioning data with accuracies down to centimeters using techniques, GNSS corrects distortions in and aerial surveys incorporated into GIS databases. Position-focused integration methods embed GNSS coordinates directly into GIS via protocols like NMEA or GPX, while technology-focused approaches leverage GNSS receivers connected to GIS software for dynamic data capture. Crowdsourced GNSS data from smartphones and vehicles feeds collaborative mapping platforms like (OSM), where user-submitted trajectories automate feature updates and generate 3D urban models by analyzing signal patterns to infer building heights and road elevations. Algorithms process these traces to filter outliers and smooth paths, enhancing map completeness in underserved areas without dedicated surveys. In professional workflows, GNSS-augmented data integrates with cloud platforms like Google Earth Engine, operational since late 2010, to model terrain at global scales by combining elevation datasets with ground-truthed positions for applications in land-use and environmental resource allocation. Advancements in mobile GIS have accelerated since with the introduction of dual-frequency GNSS , such as Broadcom's BCM47755 in the Xiaomi Mi 8 smartphone, enabling sub-meter horizontal accuracy under open skies by mitigating ionospheric errors through L1 and L5 . These support field data collection for resource management, allowing planners to map assets like utilities or green spaces directly via apps integrated with GIS servers. In scenarios, rapid GNSS surveys post the February 6, 2023, Mw 7.8 earthquake in measured co-seismic displacements at high-rate stations, informing GIS-based rupture mapping and aiding resource allocation for over 500 km of surface faulting. Such integrations underscore GNSS's role in verifiable, data-driven spatial , though accuracy depends on environmental factors like multipath in dense settings.

Timing and Synchronization

Telecommunications and Networking

Global Navigation Satellite Systems (GNSS) serve as a primary source of UTC-traceable timing for networks, enabling precise of base stations to coordinate signal transmissions and receptions. This traceability ensures that network elements maintain alignment with (UTC), which is critical for phase-locked operations in time-division duplex (TDD) systems where uplink and downlink slots must align across cells to avoid . In deployments, GNSS timing supports advanced features like , requiring absolute time accuracy of approximately 1.5 microseconds network-wide to enable coordinated multi-point transmission and efficient spectrum utilization. Without this, misaligned radio frames lead to increased and reduced throughput, as base stations fail to predict positions accurately for directed beams. Global infrastructure has depended on GPS for such since the , coinciding with the rollout of digital cellular standards like that demanded stratum-1 clock stability. Adoption of multi-constellation GNSS, incorporating systems like Galileo and alongside GPS, reduces vulnerability to constellation-specific outages by providing redundant signals and improved holdover capabilities during signal loss, thereby enhancing overall timing resilience in dense urban or jammed environments. However, GNSS reliance exposes networks to disruptions, as evidenced by attacks on in starting in March 2022, which degraded timing signals and prompted calls for diversified sources across . To counter such risks, (PTP, IEEE 1588) is deployed as a complementary or backup mechanism, distributing timing over packet networks with sub-microsecond accuracy when GNSS holdover expires, thus maintaining without external dependency.

Financial and Power Grid Synchronization

In financial markets, Global Navigation Satellite Systems (GNSS) deliver precise timing signals essential for timestamping (HFT) orders, ensuring accurate sequencing and regulatory compliance. Under the European Union's Markets in Financial Instruments Directive II (MiFID II), implemented on January 3, 2018, trading venues and firms must synchronize business clocks to (UTC) with an accuracy of 100 microseconds for electronic transactions, often achieved via GNSS-disciplined oscillators (GNSSDOs) that provide sub-microsecond precision traceable to atomic standards. This synchronization prevents disputes over trade execution order, where delays exceeding nanoseconds can alter market outcomes in HFT environments processing millions of transactions per second. GNSS timing outperforms alternatives like (NTP) in latency-sensitive applications, though it requires holdover mechanisms during signal outages to maintain compliance. For power grid operations, GNSS enables synchronization of phasor measurement units (PMUs), which capture voltage and current s across wide areas with accuracy, facilitating real-time stability assessment and blackout prevention. PMUs, synchronized to GNSS-derived UTC, generate up to 60 measurements per second—far exceeding traditional supervisory control and data acquisition () systems' 0.25–0.5 Hz rate—allowing detection of oscillations and phase imbalances that could cascade into failures, as modeled in North American grid simulations. This capability supports dynamic line rating and fault location, enhancing grid resilience in interconnected networks spanning thousands of kilometers. Dependence on GNSS introduces vulnerabilities to jamming and spoofing, which can desynchronize PMUs and induce false stability readings, potentially triggering erroneous protective relays. While the 2016 Ukraine blackout resulted primarily from cyberattacks on substations rather than GNSS disruption, subsequent analyses highlight GNSS signals' weakness to , as demonstrated in regional during the 2022 Russia- conflict affecting civilian and military systems. To mitigate holdover risks—where unsynchronized clocks drift by seconds within minutes—chip-scale atomic clocks (CSACs), developed under U.S. programs and commercialized since 2011, serve as backups, maintaining 1 microsecond accuracy for hours during outages. Over-reliance on U.S.-controlled GPS raises national security concerns for non-U.S. entities, prompting development of independent alternatives like the European Union's Galileo system, which offers dedicated timing services with enhanced authentication via the Open Service Navigation Message Authentication (OSNMA) to counter spoofing in critical infrastructure. Galileo’s Public Regulated Service (PRS), restricted to authorized users, provides resilient positioning, navigation, and timing (PNT) for finance and energy sectors, reducing vulnerability to selective GPS denial. These measures underscore causal risks in GNSS monoculture, where signal loss could amplify grid instabilities or trading disruptions absent diversified backups.

Precision Agriculture

Crop Monitoring and Variable Rate Technology

GNSS enables precise crop monitoring by facilitating mapping and georeferenced soil sampling, allowing farmers to identify spatial variability in field conditions. monitors equipped with GNSS receivers, introduced commercially in 1992, record harvest data tied to exact locations during operations, producing maps that reveal patterns in productivity influenced by , , and moisture. These maps, developed since the early , support grid-based soil sampling where GNSS guides sampling points to sub-meter accuracy, enabling targeted analysis of nutrient levels and without uniform assumptions across fields. Variable rate technology (VRT), integrated with GNSS, applies inputs like s, seeds, and pesticides at rates tailored to these variability maps, optimizing resource use by avoiding over-application in low-need zones. Adoption of VRT for has grown, with USDA data showing its use on 36% of corn and 28% of acres by 2020, driven by potential efficiency gains in input delivery. Empirical studies indicate VRT can reduce application by 10-15% on average while maintaining s, as variability maps inform prescription files loaded into GNSS-equipped applicators for adjustments. with , such as NDVI derived from or imagery, further refines monitoring; GNSS georeferences NDVI zones to yield maps, correlating vegetation health indices with on-ground data for predictive input zoning. Recent advancements in low-cost GNSS receivers, achieving centimeter-level accuracy via multi-frequency signals, have lowered barriers for smallholder farmers, enabling adoption in resource-constrained settings through affordable kits under $500. Verifiable return-on-investment (ROI) varies by size and , with peer-reviewed analyses showing payback periods of 2-4 years for VRT via input savings of 5-20% and yield uplifts up to 4% in responsive s, though initial hardware costs of $10,000-$20,000 per implement and demands can delay benefits on smaller operations. Overstated claims of universal ROI ignore site-specific factors like heterogeneity; causal evidence from controlled trials emphasizes measurable reductions in nutrient runoff alongside economic gains only where baseline variability exceeds 15-20%.

Autonomous Agricultural Machinery

GNSS enables autonomous agricultural machinery, such as unmanned tractors and harvesters, to perform straight-line farming and precise swath control without human intervention, reducing overlap and skips in field operations. Systems like John Deere's AutoTrac, introduced in the late 1990s, pioneered this capability by integrating GNSS receivers with automated steering, allowing machinery to follow predefined paths with sub-meter accuracy initially and evolving to support continuous operations. Real-time kinematic (RTK) GNSS corrections achieve centimeter-level positioning accuracy, typically 1-2 cm, essential for enabling 24/7 unmanned operations in tasks like planting, tilling, and harvesting, where deviations could damage crops or equipment. This precision supports repeatability across passes, minimizing and input waste, though it requires reliable correction signals from base stations or networks to mitigate atmospheric and multipath errors. Recent advancements incorporate multi-constellation GNSS receivers, combining signals from GPS, , Galileo, and , to enhance reliability in GNSS-challenged environments such as tree-lined fields or areas with canopy obstruction, where single-constellation systems may lose fix. Case studies of autonomous deployments demonstrate labor reductions through supervised autonomy, with technologies like GNSS auto-steer freeing operators for oversight rather than manual driving, though quantified savings vary by farm scale and integration. Dependence on RTK correction networks underscores gaps in remote rural areas, where sparse coverage necessitates on-farm setups or satellite-based alternatives like , potentially limiting scalability without expanded networks.

