Exyn has integrated the Trimble DA2 GNSS System, an RTK-capable GNSS receiver, with the Exyn Nexys autonomous mapping platform, bringing centimeter-level geospatial accuracy to SLAM-based mobile 3D mapping.
The new capability enables users to pair Exyn Nexys’ lidar-based SLAM mapping with high-precision RTK corrections, allowing teams to georeference and anchor point clouds directly in the field without relying on ground control points or post-processing workflows. The result is faster, safer, and more accurate decision-making for industries including mining, construction and critical infrastructure inspection. Intelligently combining RTK and SLAM delivers highly accurate and robust point clouds — even in challenging environments.
When paired with the real-time colorization, users gain an added layer of visual context, enabling photorealistic mapping and the extraction of immersive georeferenced 360° imagery for enhanced situational awareness and analysis.
deliver real-time, centimeter-accurate global positioning
seamlessly integrate underground and surface-level scans into unified, georeferenced datasets
accelerate project timelines by reducing dependency on traditional ground control setups
improve accuracy and alignment for as-builting, volumetric measurements, construction progress tracking / QA, and mine planning.
This enhancement is particularly useful for hybrid environments where teams operate in both GPS-available and GPS-denied zones. The Nexys with DA-2 enabled RTK allows for seamless transitions between these areas while maintaining global coordinate consistency, so Exyn Nexys can serve as a true end-to-end solution for autonomous 3D data capture.
The Trimble DA2 GNSS and Exyn Nexys integration kit is available immediately for plug-and-play compatibility.
The Archer 4 with GNSS Expansion Pod and RTK connection is now an all-in-one centimeter mapping solution.
Juniper Systems Inc. announces that the GNSS Expansion Pod for the Archer 4 Rugged Handheld is now RTK capable. Juniper Systems is also launching a new application for the Archer 4 called Archer Connect. The Archer 4 with GNSS Expansion Pod and RTK connection is now an all-in-one centimeter mapping solution.
“We are very excited to bring this update to the Archer 4,” said John Florio, senior product manager at Juniper Systems. “The Archer 4 with a GNSS Expansion Pod and an RTK correction is the optimal all-in-one high-precision mapping solution.”
Archer Connect is a utility application that allows users to easily manage their GNSS expansion pod that is attached to their Archer 4. In Archer Connect, users can set up and manage their RTK network connection. Archer Connect is available on the Google Play Store.
The GNSS Expansion Pod attaches and interfaces with the Archer 4 through the Archer’s back contact pads. This allows for a compact one-handed device. The Archer 4 is a rugged handheld device designed to work in extreme environments. Featuring Android 14 and expanded battery options for increased runtimes in the field.
Read a roundup of recent products in the GNSS and inertial positioning industry from the March 2025 issue of GPS World magazine.
Surveying and Mapping
Photo: Eos Positioning Systems
New Eco-Friendly Carrying Case For Eos Positioning Systems’ receivers
The Skadi Gold, Skadi 300 and Skadi 200 GNSS receivers will now be shipped in a field-rugged carrying case made entirely from recycled materials. The case is designed to meet the demands of professionals who utilize GNSS technology in challenging environments. Its construction incorporates durable, eco-friendly materials that can withstand various field conditions, from remote wilderness areas to urban construction sites.
A key feature is its composition of 100% post-consumer recycled resin, which significantly reduces waste and promotes environmental sustainability, according to the company. It is specifically engineered to be shock-resistant and weatherproof.The case is provided as a standard inclusion with every purchase of the Skadi Gold, Skadi 300 or Skadi 200 GNSS receivers at no additional cost.
Multibeam Sonar Designed for bathymetric surveying
The Gemini 1200id is built on the same robust platform as the Gemini 720is multibeam sonar. The device features a 120° horizontal field of view, operating at both 720 kHz and 1,200 kHz acoustic frequencies.
The Gemini 1200id incorporates advanced noise reduction technology to significantly improve the attenuation of waterborne electrical noise to enhance imaging performance. An integrated speed-of-sound sensor ensures high positional accuracy of displayed targets, while CHIRP processing technology enhances target separation over extended ranges.
Compatibility with Tritech’s Genesis software package allows users to control multiple Tritech products from a single interface to streamline operations. The company has also made software development kits available for Windows and Linux operating systems to integrate into various platforms. The sonar’s design includes a custom-developed analog front-end solution with fully differential receiver channels, making it ideal for longer-range applications.
HiPer XRa is a GNSS receiver for surveying, mapping and construction applications. It can benefit a wide variety of users, including construction professionals, surveyors, geographic information systems (GIS) professionals, archeologists, engineering firms and more. The HiPer XR supports GPS, GLONASS, Galileo, BeiDou, IRNSS, QZSS and SBAS.
The new receiver has advanced Topcon Integrated Leveling Technology (TILT) compensation, featuring a calibration-free and magnetic interference-immune integrated IMU that provides up to 60° of tilt for precision measurements in challenging positions. It has signal integrity protection, anti-jamming and anti-spoofing capabilities. Through the myTopcon NOW! website, users can access online training materials, firmware updates and additional software resources.
Airborne Lidar System Ideal for coastline and river surveying
CoastalMapper is an airborne bathymetric lidar system for coastline and river surveying. The CoastalMapper can survey coastlines and rivers 250% faster than previous sensor models, according to Leica Geosystems.
It is suitable for various mapping applications, from assessing infrastructure resilience to monitoring river floods and conducting environmental investigations.
It features a high-performance bathymetric lidar module, a Leica TerrainMapper-3 topographic lidar and an imaging sensor, integrated into a compact and lightweight sensor head. This allows the CoastalMapper to capture up to 1 million bathymetric data points and 2 million topographic data points per second while providing high-resolution imagery with a 5-cm ground sampling distance at typical flying heights.
It integrates with Leica Geosystems’ airborne mapping workflows and offers cluster processing capabilities, allowing users to analyze large datasets and reduce the time from data collection to final deliverables. These outputs can include classified point clouds, digital terrain and surface models, and various imaging products.
Surveying Kit Streamlines base station and checkpoint setup
WingtraGROUND, a comprehensive survey kit, streamlines base station and checkpoint setup for on-site post-processing kinematic surveys with the WingtraONE Gen II, a vertical takeoff and landing UAV. The kit combines receivers, checkpoints and tools into a single, portable workflow.
The system integrates hardware components with a Wingtra tablet interface, which can help surveyors confirm correct receiver placement and avoid common errors associated with improper base station setup and inaccurate coordinates.
Wingtra receivers, equipped with Emlid Reach RS3 technology, provide accuracy within 2 cm, meeting high standards for aerial data validation. These receivers can also function independently for terrestrial surveys in real-time kinematic mode, including point collection and stakeout for various applications.
Galileo HAS-Enabled Receiver Offers positioning capabilities with 20 cm accuracy
The Geode GNS3H supports Galileo High Accuracy Service (HAS). It offers positioning capabilities with 20 cm accuracy worldwide without requiring additional infrastructure or subscriptions.
It is built to withstand tough conditions, making it ideal for demanding fieldwork. The device offers various accessories, including the Geode Grip, which combines the Geode with a data collection device of choice into a single handheld solution. A backpack strap kit and survey pole are also available to enhance mobility and flexibility in the field. The GNS3H can be used for surveying, agriculture, construction, forestry, mining and archaeology.
Expanded Mapping Portfolio 3D mapping technologies and more
Topcon Positioning Systems has become an authorized distributor of Pix4D’s photogrammetry software portfolio.
The partnership aims to enhance reality capture solutions across various industries, including surveying, mapping, utilities infrastructure, public safety, forensics, and architecture, engineering and construction.
The agreement streamlines the procurement process for end users by allowing them to access Pix4D’s advanced photogrammetry software solutions through Topcon’s global distribution network.
