Category: Survey

SparkFun launches Iridium antenna

Image: SparkFun Electronics

SparkFun Electronics has released the 2J7426MPz by 2J antenna, a high-performance magnetic mount antenna designed to communicate with the Iridium satellite communication system. It is manufactured with high-quality polycarbonate (PC) and acrylic-styrene-acrylate terpolymer (ASA), a thermoplastic combination that offers strong resistance to UV, moisture, and heat and enhances mechanical properties.

The antenna housing is waterproof to IP69 standards and designed to operate in extremely harsh environments, including those with frequent exposure to water, dust and debris. It has a recommended operational and storage temperature of -40°C to +85°C. The magnetic mount allows for easy installation and removal between vehicles or assets, and it is easily converted to an adhesive type for greater flexibility.

It is delivered with a standard SMA-male connector and a standard 300 cm long coaxial LL100 cable. Iridium has certified the 2J7426MPz antenna for commercial use in connection with the Iridium communications system.

March 28, 2024
Kongsberg Discovery launches hydrographic surveying solution

Image: Kongsberg Discovery

Kongsberg Discovery has released the Seapath 385 navigation system. It is designed to enhance precision in hydrographic surveying by using advanced navigation algorithms and integrating a range of satellite signals, including GPS, GLONASS, Galileo, Beidou and QZSS, alongside geostationary satellite signals.

The system combines raw inertial sensor data from Kongsberg Discovery’s proprietary high-performance motion gyro compass (MGC) or motion reference unit (MRU) with GNSS data and corrections from real-time kinematics (RTK), precise-point positioning (PPP) or Differential Global Navigation Satellite System (DGNSS). The integration offers a robust and accurate navigation solution ideal for hydrographic surveying.

The system’s dead reckoning capabilities are attributed to its advanced inertial sensors and updated navigation algorithms. It uses GNSS antennas for both positioning and heading determination designed to add an extra layer of robustness to the system. The Seapath 385 also introduces a new post-processing format that consolidates all necessary data and system configurations into a single file, which allows for centimeter-level position accuracy through either satellite orbit and clock data or data logged from base stations.

Designed for ease of installation and continuous, reliable operation, the Seapath 385 is a modular system with a processing unit that handles all critical computations independently of the user interface on the HMI Unit. This feature offers precise measurements with a data rate of up to 200 Hz at multiple monitoring points, which makes it an ideal solution for accommodating sensors or systems that depend on motion or position data throughout the vessel.

March 27, 2024
Launchpad: Lidar systems, machine control and UAV solutions

A roundup of recent products in the GNSS and inertial positioning industry from the March 2024 issue of GPS World magazine.

SURVEYING & MAPPING

GNSS Receiver
Supports tilted measurement

PozStar P5 is a high-precision GNSS receiver. It is powered by a 1,408-channel multi-band GNSS receiver designed to improve surveying in the field. It is equipped with Bluetooth, WiFi and UHF radio. The inertial measuring unit (IMU) supports tilted measurement, which allows users to obtain quick initialization and accurate measurements with an inclination of up to 60°.

The receiver comes with radio connector options used in a frequency range of 410 MHz to 470 MHz and a 5-pin serial port, which allows for external radio system connectivity and NMEA data output. It is also weatherproof, rated IP67.
PozStar P5 can collect control and surveying data for RTK equipment to perform surveying, map input and drawing operations. The receiver can be used with PozPad, an Android-based RTK field software.
PozStar, pozstar.com

Lidar System
Designed for aerial surveying

The TrueView 540 lidar system integrates lidar technology with LP360 3D point cloud processing software to enhance survey-grade lidar applications.
The system is designed to provide enhanced data density, accuracy, and precision for aerial surveying. It combines lidar, an accurate positioning and orientation system and a full-frame industrial camera in a compact, lightweight package. It is suitable for a variety of UAVs, including the DJI Matrice 350.
The TrueView 540 features high-precision lidar technology comparable to high-end industry-standard payloads in terms of range, density and accuracy. It will be made available through GeoCue and its authorized distributors.
GeoCue, geocue.com

GNSS Solution
Combined with Septentrio’s mosaic-X5 module

The SparkFun real-time kinematics (RTK) mosaic-X5 uses the multi-constellation, multi-frequency capabilities of the Septentrio mosaic-X5 module, which aims to improve accuracy and reliability in a variety of position applications.
The RTK mosaic-X5 is a 448-channel receiver that supports all four Global Navigation Satellite Systems (GNSS) — GPS, GLONASS, BeiDou and Galileo — and one of the two regional ones, NavIC. It can function as both an RTK base and rover, which allows users to achieve horizontal positioning accuracy down to 6 mm and updates at a rate of 100 Hz.
The device incorporates the Espressif ESP32-WROVER processor, which allows for high-speed processing and a variety of connectivity options. The ESP32 provides the device with USB-C, Ethernet-over-USB and an Ethernet to WiFi Bridge mode to ensure seamless integration into any project setup.
The device also has power flexibility, including USB-C, Power-over-Ethernet, and external DC sources, along with data logging in multiple formats such as RINEX and NMEA. Housed in a custom-designed aluminum case, the RTK mosaic-X5 features a comprehensive web server interface to simplify configuration and monitoring.
SparkFun Electronics, sparkfun.com

Hybrid Mobile Mapping Solution
Combines mobile scanning with a stationary mode

The X70GO SLAM laser scanner is designed for fast and efficient large-area surveys. It combines mobile scanning with a stationary mode to scan with high resolution to enhance overall surveying capabilities.
X70GO is a real-time 3D model reconstruction device that integrates an inertial navigation module, high-performance computer and storage system. It is equipped with a 360° rotating head, which, combined with the SLAM algorithm, can generate high-precision point cloud data. The built-in 512GB memory disk stores survey results and the dismountable handle has a 1.5-hour battery life.

A 12MP RGB camera offers texture information, while a visual camera aims to enhance the real-time preview with the GOapp. Mapping results can be generated immediately inside the scanner. Users can then color the points and improve their accuracy during post-processing with GOpost software.

The system comes with a hybrid scanning capability. The X-Whizz mode combines the advantages of SLAM mode with the resolution of a static scan, which eliminates the need for multiple scan stations. Users can move around the scene to collect the entire 3D point cloud without time-consuming cloud-to-cloud alignment.

The technology incorporated in the new scanner is designed to provide extended range, a higher number of points per second and advanced onboard processing algorithms. The SLAM laser scanner is well-suited for challenging environments and can be used in a variety of applications, including BIM, industrial sites, real estate, heritage preservation, tunnels and mining.