Military and Defense Applications

Precision Targeting and Guidance

The (JDAM) integrates GPS guidance into unguided bombs, enabling conversion to precision-guided munitions (PGMs) with a (CEP) of approximately 5 meters under optimal conditions. First operationally deployed by the U.S. Air Force in 1999 during Operation Allied Force in , JDAM kits have since been fitted to thousands of Mk-84, Mk-83, and Mk-82 bombs, allowing all-weather strikes independent of laser designation. Empirical data from conflicts indicate PGMs achieve hit rates exceeding 90% in many systems, such as the APKWS laser-guided rocket and missiles, substantially reducing unintended damage compared to unguided by concentrating effects on designated coordinates. In missile systems, GNSS supports for weapons like the , which uses GPS alongside inertial for mid-course updates, achieving CEPs under 10 meters in operational tests. U.S. controls restrict selective availability and high-precision GPS receivers to prevent proliferation of military-grade accuracy, classifying certain GNSS equipment under (MTCR) guidelines for airborne applications exceeding specified velocities. Russia counters this dependency through its constellation, integrated into munitions like the Kalibr for autonomous targeting, though GLONASS civilian accuracy trails GPS at 5-10 meters versus 3.5-7.8 meters. Post-2020 upgrades to GPS Military Code (M-code), operationalized on over 20 satellites by 2020, enhance anti-jamming via and , with ground upgrades like the GPS Modernization completing initial phases in 2021 to bolster signal resilience against . However, GNSS vulnerabilities persist, as evidenced in the conflict since 2022, where Russian jamming and spoofing degraded U.S.-supplied PGMs; Excalibur artillery rounds' hit rate fell from 70% to under 10%, and HIMARS effectiveness declined similarly. These incidents have accelerated integration of inertial navigation systems () as backups in munitions, using gyroscopes and accelerometers for dead-reckoning in GNSS-denied environments, often hybridized with GPS for periodic corrections to maintain accuracy over short durations.

Reconnaissance and Personnel Tracking

GNSS receivers, such as the U.S. military's (DAGR), enable precise personnel tracking in field operations by providing secure access to encrypted via the (SAASM). Fielded in the mid-2000s, the DAGR supports (BFT) systems, which transmit real-time location data from individual soldiers or units to command centers, allowing commanders to monitor friendly positions on digital maps overlaid with terrain and threat data. This capability integrates with tactical networks to prevent incidents and coordinate movements, as demonstrated in networked BFT implementations that relay positions via satellite communications. In operations, GNSS facilitates asset monitoring for , , and (ISR) platforms, including unmanned aerial systems (UAS) configured in swarms for persistent coverage. Drone swarms leverage GNSS for autonomous and geolocation of , enabling environmental and detection of adversary movements in denied areas without risking manned assets. Military evaluations, such as the U.S. Army's exercises, have tested medium-sized UAS swarms for ISR tasks where GNSS provides the positional backbone for and swarm coordination, enhancing coverage over large areas. During conflicts in and from 2003 to 2014, GNSS-based BFT and reconnaissance tracking improved , enabling faster tactical decisions and reducing disorientation in urban and rugged terrains, with systems like contributing to over 90% availability in non-jammed conditions. However, insurgent use of low-cost jammers targeting L1 signals disrupted tracking, prompting countermeasures such as multi-frequency receivers operating on both L1 and L5 bands, which offer greater resistance to due to higher power and wider . While these applications amplify force effectiveness through precise deconfliction and rapid ISR dissemination, signal compromise risks exposing unit locations to adversaries, necessitating hybrid inertial backups for degraded environments.

Scientific and Environmental Applications

Atmospheric and Geophysical Monitoring

Global Navigation Satellite Systems (GNSS) enable ionospheric monitoring by measuring carrier-phase delays in dual-frequency signals, which are used to estimate (TEC), the integrated electron density along the signal path from satellite to receiver. These TEC maps, generated in from global GNSS networks, track ionospheric variability and support forecasting, as electron density enhancements can degrade GNSS accuracy and affect satellite communications. The integration of multi-constellation GNSS (GPS, , Galileo, ) has enhanced global TEC mapping resolution and coverage since the 2010s, reducing gaps in equatorial and polar regions compared to GPS-only systems. In geophysical applications, dense GNSS networks monitor crustal deformation by detecting millimeter-scale displacements from tectonic strain accumulation. The Plate Boundary Observatory (PBO), operated by UNAVCO, deployed 891 continuous GNSS stations along the U.S. Pacific-North American plate boundary between 2003 and 2008 to provide on interseismic and coseismic movements. GNSS excels in detecting slow-slip events (SSEs)—aseismic slips lasting days to months that release without significant seismic —offering superior over seismometers, which primarily capture high-frequency ground motions and often miss low-amplitude, long-period signals. Peer-reviewed analyses confirm GNSS time series reveal SSE spatiotemporal patterns in subduction zones, such as shallow events along the , enabling quantification of slip magnitudes from Mw 5.6 to 6.2. During the 2011 Tohoku-Oki Mw 9.0 , high-rate GNSS stations recorded coseismic displacements exceeding 2 meters within minutes, enabling rapid magnitude estimation and height forecasts that outperformed initial seismometer-based alerts, which underestimated the event scale. This demonstrated GNSS's role in earthquake early warning, as vertical displacements directly informed wave propagation models, providing warnings up to 90 minutes before inundation in coastal areas. Advances in multi-GNSS processing have since extended such capabilities globally, incorporating data from over 1,000 stations for near-real-time deformation mapping.

GNSS Reflectometry (GNSS-IR)

GNSS Reflectometry (GNSS-IR) is a passive technique that exploits the interference between direct and reflected signals from Global Navigation Satellite Systems (GNSS) to measure properties of Earth's surface, including , vegetation characteristics, and conditions. By analyzing (SNR) oscillations in GNSS receiver data, GNSS-IR infers reflector heights and surface properties without requiring active transmitters, leveraging the opportunistic reflections from constellations like GPS and Galileo. This approach enables ground-based, airborne, or spaceborne implementations, providing cost-effective alternatives to traditional sensors for . Prominent applications include retrieval, where spaceborne GNSS-R data from the Cyclone Global Navigation Satellite System (CYGNSS) mission—launched on December 15, 2016—have validated global estimates by correlating reflection coefficients with surface wetness, achieving accuracies comparable to active sensors in non-vegetated areas. CYGNSS, comprising eight microsatellites, primarily retrieves surface winds for hurricane intensity forecasting but extends to land applications like opacity and flood inundation mapping. For extent and thickness, GNSS-IR detects changes in reflection patterns over frozen surfaces, supporting monitoring where traditional struggles with penetration. height and estimation further utilize signal attenuation due to canopy structure, as demonstrated in studies integrating GNSS-R with for global vegetation water content mapping. Recent advancements include low-cost GNSS-IR implementations for water level monitoring, adaptable to flood mapping via compact receivers that process multipath interference for inundation extent. These systems offer advantages over active , such as reduced deployment costs through reliance on ubiquitous GNSS signals, enhanced global coverage from multiple illuminations, and resilience to conditions, enabling high spatiotemporal without dedicated . Despite these benefits, GNSS-IR faces limitations from weak reflected signals embedded in receiver noise, requiring robust statistical processing—such as of SNR data—to isolate multipath effects and ensure measurement verifiability, particularly in vegetated or rough terrains where direct-reflected interference patterns degrade. Signal extraction challenges persist, with amplitude separation demanding elevation angle filtering and modeling to mitigate errors from patterns or multipath.

Emerging Applications

Autonomous Vehicles and Robotics

GNSS provides essential global positioning for operating at SAE Levels 4 and 5, where centimeter-level accuracy is required for safe navigation and decision-making in dynamic environments. These systems demand positioning errors below 10 cm to enable precise lane keeping, obstacle avoidance, and trajectory planning without human intervention. Early AV trials, such as Waymo's public ride-hailing service launched in in 2017, incorporated GNSS as a core component for initial localization, fused with other sensors to achieve operational reliability. To meet these stringent requirements, AVs employ Kinematic (RTK) and Precise Point Positioning () augmentation techniques, which correct GNSS signal errors from atmospheric delays, satellite clock biases, and multipath effects, yielding horizontal accuracies of 1-2 cm in open areas. RTK uses nearby base stations for differential corrections, while PPP leverages global satellite orbit and clock products for standalone high precision, with convergence times reduced to under 100 seconds in advanced implementations. In ground robotics, such as mobile platforms for inspection or , compact RTK-GNSS receivers enable absolute positioning for tasks requiring georeferenced and path following, with demonstrated accuracies supporting robot deployment in structured environments. GNSS signals degrade in urban canyons due to signal blockage and multipath reflections, necessitating multi-sensor fusion with for , Inertial Measurement Units () for short-term , and sometimes vision systems to maintain continuity. Recent advancements, including factor graph optimization for semi-tightly coupled GNSS/IMU/ integration, have improved localization robustness in GNSS-challenged urban settings, as shown in 2023 studies achieving sub-meter errors during outages. By 2025, unified frameworks fusing these sensors have enabled high-resolution city-scale for AVs, enhancing prediction of vehicle states in dense areas. Despite its foundational role, GNSS alone cannot suffice for and localization due to inherent limitations in coverage and under foliage or structures, requiring redundant sensor suites for fault-tolerant operation. Vulnerabilities to spoofing attacks, where falsified signals mislead receivers, pose significant risks; tests demonstrate that unprotected GNSS can be exploited to alter trajectories, underscoring the need for protocols and INS-aided detection. Real-world evaluations confirm that while fused systems mitigate these threats, ongoing spoofing research highlights GNSS's reliance on complementary technologies for causal reliability in safety-critical applications.