The GNSS real-time kinematic (RTK) 5 Click — a compact add-on board for high-precision positioning and navigation demands — features the UM980, an all-constellation multifrequency RTK positioning module from Unicore, with the advanced NebulasIV SoC for enhanced performance.
It supports Swift Navigation’s Skylark precise positioning service, multiple GNSS constellations and RTK positioning for centimeter-level accuracy. The board also features JamShield technology for robust performance in challenging environments, USB connectivity for easy configuration and visual status indicators for module status and GNSS signal reception.
It can be used for a variety of applications, including surveying and mapping, precision agriculture, UAVs, autonomous robots and autonomous driving.
Multi-Band GNSS Antenna Can operate in urban environments
Levity Series’ AHP24510 (L1/L2/L-Band) and AHP54510 (L1/L5/L-Band) directional patch antennas are designed to receive signals from GPS, Galileo, GLONASS and BeiDou satellite constellations.
These antennas offer faster and more accurate signal acquisition and lock, specifically in urban environments. The L-Band capability allows compatibility with high-precision GNSS correction services. The multi-band antennas offer integral redundancy to minimize satellite security blind spots and reduce energy consumption due to faster acquisition, requiring less system uptime to save power.
The Levity Series active antennas feature a 45 mm x 45 mm x 10 mm wide-band, dual-stacked patch design with a dual-feed, low noise amplifier, providing 28 dB to 29 dB gain and filtering. They operate with a maximum antenna VSWR of 1-to-1 from 1,207 MHz to 1,603 MHz, and the passive antenna efficiency ranges from 39.93% to 68.51% in the L1 band. These antennas use right-hand circular polarization to mitigate multi-path interference.
The Levity Series includes other multi-band products for high-precision applications, such as the HP24510A and HP54510A stacked-patch passive components, and the TFM.120A surface-mount front-end module, which covers the full multi-band GNSS spectrum including L-band. These antennas are suitable for various applications, including wearables, transportation, robotics, precision agriculture and autonomous vehicles.
The M9PLUS-HCT-A-SMA is an active multi-frequency GNSS antenna designed for high-accuracy applications. It supports L1/L2/L5 GPS, Galileo, Beidou and GLONASS bands, as well as L-band correction services. The antenna utilizes Maxtena’s proprietary Helicore technology, which offers advanced pattern control, polarization purity and efficiency in a compact form factor.
It integrates a pre-filter specifically engineered to mitigate LTE interference. This is crucial for maintaining signal integrity in environments with dense mobile communication networks, where LTE signals can overlap with GNSS frequencies. The pre-filter can effectively block out-of-band LTE signals, reducing intermodulation risks and ensuring clear GNSS signal reception.
The M9PLUS-HCT-A-SMA is built with rugged, IP67 automotive-grade components and includes an integrated SMA connector. It also features an O-ring for enhanced environmental sealing. Weighing only 24 grams, the antenna is ground plane-independent, making it versatile for various installations. It is particularly well-suited for GIS and RTK applications where high accuracy and reliability are crucial.
The MostaTech G321M is a three-axis fiber optic gyroscope (FOG) that offers high-precision navigation and orientation measurement capabilities. This advanced sensor features a data rate of 8 kHz.
Key features of the G321M include an input range of 400° per second, a bias RMS of 1° per hour and an angular random walk of 0.025 °/√h. Additionally, it has a power consumption of 2 W and an initialization time of 1 second. The G321M is designed with a compact form factor, making it suitable for various applications where size and weight are critical factors.
It is ideal for UAVs, robotics, borehole surveys, image stabilization, gimbal stabilization and underwater vehicles.
High-Precision Lidar Designed for precision applications
The TV1 Lite and the TV1 UAV systems are designed for various precision applications, such as mapping and data collection.
The TV1 Lite features TrueNav technology, a Hesai 32-channel laser scanner and a FLIR 5MP global shutter camera with a 90° field of view. It also includes one year of TV1 Lite Annual Processing with support and maintenance.
TV1 offers customization options, allowing users to choose from 26 MP, 45 MP or 61 MP cameras and various Trajectory Correction Service options.
Flight Control System With autopilot functionality
The Prism Supervisor software combines UAV autopilot flight control systems with AI-based observations processed in real time, aiming to enhance UAV operations.
The system provides a programming framework and software development kit for users to create custom mission scenarios. During flight, Prism Supervisor can adapt its autopilot functionality in real time, generating mission segments and flight plans as needed.
The software features a user-friendly graphic interface for mission planning, real-time visualization and execution. It supports Windows, Linux, macOS, iOS and Android.
Remote ID Receiver Enhances airspace awareness and UAV safety
RIDER is designed to enhance situational awareness by providing real-time detection of UAV activity in sensitive areas. It also seeks to provide a clear visibility of surrounding UAV operations to help avoid potential collisions and ensure safer flight experiences.
The device features a built-in industrial chip SIM that provides global coverage through LTE-M and NB-IoT, ensuring connectivity in various environments.
It operates effectively within a temperature range of -20 °C to +60 °C and is rated IP54 for dust and water resistance. The device complies with ASTM F3411-22A and ASD-STAN EN 4709-002 standards, making it suitable for regulatory environments.
The RIDER can detect signals from up to 5 km with its default antennas and up to 10 km when using an optional high-performance antenna. It is equipped with an internal cellular and Bluetooth antenna, along with an integrated GNSS antenna that provides precise positioning and timestamping capabilities. It supports multiple GNSS frequencies and utilizes Bluetooth and Wi-Fi technologies for Remote ID communications.
Streamlined BVLOS Operations For a variety of applications
The Sentaero 6 UAV is designed for advanced over-the-horizon operations beyond visual line of sight (OTH-BVLOS). It features built-in AI and machine learning capabilities for real-time data processing. The system can be used for surveying, mapping, inspection, asset monitoring and more.
Engineered to streamline operations, the Sentaero 6 offers more accurate and up-to-date intelligence on assets. Its onboard computer can processes data mid-flight.
Future developments will include swarm operations, enabling one human to control multiple UAVs simultaneously; fully remote operations and higher safety standards, such as a parachute for urban missions, according to Censys Technologies.
SBG Systems has significantly updated its Ellipse series sensors, incorporating the latest World Magnetic Model (WMM) to enhance accuracy and reliability in navigation applications. This upgrade is available for all Ellipse sensors, including first-generation models.
Designed for unmanned systems such as UAVs, UGVs and marine platforms, the Ellipse series comprises compact, high-precision inertial sensors. These devices feature built-in three-axis magnetometers that measure Earth’s magnetic field, crucial for accurate heading and positioning data.
Updated every five years, the WMM is a globally recognized mathematical representation of Earth’s magnetic field. The latest version, released in December 2024, ensures precise heading and positioning corrections to account for ongoing geomagnetic changes.
NDAA-Compliant UAV Now integrated with ArcGIS Flight
Esri now supports the Astro Max UAV in its ArcGIS Flight application. The Astro Max is the first Blue UAS-cleared and NDAA-compliant UAV to integrate with Esri’s platform.
The Astro Max, developed by Esri partner Freefly Systems, adheres to the security and performance standards set by the National Defense Authorization Act and the Defense Innovation Unit’s Blue UAS initiative. This industrial UAV is designed to enhance the capabilities of government and enterprise users utilizing ArcGIS Flight.
Autonomous Swarm Control Controls various autonomous platforms
The Autonomous Multi-Domain Operations Resiliency Platform for Heterogeneous Unmanned Swarms (AMORPHOUS) software features a single-user interface to operate thousands of autonomous assets simultaneously. Designed with an open architecture, this software enables the U.S. and allied militaries to control a mix of uncrewed platforms, payloads and systems.
AMORPHOUS includes an intuitive and distributed command-and-control interface to give operators the flexibility to conduct a wider array of intricate military missions. This collaborative autonomy at scale will provide warfighters with a decisive overmatch capability.