Users can add an RTK module to set a point cloud in a global coordinate system. This can support adding GNSS information to that from lidar and the inertial measurement unit (IMU) in the SLAM algorithm. In situations with limited GPS connectivity – such as indoors or in challenging environments – the system will rely on lidar and the IMU for positioning purposes.
Stonex, stonex.it

Remote Sensing Payload
Integrates with UAVs and other platforms

The RESEPI lidar Gen-II remote sensing payload instrument comes in three modes: aerial mode for comprehensive airborne data collection, mobile mode for dynamic vehicular data collection and a versatile handheld/backpack that aims to provide portability and ease of use for ground personnel.

The RESEPI lidar Gen-II has a 175% increase in computing power, designed to speed up processing and enhance efficiency during complex tasks. Its memory capacity has been increased by 700%, which allows for extensive data handling and improved system performance. The system’s 50% increase in storage capacity aims to facilitate longer durations of data collection without frequent offloads.
The Gen-II features seamless integration capabilities with UAVs and other platforms. The system’s sensor-agnostic design allows for external sensors to be easily integrated, including lidar and cameras. It also can compute point clouds, trajectories and solutions in real-time, which is critical in time-sensitive missions. The system can be used in a variety of applications including mapping, inspection, autonomous vehicles, navigation and robotics.
Inertial Labs, inertiallabs.com

Mapping Software
With upgraded cloud capabilities

The Correlator3D mapping software now has upgraded cloud capabilities. With its distributed processing capabilities, Correlator3D allows users to scale their processing to match individual operational needs.
With the upgrade, Correlator3D can process large mapping projects and deliver results from UAV, aircraft and satellite imagery. It features a software package – a patented, end-to-end photogrammetry solution — designed to generate high-quality geospatial data from a variety of sources, including satellite and aerial imagery and UAVs. The upgrade aims to improve the technology’s performance in diverse cloud scenarios.
Correlator3D is designed to provide aerial triangulation (AT) and generate dense digital surface models (DSM), precise digital terrain models (DTM), point clouds, orthomosaics, 3D models and vectorized 3D features. By using GPU technology and multi-core CPUs, Correlator3D offers enhanced processing speed to support the rapid production of large datasets.
SimActive, simactive.com

MOBILE

Handheld GNSS Data Collector
Ideal for construction surveying

TDC6 is a handheld GNSS data collector designed for high-performance construction surveying. The device allows contractors to work with more complex data sets more effectively in the field, connect to the office for on-the-spot approvals, and quickly communicate changes to field crews.

The small, rugged device offers integrated Wi-Fi and Bluetooth, built-in cameras and 5G compatibility in a lightweight, shock-, dust- and water-resistant package. The device integrates seamlessly with Trimble data collection applications, including Trimble TerraFlex GIS software and Trimble Access survey field software, as well as third-party apps such as Esri ArcGIS Field Maps.
Trimble Geospatial, geospatial.trimble.com

Military-Grade Antennas
Designed for mission-critical applications

This advanced military-grade antenna product line includes ruggedized GPS, manpack omni and vehicle omni antennas. The products are designed for mission-critical applications such as vehicle navigation, personnel communications, vehicle communications, electronic warfare, and jamming.
The antennas meet MIL-STD-810 to offer durability while adhering to strict quality standards. The antennas also are compliant with the Trade Agreements Act (TAA), which makes them suitable for government and defense applications.
Built to withstand tough conditions, these antennas feature heavy-duty construction and a rugged design for long-lasting performance in challenging environments. They are designed to perform in extreme weather conditions and on rough terrains.
Its robust construction and NATO/U.S. standard mounting options aim to simplify integration into various setups during critical operations.
Fairview Microwave, fairviewmicrowave.com

Trimble SiteVision Software 5.0. (Image: Trimble)

Outdoor Augmented Reality System
With 3D scanning capabilities

SiteVision Software 5.0 is a high-accuracy outdoor augmented reality system, now with a 3D scan tool. The new 3D scan tool allows users to use lidar sensors available on some Apple Pro devices. The Trimble DA2 GNSS receiver is designed to capture point clouds efficiently and accurately with a single handheld solution.
Users can visualize 3D scan data directly in the field with SiteVision’s augmented reality view. The software allows users to create as-builts of the job site on the go, measure and plan resource allocation, reduce scan times, supplement UAV data and more by combining scanning and precision in a mobile solution. The product aims to facilitate practical and accessible field-to-office workflows for surveyors, contractors and engineers.
Trimble Geospatial, geospatial.trimble.com

OEM

Two LTE Modules
With integrated GNSS

The LTE-M cellular module series, the SARA-R52 and LEXI-R52, are designed to meet the needs of industrial applications requiring both positioning and wireless communication capabilities. Based on the u-blox UBX-R52 cellular chip, these modules are designed for a variety of internet of things (IoT) use cases, including both fixed and mobile applications.

The UBX-R52 chip is designed to simplify product design by reducing the need for additional components. It includes SpotNow, a positioning function developed by u-blox, which aims to provide location data with an accuracy of up to 10 m within a few seconds. This function is targeted at applications requiring occasional tracking, such as waste management, personal trackers and industrial machinery.

The chip’s uCPU feature allows the execution of custom software directly on the chip and eliminates the necessity for an external microcontroller unit (MCU). The smart connection manager (uSCM) is a feature designed to manage connectivity automatically, focusing on optimizing performance or minimizing power consumption under varying connection conditions.

The R52 series introduces the SARA-R520M10 combo module, which is equipped with an integrated u-blox M10 GNSS receiver. This module is designed to provide simultaneous GNSS and cellular connectivity, supporting applications that require continuous or periodic tracking with features such as low power consumption, improved time-to-first-fix (TTFF) and increased RF sensitivity.

Unlike many LTE-M modules that typically offer an RF output power of 20-21 dBm, the new R52 series modules offer a higher output power of 23 dBm to improve connectivity in difficult coverage areas. The LEXI-R52 offers the same functionalities as the SARA-R52 but comes in a smaller form factor, making it ideal for applications with space constraints, such as wearable technology.