Drones and Unmanned Aerial Systems

Global Navigation Satellite Systems (GNSS) are integral to unmanned aerial vehicles (UAVs), providing the primary means for real-time positioning, velocity estimation, and attitude determination essential for autonomous flight control and precise payload delivery. These systems enable UAVs to maintain stable trajectories during takeoff, waypoint navigation, and landing, with multi-constellation receivers (e.g., GPS, Galileo, GLONASS) enhancing redundancy and availability compared to single-system reliance. In payload delivery scenarios, such as medical or parcel drops, GNSS accuracy ensures targeting within meters, minimizing drift from wind or sensor noise. Beyond-visual-line-of-sight (BVLOS) operations, which allow UAVs to fly outside direct pilot oversight, depend heavily on GNSS for safe and collision avoidance. The U.S. (FAA) has issued waivers for BVLOS since prior to 2020, with approvals rising from 1,229 in 2020 to 26,870 in 2023, facilitating commercial uses like spraying—where drones apply pesticides or fertilizers with centimeter-level targeting—and infrastructure inspection, such as scanning power lines or bridges for defects without human risk. These applications leverage real-time kinematic (RTK) GNSS corrections to achieve sub-decimeter horizontal accuracy, enabling efficient coverage of large areas like crop fields exceeding 100 hectares per flight. The European Union's Galileo High Accuracy Service (HAS), operational since January 2023, delivers free precise point positioning () corrections via the E6-B signal, achieving 20 cm accuracy worldwide without local base stations, which supports coordinated swarms for tasks like synchronized spraying or mapping. Empirical tests indicate HAS reduces positioning errors in UAV applications by up to 80% relative to open-service GNSS, from meter-level to sub-meter, enhancing swarm stability by minimizing cumulative drift in multi-UAV formations. Independent validations confirm convergence times under 20 minutes for decimeter precision, critical for dynamic swarm operations. GNSS enables scalable UAV surveying, where fleets cover expansive areas for topographic data collection at rates 10 times faster than manned methods, supporting payload-integrated sensors like for . However, urban environments introduce multipath reflections and signal obstructions from buildings, degrading GNSS accuracy to tens of meters and prompting hybrid navigation fusing (VO)—which tracks features via onboard cameras—with inertial measurement units () to sustain localization during outages. Such integrations, as demonstrated in field trials, maintain UAV pose estimation within 0.5 meters even under 50% GNSS signal loss, though they increase computational demands on flight controllers.

Internet of Things (IoT) and Smart Infrastructure

Low-power Global Navigation Satellite System (GNSS) receivers enable efficient in () applications by minimizing energy consumption while maintaining positioning accuracy for battery-constrained devices such as tags and fleet trackers. These receivers support multi-constellation tracking across GPS, , Galileo, and signals on multiple frequency bands, achieving position fixes with power draws as low as 10-20 mW during acquisition and under 5 mW in tracking mode, which extends device battery life to months or years in intermittent-use scenarios. In , such GNSS- tags monitor pallets, containers, and vehicles in , providing geofencing alerts and route optimization data to reduce losses from theft or misplacement by up to 30% in operations. In smart , GNSS integrates with urban systems to optimize and , as demonstrated in Singapore's pilots during the under its Intelligent Systems framework. GNSS-equipped s and infrastructure sensors collect aggregated mobility data to inform dynamic signal timing and , contributing to overall traffic reductions of 10-15% in central areas following the rollout of enhancements. This approach leverages GNSS for precise localization, enabling city-wide analytics that prioritize high-occupancy routes and integrate with traffic cameras for predictive modeling, thereby improving urban throughput without relying solely on fixed gantries. Recent advancements fuse connectivity with GNSS in networks for sub-meter real-time monitoring of assets, such as bridges and utilities, where hybrid positioning mitigates urban multipath errors through cellular-assisted corrections. Experimental integrations have shown positioning accuracies improving to 1-2 meters in dense environments, supporting applications like alerts that enhance system reliability by processing location data at network edges. Emerging paradigms further address intermittent GNSS signals in deployments by offloading to local nodes, using predictive algorithms to interpolate positions during outages and reducing latency for time-sensitive urban controls. This technique sustains tracking continuity in shadowed areas, with power-efficient recalibration boosting overall node uptime by 20-50% in field tests.

Limitations and Challenges

Signal Interference and Vulnerabilities

GNSS signals, typically received at power levels below -125 dBm, are inherently weak due to their from space-based satellites over vast distances, rendering them susceptible to from low-power, inexpensive jammers that can broadcast on the same frequencies. These devices, such as portable units akin to cigarette lighters, operate at effective jamming-to-signal ratios as low as 40 , overwhelming receivers and causing loss of lock within kilometers of the source. Jamming incidents have escalated in Eastern Europe amid geopolitical tensions, particularly since Russia's invasion of Ukraine in 2022, with widespread disruptions in the Black Sea and regions affecting . For instance, nearly 123,000 flights over the experienced interference in the first four months of 2025 alone, attributed to Russian systems, leading to failures and emergency diversions. In September 2025, a plane carrying President encountered GPS jamming during landing in , highlighting the operational risks to air traffic. These events demonstrate jamming's potential as a denial-of-service threat, where receivers lose positioning capability without alternative mitigations. Spoofing, a more sophisticated , involves transmitting signals that mimic authentic GNSS transmissions to deceive receivers into computing false positions or times, often evading basic detection. Empirical analyses from the Institute of Navigation () indicate that spoofing can be detected through signal and carrier differentials using multi-antenna arrays, achieving high reliability in controlled tests by identifying inconsistencies in signal arrival or pseudoranges. However, civilian receivers remain exposed, as they rely on unencrypted legacy signals like GPS L1 , lacking the anti-spoofing features of military codes. The U.S. military's M-code, rolled out progressively on satellites since the early 2020s, provides enhanced resistance to jamming and spoofing via higher power and , enabling secure operations in contested environments. In contrast, civilian GNSS users face persistent vulnerabilities due to dependence on open signals, with no equivalent protections, amplifying risks in overreliant infrastructures. This overdependence on satellite-based systems overlooks terrestrial backups like eLoran, a low-frequency ground-based alternative offering signals millions of times stronger than GNSS, immune to space-specific threats and capable of providing resilient positioning over 1,200 miles. Implementing such systems could mitigate systemic risks without shared failure modes.

Accuracy Degradation Factors

The accuracy of Global Navigation Satellite Systems (GNSS) is fundamentally limited by propagation delays through the atmosphere, signal reflections, and geometric configurations of satellites. Ionospheric scintillation, characterized by rapid fluctuations in signal amplitude and phase due to irregularities, primarily affects GNSS receivers in equatorial and high-latitude regions, causing cycle slips and positioning errors exceeding several meters during severe events. occurs when signals reflect off surfaces like buildings or terrain, introducing errors of 1-10 meters in environments by creating non-line-of-sight paths that interfere with direct signals. Satellite geometry, quantified by Dilution of Precision (DOP) metrics such as GDOP or PDOP, degrades accuracy when visible satellites are clustered in or , amplifying pseudorange errors by factors up to 2-5 times under poor configurations. Line-of-sight blockages in environments like tunnels, dense forests, or urban canyons interrupt direct signals, leading to complete signal loss and reliance on fewer satellites, which exacerbates DOP and can result in outages lasting seconds to minutes. Prior to May 1, 2000, the U.S. implementation of Selective Availability intentionally degraded civilian GPS signals by introducing clock and errors, limiting standalone accuracy to approximately 100 meters 95% of the time; its discontinuation improved global civilian positioning to 10-20 meters under nominal conditions. Dual-frequency receivers, enabled by satellites launched since 2018 and similar advancements in other GNSS constellations, mitigate ionospheric delays by differencing L1 and /L5 signals, reducing errors by up to 90% compared to single-frequency systems. Satellite-Based Augmentation Systems (SBAS), such as WAAS in , provide real-time corrections for ionospheric, tropospheric, and errors, enhancing accuracy to 1-3 meters in open skies, though effectiveness diminishes under heavy blockage where fewer reference signals are available. Multi-constellation use (e.g., GPS + Galileo) further improves availability by increasing visible satellites, mitigating impacts by up to 60% in affected regions.

Geopolitical and Regulatory Issues

The government discontinued Selective Availability for GPS on May 1, 2000, under President , eliminating intentional degradation of civilian signals to enhance global accessibility and accuracy, thereby committing to non-discriminatory use while retaining military override capabilities. This policy shift reduced U.S. unilateral control over global navigation, prompting rival systems; China's achieved full global operational capability on June 23, 2020, with the launch of its 55th satellite, providing positioning accuracy comparable to GPS and serving over 140 countries through integration with the for infrastructure projects like ports and railways. The European Union's Galileo system contrasts with a free Open Service available to all users for basic positioning and timing, while its Public Regulated Service employs and anti-jamming features exclusively for authorized governmental and entities, ensuring robustness in hostile environments without broad civilian access. National controls over GNSS foster geopolitical tensions, as systems like Russia's and emerging constellations enable strategic independence; for instance, BeiDou's deployment in Belt and Road partner nations supports China's export of and logistics technologies, potentially eroding reliance on Western systems amid U.S.-China competition. Regulatory frameworks address usage restrictions, with privacy laws mandating consent for GNSS-based tracking in applications; in the U.S., over 20 states prohibit non-consensual installation of tracking devices on , reflecting concerns over unauthorized location balanced against benefits like response and efficiency. In the , GDPR imposes strict data minimization and explicit consent for processing GNSS-derived location data, curbing commercial overreach while enabling public safety uses such as traffic optimization. Empirical evidence indicates that overly stringent regulations can stifle GNSS-dependent innovation; for example, initial U.S. FAA rules confined commercial drones to visual-line-of-sight operations until 2016 reforms, delaying beyond-visual-line-of-sight applications like package delivery and agricultural monitoring, which studies link to reduced R&D investment and slower market entry compared to less restrictive jurisdictions. Such delays contrast with safety gains from regulated integration, underscoring the need for adaptive policies that mitigate risks without preemptively constraining technological advancement, as evidenced by post-reform surges in drone patents and deployments.