L3Harris is developing prototypes using the AMORPHOUS architecture on contracts for the U.S. Army and the Defense Innovation Unit. AMORPHOUS has demonstrated flexibility and interoperability by controlling multiple, separate assets across multiple vehicle types operating in different domains during government-managed tests.
AMORPHOUS supports decentralized decision-making, which enables individual, uncrewed assets to perform tasks autonomously and make real-time tactical decisions inside the network.
Advanced Counter-UAV Radar Multi-console radar control and display system
Cambridge Pixel has developed a radar control and display system for Weibel Scientific’s XENTA surveillance radar, which is designed for modern air defense and counter-unmanned aerial systems (C-UAS) applications.
The XENTA radar includes 3D target tracking, continuous target illumination and synthetic receiver beamforming. It is available in two configurations: the XENTA-M for short-range air defense and the XENTA-C for C-UAS operations.
The system is designed to work seamlessly with third-party command-and-control systems, enhancing operational efficiency.
Cambridge Pixel’s library of radar processing software allows users to develop a tailored radar controller specific to the XENTA radar’s requirements. Enhancements were made to existing functionalities, such as improved MIL-STD-2525 overlay graphics and support for dual-redundant operator consoles.
The XENTA radar system can detect small UAVs at distances exceeding 7 km and classify them beyond 5 km. This capability makes it suitable for various applications, including airport security, border control, critical infrastructure protection and event security.
The Pelican 2 agricultural spray UAV has an expanded 300-liter payload capacity and can cover up to 5.3 ha/hr.
It incorporates several technological enhancements designed to meet the demands of agriculture applications. The aircraft features an upgraded four-motor electric propulsion system, a wider 18-m spray swath and advanced lidar and radar systems for fully autonomous day-and-night spraying. These improvements aim to increase efficiency and precision in aerial application while reducing operational costs for farmers.
The Pelican 2’s airframe and structural components are constructed from carbon fiber composites, corrosion-resistant metallic components and 3D-printed assemblies.
A roundup of recent products in the GNSS and inertial positioning industry from the December 2024 issue of GPS World magazine.
Mapping
Photo: SPH Engineering
GPR System For terrestrial and airborne applications
The Zond Aero 500 NG is a versatile ground penetrating radar (GPR) system designed for both terrestrial and drone-mounted surveys, suitable for applications such as utility scanning, sinkhole detection, glaciology and geological studies. It operates in dual mode, allowing for ground-based and airborne surveys, enhancing data collection flexibility. Key specifications include a center frequency of 500 MHz, an operating bandwidth of 200 MHz – 900 MHz, a sampling rate of 25,600 samples per second and a scan rate of 50 scans per second, with depth penetration up to 4 meters in average soil conditions. The system features advanced electronics for real-time data collection, which can significantly improve the signal-to-noise ratio. It is compatible with DJI Matrice 300/350 UAVs for airborne applications.
Streamlined Lidar Mapping YellowScan’s Surveyor Ultra integrated with DeltaQuad Evo
Integrating YellowScan’s Surveyor Ultra with the DeltaQuad Evo platform allows users to collect high-precision, high-density data across 1,200 hectares in a single flight while simultaneously capturing lidar and RGB data.
DeltaQuad Evo’s long-range flight capabilities and efficient vertical take-off and landing (VTOL) design, paired with the Surveyor Ultra’s lidar technology, allow users to streamline their workflows to reduce time spent in the air and on post-processing tasks, making it particularly beneficial for large infrastructure projects, forestry analysis and environmental monitoring. The system can be used for surveying, construction, forestry and environmental research.
Airborne Mapping System With a ‘cross-fire’ scan pattern
The VQ-1560 III-S is a dual-channel laser scanning system designed for airborne mapping applications. Its “cross-fire” scan pattern allows for simultaneous forward and backward viewing at the edges of the swath, along with a nadir view in the center. This configuration optimizes point distribution for effective target sampling. With pulse repetition rates reaching up to 4.4 MHz, the VQ-1560 III-S can operate at altitudes of up to 1,600 m above ground level (AGL). At a lower pulse repetition rate of 560 kHz, it can function at altitudes as high as 3,900 m AGL.
The system features inertial measurement unit (IMU) and GNSS integration, with the option to include one or two high-resolution RGB/NIR cameras. It is ideal for professionals in fields such as urban planning, forestry and environmental monitoring.
This bathymetric lidar system is designed for coastal and inland water mapping. It combines high-resolution topographic and bathymetric capabilities, allowing for seamless data collection across land and sea. It can be used for coastal zone management, environmental monitoring, infrastructure planning and more.
Fathom delivers data quickly by leveraging real-time quality control with Onboard and scalable processing with a CARIS workflow. It also includes a built-in topographic lidar and a multispectral camera for coastal surveys at a coverage of 50 km2/hour.
The Geode Grip is a mounting accessory featuring a specialized bracket. It allows users to securely attach smartphones directly to Juniper’s Geode GNSS receivers, offering an integrated and streamlined data collection solution.
The Geode Grip is a tool designed for professionals in surveying, mapping and geographic information systems (GIS) to enhance mobile data collection. It replaces the traditional survey pole with a handheld setup that aims to improve ergonomics. It is ideal for field projects that require precise location data and mobile data collection, such as environmental research, land surveying, agriculture and infrastructure engineering.
New Product Bundle For high-accuracy GNSS applications
Quectel Wireless Solutions has unveiled a new product bundle designed to facilitate the development of high-accuracy GNSS applications. The bundle includes the LG290P GNSS module, which is a quad-band, multi-constellation device capable of receiving signals from various satellite systems, including GPS, GLONASS, Galileo, BDS, QZSS and NavIC. The LG290P is engineered for high precision and supports RTK positioning, allowing for centimeter-level accuracy even in challenging environments. It can be used in diverse applications, such as autonomous vehicles, precision agriculture and surveying.
In addition to the LG290P module, the bundle includes options for either the YEGN103W8A geodetic antenna or the YEGD006U1A patch antenna. Both antennas are designed to operate within the same frequency bands as the GNSS module and are compliant with environmental regulations such as RoHS. This pre-integrated solution simplifies developers’ procurement and integration process by providing a one-stop solution that combines antennas with GNSS modules and RTK correction services.
Lidar Camera Payload For surveying and mapping applications
The RESEPI Ultra LITE is a lightweight payload combining lidar and camera technology for advanced surveying and mapping applications. The system integrates the XT-32 lidar scanner to offer users advanced data accuracy and point density across various operational modes.
It has a compact design with a 5MP colorization camera, making it ideal for small unmanned aerial systems (SUAS) with strict volume constraints. It can be used for aerial and ground-based applications, including utility mapping, construction volumetrics, precision agriculture, forestry, site surveying and mining. Designed for seamless integration, the system is compatible with a wide range of platforms such as Freefly, WISPR, DJI, Sony and mobile setups. Inertial Labs’ proprietary SnapFit adapters ensure quick and secure mounting to enhance the system’s adaptability.
The Leica GS05 is a compact and lightweight GNSS smart antenna designed for surveying tasks, featuring calibration-free tilt compensation. This robust device allows for accurate measurements even when the survey pole is tilted up to 30°, enhancing data collection in challenging environments. Its integration with Leica Geosystems’ portfolio, including Leica Captivate software and total stations, seeks to maximize efficiency. The GS05 can function as both a base and an RTK rover, supporting single base stations and RTK networks such as Leica SmartNet.
Intrepid is a GNSS/INS system integrated with the SeaBat T20-ASV processor and includes a compact IMU and two GNSS antennas, ensuring reliable and precise positioning.
It can automatically stream data to third-party software. This eliminates the need for manual sensor interfacing and reduces downtime. The Intrepid GNSS/INS benefits users in marine surveying applications by providing the precise navigation necessary for operational efficiency. Its intuitive design allows for simple configuration.