These additions to u-blox’s LTE-M module portfolio are designed to address the integration of GNSS and wireless communication in industrial IoT applications, offering solutions for a range of use cases that require robust connectivity.
u-blox, u-blox.com

UAV

GNSS-Denied Navigation Kit
For challenging environments

This GNSS-denied navigation kit is designed to offer navigation capabilities in challenging environments. It combines UAV Navigation’s attitude and heading reference system (AHRS), the POLAR-300, with its Visual Navigation System, the VNS01, to offer advanced dead reckoning navigation capabilities with minimal drift.
The technology has error rates as low as 0% to 1% over covered distances. This is made possible by the kit’s visual-based technology, which allows for precise attitude and position estimation to stabilize flights in challenging conditions. The kit is equipped with advanced algorithms that can detect and counter sophisticated spoofing and jamming techniques to offer reliable and secure navigation, even in the face of potential signal disruptions. The kit can be used in both civil and defense sectors.
UAV Navigation-Grupo Oesía, uavnavigation.com

Lidar UAV Solution
Offers immediate access to terrain information

The lidar UAV mapping solution combines the WingtraOne GEN II UAV with a newly developed lidar sensor. This integration aims to advance UAV lidar efficiency, increase accuracy and simplify integration.
The solution incorporates a Hesai scanner, Inertial Labs IMU and NovAtel GNSS receiver designed to optimize data acquisition and reduce the need for post-processing strip alignment. This advancement offers immediate access to precise terrain information following each flight and enhances the efficiency of mapping and photogrammetric analysis in various sectors.
One of the key features of the lidar system is its reduced field time, with no calibration needed and a one-minute initialization process. The Wingtra lidar application and the system’s automated features offer a streamlined data capture process, which makes it accessible even to those new to lidar technology.
The solution offers a vertical accuracy of 3 cm from a 60 m flight height, with leading point density in its class. The WingtraOne GEN II’s design and automated flight patterns offer consistent results across different pilots.
Wingtra, wingtra.com

MACHINE CONTROL

GNSS Smart Antenna
Designed for industrial environments

AntaRx-Si3 is a GNSS/INS smart antenna housed in an ultra-rugged enclosure, designed for straightforward installation on machinery such as agricultural robots. It combines Septentrio’s centimeter-level GNSS positioning with an inertial measurement unit (IMU) within the same enclosure as the GNSS antenna, which uses FUSE+ technology.

The AntaRx-Si3 is designed for challenging industrial environments where GNSS signals are at risk of obstruction, such as under heavy foliage. The antenna’s exterior is crafted from impact-resistant polycarbonate with an IP69K rating and can withstand significant shocks, vibrations, and harsh environmental conditions.
It uses Septentrio’s GNSS+ algorithms to offer advanced multipath mitigation to operate in environments where satellite signals could be reflected off surrounding machinery or structures, such as silos. The antenna delivers high update rates and low latency positioning, which are crucial for the control loops of autonomous movements or rotations.
Septentrio, septentrio.com

3D Machine Control Software
Suitable for construction sites

The Leica MC1 software platform is designed to guide and automate machine control solutions.
Leica MC1 machine control software continues to evolve toward achieving a smart digital reality, with features such as Modify Models and surface logging. It compares the design model to the actual position of the machine’s cutting edge, such as the bucket or blade edge. The technology aims to assist operators in positioning machinery to achieve the planned design while allowing for a live digital representation of the progress. The software automatically controls the position of the machine’s cutting edge.

It is carried by the rugged hardware platform, the Leica MCP80 panel and MDS Series docking station, offering an interchangeable panel between machines on a job site. The MC1 platform is supported by the cloud-based Leica ConX productivity platform to offer more efficient management of heavy construction projects.
Leica Geosystems, part of Hexagon, leica-geosystems.com

March 18, 2024
Leica Geosystems unveils airborne lidar sensor

Image: Leica Geosystems

Leica Geosystems, part of Hexagon, has introduced the Leica TerrainMapper-3 airborne lidar sensor. It features new scan pattern reconfigurability to support a variety of applications and requirements in a single system.

The system offers three scan patterns, which allow users to customize the sensor’s performance to fit specific applications. Its circle scan patterns are designed to improve 3D modeling of urban areas or steep terrains. The ellipse scan patterns use data capture for more traditional mapping applications. Skew ellipse scan patterns are aimed at improving point density for infrastructures and corridor mapping applications.

The sensor has a high scan speed rate and a 60° adjustable field of view to maximize data collection with fewer flight lines. The TerrainMapper-3 is complemented by the Leica MFC150 4-band camera, which operates with the same 60° field of view coverage as the lidar for exact data consistency.

The device’s reduced beam divergence offers more accurate results, while its new multiple pulses in air (MPiA) handling is designed to deliver more consistent data acquisition, even in steep terrain.

The new system introduces possibilities for real-time full waveform recording at maximum pulse rate to open opportunities for advanced and automated point classification.

March 14, 2024
Scripps Institution of Oceanography establishes a geodesy program
In my November 2023 GPS World newsletter, I highlighted the announcement made by the National Geodetic Survey (NGS) of the recipients of the NOAA FY 23 Geospatial Modeling Competition Awards. The grantees’ proposals include developing models to address what NGS denotes as the Intra-Frame Deformation Model (IFDM). The primary objectives of these projects are to modernize geodetic tools and models, as well as to develop a geodetic workforce for the future. A significant improvement in the new, modernized National Spatial Reference System (NSRS) is the time-dependent component being incorporated in the computation of reference epoch coordinates (RECs). That said, developing models that accurately capture the time-dependent component is extremely important to providing reliable, consistent, and accurate RECs. My February 2024 newsletter highlighted NGS’s grant to The Ohio State University for developing a fully kinematic reference frame for the Continental United States and Canada. Similar to the OSU project, a goal of the Scripps Institution of Oceanography (SIO) project is to provide an accurate IFDM, which will provide reliable, consistent and accurate RECs. On Jan. 10, 2024, Yehuda Bock, Ph.D., gave a presentation about this at the general membership meeting of the American Association for Geodetic Surveying (AAGS). His presentation can be downloaded from the AAGS’s website: https://aagsmo.org/.

Summary of the SIO Geospatial Award. (Image: NGS website)

Bock is director of the California Spatial Reference Center (CSRC), which is responsible for “establishing and maintaining an accurate state-of-the-art network of GPS control stations for a reliable spatial reference system in California.” I highlighted the CSRC in my June 2023 GPS World Newsletter.

Yehuda’s proposal included the following three activities:
- Create a formal Geodesy Program at SIO to address the nationwide deficiency of geodesists. Expand current geophysics curriculum – funding for five graduate students.
- Develop an IFDM to supplement the NSRS for users in regions with significant ground motions, using GNSS and InSAR/GNSS displacement fields (funded by NASA projects) and underlying geophysical models. CSRC will exercise the IFDM through its community of public, private and academic users of precise spatial referencing in our challenging region of secular and transient crustal movements.
- Investigate a unified vertical reference frame, including a marine geoid optimized to be consistent with the full spectrum of observations from modern gravimetric geoids (e.g., GRAV-D, ICGEM), remotely sensed observations (e.g., SWOT, ICESat-2), in situ ocean observations and assimilating ocean models and the TRF.
Yehuda’s project includes creating a formal geodesy program at SIO that will help to address the geodesy crisis. Anyone keeping up with my columns knows that I have been highlighting the geodesy crisis and programs that advance the science of geodesy (July 2020, November 2022, and December 2022).