References

  1. [1]
    What is GNSS | EU Agency for the Space Programme
    Jan 15, 2025 · Global Navigation Satellite System (GNSS) refers to any satellite constellation that provides global positioning, navigation, and timing services.
  2. [2]
    GNSS - Global Navigation Satellite System - NASA Earthdata
    A Global Navigation Satellite System (GNSS) is a space geodesy technique that provides autonomous geospatial positioning with global coverage.
  3. [3]
    Global Navigation Satellite Systems (GNSS) - UNOOSA
    GNSS are used in all forms of transportation: space stations, aviation, maritime, rail, road and mass transit. Positioning, navigation and timing (PNT) play a ...
  4. [4]
    Global navigation satellite systems (GNSS) - Eurocontrol
    GNSS can support navigation applications in all phases of flight as well as surveillance applications such as ADS-B. It ensures: accuracy in terms of position, ...
  5. [5]
    Satellite Navigation - GPS - User Segment - Non-Aviation
    Nov 19, 2021 · Today, many farmers use satellite navigation to conduct precision farming operations such as chemical and fertilizer application. Satellite ...
  6. [6]
    GNSS Technology Research - National Geodetic Survey - NOAA
    Surveying using high accuracy GNSS is used for safe navigation, road construction, and maintenance, including the evaluation of the structural integrity of ...
  7. [7]
    GNSS Applications - Navipedia
    Jan 30, 2015 · GNSS applications are applications that use GNSS systems for its functionality. GNSS applications use GNSS Receivers to collect position, velocity and time ...Civil Applications · GNSS-based Products · Space Applications
  8. [8]
    [PDF] Global Navigation Satellite Systems and Their Applications - UNOOSA
    Global Navigation Satellite System (GNSS) plays a significant role in high precision navigation, positioning, timing, and scientific questions related to ...<|separator|>
  9. [9]
    Advances in GNSS Positioning and GNSS Remote Sensing - PMC
    Feb 12, 2024 · GNSSs offer various PNT applications in the domains of aviation, maritime, and land. Engineers have attempted to implement autonomous GNSSs in ...
  10. [10]
    Sport and fitness wearables | u-blox
    Interested in monitoring the performance of members of a team within the field? These trackers enable high-precision GNSS location, including corrections.
  11. [11]
    GNSS vs GPS: Understanding the Differences and Why They Matter
    Jul 19, 2024 · Widely Used: GPS is widely used in applications where sub-meter accuracy is sufficient, such as personal navigation, fitness tracking, and ...
  12. [12]
    The Plane Crash That Gave Americans GPS - The Atlantic
    Nov 3, 2014 · On the first day of September in 1983, the Soviet Union shot down a plane. Its military officers thought it was a spy plane, they said later.
  13. [13]
    How KAL007 tragedy gave civilians access to GPS - The Korea Herald
    Jul 6, 2023 · On early Sept. 1, 1983, a Soviet interceptor shot down Korean Air Flight 007 en route from New York City to Seoul via Anchorage.
  14. [14]
    How an Airline Tragedy Brought GPS to the Masses - VICE
    Apr 11, 2017 · On August 30, 1983, KAL Flight 007 departed from John F. Kennedy International Airport in New York City, bound for Seoul, South Korea, with 269 ...Missing: access history
  15. [15]
    https://afdc.energy.gov/files/u/publication/navigation_api_route_fuel_saving.pdf
  16. [16]
    Accuracy of satellite positioning using GNSS receivers in sports ...
    The GNSS module is fundamental for outdoor runners, enabling them to accurately track the distance covered, especially when navigating outside athletic tracks.
  17. [17]
    S-GNSS Wear - Focal Point Positioning
    Sep 30, 2025 · S-GNSS Wear improves GNSS accuracy and reliability, which means fitness trackers present a more accurate picture of the distance travelled ...
  18. [18]
    GPS Vs. GLONASS Vs. Galileo: What's The Best GNSS | Family1st
    These devices use GPS to help individuals monitor their movements, track their fitness progress, and ensure the safety of loved ones by knowing their precise ...
  19. [19]
    Performance-Based Navigation (PBN) and Area Navigation (RNAV)
    For an aircraft to meet the requirements of PBN, a specified RNAV or RNP accuracy must be met 95 percent of the flight time. RNP is a PBN system that includes ...
  20. [20]
    pbn Overview - ICAO
    PBN defines performance requirements for aircraft navigation, using RNAV and RNP for flexible routes, and is ICAO's effort to harmonize navigation.
  21. [21]
    Satellite Navigation - GPS - User Segment - Aviation
    Nov 27, 2024 · Reduced separation minimums resulting in increased capacity and capabilities; Significant savings from shortened flight times and reduced fuel ...
  22. [22]
    Localiser Performance with Vertical Guidance (LPV) - SKYbrary
    RNAV GNSS approaches that can be conducted down to LPV minima are characterised by a coded Final Approach Segment (FAS) data block. The FAS is defined laterally ...
  23. [23]
    Satellite Navigation - GPS/WAAS Approaches
    Oct 8, 2025 · Airports with Global Positioning System ( GPS ) or WAAS-enabled LPV/LP approach. All US Approaches · Canadian LPVs (enabled by WAAS ); Map of ...
  24. [24]
    Satellite Navigation - GBAS - Benefits | Federal Aviation Administration
    Nov 27, 2024 · GBAS benefits include increased capacity, reduced controller workload, fuel savings, uplinked procedures, and potential noise reduction.
  25. [25]
    Automatic Dependent Surveillance - Broadcast (ADS-B)
    Sep 29, 2025 · ADS-B Out works by broadcasting information about an aircraft's GPS location, altitude, ground speed and other data to ground stations and other ...Missing: GNSS | Show results with:GNSS
  26. [26]
    [PDF] Aviation Considerations for Multi-Constellation GNSS - UNOOSA
    Dec 8, 2008 · Benefits of Multi-Constellation RAIM. • Combining signals from multiple constellations can provide significantly greater availability and.
  27. [27]
    The presence of satellites in general aviation - Transports Canada
    Dec 16, 2019 · GNSS s have shown exceptional reliability; however, they are still susceptible to technical failure. A recent example is Galileo's week-long ...
  28. [28]
    EASA and IATA Publish Comprehensive Plan to Mitigate the Risks ...
    Jun 18, 2025 · Reported incidents of interference with GNSS signals, known as jamming and spoofing, have been increasing across Eastern Europe and the Middle ...Missing: WAAS GBAS
  29. [29]
    GNSS spoofing threatens airline safety, alarming pilots and aviation ...
    Sep 24, 2024 · Aviation safety officials said spoofing has disrupted some flights but has not posed major safety risks. Pilots are trained to use A-PNT systems ...Missing: WAAS GBAS
  30. [30]
    [PDF] Mitigating gnss vulnerabilities in aviation - ICAO
    Jul 30, 2025 · 2. Use of dual frequency multi-constellation (DFMC) GNSS provides some robustness to. GNSS RFI. The modernized signals with higher chipping ...
  31. [31]
    GNSS for Marine and Maritime Applications - Taoglas
    Jun 12, 2025 · There's an enormous market for GNSS applications focused on marine and maritime use cases, from navigation to asset tracking.
  32. [32]
    ECDIS Implementation - Officer of the Watch
    Sep 19, 2012 · Moreover, ECDIS should also comply with the following IEC test standards: IEC Standard 60945 (2002): Maritime navigation and radio ...
  33. [33]
    Revision of the IMO's Performance Standards for ECDIS. Three ...
    ECDIS units on board of the ships are required to comply with one of three performance standards (either IMO resolution A.817(19) [18], as amended [19],[20], ...
  34. [34]
    IMO and the GNSS - Inside GNSS - Global Navigation Satellite ...
    Sep 19, 2017 · Ships and ports have come to rely on global navigation satellite systems (GNSS) for a huge array of applications relating to position, velocity ...
  35. [35]
    What is Differential GPS (DGPS): A Complete Guide - Marine Public
    DGPS, or Differential GPS, enhances standard GPS accuracy by applying corrections calculated from reference stations to reduce measurement errors.
  36. [36]
    Chapter 4: GNSS error sources - NovAtel
    Multipath error occurs when a signal from the same satellite reaches a GNSS antenna via two or more paths, such as reflected off the wall of a building. Because ...
  37. [37]
    Marine GPS/GNSS Positioning Systems and Devices
    Oct 8, 2025 · Offshore Energy and Exploration – GNSS devices are used to position offshore platforms, subsea infrastructure, and remotely operated vehicles ...
  38. [38]
    Fisheries & Aquaculture - LETO SPACE
    Precision Navigation for Fishing Vessels: GNSS enables fishing vessels to navigate with unprecedented accuracy, allowing fishermen to precisely locate and ...Missing: exploration | Show results with:exploration
  39. [39]
    Basic performance and future developments of BeiDou global ...
    Jan 20, 2020 · This paper describes the basic performance of BDS-3 and suggests some methods to improve the positioning, navigation and timing (PNT) service.Missing: enhancements maritime
  40. [40]
    The Ever-Changing Uses for GNSS in Maritime
    There are several uses for GNSS in marine navigation. It is used for open sea navigation, harbor entrances and approaches, and positioning (vessel ...
  41. [41]
    Rail Applications - Navipedia - GSSC
    Sep 18, 2014 · Rail systems throughout the world are beginning to use GNSS to track the movement of locomotives, rail cars, maintenance vehicles, and wayside equipment in ...Missing: land | Show results with:land
  42. [42]
    The Role of GNSS-RTN in Transportation Applications - MDPI
    Specifically, GNSS constitutes the backbone of the Automatic Vehicle Location (AVL) technology used in fleet management services. Fleets of trucks, couriers, ...
  43. [43]
    Autopilot | Tesla Support
    No. Autopilot is only available on Tesla vehicles built after September 2014, and functionality has changed over time based on the addition of new hardware and ...Missing: GNSS GPS