Miniature MEMS Sensor-Based IMU Can withstand high shock and vibrations
The KERNEL-201 features three-axis MEMS accelerometers and gyroscopes that offer ultra-low noise, high bandwidth and minimal latency. These characteristics make it ideal for applications such as pointing, stabilization and navigation in systems where performance and size are critical. Its volume of 0.38 cubic inches offers a high dynamic range.
Fully calibrated and temperature-compensated, the unit offers consistent, precise measurements even in challenging environments. It features an in-run bias stability of up to 0.7 deg/hr for gyroscopes and 0.005 mg for accelerometers, along with a low angular random walk (ARW) of 0.065°/√hr and velocity random walk (VRW) of 0.015 m/sec/√hr.
The unit is designed to withstand high shock and vibration while maintaining peak performance, making it suitable for a wide range of challenging applications. The KERNEL-201 can be integrated into various high-level systems, such as motion reference units (MRUs), GPS-aided inertial navigation systems (INS) and attitude and heading reference systems (AHRS). It offers continuous built-in testing (BIT), customizable communication protocols and flexible power options.
Smart Choke Antenna Offers comprehensive GNSS signal reception
The VCS6000XF full band smart choke antenna is engineered for CORS applications. It combines Tallysman Verachoke antenna elements with Septentrio’s Mosaic X5 full-band receiver to offer an integrated solution for OEM CORS systems.
The VCS6000XF offers comprehensive GNSS signal reception, including GPS/QZSS L1/L2/L5, GLONASS G1/G2/G3, Galileo E1/E5a/E5b/E6/E5 AltBoc, BeiDou B1/B2/B2a/B3, NavIC L5, SBAS and L-Band correction services.
The antenna features a 0.5 mm phase center variation and utilizes Calian’s eXtended filtering for near-band signal interference mitigation. The integrated Septentrio Mosaic X5 receiver provides capabilities such as anti-jamming, anti-spoofing, scintillation mitigation and receiver integrity by combining the antenna and receiver in the choke ring antenna.
On Dec. 20, ComNav Technology launched its Venus Laser RTK, a GNSS receiver with a millimeter-level laser that enables rod-less surveying. This product is a part of ComNav’s Universe Series of GNSS receivers.
Venus Laser RTK comes with an inertial measurement unit (IMU), which can be used in its traditional mode, with a range pole or in laser mode, which does not require a range pole, enabling GNSS surveying beyond typical limitations. In traditional mode, it has tilt compensation up to 60 degrees with an accuracy of 2.5 cm; in laser mode, it has the same tilt compensation but an accuracy of 5.5 cm.
This GNSS receiver is powered by a SinoGNSS K8 high-precision module, capable of up to 1,590 channels. It can survey using GPS, BDS-2, BDS-3, GLONASS, Galileo, QZSS, and SBAS constellations.
Other features include Bluetooth connectivity, more than 20 hours of battery life, and the fact that it is dust and waterproof. Venus Laser RTK can also withstand harsh environments and is designed to survive more than a two-meter drop.
First, happy New Year to everyone. As a follow up to my November 2022 column on the geodesy crisis, I’d like to highlight that the National Geospatial Advisory Committee (NGAC) of the Federal Geographic Data Committee (FGDC) just adopted a resolution on the need for the federal government to understand and aggressively address the US geodesy crisis. See below. This is great news and, hopefully, the FGDC and others will follow up with discussions with other organizations such as the Office of Science and Technology Policy (OSTP) in the White House.
Now for this month’s column. Last year the National Geodetic Survey (NGS) started suppressing height information in Southeast Texas (see my April 2021 and June 2021 columns). See below for more information. Last year’s columns highlighted the potential effects of subsidence on published heights in the Houston, Texas, region which implied that most of the published heights, which are based on older surveys in the region, are not current or accurate. At the time of NGS’s announcement, only 28 marks with orthometric heights were published on NGS datasheets in southeast Texas. Click here for more information and see below.
This column will provide an update on the following: the current set of published orthometric heights in the southeast Texas region based on recent GNSS surveys performed during 2021 and 2022, NGS’s rules for estimating and publishing GNSS-derived orthometric heights using OPUS Projects, and the status of NGS’s GPS on Benchmarks program.
I always retrieve the latest published coordinates using NGS’s datasheet website routine. See the graphic below of the published NAVD 88 orthometric heights as of Nov. 20, 2022 (I used NGS’s monthly archive by State retrieval option). There are currently 147 marks with published orthometric heights within NGS’s definition of the southeast Texas zone of subsidence. From mid-October to early December of 2022, another GNSS project sponsored by the Harris-Galveston Subsidence District (HGSD) was performed in the region. In this project, 154 marks in the southeast Texas region were observed. The results of this project should be published and disseminated by NGS in the spring of this year.
Latest Published Heights in Southeast Texas. Image: Dave Zilkoski
The current version of OPUS projects allows the user to estimate NAVD 88 orthometric heights, providing they adhere to NGS’s recommendations and procedures. A presentation titled “Heights Suppression in Southeast Texas” by Boris Kanazir, NGS, provides guidance on estimating NAVD 88 orthometric heights using OPUS projects.
See below for the requirements for number of occupations, duration of each session, and the spacing of marks with valid NAVD 88 published orthometric heights.
The requirements include:
a minimum of two NAVD 88 control marks per new mark observed
a mark must be observed twice on different days and at different times of the day
the maximum distance between new marks and NAVD 88 control is between 30-50 km, based on session duration
I like to think of this concept as drawing Venn diagrams around marks. See below for an example of the concept.
Venn Diagram. Image: Dave Zilkoski
So, what does this mean in the real world? The map below demonstrates the concept in the Houston-Galveston, Texas, region. As shown, many of the 30 km circles overlap, indicating that in these overlapping areas there are two CORS with published NAVD 88 orthometric height. This means that a user can occupy a mark for two hours and use the data from two CORS as NAVD 88 control. Of course, the mark must be occupied twice for redundancy.
30 km Radius Circles around SE TX CORS with NAVD 88 Heights. Image: Dave Zilkoski
Increasing the radius to 40 km includes more overlapping areas. This means that the user would have more overlapping areas with two CORS that have published NAVD 88 orthometric heights, but the marks would have to be occupied twice for at least four hours each time.
Image: Dave Zilkoski
Now, when you apply a 30 km radius around the current 147 marks that have published NAVD 88 heights, most of the region has overlapping areas (see below). This means that the user could occupy two of the NAVD 88 marks along with any new marks for at least two hours.
30 km Radius Circle Around all 147 NAVD 88 Marks in SE TX. Image: Dave Zilkoski
The previous figure may seem confusing because of all the circles. In the example below, based on only two marks, 11 marks fall inside the overlapping sections of the two circles. They could be established using the two NAVD 88 control marks that were used to make the 30 km circles.
Example of Two 30 km Radius Circles. Image: Dave Zilkoski
As depicted in my June 2021 column, the Houston-Galveston, Texas, region is subsiding. The map below provides the latest estimates of subsidence in Houston-Galveston, Texas, region based on a Harris-Galveston Subsidence District (HGSD) report “Determination of Groundwater Withdrawal and Subsidence in Harris and Galveston Counties – 2021“ published in 2022. Most of the rates are small, less than 0.5 cm/year, but some are greater than 1 cm/year. This means that some marks may have subsided around 5 cm in five years.
Estimate of subsidence in SE TX. Image: Dave Zilkoski
The surveying and mapping community has done a tremendous job of increasing the number of published heights in the Houston-Galveston, Texas, region (from 28 to 147). That said, the amount of movement in the Katy region is more than -2 cm/year (see box titled “Estimate of Subsidence in the Katy Area”). That means, the marks in this area may subside 10 cm in five years.