Yehuda showed a slide that highlighted “What Geodesy Can Tell Us About Earth.” Looking at the slide, geodesists are needed in the field of climatology, meteorology, hydrology, geology, volcanology, oceanography, and glaciology, as well as surveying, mapping, and navigation. All these disciplines study Earth’s dynamic processes and involve geodesy.

From Yehuda Bock Ph.D.’s presentation to the AAGS General Membership Meeting. (Image: AAGS website)

The images “Geodesy Curriculum at SIO (PhD, MSc)”, “Geodesy Courses – 1” and “Geodesy Courses – 2” provide information about the Geodesy Program as SIO.

From Yehuda Bock, Ph.D.’s Presentation to the AAGS General Membership Meeting. (Image: AAGS website)

Notice that some of the courses focus on topics that are important to real world applications. For example, GNSS precise point positioning applications to seismotectonics, GNSS signal propagation applications to atmospheric remote sensing and GNSS reflection: soil moisture and sea level and the vertical datum.

From Dr. Yehuda Bock Ph.D.’s presentation to the AAGS General Membership Meeting. (Image: AAGS website)

FromYehuda Bock, Ph.D.’s presentation to the AAGS General Membership Meeting. (Image: AAGS website)

In addition to the graduate-level courses, they are proposing an undergraduate course titled Geodesy and Geospatial Information. The purpose of the course is to provide students with the skills in geospatial systems that will provide opportunities for eventual employment in the public and private sectors.

Proposed Undergraduate Course

Title: Geodesy and Geospatial Information

Course justification and content objectives: Geodesy is the study of Earth’s size (geometry), shape (gravity field) and deformations (e.g., plate tectonic motions, subsidence). It provides access to a well-defined spatial reference system for precise geospatial information (latitude, longitude, height, elevation with respect to sea level) used for positioning, navigation, surveying and mapping. Geodesy is also an important discipline within the earth, atmospheric and oceanographic sciences, using observations of GPS and other satellite navigation constellations, remote sensing platforms (satellite and drone), and various terrestrial sensors. It is a data- and analysis-intensive discipline increasingly requiring modern data science methods. This introductory course will provide students with a solid background in geospatial systems for eventual employment in the public and private sectors. The course will also serve as a pipeline to the geodesy track at SIO/Earth Sciences and to other academic institutions and to alleviate the nationwide deficiency of geodesists. The objective is to provide basic knowledge of geodetic concepts for Earth and data scientists and the underlying geodetic framework for precise spatial information.

Learning objectives:
- Acquire basis concepts of geodetic science.
- Provide overview of geodetic instrumentation and observations.
- Develop elementary skills in geodetic data analysis.
- Explore existing geodetic infrastructure and data repositories.
- Experience hands on visualization and manipulation of geospatial information.
- Understand the underlying geodetic framework for precise spatial information systems.
- Provide example of data science applications in solving geodetic problems.
Preferred background: statistics, linear algebra, Matlab/Python

In my opinion, universities should provide a general elective course for undergraduate students that provides an introduction in how geodesy influences your daily routines. For example, how does my phone know where I am and how does it know the best route I should take to get to my destination?

How Does My Phone Know Where I Am? (Image: Dave Zilkoski)

The second task in the SIO proposal is to develop an IFDM. The concept of an IFDM is part of NGS’ modernized, NSRS. Several of my previous My July 2023 GPS World newsletter highlighted a presentation by Yehuda discussing a kinematic datum that uses an intra-frame velocity model to estimate positions at any time with respect to a reference frame and epoch.

As I mentioned in my July 2023 newsletter, California’s geodetic network is significantly affected by crustal movement. To help address this issue, the CSRS updated the NAD 83 coordinates, it is denoted as CSRS epoch 2017.5 (NAD 83). Part of the implementation of the CSRC epoch 2017.50 (NAD 83) was to have the new epoch-date coordinates transmitted with RTCM 3.0 data streams. This is something that other RTN operators from around the nation will have to do after NGS publishes the NSRS coordinates. The CSRS is a model from which others can learn.

During his presentation to AAGS, Yehuda highlighted his methodology of integrating InSAR and GNSS to develop an IFDM that provides for higher spatial resolution to improve the model between GNSS stations.

The boxes titled “SCIP Dynamic Datum Utility” and “Output from SCIP Utility” provide an example of an input and output of the utility, and the box titled InSAR/GNSS Integration for Higher Spatial Resolution” is a conceptual diagram of the concept.

Not only has this abbreviation been spelled out before, but here the full phrase appears three times, in three consecutive sentences.

SCIP Dynamic Datum Utility. (Image: SOPAC website)

Output from SCIP Utility. (Image: (SOPAC Website)

From Yehuda Bock Ph.D.’s Presentation to the AAGS General Membership Meeting
(Image: AAGS website)

The image provides an example of the concept in the San Joaquin Valley, California.

InSAR/GNSS Integration Example.

The following statement is in the note section of the slide:

“Area of subsidence in San Joaquin Valley. Our weekly displacement time series at GNSS station P056 shows significant changes in subsidence rate over the period 2006 to 2022, for a total of 3.3 feet that reflects periods of drought and increased groundwater use. On the upper right is the InSAR time series at that location for a shorter period of time.” This shows the potential of using InSAR to improve the IFDM in areas of sparse CORS.

The third item in the proposal is to “Investigate a unified vertical reference frame, including a marine geoid optimized to be consistent with the full spectrum of observations from modern gravimetric geoids (e.g., GRAV-D, ICGEM), remotely-sensed observations (e.g., SWOT, ICESat-2), in situ ocean observations and assimilating ocean models, and the TRF.”

The images below provide a list of the reference surfaces involved in unifying the vertical reference frames and the observing systems involved in the project. Understanding the geoid at the land-sea interchange is important to estimating accurate GNSS-derived orthometric heights along the coast as well as in the oceans. My August 2021 newsletter highlighted the concept of establishing an International Height Reference System (IHRS) so that all countries could provide physical heights across their boundaries and over the oceans. This project would support that international activity.

From Yehuda Bock Ph.D.’s Presentation to the AAGS General Membership Meeting. (Image: AAGS website)

From Yehuda Bock Ph.D.’s Presentation to the AAGS General Membership Meeting. (Image: AAGS website)

This newsletter and my previous GPS World newsletter highlighted two of the grantees, \SIO and OSU, which included developing models to address what NGS denotes as the IFDM.