  44. [44]
    [PDF] Developments in Modern GNSS and Its Impact on Autonomous ...
    Feb 13, 2020 · In more advanced systems, the perceptual sensors are fused in a single detector. The Tesla 'navigate on autopilot' feature evolves beyond.
  45. [45]
    How Idle Time Reduction Reduces Fleet Costs - MiX by Powerfleet
    GPS tracking is one of the most effective ways to reduce idling time, as it provides fleet managers with real-time data and visibility into the whereabouts and ...
  46. [46]
    Positive Train Control (PTC) | FRA - Federal Railroad Administration
    Oct 10, 2023 · Positive Train Control (PTC) systems are designed to prevent train-to-train collisions, over-speed derailments, incursions into established work zones.
  47. [47]
    Positive Train Control Systems - Federal Register
    Oct 28, 2024 · On December 29, 2020, FRA announced that railroads had fully implemented FRA-certified and interoperable PTC systems on all PTC-mandated main ...
  48. [48]
    GPS and Positive Train Control
    This advanced safety technology, required by federal law, will be operational on over 60,000 miles of the national rail system in the 2018 to 2020 timeframe.
  49. [49]
    RTK Positioning: Key Milestones - Bench Mark USA
    Sep 9, 2024 · The early 1990s saw the first practical implementations of RTK, leveraging advances in GPS technology and signal processing. These early RTK ...
  50. [50]
    [PDF] User Guidelines for Single Base Real Time GNSS Positioning
    Disturbances and variations in the atmosphere can affect RT accuracy and integrity to the extent of making the solution too inaccurate for surveying and ...
  51. [51]
    https://gpsgeometer.com/en/blog/gnss-rtk-guide-surveying-equipment-for-precise-positioning
  52. [52]
    (PDF) Precise Point Positioning: Is the era of differential GNSS ...
    The concept of Precise Point Positioning (PPP) using Global Navigation Satellite System (GNSS) technology was first introduced in 1976. However, it took until ...
  53. [53]
    [PDF] Real Time Precise Point Positioning: Are We There Yet?
    Jul 18, 2013 · This paper provides a brief history of the development of real-time PPP and reviews the recent advances made in PPP with an emphasis on the.
  54. [54]
    Hybrid Positioning uses GNSS and robotic total stations
    Our Hybrid Positioning technology combines GNSS positioning and optical robotic measurements on one rover pole.
  55. [55]
    Continuing USGS Projects Involving GNSS
    Feb 25, 2014 · With GPS, the effort involved in the baseline part of the surveying, and in some cases the site data collection, can be substantially reduced.Missing: empirical | Show results with:empirical
  56. [56]
    [PDF] U.S. Geological Survey Techniques and Methods 11-D1
    Chapter D1 of book 11 (TM 11–D1) deals with vertical datum establishment using survey-grade Global Navigation Satellite Systems (GNSS). This edition of “Methods ...
  57. [57]
    GNSS vs. RTK: Understanding the Difference and Choosing the ...
    Nov 18, 2024 · Limited Coverage Range: Since RTK relies on a base station, the rover must be within a certain distance (typically 10-20 km) to maintain ...
  58. [58]
    RTK Systems - Navipedia - GSSC
    Jul 27, 2018 · A RTK base station covers a service area spreading about 10 or 20 kilometres, and a real time communication channel is needed connecting ...
  59. [59]
    Performance of PPP and PPP-RTK with new-generation GNSS ...
    Jul 1, 2025 · In this contribution, we comprehensively overview the developmental history of major systems and the construction of global satellite-based ...
  60. [60]
    Learn how Emlid can deliver GNSS accuracy for your GIS projects
    Sep 10, 2025 · The application of GNSS in GIS allows professionals to collect spatial data with centimeter-level accuracy, streamlining decision-making and ...
  61. [61]
    GNSS and GIS Integration - Geographic Book
    Jan 30, 2023 · One way to integrate GNSS data with GIS is to directly input the data into GIS software using data transfer protocols such as NMEA, RTCM, or GPX.Integration Techniques · Position focused and... · Methods of integration · ActiveX
  62. [62]
    (PDF) GIS and GNSS Integration Techniques for Earth Observations
    Jul 23, 2024 · GNSS and GIS integration can be done through position-focused and technology-focused integration. Position-focused integration uses GNSS ...
  63. [63]
    3D map creation using crowdsourced GNSS data - ScienceDirect.com
    This paper proposes and implements a novel approach to generate 3D maps for free using Global Navigation Satellite Systems (GNSS) signals, which are globally ...
  64. [64]
    Using Crowdsourced Trajectories for Automated OSM Data Entry ...
    This paper suggests an automatic mechanism, which uses raw spatial data (trajectories of movements contributed by contributors to OSM) to minimise the ...
  65. [65]
    Google Earth Engine Applications Since Inception: Usage, Trends ...
    Sep 20, 2018 · Established towards the end of 2010, it provides access to satellite and other ancillary data, cloud computing, and algorithms for processing ...
  66. [66]
    GMTED2010: Global Multi-resolution Terrain Elevation Data 2010
    The Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) dataset provides global elevation data at 7.5 arc-seconds resolution, compiled from various ...
  67. [67]
    Precise Point Positioning Using World's First Dual-Frequency GPS ...
    In 2018, Xiaomi mobile brand released the world's first dual-frequency GNSS smartphone, Xiaomi mi 8. This smartphone is fitted with Broadcom's BCM47755 chip ...
  68. [68]
    GNSS smartphones positioning: advances, challenges ...
    Nov 16, 2021 · However, in May 2018, the Xiaomi Mi 8 equipped with the new Broadcom BCM47755 GNSS chipset was released as the world's first dual-frequency GNSS ...
  69. [69]
    Insights from the 2023 Mw 7.8 Kahramanmaraş Earthquake
    May 6, 2025 · We apply their method to sum the horizontal displacements of 24 high-rate GNSS stations in the direction predicted by fault slip at the hypocenter of the 2023 ...
  70. [70]
    Kinematic Rupture Model of the 6 February 2023 - GeoScienceWorld
    Nov 9, 2023 · The 2023 M w 7.8 southeast Türkiye earthquake was recorded by an unprecedentedly large set of strong‐motion stations very close to its rupture.Final Slip Model And Rupture... · Discussion · Rupture Velocity Along The...
  71. [71]
    Modernizing land use planning with GNSS tools and GIS mobile apps
    Aug 6, 2025 · Learn how a 400-year-old UK garden site was transformed with land use planning tools using Reach RS2 and ArcGIS mobile apps.
  72. [72]
    United Nations Workshop on GNSS and Related Space ... - UNOOSA
    SDG 11: Sustainable Cities and Communities - GNSS is widely used for urban planning in order to pinpoint structures and reference points for cadastral and urban ...
  73. [73]
    5G synchronization requirements and solutions - Ericsson
    Jan 13, 2021 · UTC traceability does not imply that UTC time is recovered or that leap seconds are used; in fact, the 3GPP also requires the use of continuous ...
  74. [74]
    Synchronization and the impact of UTC discontinuities - ITU
    May 30, 2023 · This requires UTC traceability to coordinate the transmission of the start of radio frames between adjacent base stations, thereby preventing ...
  75. [75]
    5G is all in the timing - Ericsson
    Aug 8, 2019 · Beam-forming with NR-TDD, on the other hand, requires absolute time sync ~1.5 μs (synchronization across the whole network). In general, a mix ...Ran Drivers Of Timing And... · Time And Phase Sync... · Transport Network...
  76. [76]
    [PDF] 5G Network Synchronization - GPS World
    can then be made traceable to an external clock. ▫ Coordinated Universal Time (UTC) is the basis for civil time today. This 24-hour time standard is kept ...
  77. [77]
    Why multi-frequency and multi-constellation matters for GPS/GNSS ...
    Those receivers that have access to the highest number of constellations and signals offer the best positioning availability, accuracy and resilience even in ...
  78. [78]
    [PDF] GNSS Jamming and Spoofing: how serious can it be? - EUPOS
    March 2022: GNSS permanent attacks especially on Ukrainian critical network infrastructure. Page 7. Deliberate interference.
  79. [79]
    Timing alternatives for critical applications in GNSS-denied ...
    May 29, 2024 · Network based timing services using Precision Time Protocol (PTP) are widely deployed in critical infrastructure to address GNSS/GPS-denied ...
  80. [80]
    [PDF] GNSSDO Use Case: Financial Services - Microchip Technology
    Regulations such as the Markets in Financial Instruments Directive II (MiFID II) mandate timestamp accuracy within 100 microseconds, making reliable timing ...
  81. [81]
    Time Synchronization: Time is at the Heart of MIFID Regulation
    The Trouble with Time​​ MiFID II requires the accuracy of such reports to be as low as the 100-microsecond level for high-frequency trading firms, and for voice ...
  82. [82]
    Synchrophasors - Grid Stabilization Solutions - Arbiter Systems
    Synchrophasor measurement of phase shift across portions of the grid can be used to estimate stress and predict system stability.
  83. [83]
    A critical review on phasor measurement units installation planning ...
    From its inception, the PMU was extensively established to monitor, protect, and control power networks by providing synchronized measurements through GPS.
  84. [84]
    Ukraine attacks changed Russian GPS jamming
    Dec 20, 2022 · On the first day of the attacks, GPS interference was detected around Moscow, at two airbases to the east, and near the Engels-2 airbase.
  85. [85]
    [PDF] GLOBAL POSITIONING SYSTEM TIMING CRITICALITY ...
    Phasor measurement units use GPS time for better than 1 μs accuracy, but may also use atomic clocks for backup. The electric power grids, thus, may be becoming ...
  86. [86]