Estimate of subsidence in the Katy Area. Image: Dave Zilkoski
Heights that change 10 cm cannot be considered NAVD 88 control marks. NGS’s OPUS Projects User Guide states the following about superseding a mark’s coordinates:
“Users should review the newly adjusted coordinates on user marks to decide whether they recommend that the user mark be re-determined (re-published). Typically, this would happen if the coordinates have shifted by more than 2 centimeters horizontally or 4 cm vertically from the published coordinates marks.”
Therefore, these marks in the Katy region may not be valid NAVD 88 control marks in about two years. Even marks that are subsiding at 1 cm/year may not be valid NAVD 88 control marks in about four years.
The community needs to maintain these marks to account for movement in the region. As previously stated, the Harris-Galveston Subsidence District (HGSD) has marks, denoted as PAMS, that are occupied continuously for a week several times throughout the year. These PAMS and the CORS in the area could be used to estimate crustal movement rates and maintain a set of valid, published heights in the region. See the boxes titled “ArcGIS Online HGSD Subsidence Rates” and “PAM 98 Subsidence Rate.” Additionally, the Texas Spatial Reference Center (TSRC) could provide the appropriate services to help maintain the published coordinates. The TSRC website states, “The technical mission of TSRC is to conduct basic and applied research contributing to NGS’s national Height Modernization program. TSRC is a repository for information used by researchers to develop improved understanding of elevation, geodetic and vertical datums in the state of Texas. The TSRC goal is to re-establish accurate evaluations throughout Texas in cooperation with qualified geospatial scientists, professional engineers, and professional land surveyors.”
In 2025, NGS will replace all three North American Datum of 1983 (NAD 83) frames and all vertical datums, including the North American Vertical Datum of 1988 (NAVD 88), with four new terrestrial reference frames and a geo-potential datum. As stated in my previous columns – April 2022, April 2021, June 2020 – the new reference frames will rely primarily on Global Navigation Satellite Systems (GNSS) as well as on a gravimetric geoid model. These new reference frames will be easier to access and to maintain than the current NSRS. NGS will provide tools similar to the OPUS suite of routines that will facilitate users’ ability to submit data to NGS to maintain and publish survey marks. See the graphic below.
I would like to highlight that NGS has extended the cut-off date for submitting data for use in the 2022 Transformation Tool. The new cut-off date is Sept. 30 (see below).
This column provided an update on the current set of published orthometric heights in the southeast Texas region based on recent GNSS surveys performed during 2021 and 2022, NGS’s rules for estimating and publishing GNSS-derived orthometric heights using OPUS Projects, and the status of NGS’s GPS on Benchmarks program. Additionally, it highlighted that the NGAC of the FGDC adopted a resolution on the need for the federal government to understand and aggressively address the United States geodesy crisis. This is a good step forward, and I hope that others will follow up with discussions with other organizations such as the OSTP in the White House. Finally, “The Geodesy Crisis” white paper can be downloaded from the American Association for Geodetic Surveying (AAGS) website.
I hope everyone has a happy new year filled with optimism, happiness and a generous amount of enthusiasm and fun.
With the last generation of trained geodesists either retired or getting ready to retire, we are at a critical stage of not being able to meet the geospatial needs of the future,” wrote David B. Zilkoski in his Nov. 1 Survey Scene column on our website. Few people, he pointed out, realize our $1 trillion geospatial economy — from precision agriculture to smart cities, from UAVs to location-based services — depends on geodesy. A collapse of geodesy would also harm our efforts to monitor rapid changes in the Earth’s surface due to sea-level rise, the deformation of tectonic plates, and temporal changes in the Earth’s water reservoirs.
Federal agencies, Zilkoski recalled, used to send staff to be trained in geodesy because they needed geodesists for such significant projects as the readjustment of the U.S. national horizontal and vertical geodetic networks. Now, while U.S. federal agencies still require this expertise to develop and refine geodetic models and tools, so do major U.S. companies for everything from routing delivery trucks to controlling earth-moving equipment to guiding tractors.
A January 2022 white paper by Mike Bevis and others titled “The Geodesy Crisis” reported that China has more geodesists than the rest of the world combined, and the number of Ph.D. geodesists in the entire Department of Defense, including the National Geospatial-Intelligence Agency (NGA), is approaching zero.
I discussed the geodesy crisis with Everett Hinkley, who works for the federal government, serves as a subject-matter expert on several high-level boards, and dubs himself a “concerned citizen geodesist.”
Matteo Luccio: How did we get here? Was it due in part to the success of GPS?
Everett Hinkley: The factors include:
1. In the early 1990s, the U.S. government largely disinvested in academic research and academic sponsorship in geodesy. Without student sponsorship, the few university programs that produced geodesy experts withered on the vine.
2. Math and science skills in U.S. public schools have declined.
3. More subtly, there was a subliminal and misguided notion that “Now that we have GPS, why do we need to continue to improve our geodetic models?”
ML: If left unaddressed, in what fields or applications will the crisis manifest first?
EH: In areas where precise positioning is critical: cadastral mapping, self-driving vehicles, sea-level rise (a growing danger) and others. The effects will be felt incrementally, at least at first.
ML: Are some geographic regions of the United States particularly vulnerable to some effects of the crisis due to high subsidence, drift or other ground movements/changes?
EH: Yes. The two areas that will show the first signs of divergence between actual and assumed locations are those that are tectonically active (both horizontally and vertically) and low-lying coastal ones.
ML: Besides funding, what could entice college students to enter the field?
EH: Basic marketing is needed by the geospatial community at large. We need to reach out to math “stars” in high school and let them know that pursuing a career in geodesy will guarantee them employment after graduating from college.
Geodesy without math equations: Is that possible? The answer is no, but basic geodetic concepts can be described without using complex math equations.
My previous column addressed the geodesy crisis in the United States. (See also this.) The newsletter was highlighted on LinkedIn (thanks, Jay); more than 235 individuals reacted to the post and there were 25 reposts.
I’m pleased so many people are interested in highlighting the discussion of the inverted pyramid. One reader of my column asked for material for non-geodesists to obtain a better understanding of geodetic concepts.
Geodesy does involve advanced mathematics that may not be familiar to some people. That said, there are various online lessons and tutorials that describe the basic concepts without using complex math equations.
As mentioned in my previous column, geodesy is involved with anything related to positioning. For example, have you ever wondered how your phone appears to know where you are on a digital map while you’re walking or driving down the street? Geodesy provides the foundation for all geospatial products and services.
Image: Dave Zilkoski
Location on a Map
A goal of mine has always been to get individuals (young and old) interested in obtaining a better understanding of geodesy. In my opinion, high schools and colleges should include courses that explain to students how their phones know where they are, why the Earth is not a sphere, how the movement of tectonic plates are measured and why, basic concepts of how satellites orbit the earth, and how geographic coordinates are important to making maps and their use in establishing an accurate geographic information system (GIS).
A good first step is to get high school teachers interested in the topic. When I was employed by the National Geodetic Survey (NGS), a group of us worked with local high school students to map their football field using GPS. They acquired observations in the field, and then downloaded the coordinates into their GIS. The teacher was instrumental in integrating the application into the students’ curriculum.
A reader of my last column suggested I provide concrete, meaningful things to lower the barrier of entry. I’m not exactly sure how to lower the barrier of entry — geodesy does require an individual to have a certain level of mathematical knowledge.
Since I retired from NGS, I have helped homeschool my eight grandkids. The one thing that I’ve found is that young students apparently either “like” math or they “hate” math. At least with my grandkids, there doesn’t seem to be an in between.
At this moment, I don’t believe any of my grandkids will become geodesists; well, actually, there’s still a possibility that one may have a “love for mathematics.” It appears that most students don’t really see a reason to learn math. They can use their phones or calculators to do what they need.
The reader suggested that the geodesy community could publish free, high-quality, web-based resources for the public. The reader made the following suggestions:
A set of 3D-printable designs for rudimentary survey tools; alternatively, how to acquire/build the tools in the most economical way possible. Even something that would be considered a “toy” that can be given to a child would be good.