The SIO program includes creating a formal geodesy program at SIO that will help to address the geodesy crisis. In addition to the graduate level courses, they are proposing an undergraduate course that will provide students with the skills in geospatial systems that will provide opportunities for eventual employment in the public and private sectors. My next newsletter will address another NGS geospatial modeling grant awardee – Oregon State University’s proposal.
March 6, 2024
Topcon boosts support for Get Kids into Survey project

Topcon Ninja Wildcat, one of the sponsored characters featured in the Get Kids into Survey campaign. (Image: Topcon)

Topcon Positioning Systems has expanded its support for the Get Kids into Survey (GKiS) project, now serving as the exclusive sponsor of the Global Brand Ambassador Hub. This new platform will offer a comprehensive range of resources to the project’s Brand Ambassadors, a worldwide community of volunteers who visit schools to advocate for surveying as a career and introduce students to the surveying and geospatial industries.

Get Kids into Survey originated in 2017 and was initiated by cofounder Elaine Ball through the creation of a poster that surveyors could use to explain the profession to children. Since its inception, the project has continued to highlight the work of surveyors for young audiences, backed by an industry keenly aware of the necessity to attract the next generation of surveyors.

The Hub will allow GKiS to develop and host resources for the global network of ambassadors and aims to increase participation in career fairs, workshops and educational activities across more than 30 countries.

By sponsoring a homework project with GKiS, Topcon will also have its own unique GKiS cartoon character, Yumi the Wildcat Survey Ninja. Yumi will be the face of the Topcon brand to young aspiring surveyors and be given her own Character Spotlight on the GKiS blog.

Research conducted by Topcon has shown that nearly a third of construction managers throughout Europe have identified skill shortages as a major challenge in their projects.
According to Topcon, this shortage stems from a combination of experienced employees leaving the industry and a lack of recruits. Programs such as GKiS represent just one example of the outreach and educational initiatives designed to address and reverse this trend.

“The GKiS project is about lifting the lid on the geospatial and survey industries for young people, and showing that they are exciting, future-gazing and technology-driven careers,” said Elaine Ball, co-founder of GKiS.

March 5, 2024
In the Field: Help survey monuments complement GNSS
Figure 1: Utility access box installed over CORS reference mark Whitefish Pt A (NGS PID AA8050) at USCG lighthouse. (Photo: Jeff Olsen)

GNSS users who appreciate that physical monuments can provide verification of GNSS observations can do four things to preserve those monuments and make them more accessible. References below are to U.S. national agencies, but most countries have equivalent agencies.
1. Install a valve box over each buried control point recovered or set, whether the point is for boundary or geodetic surveying. Include National Geodetic Survey (NGS) deep-rod marks that have a buried logo cap.
2. Advocate with the Secretary of the Interior and United States Geological Survey (USGS) director that USGS scan its paper geodetic data sheets and post the scanned pdf files online.
3. Adopt the geodetic marks in your area. Visit them. Keep them free of brush or other blockages. Maintain descriptions and photos up to date by submitting recovery notes to NGS as needed. Participate in the NGS GPS on Benchmarks program.
4. Consider recovering all the marks in an NGS level line. Alternatively, all the USGS marks in a 15’ quadrangle, the geographic unit USGS uses to publish its geodetic data.
Figure 2: Example of USGS vertical data published by 15’ quadrangle.

Regarding the first of these actions, a valve box is a utility standard. It identifies to non-surveyors that there is something under the box to which one should pay attention, thus increasing the mark’s chances of survival.

The box lid is generally obvious, eliminating or at least reducing the search time for surveyors, who only need to walk up to the box.

It replaces the soil that previously covered the mark, reducing excavation time. A surveyor only needs to open the lid and brush off the mark. Rectangular and round boxes in several sizes are available to accommodate different-sized monuments. While the time and materials to install a box may be an overhead cost to your company, it is well worth the investment.

Regarding the second of these actions, the positions and heights published for most USGS control marks are based on superseded datums. However, that old data can be useful for evaluating trends. The marks are usually stable and can be reused in new projects.

While NGS has observed some of these marks and published datasheets for them, they are by far the minority of all the USGS marks in the country.

There are thousands of these sheets, 50 shelf-feet of them, organized by 15’ quad. Some sheets, mainly in the East, have been scanned and put online by various state agencies or utility companies. The USGS Rolla office has scanned most of the eastern states but has not posted the files online.

Generally, a request for USGS geodetic data turns into a request for paper sheets, such as those shown in Figure 2, to be scanned and emailed. Putting them online would preserve this record of what it took to survey and map our country, allowing the marks to be tied into new control surveys.
February 27, 2024
Launchpad: Lidar systems, PNT platforms and UAVs

A roundup of recent products in the GNSS and inertial positioning industry from the February 2024 issue of GPS World magazine.

SURVEYING & MAPPING

Handheld GIS Data Collection Solution
For outdoor operations

The handheld P6H solution is designed for GIS data collection and outdoor operations. Featuring a GNSS high-precision positioning module, rugged IP67-rated design, and 6-inch sunlight-readable display, the P6H offers positioning accuracy in harsh environments.
Equipped with a SinoGNSS self-developed high-precision K8 board and antenna, it can track all running and planned constellations with 1,590 channels, including GPS, BeiDou, GLONASS, Galileo, QZAA, IRNSS, and SBAS.

The P6H offers users centimeter- or decimeter-level accuracy. Its IP67 rating protects against dust and water to enhance its efficiency and durability in tough environments.

The device comes equipped with Survey Master and robust GIS functions, which allow users to take measurements of geographic elements and store the results as attribute data for subsequent analysis, calculation, and visualization. It also includes a mock location function for users to accurately share Survey Master’s position with P6H. The location data can then be accessed on a third-party GIS software.

It is also compatible with common GIS software such as ArcGIS Collector, Mapit GIS, and QGIS. Additionally, the P6H features an 8-core 2.0 GHz processor, up to 128 GB of storage and up to 6 GB of RAM to offer users smooth software operation and efficient data processing.

PH6, which features a high-precision GNSS module and antenna, also incorporates 4G LTE, Wi-Fi, and Bluetooth to improve its data transmission and sharing capabilities.

ComNav Technology, comnavtech.com

Bathymetric Lidar System
Maps underwater topography

YellowScan Navigator is a bathymetric lidar system designed for surveyors to map underwater topography in rivers, ponds, and coastal areas.

The system features a laser scanner developed in-house over the course of five years and has been heavily tested to achieve optimal performance. The compact system can map waterbeds with a depth of up to 3 m and can reach a depth of 18 m in perfectly clear water conditions, according to the company. It can be flown up to 100 m above the water surface and provides measurements with an accuracy of 3 cm. Additionally, a camera is embedded for true-color data visualization.

YellowScan, yellowscan.com

3D Model Editing Software
For aerial surveying, transportation, and emergency responses

DJI Modify is an intelligent 3D model editing software. It can be seamlessly integrated with DJI’s enterprise UAVs and 3D modeling and mapping software, DJI Terra. When integrated with these products, the software can be used for aerial surveying, transportation, and emergency responses.