    [PDF] Economic Benefits of the Global Positioning System (GPS)
    Jun 1, 2019 · (DARPA) funding and collaboration, developed the chip-scale atomic clock (CSAC), which is now being developed and marketed by private ...
  87. [87]
    New Galileo Timing Service Message Operational Service Definition ...
    Dec 5, 2024 · A dedicated Timing Service as part of the Galileo Second Generation mission is developed to provide an enhanced service focus on critical infrastructure ...Missing: trading power
  88. [88]
    [PDF] GALILEO for TIMING and SYNCHRONISATION APPLICATIONS
    European GNSS to power the next-generation of high-precision Timing & Synchronisation applications in the telecommunications, energy and finance sectors.
  89. [89]
    GPS Wars - National Security Archive
    Jul 17, 2019 · These uses include time-stamping financial transactions from ATMs to high-speed trading; synchronizing and regulating the electric grid ...
  90. [90]
    Setting the Record Straight on Precision Agriculture Adoption
    Jul 1, 2019 · The first commercially successful grain yield monitors were introduced in 1992. The combination of GNSS-enabled soil sampling, variable rate ...Results · Government Studies Using... · Yield Monitoring And Mapping
  91. [91]
    Precision Farming - National Museum of American History
    Oct 10, 2025 · In the 1990s agricultural engineers began combining on-the-go crop yield readings with GPS tracking to create crop yield maps. A black box ...Missing: GNSS | Show results with:GNSS
  92. [92]
    [PDF] Precision Agriculture in the Digital Era: Recent Adoption on U.S. Farms
    Digital agriculture, including precision agriculture, has increased since 1996, with substantial adoption of yield/soil maps and VRT on corn/soybean acreage, ...Missing: verifiable | Show results with:verifiable
  93. [93]
    Variable Rate Technology and Its Application in Precision Agriculture
    Jan 23, 2025 · The VRT enables growers and their crop advisors to precisely apply the agricultural inputs (such as water, nutrients, chemicals, etc.) at ...Missing: GNSS | Show results with:GNSS
  94. [94]
    NDVI In Remote Sensing: Definition & Crop Health Guide - Farmonaut
    Crop Health Monitoring: Regular NDVI measurements allow farmers to track crop health throughout the growing season. Variable Rate Application: NDVI maps can ...Missing: GNSS | Show results with:GNSS
  95. [95]
    (PDF) Recent advances and applications of low-cost GNSS receivers
    Jan 2, 2025 · Despite drawbacks, LC GNSS receivers have been successfully applied in surveying, mapping, geodetic monitoring, precision agriculture, ...
  96. [96]
    [PDF] The Value of Data/Information and the Payoff of Precision Farming*
    Precision farming in crop production includes the use of global positioning systems (GPS), yield monitors and variable rate application technology to more ...
  97. [97]
    Benefits and Evolution of Precision Agriculture - USDA ARS
    Jan 10, 2025 · Precision agriculture is a general term to describe farming tools based on observing, measuring, and responding to within-field variability via crop management.
  98. [98]
    GPS Correction Technology Lets Tractors Drive Themselves
    The Global Positioning System (GPS) was still new in the mid-1990s when John Deere, based in Moline, Illinois, started using it to enable precision agriculture.Missing: date | Show results with:date
  99. [99]
    [PDF] JOHN DEERE PRECISION AG TECHNOLOGY
    Ever since John Deere released our first yield mapping and. AutoTrac™ guidance solution over 20 years ago, our industry- leading precision ag solutions have ...Missing: date GNSS
  100. [100]
    How ag machines use GNSS for greater harvesting efficiencies
    Mar 27, 2025 · Accuracy and Reliability. Nearly all PA practices require RTK, which gives repeatable accuracy of 1 cm to 2 cm. “I have this conversation daily ...
  101. [101]
    Accuracy Of RTK GPS, Agri GPS RTK: 7 Top Advances - Farmonaut
    RTK GPS delivers centimeter-level accuracy, up to 25 times more precise than standard GPS, using real-time correction signals.
  102. [102]
    https://agristuff.com/farming/automation-in-agriculture-labor-savings-safety-and-where-to-start/
  103. [103]
    What Is RTK and Why Use It in Agriculture? - FieldBee
    May 13, 2022 · RTK (Real-Time Kinematic) is a satellite correction technology that boosts GNSS accuracy from a few metres down to just a few centimetres.Missing: rural | Show results with:rural
  104. [104]
    What is an RTK Corrections Network? | Point One Nav
    Apr 20, 2024 · RTK networks offer scalability advantages, allowing the infrastructure to expand and adapt to evolving user requirements and coverage needs. As ...Missing: rural | Show results with:rural
  105. [105]
    Joint Direct Attack Munition GBU- 31/32/38 - AF.mil
    Growth of the JDAM family of weapons expanded to the MK-82 500-pound version, which began development in late 1999. Enhancements such as improved GPS accuracy, ...Missing: Gulf War
  106. [106]
    Operation Desert Storm and the 'JDAM Revolution' - HistoryNet
    Sep 7, 2021 · The circular error probable—the radius of a circle in which 50 percent of the bombs would fall—is under 43 feet. Warhead JDAM kits are fitted to ...
  107. [107]
    APKWS Laser-Guided Rockets: More bang for the buck - BAE Systems
    Apr 21, 2020 · First employed in 2012, APKWS rockets have been fired thousands of times. In combat, the APKWS rocket has achieved greater than 90% hit rate.
  108. [108]
    Precision Guided Munitions and the New Era of Warfare
    Another Apache unit scored 102 hits for the expenditure of 107 Hellfire missiles, a hit rate of better than 95 per cent.32. The reaction of Iraqi forces to ...
  109. [109]
    [PDF] U.S. Export Controls on GPS/GNSS Equipment
    Mar 18, 2022 · military applications (MT if designed or modified for airborne applications and capable of providing navigation information at speeds in ...
  110. [110]
    GLONASS: Russia's GNSS vs GPS - Coverage & Accuracy - AutoPi
    Aug 14, 2025 · GLONASS provides an accuracy of 5-10 meters for civilian use. Accuracy: GPS provides an accuracy of around 3.5-7.8 meters for civilian use.
  111. [111]
    GPS Anti-Jam M-Code Takes Two Steps Forward - Breaking Defense
    Aug 7, 2020 · The highly encrypted M-Code to protect GPS signals from jamming and spoofing currently is enabled on 22 GPS satellites of various generations.
  112. [112]
    [PDF] GPS MODERNIZATION DOD Continuing to Develop New Jam
    Jan 19, 2021 · The Air Force operationally accepted the COps software upgrade in March 2020. The total program cost for. COps is $165 million. Military Code (M ...
  113. [113]
    Another US precision-guided weapon falls prey to Russian ...
    Apr 28, 2024 · U.S.-provided precision-guided munitions have failed in mission after mission in Ukraine, taken down by Russian electronic warfare.Missing: accuracy | Show results with:accuracy
  114. [114]
    Russian jamming of U.S. weapons in Ukraine forces Pentagon to ...
    to less than 10 percent hitting ...
  115. [115]
    U.S. military doubles down on GPS despite vulnerabilities
    Aug 9, 2021 · Military combat aircraft use GPS paired with inertial navigation systems so if GPS goes out the pilot can still complete the mission. Inertial ...
  116. [116]
    U.S. Army Taking a Layered Approach to PNT - Inside GNSS
    Jun 3, 2025 · MAPS provides reliable PNT to mounted Army platforms, including ground vehicles, watercraft and munition systems, even when GPS is denied.
  117. [117]
    Military GPS (DAGR) - BAE Systems
    Unlike commercial GPS receivers, DAGR provides secure, military SAASM-based GPS in the most reliable and proven handheld form available today.
  118. [118]
    Rockwell-Collins Defense Advance GPS Receiver (DAGR)
    The DAGR uses state of the art GPS technology, including "All in View" satellite tracking and the Selective Availability Anti-Spoofing Module (SAASM).
  119. [119]
    The Blue Force Tracker System - Time and Navigation
    Blue Force Tracker is a system that gives commanders and troops in the field a real-time picture of the battlefield not possible with conventional maps.Missing: GNSS applications
  120. [120]
    [PDF] UNMANNED AERIAL SYSTEMS (UAS) FOR INTELLIGENCE ...
    A compelling ISR use case for UAS swarms is for real-time mapping of a nearby contested envi- ronment. In such an operation, using software, a swarm of ...Missing: GNSS | Show results with:GNSS
  121. [121]
    U.S. Army To Explore ISR Drone Swarms This Year
    Feb 28, 2024 · The US Army will assess cutting-edge capabilities for swarming, medium-sized unmanned aerial systems during the Vanguard 2024 exercise at Fort Huachuca.Missing: GNSS | Show results with:GNSS
  122. [122]
    Army set to modernize Blue Force Tracking network | Article
    Jan 29, 2018 · The US Army is beginning a long-term initiative to significantly upgrade its key situational awareness network Blue Force Tracking, commonly known as BFT.Missing: GNSS applications<|separator|>
  123. [123]
    The Secret History of Iraq's Invisible War - WIRED
    Jun 14, 2011 · 'Aircraft, vehicles, ships, and troops' are all on the new jammer's target list. But before it gets into troops' hands, the countermeasure gets ...
  124. [124]
    Resiliency in PNT: GPS/GNSS Jamming and Spoofing
    However, the L5/E5, E6, and L2C (Civilian) bands have started being deployed, and the current generation of GNSS receivers will operate in all these bands.
  125. [125]
    Total Electron Content - Space Weather Prediction Center - NOAA
    For ground to satellite communication and satellite navigation, TEC is a good parameter to monitor for possible space weather impacts.
  126. [126]
    Total Electron Content (US-TEC and GloTEC)
    The Space Weather Prediction Center (SWPC) provides real-time total electron content as part of its mandate to provide real-time monitoring and forecasting ...
  127. [127]
    Multi-Global Navigation Satellite System for Earth Observation - MDPI