A list of software tools (preferably open source) relevant to the subject and how to use them in this context.
Introductory material intended for young audiences.
This column will provide some free online lessons and tutorials that describe the concepts associated with geodesy and surveying. Some of the online videos are at a level for young audiences, and some are aimed at individuals with more advanced education. Let’s start with the young audience.
Lessons for Kids
The website “Get Kids into Survey” provides materials focused on kids. The website states: “Bringing young people into the exciting world of survey through pioneering content and engaging experiences.” See the boxes titled “Get Kids into Survey Website,” “Get Kids into Survey Website – Poster Page,” and “Get Kids into Survey Website – World Without Surveyors Poster.”
Get Kids into Survey Website
Screenshot: Get Kids lnto Survey
Get Kids into Survey Website – Poster Page
Screenshot: Get Kids into Survey
Get Kids into Survey Website – World Without Surveyors Poster
Screenshot: Get Kids into Survey
The GPS.gov website has lessons describing GPS that are designed for kids. One lesson introduces the concept of GPS trilateration. The lesson explains how GPS positioning works on two basic mathematical concepts:
trilateration, which literally means positioning from three distances, and
the relationship between distance traveled, rate (speed) of travel, and amount of time spent traveling.
This was developed by NGS for a National Science Teachers Association Conference. You can download both the instructions and map.’
GPS Trilateration Lesson
Screenshot: GPS.gov website
The following are several videos that describe the concept of trilateration.
This video explains trilateration and how the GPS ranges (distances from the satellite to the receiver) are computed.
This video uses distances on a map to describe trilateration.
Here is a detailed description of trilateration and why you need the fourth satellite.
Now, let’s look at some free online lessons and tutorials that describe the concepts associated with geodesy. As previously stated, some of the online videos are at a level for young audiences, and some are aimed at individuals with more advanced education. Most of them describe the concepts using diagrams with narratives, and without complex math equations. NGS provides a number of videos that can be downloaded here.
NGS, in partnership with the COMET program, has developed a series of self-paced lessons on geodetic and remote sensing topics. Users have to create a free user account to gain access to the courses. Users will have the option of printing out a certificate upon successful completion of a quiz at the end of each lesson.
The lessons are rated by skill level ranging from “Suitable for Non-Scientists” to “Requires some Prior Knowledge of the Topic.”
The COMET program provides teaching and training resources for the geoscience community. All of the content is completely free, but an account does need to be created. The COMET program is part of the University Corporation for Atmospheric Research (UCAR) Community Programs.
NGS Online Lessons
Screenshot: NGS Website
NGS and COMET Educational Videos
NGS also has a website that contains educational videos. Again, NGS, in partnership with the COMET Program, has developed short videos on topics related to geodesy and mapping.
NGS Educational Videos
Screenshot: NGS Website
This link provides a tutorial on “Why is geodesy the framework behind all mapping and navigation?” The article states. “If you think about it, the whole field of geomatics lies on the shoulders of geodesists. Because it’s really geodesy that is the framework behind all surveying, mapping and navigation.”
What Is Geodesy?
Screenshot: Gisgeography Website
NASA’s Eratosthenes Estimating the Circumference of the Earth by Looking Down a Well
NASA offers a video titled “Looking Down a Well: A Brief History of Geodesy.” This video explains how it all started when Eratosthenes estimated the circumference of the Earth by looking down a well. It highlights how, over time, the field of geodesy has expanded and evolved dramatically, and how NASA uses technology such as radio telescopes, ground surveys, and satellites to contribute.
NASA’s Video on Looking Down a Well
UNAVCO Measures Plate Tectonics with Geodesy
UNAVCO, a non-profit university-governed consortium, facilitates geoscience research and education using geodesy. UNAVCO has a video that describes the tectonic plates and how geodesists measure their movements. Another UNAVCO video describes what geodesy actually is, as well as geodesy’s application in our everyday lives (UNAVCO’s 2017 USIP geoscience video production). Visit UNAVCO’s website to learn more about its mission.
Geodetic Software Tools
NGS provides tools that focused on meeting the needs of the surveying and mapping community. A few may be of interest to non-geodetic individuals. A map tool can be used to locate marks near someone’s location.
Production NGS Map
Screenshot: NGS Website
UNAVCO also has interactive tools that may be of interest to geospatial users. See the boxes below titled “UNAVCO Interactive Tools” and “UNAVCO Spotlight.”
Screenshot: UNAVCO Website
Screenshot: UNAVCO Website
3D Printer of Surveying Equipment
Now, let’s address the 3D printing of surveying equipment and tools. I’m not familiar with using a 3D printer, but I found several websites that provide information on surveying equipment. Some of the sites provide free information and others charge for their services. See the websites 3D Printer of Total Station and 3D Printer of GNSS Equipment.
3D Printer of Total Station
Screenshot: CULTS Website
3D Printer of GNSS Equipment
Screenshot: 3dmdb Website
I’m pleased a lot of people are interested in highlighting the discussion of the inverted pyramid. As commented by several individuals in the LinkedIn responses, the surveying and remote sensing (which includes photogrammetry) communities are experiencing the same crisis as geodesy. In my opinion, they are all related, because the surveying and mapping community provides tools other disciplines use.
As stated in my last column, the surveying and mapping community can do the following to help:
actively market geodesy in high schools as a rewarding career for the math stars before college entry
build back, support and sponsor geodesy programs at select universities; this support needs to be strategic with backing from the highest levels of the U.S. government
encourage U.S. government support in the form of grants, professional development of staff, and research collaborations/affiliations.
As previously mentioned, one of my goals has always been to get individuals (young and old) interested in obtaining a better understanding of geodesy. I hope this column helps to whet the appetite of some individuals to obtain a better knowledge of geodesy. Maybe even some high school and college teachers will introduce geodetic concepts in their lectures.
Writing about the geodesy crisis is a good first step, but we need to find champions that can influence high school and university teachers and administrators, federal and state government program managers, and congressional representatives.
Please feel free to email me at [email protected] if you have suggestions on how to lower the barrier of entry into the world of geodesy.
Trimble and Exyn Technologies are developing multi-platform robotic autonomy for complex, GPS-denied environments. (Photo: Trimble)
Trimble and Exyn Technologies are working on a proof of concept for a fully autonomous surveying solution for construction.
The solution will integrate the Boston Dynamics Spot robot, the ExynPak powered by ExynAI, and the Trimble X7 total station. It will enable fully autonomous missions inside complex and dynamic construction environments, which can result in consistent and precise reality capture for production and quality-control workflows.
Autonomous robots powered by ExynAI can sense and avoid obstacles, dynamically adapting to the complexity of construction environments. To ensure safety and efficiency, the ExynPak integrates with a robot, supporting Level 4 of autonomous exploration missions without requiring the robot to “learn” about its environment beforehand.
A surveyor can define a 3D volume for a mission, and then the integrated robotic solution handles the complexities of self-navigation without needing a map, GPS or wireless infrastructure.
The integration of the Trimble X7 provides high-speed, high-accuracy 3D laser scanning to capture the state of the environment. The captured data can be uploaded to the Trimble Connect collaboration platform and shared with project stakeholders for further analysis, including a comparison to building information models (BIM) and previous scans to monitor quality and progress. The result is a detailed and accurate map collected with minimal human intervention and risk.
Exyn and Trimble will be demonstrating their technology at the Trimble Dimensions+ Conference Nov. 7-9 in Las Vegas.
The D70 is the latest release in the Boreas digital FOG (DFOG) series, offering a new performance grade with superior accuracy, exceptional stability and reliability. The technology is suited to surveying, mapping and navigation across subsea, marine, land and air applications.