DJI Modify paired with DJI Terra offers users an end-to-end solution from modeling to model editing. Once DJI Modify has been enabled, DJI Terra files for model editing are automatically generated, including pre-identified objects and pre-processing of the model. It is designed to make repairing common 3D model defects seamless and efficient. As of early 2024, DJI Modify will only support repairing models built by DJI Terra.

DJI Modify allows for model files to be quickly imported and exported to the DJI Terra and other third-party software. Its intelligent auto-repair editing supports flattening, editing textures, repairing water surfaces, removing floating parts, and filling holes. Edits can be made using one-click repairs or manually by selecting custom polygons, areas or meshes.

The software’s smoother model display technology allows high- and low-quality models to be viewed and edited in a single interface. Changes made can be synchronized across both models and previewed immediately, which allows users to address model editing issues in real-time.

DJI, store.dji.com

OEM

GNSS/IMU
Uninterrupted position, orientation, and dynamics

RT3000 v4 GNSS inertial measurement unit (IMU) combines two survey-grade GNSS receivers with OxTS’ IMU10 inertial technology. The RT3000 v4 offers uninterrupted position, orientation and dynamics in challenging environments.

The IMU will reach the desired specification within three minutes of low dynamic movements, which reduces the time and space required for high dynamic maneuvers before each data collection.

Users can customize the INS with optional features and software integrations to create the ideal INS for individualized projects, including lidar surveying and mapping or positioning in GNSS-denied or challenged environments.

Oxford Technical Solutions (OxTS), oxts.com

Precision Lidar Technology
Provides vision capabilities in challenging environments

The Eyeonic Vision System Mini (Eyeonic Mini) supports sub-millimeter resolution in a reduced size. The system integrates a full multi-channel FMCW lidar on a single silicone photonic chip and an integrated FMCW lidar system-on-chip (SoC).

The Eyeonic Vision Chip combines crucial photonics functions into a coherent vision sensor. The system’s accuracy stems from a 4-channel FMCW LiDAR chip — supported by Indie Semiconductor Surya SoC technology — to provide robots with sub-millimeter depth precision from distances exceeding 10 m.

The technology offers enhanced precision and can be used in automation, including warehouse logistics and artificial intelligence (AI) machine vision applications. Palletizing robots equipped with the Eyeonic Mini can view and interact with pallets, which aims to optimize package placement and truck loading with greater efficiency and safety.

SiLC Technologies, silc.com

PNT Platform
Used in critical defense operations

The Endura Epoch Platform provides robust and resilient positioning, navigation, and timing (PNT) services critical in defense operations.
The MEMS oven-controlled oscillator (OCXO) can boost the resilience of PNT systems and other equipment, including radars, field and airborne radios, satcom terminals, and avionics against spoofing, jamming and other disruptions in GPS signals.

Based on the Epoch Platform, the Endura Epoch MEMS OCXOs are designed to meet the challenging shock and vibration conditions found in aerospace and defense. These devices are manufactured using semiconductor processes that deliver the reliability and quality expected from silicon devices. The same level of reliability cannot be achieved by quartz crystal OCXOs, specifically in extreme conditions.

The Endura Epoch MEMS OCXOs, compared to quartz crystal OCXOs, includes various features and benefits, including programmable frequencies from 10 to 220 MHz; a 20,000 g shock survivability rating; up to 20 times better frequency stability over temperature; up to three times better Allan deviation, a measure of short-term frequency stability; surface-mountable, small footprint and low height 9.0 x 7.0 x 3.6 mm; low weight of 0.35 g; 420 mW steady state power.

SiTime Corporation, sitime.com

IMU
With an XYZ-axis gyroscope and accelerometer

The SCH16T-K01 is an inertial measurement unit (IMU) featuring a XYZ-axis gyroscope and a XYZ-axis accelerometer, for a total of six degrees of freedom.

The SCH16T-K01 includes a sophisticated gyro with typical bias instability of 0.5 dph and up to 0.3 mdps/√Hz noise density. The accelerometer has a dynamic range of up to 26 g, which provides resistance against saturation and vibration.

The component’s output is internally cross-axis compensated, which eliminates the need for extensive calibration. Through the integration of these features, the SCH16T-K01 can deliver accurate measurements in machine control and guidance without field calibrations.

It is suited for industrial applications such as construction and agricultural machines, material handling equipment, marine instrumentation, robotics, and UAVs.

Murata, murata.com

3-Axis Optical Gyroscope IMU
For GPS-denied environments

The ANELLO X3, a 3-axis optical gyroscope inertial measurement unit (IMU), is designed for GPS-denied and challenging environments.

The IMU leverages ANELLO SiPhOG (Silicon Photonics Optical Gyroscope) technology and serves as a light, low-power tri-axial optical gyroscope offering high accuracy, performance, and reliability for autonomous applications.

The ANELLO X3 can be used in a variety of applications, including autonomous commercial and defense applications involving robots, UAVs, electric vertical take-off and landing (eVTOL) aircraft and various maritime and land vehicle applications, including high-accuracy surveying and mapping.

ANELLO Photonics, anellophotonics.com

MOBILE

Smart Antenna
Centimeter-level RTK positioning

The AntaRx smart antenna is designed for machine automation and control in construction, precision agriculture, and logistics. It is enclosed in a rugged and compact housing for simplified installation and can handle high levels of shocks and vibrations, making it ideal for harsh industrial environments such as construction and mining.

The multi-frequency receiver offers centimeter-level real-time kinematic (RTK) positioning and can be used in inertial navigation system (INS) integration, dual antenna mode, and 4G cellular communication. It is available in several configurations, including as a GNSS smart antenna or a GNSS/INS smart antenna system and can be integrated as an inertial measurement unit (IMU).

The receiver technology integrates the company’s GNSS+ algorithms, including advanced multipath mitigation, which offers uninterrupted operation in challenging conditions such as near high structures or machinery.

Septentrio, septentrio.com

Handheld Scanner
With SLAM technology

The Lixel X1 is a powerful 3D scanner that combines lidar, visible-light and motion cameras, and high-precision inertial sensing using SatLab’s simultaneous localization and mapping (SLAM) technology.

Data and scene reconstruction can be previewed in real time and can be exported immediately after scanning without the need for post-processing, which aims to simplify workflows and enhance efficiency.

The system enables scans to be resumed from breakpoints, which allows surveys to be broken up into convenient segments. It provides up to 60 minutes of continuous operation and can be easily mounted to UAVs and other mobile mapping platforms.

SatLab Geosolutions, satlab.com

Ceramic Antenna
For connectivity on L1 GNSS signals

Admotus is a surface-mount ceramic antenna designed for connectivity on L1 GNSS signals on all constellations, including GPS-L1 at 1575.42 MHz; GLONASS L1, 1602MHz; Galileo L1, 1575.42 MHz; BeiDou (B1); and QZSS. It offers comparable performance to a small patch antenna on a small ground plane.