    In this paper, the recent developments and new application progress of multi-GNSS in Earth observation are presented and reviewed.
  128. [128]
    A History of UNAVCO: Four Decades of Advancing Geodesy - 2025
    Jul 11, 2025 · Between 2003 and 2008, UNAVCO PBO staff installed 891 permanent GPS stations to monitor the active plate boundary between the North American and ...
  129. [129]
    Shallow slow slip events along the Nankai Trough detected by ...
    Jan 15, 2020 · Slow slip events discovered around the shallow side of coupling regions have a spatiotemporal relationship with other slow earthquakes.Missing: superior peer-
  130. [130]
    Detection of slow slip events along the southern Peru - Seismica
    Jun 10, 2024 · We detect 33 events with durations ranging from 9 to 40 days and magnitudes from Mw 5.6 to 6.2. The moment released by these aseismic events seems to scale ...Missing: superior peer-<|separator|>
  131. [131]
    Warnings from the Ionosphere | NASA Earthdata
    Dec 28, 2020 · GPS may be able to pace tsunamis. On March 11, 2011, a powerful earthquake shook Japan. Pressure had built along a deep ocean trench off the ...
  132. [132]
    Instant tsunami early warning based on real-time GPS - NHESS
    May 17, 2013 · Taking the 2011 Tohoku earthquake as an example, we demonstrate the ability of real-time GPS to provide qualified tsunami early warning within minutes.Missing: GNSS | Show results with:GNSS
  133. [133]
    GPS/GNSS Data | Data | GAGE - UNAVCO.org
    Apr 8, 2025 · Seafloor geodesy monitors the precise movements and deformations of the Earth's crust beneath the oceans. Using acoustic signals, GNSS, and ...GNSS Data Access Notebooks · Real-Time GPS/GNSS Data · Data Access Methods
  134. [134]
    Remote sensing and its applications using GNSS reflected signals
    May 27, 2024 · Several ground-based experiments have demonstrated the GNSS-R's sensitivity to geophysical parameters such as soil moisture, snow depth, biomass ...
  135. [135]
    Assessing environmental changes with GNSS reflectometry
    May 8, 2024 · These signals can be used to detect snow depth, ice thickness, vegetation growth, soil moisture and sea level change by employing the GNSS ...
  136. [136]
    Soil Moisture Sensing Using Spaceborne GNSS Reflections ...
    Apr 19, 2018 · These results show that CYGNSS, and future GNSS reflection missions, could provide global SM observations. Key Points. Bistatic radar ...<|separator|>
  137. [137]
    Retrieval and evaluation of surface soil moisture from CYGNSS ...
    Jan 1, 2024 · The Global Navigation Satellite System-Reflectometry (GNSS-R) can estimate land surface soil moisture (SSM) as a viable and promising ...
  138. [138]
    Latest Advances in the Global Navigation Satellite System ... - MDPI
    Land applications have evolved considerably in the past few years; studies have used GNSS-R for soil moisture, vegetation opacity, and wetland detection and ...
  139. [139]
    Real‐Time Water Levels Using GNSS‐IR: A Potential Tool for Flood ...
    Feb 28, 2024 · We present a new technique for obtaining water levels in real-time using multiple compact Global Navigation Satellite System antennas · The ...Missing: smartphone mapping
  140. [140]
    GNSS Reflectometry-Based Ocean Altimetry: State of the Art ... - MDPI
    Because of its numerous advantages such as low cost, multiple signal sources, and all-day/weather and high-spatiotemporal-resolution observations, this new ...
  141. [141]
    Signal-to-Noise Ratio Analyses of Spaceborne GNSS-Reflectometry ...
    This paper analyses the signal-to-noise ratio (SNR) of the GNSS-R measurements from Galileo and BeiDou-3 (BDS-3) systems, which is one of the important ...
  142. [142]
    [PDF] Statistical Analysis of Surface Reflectivity with GNSS Reflected ...
    Feb 21, 2020 · Generally, GNSS reflected signals are treated as a source of noise, i.e. multipath, in PNT, but they contain information about the surface from ...
  143. [143]
    Feasibility Demonstration of Using the Signal‐to‐Noise Ratio ...
    Apr 20, 2025 · First, it is difficult to separate the reflected amplitude from the raw SNR observation, and the amplitude also attenuates with the increase of ...
  144. [144]
    Testing RTK & PPP for Precise Positioning in CAVs - Spirent
    Feb 18, 2019 · Testing RTK and PPP for precise positioning in connected and autonomous vehicles · RTK and PPP increase GNSS accuracy to centimetre level.
  145. [145]
    RTK, PPP and autonomous - GNSS store
    The accuracy is 10 cm CEP50, with a convergence time of 5 minutes globally and 100 seconds in the future for the PPP-RTK mode in Europe.
  146. [146]
    Autonomous vehicles connect the world - GPS World
    Sep 27, 2023 · It launched its first public trial of autonomous ride-hailing vehicles, called Waymo One, in Phoenix, Arizona in 2017, and has expanded its ...
  147. [147]
    A compact RTK‐GNSS device for high‐precision localization of ...
    Mar 28, 2024 · Localization is an essential technology that allows mobile robots to obtain absolute and relative position information necessary to provide ...
  148. [148]
    https://ui.adsabs.harvard.edu/abs/2023MSSP..20510862G/abstract
  149. [149]
    (PDF) Improved Multi-sensor Fusion Positioning System Based on ...
    For GNSS challenging environments, we give a semi-tightly coupled sensor fusion system based on factor graph optimization. The system is tightly coupled with ...
  150. [150]
    LiDAR, GNSS and IMU Sensor Alignment through Dynamic Time ...
    Jul 11, 2025 · We propose a unified framework that fuses LiDAR, GNSS, and IMU data for high-resolution city-scale mapping.
  151. [151]
    Fixing Positioning: Why GNSS Alone Fails Utility Robots - Wevolver
    Jun 17, 2025 · The modular design allows for adaptation to various sensors and robot platforms, including drones, ground robots, and industrial vehicles.Gnss Limitations · Key Advantages · Real-World Use Cases In...<|control11|><|separator|>
  152. [152]
    [2010.11722] Prediction-Based GNSS Spoofing Attack Detection for ...
    Oct 16, 2020 · Due to the lack of encryption, open-access of the coarse acquisition (C/A) codes, and low strength of the signal, GNSS is vulnerable to spoofing ...
  153. [153]
    Adversarial Evasion Attacks on SVM-Based GPS Spoofing Detection ...
    Oct 2, 2025 · A GPS spoofing attack refers to an attack where an attacker alters the location information of a vehicle by maliciously manipulating the GPS ...
  154. [154]
    GNSS-Inertial Navigation for BVLOS Drones | UST
    Jul 15, 2020 · Unmanned aerial vehicles (UAVs) used for BVLOS applications such as delivery, mapping and aerial surveying must maintain precise positioning ...
  155. [155]
    GNSS Jamming Protection for Autonomous Drones | UAV Navigation
    Most autonomous drones depend heavily on Global Navigation Satellite Systems (GNSS) like GPS, Galileo, GLONASS, or BeiDou to maintain accurate positioning, ...
  156. [156]
    GNSS Forecasting Takes Guesswork out of UAV BVLOS Mission ...
    Aug 5, 2021 · In a free webinar, learn how to leverage existing standards and sensor packages, and how to augment them with GNSS forecasting to open up the ...
  157. [157]
    [PDF] FAA Has Made Progress in Advancing BVLOS Drone Operations but ...
    Jun 30, 2025 · FAA increased approvals for BVLOS operations from 1,229 in 2020 to. 26,870 in 2023. FAA used small UAS rule waivers, air carrier operating.
  158. [158]
    /blogs/insights/cm-level-accuracy-bvlos-drone-flight - u-blox
    Oct 3, 2025 · Infrastructure inspection – Precise hovering near powerlines, pipelines, and railways; Agriculture – Coordinated swarm drone operations for ...
  159. [159]
    Agricultural spraying drones: A comprehensive review - ScienceDirect
    Due to the various advantages of spraying drones, they are used for precision agriculture in different countries like China. ... Role of gps and gis in precision ...
  160. [160]
    Galileo High Accuracy Service (HAS) - GSC-europa.eu
    The Galileo High Accuracy Service (HAS) provides free of charge access, through the Galileo signal (E6-B) and by terrestrial means (Internet), to the ...
  161. [161]
    Galileo for UAS - Unmanned Valley
    Mar 5, 2025 · Galileo: Offers a standard accuracy of 1 meter and, with the High Accuracy Service (HAS), even up to 20 cm. Signal Security GPS: Features a ...<|separator|>
  162. [162]
    What is Galileo High Accuracy Service? - Get Rugged
    Feb 27, 2025 · Galileo HAS is a Precise Point Positioning (PPP) solution that delivers high-accuracy positioning. Unlike some commercial high-accuracy GNSS services, Galileo ...
  163. [163]
    Galileo High Accuracy Service (HAS) - Navipedia - GSSC
    The Galileo High Accuracy Service (HAS) will provide free of charge high-accuracy PPP corrections, in the Galileo E6-B data component and by terrestrial means.
  164. [164]
    BVLOS vs BLOS for UAS and Drone Operations - Spirent
    May 16, 2022 · Precise positioning and navigation is critical for BVLOS, and this typically depends on GNSS. A drone's GNSS receiver needs radio line of sight ...
  165. [165]
    Gnss-denied unmanned aerial vehicle navigation: analyzing ...
    Apr 7, 2025 · The simulation results showed a 21.4% reduction in positioning error, demonstrating clear improvements in both accuracy and robustness.
  166. [166]
    R-LVIO: Resilient LiDAR-Visual-Inertial Odometry for UAVs in GNSS ...
    R-LVIO is a resilient multi-sensor fusion system using LiDAR, cameras, and IMUs for UAV localization in GNSS-denied environments, achieving state estimation.
  167. [167]
    Low-power GNSS techniques enable longer life for location devices
    Nov 12, 2024 · GNSS tracking devices can achieve low power consumption, but maintain tracking efficiency by employing the right low power GNSS techniques.
  168. [168]
    Advanced IoT Tracking with Cellular and Low Power GNSS - Sequans
    IoT trackers are being used to locate everything from personal assets like luggage, wallets, bikes, motorcycles, and automobiles, to industrial pallets, fleets ...
  169. [169]