“We are thrilled to expand the Boreas series with the D70. It’s a system that will provide additional flexibility in the Boreas family, making ultra-high accuracy inertial navigation far more affordable than with previous FOG INS systems,” said Xavier Orr, CEO and co-founder of Advanced Navigation. “This patented technology opens the possibility for adopting FOG INS systems across a much broader range of vehicular applications, particularly autonomous vehicles and aircraft where weight and size are at a premium.”
Boreas D70 combines closed-loop DFOG and accelerometer technologies with a dual-antenna real-time kinematic (RTK) GNSS receiver. These are coupled with Advanced Navigation’s artificial-intelligence-based fusion algorithm to deliver accurate and precise navigation.
The system features ultra-fast gyrocompassing, acquiring and maintaining an accurate heading under demanding conditions. While the D70 does contain a GNSS receiver, it is not required for gyrocompass operation.
Based on the company’s DFOG technology, the D70 delivers a 40% reduction in size, weight, power and cost (SWaP-C) when compared to systems of similar performance.
0.01° roll and pitch
0.1° secant latitude heading (gyrocompass)
0.01°/hour bias instability
10 mm position accuracy
The Boreas Series
The Boreas DFOG series features ultra-fast gyrocompassing and can acquire heading, either stationary or dynamically, in less than two minutes. The gyrocompassing allows the system to determine a highly accurate heading without any reliance on magnetic heading or GNSS.
The technology stems from Advanced Navigation’s artificial intelligence sensor-fusion algorithm allowing the system to extract significantly more information from the data. It is designed for control applications, with a high level of health monitoring and instability prevention to ensure stable and reliable data.
Advanced Navigation designed Boreas from the ground up for reliability and availability. The hardware and software are designed and tested to international safety standards and have been environmentally tested to MIL-STD-810. The system achieves a mean time between failure (MTBF) of more than 70,000 hours.
Additional features of the Boreas D70 include Ethernet, CAN and NMEA protocols, as well as disciplined timing via a PTP server and 1 PPS. An embedded web interface provides full access to all of the device’s internal functions and data. Internal storage allows for up to 1 year of data logging.
About DFOG Technology
DFOG is patented technology, which has been developed over 25 years involving two research institutions. DFOG was created to meet the demand for smaller and more cost-effective FOGs, while increasing reliability and accuracy.
The first generation of FOG, made available in 1976, used analog signals and analog-signal processing. The second generation was developed in 1994 and is still used to this day. It improved upon the first generation with a hybrid approach using an analog signal in the coil with digital signal processing.
In 2021, FOG evolved into DFOG. This third generation of FOG sets itself apart by being completely digital, providing higher performance and reliability while enabling a 40% reduction in SWaP-C.
To achieve this, three different yet complementary technologies have been developed to improve the capabilities of FOG.
Digital Modulation Techniques. DFOG uses a specially developed digital modulation technique passing spread spectrum signals through the coil. The new digital modulation technique introduced in DFOG technology allows in-run variable errors in the coil to be measured and removed from the measurements. This makes DFOG significantly more stable and reliable than traditional FOGs. It also allows a smaller FOG with less coil length to achieve the accuracy of one with a longer coil.
Revolutionary Optical Chip. By integrating five sensitive components into a single chip and removing all the fiber splices, the size, weight and power are reduced considerably while significantly improving reliability and performance.
Specially Designed Optical Coil. DFOG employs a specially designed closed-loop optical coil, developed to take full advantage of the digital modulation techniques. The design allows for optimum sensing of in-run variable coil errors using the new digital modulation technique. It also provides a very high level of protection for the optical components from shock and vibration.
TOPODRONE, a Swiss-based designer and manufacturer of high-precision lidar equipment for installation on drones, vehicles and backpacks, launched AQUAMAPPER, a UAV-based solution for bathymetric surveying and marine construction.
AQUAMAPPER contributes to a complete set of photogrammetry, lidar and bathymetry surveying solutions from TOPODRONE. The product, compatible with the DJI Matrice 300 RTK, provides a combination of high-speed efficiency (up to 14 km/h) and accuracy mounted on a UAV. The application areas include an open sea bathymetric survey up to 100m depth, quantity survey and calculation of sediments and periodic maintenance survey of storage pools.
Photo: TOPODRONE
The new data-collecting device has been successfully used alongside TOPODRONE’s LiDAR ULTRA equipment for airborne surveying at a highway construction project in one of the toughest terrains in Romania, EU, including 7 tunnels, 24 bridges and 18 viaducts. The project was performed by the Romanian company GRAPHEIN TOPO SA to deliver a full digital twin of a studied area.
Photo: TOPODRONE
The TOPODRONE LiDAR ULTRA on board a DJI M300 drone was used to capture laser scanning data from an altitude of 100 m to 120 m over rugged terrain forest area to cover a corridor 32 km long and 400 meters wide in 14 flights while AQUAMAPPER connected to the same DJI M300 drone performed a bathymetric survey over six river crossings.
“The key advantage of the new bathymetric equipment from TOPODRONE is the ability to capture a riverbed with centimeter-level accuracy with high speed in fully automatic mode and without using any boat,” said Andrei Sueran of GRAPHIEN TOPO SA. “The combination of an echosounder, GNSS and inertial measurement system helps to get accurate results after data post-processing.”
On Aug. 5, the National Geodetic Survey (NGS) stated it will be updating the NOAA CORS to be aligned with the latest International Terrestrial Reference frame, ITRF2020 (see below). As stated in the announcement, NGS will soon compute a third multi-year continuously operating reference station (CORS) solution, MYCS3.
The last multi-year CORS solution, MYCS2, was performed by NGS in 2019. I discussed the MYCS2 in my February 2019 and April 2019 columns. This new multi-year CORS solution will be important to the 2022 modernized National Spatial Reference System (NSRS), because NGS will establish a strict mathematical relationship between the 2022 NSRS frames and the ITRF2020 frame. This will allow direct access to the NSRS (NOAA Technical Report NOS NGS 67).
NGS Aligns National System to Global Reference Frame
August 5, 2022
The International Global Navigation Satellite System (GNSS) Service, which provides GNSS data products globally, recently released a new GNSS-only version of the International Terrestrial Reference Frame. This provides GNSS users access to the reference frame through coordinate functions for a global set of reference stations. In response, NGS will soon compute the multi-year Continuously Operating Reference Station (CORS) Solution 3, which will modernize the National Spatial Reference System. Aligning the National Spatial Reference System with the updated global reference frame will allow greater access for the global community of scientists, educators, and commercial users of location science.
For more information, contact: Phillip McFarland
As in the past, the multi-year CORS solution will mean that the NOAA CORS coordinates will be updated to be consistent with the latest International Terrestrial Reference Frame of 2020 (ITRF2020). The International GNSS Service provides information about its GNSS products and services. Readers can find information on the latest International Terrestrial Reference Frame 2020 here. This column will provide basic information on the ITRF2020. Please note: NGS stated that it will soon start computing the third multi-year CORS solution, but — as of October — all NOAA CORS coordinates are still based on MYCS2 and provide coordinates in ITRF2014 epoch 2010.00 and NAD 83 (2011, MA11, PA11) epoch 2010.00. As in the past, NGS will provide advance notice before publishing the results of its third multi-year CORS solution.
A document on the ITRF website stated the ITRF2020 is expected to be an improved solution compared to the previous solution, ITRF2014. It listed several innovations introduced in the ITRF2020 processing.
ITRF2020 is the new realization of the International Terrestrial Reference System. Following the procedure already used for previous ITRF solutions, the ITRF2020 uses as input data time series of station positions and Earth Orientation Parameters (EOPs) provided by the Technique Centers of the four space geodetic techniques (VLBI, SLR, GNSS and DORIS), as well as local ties at colocation sites. Based on completely reprocessed solutions of the four techniques, the ITRF2020 is expected to be an improved solution compared to ITF2014. A number of innovations were introduced in the ITRF2020 processing, including:
The time series of the four techniques were stacked all together, adding local ties and equating station velocities and seasonal signals at colocation sites;
Annual and semi-annual terms were estimated for stations of the 4 techniques with sufficient time spans;
Post-Seismic Deformation (PSD) models for stations subject to major earthquakes were determined by fitting GNSS/IGS data. The PSD models were then applied to the 3 other technique time series at earthquake colocation sites.