The ceramic antenna has an ultra-low profile measuring a mere 1.0 x 0.5 x 0.5 mm, requires 7 x 15 mm clearance area and offers improved performance on small PCB sizes.

Admotus offers a peak gain of 0.9 dBi with an average gain of –2.6 dB and offers maximum return loss of –11.5 dB and a maximum VSWR of 1.8:1. A companion evaluation PCB is also available for internal analysis.

It is suitable for all GNSS positioning applications in the L1 band (1559 – 1609 MHz) such as wearable devices for fitness and medical monitoring, small portable tracking devices used to track keys, pets, bikes, UAVs, agricultural robotics, and telematics devices.

Antenova, antenova.com

Rugged Tablet
For mobile field workers

The Mesa 4 Rugged Tablet features a 7-inch display and runs on Windows 11. It is designed to provide powerful rugged computing and data collection to mobile field workers.

The Mesa 4 comes with a new Intel N200 processor. It offers up to three times the CPU performance of the Mesa 3 and has an increased RAM size and speed to enhance its processing power. Mesa 4 has an IP68 rating, MIL-STD-810H certification and ergonomic design for all-day carrying.

Juniper Systems, junipersys.com

UAV

UAV Ground Control System
On an 8-inch rugged tablet

The Ground Control System (GCS) for UAVs is centered around RuggON’s LUNA 3 8-inch rugged tablet. It is designed to provide real-time control, telemetry, and satellite positioning for connected UAVs.

GCS is designed to provide users more control over a variety of UAVs by using the LUNA 3 rugged tablet, which has a large and high-definition screen to provide video feedback during operations. The system is also certified to provide GNSS positioning and tracking services.

Featuring a low-latency video software decoder, GCS allows for real-time high-resolution video viewing and data collection. Engineered to withstand dust, shock, and water, the control system can withstand challenging environments.

The LUNA 3 8-inch rugged tablet stands as a powerful and efficient model within its class, powered by an Intel Core i5 processor (1145G7E) with Intel Iris Xe graphics and the Windows operating system. Its sunlight-readable display supports night and stealth modes, which is cruicial for law enforcement and military applications. The tablet offers touchscreen functionality for enhanced operator convenience, complemented by ethernet and optional Wi-Fi 6, and 4G LTE connectivity.

RuggON, rugon.com

VTOSL
Bridging the gap between land and sea

The VT-Naut, vertical takeoff and short landing (VTOSL) is a versatile aerial solution designed for a variety of applications, including high-precision mapping and surveying for inspection, scouting, observation, and agriculture.

The VT-Naut can land on water, which makes it ideal for shipboard or coastal operations, and opens new ways for users to collect and observe data. It has a long-range telemetry link of 30 km and a flight endurance of up to 90 minutes. Its compact and robust body design provides durability and resilience in harsh environments.

The VT-Naut UAV system offers a cost-effective alternative to full VTOL platforms, particularly for users who require extensive surveying capabilities and have some flexibility in landing site selection. The system eliminates the extra costs associated with acquiring and operating a VTOL multirotor drone.

Aeromao, aeromao.com

Folding UAV
For challenging environments

The AIDrone UAV is designed for a variety of applications, from infrastructure inspections and renewables to defense and public safety.
The UAV features a high-performance payload, fitted with a 64MP EO/IR camera mounted on a dual-axis gimbal that can support vertical rotation of up to 200°. AIDrone can spot millimeter-sized cracks and detect subtle temperature changes in challenging environments.

AIDrone uses Nearthlab’s vision-based autonomous flight technology to operate autonomously — in zero-light and GPS-denied environments — both indoors and outdoors.

It weighs around 4 lbs and has a foldable structure. AIDrone is designed for intelligence, surveillance, and reconnaissance (ISR) purposes, which makes it ideal for crisis management scenarios such as wildfire response and law enforcement.

Nearthlab, nearthlab.com

ISR UAV
With jamming resistant-radio

The Ghost Dragon intelligence, surveillance, and reconnaissance (ISR) UAV offers higher resistance against jamming and spoofing. The UAV is equipped with a thermal and visual light camera and jamming-resistant radio. Its wide frequency hopping radio is used to provide a jamming-resistant video and telemetry link, which makes it difficult to detect the UAV and interfere with the mission.

The Ghost Dragon ISR uses a dual-band GNSS module that operates on both L1 and L5 bands, which allows for flight operations even in challenging environments. The UAV can operate in radio silence mode in the presence of GNSS and store reconnaissance data on an encrypted SD card to view after the UAV has landed. The video and target location information streamed to the operator is also georeferenced.

The UAV can be redirected, flown back to base, or handed to another operator at a different ground control station at any time.

Krattworks, krattworks.com

February 27, 2024
Aligning the trades: GNSS for architecture, engineering and construction

Surveyors for architecture, engineering, and construction projects require GNSS receivers that have high accuracy and are rugged enough to survive the dust, water, and inevitable drops that they will endure at construction sites. They also need to be able to easily share data with architects, engineers, planners, and tradespeople, both at the sites and at the office.

Photo: Juniper Systems

Juniper Systems, which has more than 30 years of experience in mapping and data collection in a wide variety of applications across industries, recently released a real time-kinematics (RTK) activation for its Geode GNSS receiver that allows mapping accuracy down to a centimeter. Pairing a Geode with the company’s Uinta mapping and data collection software and a Mesa rugged tablet makes it easy for users to share their data — such as the locations of fiberoptic telecommunication lines or of utility manhole covers — with other people working on site or at the office. The Geode and the Mesa meet IP68 protection certification for water and dust ingress; they also have MIL-STD-810G certification against drops, vibration, and extreme temperatures.

In this month’s cover image, the Geode is at the top of the survey pole, the Mesa Rugged Tablet is mounted near the user’s hand, and the screen on the Mesa depicts the Uinta mapping software.

On construction sites, surveying is an ongoing process. Surveyors are the first on the site, before any other work begins, and the last ones there, to map the project “as built.” Total stations with GNSS receivers, as well as tablets and other mobile digital devices are their essential tools, increasingly complemented by unmanned aerial vehicles (UAV) and lidar scanners. Accuracy is their key contribution. In this month’s cover story on GNSS for architecture, engineering, and construction (AEC), we highlight three building projects: a skyscraper in Sweden, a highway in China, and a luxury resort in the Caribbean.

Check out these perspectives on architecture, engineering and construction:

ComNav Technology: Building Sweden’s Tallest Tower

CHCNAV: Expanding a Highway in China

EOS Positioning Systems: Building a System to Build an Island Resort

February 27, 2024
Seen & Heard: Deep sea coral reefs and lava in Iceland

“Seen & Heard” is a monthly feature of GPS World magazine, traveling the world to capture interesting and unusual news stories involving the GNSS/PNT industry.