    Space Technology Drives Singapore's Smart Cities and Urban ...
    Sep 20, 2023 · “With GNSS, we will be able to better collect aggregated traffic data, to help improve traffic management and transport planning.
  170. [170]
    The Impact of Singapore Congestion Pricing on Urban Mobility
    Jun 16, 2025 · Car trips into central Singapore came down 10-15 % in the two years after introduction of the Electronic Road Pricing scheme. Future of ...
  171. [171]
    Singapore Smart Traffic System is Redefining Urban Mobility
    Nov 12, 2024 · Singapore's Smart Traffic System uses real-time data, ERP, and ITS to manage traffic, reduce congestion, and improve safety.
  172. [172]
    Integration of 5G and GNSS Technologies for Enhanced Positioning
    Aug 9, 2025 · This paper presents an experimental study on the integration of the fifth generation (5G) cellular networks and the Global Navigation Satellite ...
  173. [173]
    GNSS IoT Positioning: From Conventional to Cloud-Based
    Jun 15, 2018 · Cloud-based GNSS may be able to deal with the constraints faced by IoT sensors by migrating the signal processing tasks from the sensor to ...
  174. [174]
    Improving GNSS Resiliency Using Edge AI Solutions - RIP
    Oct 22, 2024 · Our strategy will explore how Edge AI can enhance GNSS resiliency in challenging scenarios by bringing intelligence to the edge node.Missing: intermittent IoT
  175. [175]
    Low‐complexity framework for GNSS jamming and spoofing ...
    Oct 29, 2020 · GNSS signals have extremely low power at the ground surface (e.g. −160 dBm for L2 GPS), and thus, are highly vulnerable to in-band jamming.
  176. [176]
    [PDF] Study of Interference Effects on GPS Signal Acquisition
    Thus a signal strength of -150 dBm should be able to be acquired and tracked by a GPS receiver to provide position. A GPS signal below the. -135 dBm power level ...
  177. [177]
    [PDF] GNSS Jamming - Tempest Telecom Solutions
    Small, cigarette lighter-type jammers are designed to disable tracking devices in cars, vans or lorries, and broadcast white noise on the GPS L1 frequency at.
  178. [178]
    INS-aided GNSS jamming protection in support of resilient train ...
    Accordingly, this study focuses on a 40 dB JSR scenario, corresponding to the specified −130 dBm GPS signal and −90 dBm jamming power configuration. A 5 ...
  179. [179]
    Understanding How GPS Jamming Works Amid Rise In Reported ...
    Sep 3, 2025 · GPS jamming and spoofing cases are on the rise, according to aviation analysts, especially in aviation and maritime sectors, particularly around ...
  180. [180]
    Russian GPS jamming disrupted 123000 flights over Baltic airspace
    Sep 7, 2025 · Nearly 123,000 flights over the Baltic were disrupted by Russian jamming in the first four months of 2025, a report to the UN aviation body ...
  181. [181]
    What to know about Russia's GPS jamming operation in Europe
    commonly known as GPS — to mislead a phone, ship or ...
  182. [182]
    GNSS spoofing detection through spatial processing | NAVIGATION
    In this paper, we present an algorithmic framework for signal-geometry-based approaches of GNSS spoofing detection.
  183. [183]
    [PDF] GNSS Spoofing Detection using Two-Antenna Differential Carrier ...
    Jun 28, 2014 · The spoofing detection system consists of two GNSS patch antennas, GPS receiver hardware and software, and spoofing detection signal processing ...
  184. [184]
    GPS Modernization: Delays Continue in Delivering More Secure ...
    Sep 9, 2024 · DOD has been working for years to upgrade GPS with a military-specific signal known as M-code that resists interference or jamming.Missing: rollout 2020s civilian GNSS
  185. [185]
    Encrypted GPS M-Code: It's Here, and It's Critical - Safran
    M-Code is designed to give military receivers better defense against jamming, operate in dense vegetation, enhance their ability to track the GPS satellites, ...Missing: rollout 2020s
  186. [186]
    U.S. Army partnerships bring critical Assured PNT capabilities to ...
    May 14, 2025 · In one PGK M1156 variant, the M1156E5, PM CAS incorporated an anti-jam capability that enhances operational ability in areas where GPS is ...
  187. [187]
    eLoran: Part of the solution to GNSS vulnerability - GPS World
    Nov 3, 2021 · eLoran, which has no common failure modes with GNSS, could provide continuity of essential timing and navigation services in a crisis.
  188. [188]
    eLoran: Resilient Positioning, Navigation, and Timing Infrastructure ...
    Nov 4, 2020 · Compared to GNSS, enhanced Loran (eLoran) is more resistant to jamming and is recommended as a realistic alternative to GNSS.<|control11|><|separator|>
  189. [189]
    Innovation: Enhanced Loran - GPS World
    Nov 23, 2015 · eLoran is an independent dissimilar complement to GNSS. It allows GNSS users to retain the safety, security and economic benefits of GNSS even ...
  190. [190]
    Impact of ionospheric scintillation on GNSS receiver tracking ...
    Oct 13, 2011 · In the case of Global Navigation Satellite System (GNSS) receivers, scintillations can cause cycle slips, degrade the positioning accuracy and ...Missing: factors DOP
  191. [191]
    Survey on signal processing for GNSS under ionospheric scintillation
    Under scintillation, GNSS signals are affected by amplitude and phase variations, which mainly compromise the synchronization stage of the receiver. To ...
  192. [192]
    Distinguish ionospheric scintillation and multipath in GNSS signals ...
    Electron density irregularities present within the ionosphere induce significant fluctuations in global navigation satellite system (GNSS) signals. Fluctuations ...
  193. [193]
    Investigation of the impact of Ionospheric Scintillation on GNSS ...
    Oct 1, 2021 · All these factors increase the dilution of precision due to inefficient geometry of visible satellites. This affects the reliability and ...<|separator|>
  194. [194]
    An Introduction to GNSS Positioning – Focal Point
    Oct 14, 2024 · This article provides an introductory guide to GNSS positioning, covering how it works, the factors impacting location and timing accuracy ...Missing: personal | Show results with:personal
  195. [195]
    How GPS Actually Works – And Why Accuracy Varies - Watch & Navy
    Jul 1, 2025 · GPS relies on a direct line of sight to multiple satellites. When that line is broken by buildings, trees, tunnels or even your own body ...
  196. [196]
    Selective Availability | GPS.gov
    By turning it off, the President immediately improved GPS accuracy for the entire world. The United States has no intention of reactivating SA ever again.
  197. [197]
    The Real Reason Selective Availability Was Turned Off
    Jul 1, 2000 · But today, the removal of SA has moved GPS from a +/- 100-meter navigation system to one providing all users with +/- 10 to 20 meters (32.8 to ...Missing: GNSS | Show results with:GNSS
  198. [198]
    Markov Chain‐Based Stochastic Modeling of Deep Signal Fading ...
    Jun 24, 2021 · The Global Positioning System (GPS) has launched a number of new satellites since 2010 that broadcast two frequencies in aeronautical bands ...
  199. [199]
    Dual-frequency GPS tracking: addressing accuracy and reliability in ...
    By leveraging both bands, dual-frequency GPS corrects errors that single-band systems can't, dramatically boosting accuracy and consistency in location tracking ...2. Multipath Errors And... · 4. Signal Jamming Resistance · Rtk: Precision Beyond...<|separator|>
  200. [200]
    Global Navigation Satellite System [Explained]
    Mar 8, 2023 · A Global Navigation Satellite System (GNSS) consists of a constellation of satellites orbiting the Earth in very specific trajectories.
  201. [201]
    Accuracy assessment of Precise Point Positioning with multi ...
    Feb 20, 2018 · The analyses show accuracy improvements of up to 60% under conditions of strong scintillation when using multi-constellation data instead of GPS data alone.
  202. [202]
    Selective Availability Feature Eliminated from GPS III Satellites
    In May 2000, at the direction of President Bill Clinton, the U.S government discontinued its use of Selective Availability in order to make GPS more responsive ...Missing: ended | Show results with:ended
  203. [203]
    China's GPS rival Beidou is now fully operational after final satellite ...
    Jun 24, 2020 · Work on Galileo started much later, but the EU network is expected to become fully operational by the end of 2020. The US, Russian and now ...
  204. [204]
    BeiDou: China's GPS Challenger Takes Its Place on the World Stage
    Apr 14, 2022 · This closer look sheds light on the likely impact of BeiDou, as it considers the system's integration with China's Belt and Road Initiative (BRI) ...
  205. [205]
    Galileo Public Regulated Service (PRS) - Navipedia - GSSC
    The Galileo Public Regulated Service (PRS) provides position and timing restricted to government-authorised users, for sensitive applications.Missing: trading | Show results with:trading
  206. [206]
    China's BeiDou, GPS and great power competition
    Aug 7, 2023 · The focus of Sewall's paper, though, is the way BeiDou supports China's Belt and Road and Digital Silk Road initiatives to gain influence and ...
  207. [207]
    Summary Private Use of Location Tracking Devices: State Statutes
    A person may not knowingly install a tracking device or tracking application on another person's property without the other person's consent. ... (b) The ...Missing: GNSS | Show results with:GNSS
  208. [208]
    Regulation and innovation: How should small unmanned aerial ...
    Regulation both promotes and suppresses innovation. Good regulation is effective in terms of realizing social values and objectives, and is efficient in ...
  209. [209]
    Navigating The Skies of Regulation and Innovation
    Sep 23, 2024 · This study presents a comparative examination of the regulatory landscapes governing UAV operations in the European Union (EU) and the United States (US).