The box below provides a good summary of the International Reference Frame and why it’s important to the scientific community as well as the surveying and mapping community. Readers can download the article from the June 2022 International GNSS Service Issue 4 newsletter. Users also can sign up to receive notices and newsletters from the International GNSS Service.
What is the current rate of sea level rise in different regions of the globe? How does our Earth deform under the effect of plate tectonics, seismic phenomena, or the melting of ice caps? How the Earth’s center of mass is varying? How to determine the position of a point on the surface of a constantly deforming Earth and compare it to positions estimated decades apart? The answers to these fundamental questions for understanding the dynamics of our planet require the availability of a global, long-term stable terrestrial reference frame, but preferably a standard reference so to ensure interoperability and consistency of various measurements collected by sensors on the ground, or via artificial satellites. The International Terrestrial Reference Frame (ITRF) is the standard reference recommended by a number of international scientific organizations, including the International Union of Geodesy and Geophysics (IUGG) and the International Association of Geodesy (IAG) for earth science, satellite navigation and operational geodesy applications. The ITRF is an international effort that is built on the investments of space and mapping agencies, universities and research groups in operating geodetic observatories, archiving and analyzing the collected geodetic observations to derive not only the ITRF, but also critical geodetic products for science and society.
The ITRF integrates and unifies technique-specific reference frames provided by the four IAG’s international services of space geodetic technique (DORIS/IDS, GNSS/IGS, SLR/ILRS, VLBI/ IVS). It is supplied to the users in the form of temporal coordinates of more than 1500 stations, Earth Orientation Parameters, as well as parametric functions describing nonlinear station motions: seasonal signals due to mainly loading effects and post-seismic deformations for sites subject to major earthquakes. It is necessary to regularly update the ITRF (approximately every 5 years) in order to benefit from continuous observations so to improve its accuracy, considering station position temporal variations due to geophysical phenomena.
The ITRF is maintained by a research group at IGN-France and IPGP (Institut de Physique de Globe de Paris), and whose new release called ITRF2020 was published on April 15 and accessible here: https://itrf.ign.fr/en/solutions/ITRF2020. The ITRF2020 brings significant improvements compared to previous achievements: it confirms the estimate of the position of the center of mass of the Earth as it was determined in 2016, but also provides its seasonal variations; it improves the accuracy of the scale of the frame at the millimeter level, which represents a gain in precision of a factor of 8 on the measurement of the size of the Earth (compared to that determined in 2016); it provides a precise quantification of co- and post-seismic displacements caused by devastating earthquakes, such as that of Sumatra in 2004, Chile in 2010 and Japan in 2011. The IAG Services rely on the ITRF to align their geodetic products to it, and therefore disseminate it widely among the various users. In particular, using the IGS products, such as the orbits, allows a universal access in space and time to the ITRF.
As stated in the article by Zuheir Altamimi, ITRF2020 involves IAG’s international services of four space geodetic techniques: DORIS/IDS, GNSS/IGS, SLR/ILRS, VLBI/ IVS. Computing an International Terrestrial Frame is very complex and requires analyses of difference types of geodetic and geophysical data. It is beyond the scope of this column, but online is more detailed technical information.
For this column, I downloaded the station lists from the four space geodetic techniques and provided a few plots that depict the location and velocities of these sites. The box below depicts the location of the space geodetic techniques around the world. As indicated in the plot, some locations have more than one technique collocated at the same site.
Plot of the Four Different Space Geodetic Techniques
Image: Dave Zilkoski
The following plots depict the locations using each space geodetic techniques: GNSS sites, DORIS sites, SLR sites and VLBI sites.
Plot of GNSS Sites
Image: Dave Zilkoski
Plot of DORIS Sites
Image: Dave Zilkoski
Plot of SLR Sites
Image: Dave Zilkoski
Plot of VLBI Sites
Image: Dave Zilkoski
The box below shows the location of the techniques in the conterminous United States.
Plot of the Four Different Space Geodetic Techniques in the CONUS
Image: Dave Zilkoski
The plot below depicts the sites in the state of Alaska.
Plot of the Four Different Space Geodetic Techniques in the Alaska
Image: Dave Zilkoski
The images below depict each of the four space geodetic techniques in the conterminous United States.
Plots of the Space Geodetic Techniques by Technique in the CONUS
Plot of GNSS Sites in CONUS Image: Dave Zilkoski
Plot of DORIS Sites in CONUS (Image: Dave Zilkoski)
Plot of SLR Sites in CONUS (Image: Dave Zilkoski)
Plot of VLBI Sites in CONUS (Image: Dave Zilkoski)
Altamimi’s article on the ITRF2020 stated it is “necessary to regularly update the ITRF (approximately every 5 years) to account for station position temporal variations due to geophysical phenomena.” My February 2022 column discussed the tectonic plates and why is it necessary to account for movement in a geodetic reference frame. As I stated then, coordinates basically change because the Earth’s surface is moving due to the movement of major tectonic plates. See the box titled “What is Tectonic Shift?” for information about why it is called plate movement or tectonic shift. The world’s geodesists understand this and are attempting to manage the changing coordinates by providing a time-dependent component of the international terrestrial reference frame.
The box below depicts the horizontal velocity based on the ITRF2020 velocities (downloaded on 08/12/2022).
Plot of the Horizontal Velocity Vectors based on the ITRF2020 Velocities
Image: Dave Zilkoski
The box below depicts the horizontal velocities in the North America. These vectors look very similar to the velocities reported in my February 2022 column.
Plot of the Horizontal Velocity Vectors in North America based on the ITRF2020 Velocities
Image: Dave Zilkoski
For a comparison to North America vectors, the box below depicts the velocity vectors in Europe.
Plot of the Horizontal Velocity Vectors in Europe based on the ITRF2020 Velocities
Image: Dave Zilkoski
They are similar in magnitude, but not in direction. Once again, looking at the map of tectonic plates, North America is located mostly on the North American plate and Europe is on the Eurasian plate.
Australia is on the Indo-Australian plate and has some fairly large horizontal velocities vectors. See the box below.
Plot of the Horizontal Velocity Vectors in Australia based on the ITRF2020 Velocities
Image: Dave Zilkoski
So, what’s the difference between ITRF2014 and the new ITRF2020? The box below provides the 14 transformation parameters from ITRF2020 to ITRF2014. These transformation parameters have been estimated using 131 stations located at 105 sites. See the box “Plot of the Stations used in the Transformation Parameters from ITRF2020 to ITRF2014” for the location of these stations. Notice that the translation values in X,Y,Z are very small (<1.5 mm) between the two reference frames.
Transformation Parameters from ITRF2020 to ITRF2014
X,Y,Z are the coordinates in ITRF2020, and XS,YS,ZS are the coordinates in ITRF2014.
Plot of the Stations used in the Transformation Parameters from ITRF2020 to ITRF2014
Image: Dave Zilkoski
The transformation parameters from ITRF2020 and past ITRFs are provided in the table below. As indicated in the table, most of the changes in X,Y and Z are very small since ITRF2005.
Transformation Parameters from ITRF2020 to Past ITRFs
As previously stated, the third multi-year CORS solution will be important to the new 2022 modernized National Spatial Reference System (NSRS) because NGS will establish a strict mathematical relationship between the 2022 NSRS frames and the ITRF2020 frame. This will allow direct access to the NSRS, according to NOAA Technical Report NOS NGS 67. Again, there will not be any changes to NGS’s NOAA CORS coordinates due to ITRF2020 until NGS completes its third multi-year CORS solution.
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