Photo: NOAA Ocean Exploration

Exploring the Largest Deep-Sea Coral Reef

Scientists have mapped the largest deep-sea coral reef, stretching hundreds of miles off the U.S. Atlantic Coast. While researchers have known since the 1960s that some corals were present off the Atlantic Coast, the reef’s size remained a mystery until new underwater mapping technology made it possible to construct 3D images of the ocean floor. The National Oceanic and Atmospheric Administration (NOAA) and a team of scientists recently published maps of the reef in the journal Geomatics. The reef extends for about 310 miles from Florida to South Carolina. The total area is nearly three times the size of Yellowstone National Park.

Photo: ESA

Lava in Iceland

Grindavík, a tiny town in Iceland, stands on the brink of volcanic lava flow in images captured by the European Space Agency (ESA). The lava originates beneath the Svartsengi volcano system — roughly 2.5 miles north of the town — which erupted on December 18 and January 14. ESA’s Sentinel2 satellite revealed the glow of the lava flow’s heat, not far from houses and other infrastructure within Grindavík. The town, with just 3,800 residents, has faced constant evacuations, as well as mini-earthquakes as a result, The Guardian reported.

Photo: Maris Maskalans / iStock / Getty Images Plus / Getty Images

Lidar Reveals Lost Cities in the Amazon

In the Amazon rainforest, archeologists have discovered a vast and highly complex system of ancient cities dating back nearly 3,000 years. Located in Ecuador’s Upano Valley, the structures lie in the eastern foothills of the Andes mountains, according to a study published in the journal Science. After more than 20 years of research, the ancient urban centers were only discovered when the Ecuadorean government employed lidar technology. Researchers from France, Germany, Ecuador and Puerto Rico conducted a lidar survey that covered roughly 300 km2, which revealed a landscape full of organized human activities, including more than 6,000 rectangular earthen platforms, as well as agricultural terraces and drainage systems. According to the study, these structures formed at least 15 distinct settlements, which were connected by a system of wide, straight roads.

Photo: nickalbi / iStock / Getty Images Plus / Getty Images

Tracking Cattle from Space

Australian scientists are attempting to track 1,000 cattle and buffalo using artificial intelligence (AI), and GPS satellites, reported euronews.next. An estimated 22,000 cattle and buffalo roam free in a remote area of Arnhem Land, Australia, though the exact number is unknown. Scientists are now collaborating with stockmen and indigenous rangers in a four-year program that involves monitoring feral animals from space. Titled SpaceCows, the remote herd management system is backed by the Australian government’s Smart Farming Partnership initiative. Local rangers and stockmen are chasing and catching animals to attach solar-powered tags with GPS receivers.

February 27, 2024
ComNav Technology: Building Sweden’s Tallest Tower

When completed, the Karlatornet will be Sweden’s tallest building and redefine the skyline of the city of Gothenburg, rising to 74 stories and 246 meters (the Burj Khalifa in Dubai, currently the tallest human-made structure, is 828 meters high). Ensuring that the building remains stable even when deformed by very strong winds, sun exposure, seismic activity, settling or shrinkage will require very high precision construction methods. To ensure its vertical alignment, the engineers are using the core wall control survey (CWCS) method, which relies on active GNSS control points, and SinoGNSS T300S high accuracy GNSS receivers.

A SinoGNSS multi-constellation T300 GNSS receiver and a 360° prism mounted at the top of a building under construction. (Photo: ComNav Technology)

The CWCS method was first used during the construction of the Burj Khalifa and was subsequently applied in the construction of many other high-rise buildings around the world. Swedish surveying company Teodoliten decided to apply this method for the Karlatornet project. Core walls, which are key structural components of high-rises, require a layered construction approach, with multiple concrete pours for each core wall element. CWCS makes it possible to precisely align these core walls with the vertical axis of the building during construction, using GNSS receivers, total stations, inclinometers, and other tools.

When constructing a tall building, it is essential to continuously measure the positions of various elements at its summit to ensure their vertical alignment. This is typically done by placing at the top of the building four GNSS receivers — referred to in this context as active GNSS control points — each with a 360° prism at the bottom. By sighting the prisms and using the 3D coordinates from the GNSS receivers, a surveyor then sets up a total station. This obviates the need for an extensive array of ground control points, which are often not visible from the top, and for holes in the slabs to accommodate vertical laser plummets. Additionally, observations from a nearby reference station are used to post-process the data from the GNSS receivers in post-processed kinematic (PPK) mode to achieve an accuracy of a few millimeters. The Karlatornet project uses four SinoGNSS multi-constellation T300 GNSS receivers for the active control points.

It is also necessary to correct for the movement of the survey platform as the building’s main axis is flexed by the loads applied to it during construction. This is achieved by placing a series of high-precision dual-axis inclinometers along the core walls and then applying a least squares adjustment that takes into consideration the floor height of the measuring devices.

The SinoGNSS T300 receivers operating in GNSS-RTK mode also will be used to monitor and document post-construction building deformations.

February 27, 2024
Stonex launches hybrid mobile mapping solution

Image: StoneX

Stonex has launched the X70GO SLAM laser scanner designed for fast and efficient large-area surveys. It combines mobile scanning with a stationary mode to scan with high resolution to enhance overall surveying capabilities.

X70GO is a real-time 3D model reconstruction device that integrates an inertial navigation module, high-performance computer and storage system. It is equipped with a 360° rotating head, which, combined with the SLAM algorithm, can generate high-precision point cloud data. The built-in 512GB memory disk stores survey results and the dismountable handle has a 1.5-hour battery life.

A 12MP RGB camera offers texture information, while a visual camera aims to enhance the real-time preview with the GOapp. Mapping results can be generated immediately inside the scanner. Users can then color the points and improve their accuracy during post-processing with GOpost software.

The system comes with a hybrid scanning capability. The X-Whizz mode combines the advantages of SLAM mode with the resolution of a static scan, which eliminates the need for multiple scan stations. Users can move around the scene to collect the entire 3D point cloud without time-consuming cloud-to-cloud alignment.

The technology incorporated in the new scanner is designed to provide extended range, a higher number of points per second and advanced onboard processing algorithms. The SLAM laser scanner is well-suited for challenging and demanding environments and can be used in a variety of applications, including BIM, industrial sites, real estate, heritage preservation, tunnels and mining.

Users can add an RTK module to set a point cloud in a global coordinate system. This can support the addition of GNSS information to lidar and inertial measurement unit (IMU) in the SLAM algorithm. In situations with limited GPS connectivity – such as indoors or in challenging environments – the system will rely on lidar and the IMU for positioning purposes.

February 26, 2024