The Mobile World Conference (MWC) returns to the Las Vegas Convention Center on September 26 to 28, 2023.

The event will feature exhibition from major U.S. operators, including AT&T business, T-Mobile business, and Verizon business as well as new sessions dedicated to sports and entertainment, software developers and the GSMA’s SEC CON event.

MWC, in partnership with the Cellular Telephone Industries Association (CTIA), invites industry leaders and attendees to connect and discuss topics such as the industry’s transition to a circular economy, the future role of artificial intelligence (AI) in society, and what comes after 5G.

To reflect the United States’ position as a global technology hub and a market at the forefront of 5G innovation, the event is centered around four key themes:

• 5G Acceleration, as adoption explodes to become the most common mobile technology in North America by 2025.
• Age of AI, as the world awakes to the opportunities and challenges of generative AI.
• Digital Everything, as the expansion of digital technologies is felt across every industry, from sports and entertainment to manufacturing, financial services and smart mobility.
• Enterprise Mobility, as the revolutionary phase of 5G in enterprise is well underway.

The event will feature a variety of keynote speakers, including Amanda Toman, the director for the Public Wireless Supply Chain Innovation Fund at the National Telecommunications and Information Administration (NTIA) within the U.S. Department of Commerce.

For the first time, the GSMA will bring its SEC CON event to MWC Las Vegas on day two, welcoming leading security experts to explore the importance of keeping telecoms infrastructure secure in times of conflict.

A full directory and registration can be found on the MWC Las Vegas website.

Sentient Vision Systems has completed live demonstrations of its visual detection and ranging (vidar) payload enabled by artificial intelligence (AI) on Edge Autonomy’s VXE30 unmanned aerial vehicle (UAV).

The VXE30 is the latest version of the Stalker series of small UAVs from Edgewater Autonomy. When coupled with vidar, the VXE30 offers a passive, wide-area search capability, enabling it to serve a variety of maritime operations.

Vidar, developed by Sentient, uses AI, computer vision, and machine learning integrated with electro-optic and infrared (EO/IR) sensors to passively detect objects that are difficult for the human eye to spot or to recognize on a conventional radar.

This technology has been deployed on intelligence, surveillance, and reconnaissance missions (ISR), maritime patrol and border protection, as well as search and rescue missions since 2015. It is proven in conditions up to Sea State 6, which is defined as very rough with waves of 4m to 6m.

Last month’s column highlighted GEO-ESCON and how it supported the advancement of the science of geodesy. That said, the National Geodetic Survey (NGS) has been working to improve the National Spatial Reference System (NSRS) by replacing the North American Datum of 1983 (NAD 83) frame and all vertical datums, including the North American Vertical Datum of 1988 (NAVD 88), with four new terrestrial reference frames and a geopotential datum. Many of my previous GPS World columns have addressed various phases of the project.

Recently, NGS has developed an Alpha site to enable users to preview preliminary NSRS products and services. I mentioned the Alpha site in my July column, in which I highlighted NGS’s presentations on the new NSRS at the International 2023 FIG Working Week.

The concept of the Alpha site is to provide examples of the content, format, and structure of data and products that NGS plans to release as a part of the modernized NSRS.

NGS highlights that these products are for illustrative purposes only and do not contain any authoritative NGS data or tools. It states that they are under active development and are subject to change without notice.

That said, NGS would like everyone to try the Alpha products and provide feedback to NGS. The first two Alpha products are State Plane Coordinate System of 2022 (SPCS2022) and NGS Coordinate Conversion and Transformation Tool (NCAT). On July 20, NGS held a webinar previewing the Alpha site. Readers can download the powerpoint and video of the presentation here.

As usual, Michael Dennis of NGS did a great job of describing the new SPCS2022, and the differences between the State Plane Coordinate System of 1983 (SPCS83) and SPCS2022. I have included a few of his slides that highlight the SPCS2022.

First, SPCS2022 has significantly more zones than the current SPCS83 zones. Second, SPCS83 map projections were designed to minimize linear distortion at ellipsoid surface, whereas the SPCS2022 map projections were designed to minimize linear distortion at topographic surface. The purpose being to reduce the difference between projected “grid” and “actual” ground distances.

Dennis described NGS’s distortion design performance as seen in the image below. He explained that the performance is a range of +/- distortion for a zone, such as +/-50 ppm. The analysis involved determining parameters where the range includes 90% of the population, 75% of the cities and towns, and 50% of the total area. He highlighted those zones designed by NGS that where typically limited to +/- 50 ppm design criteria, but many low distortion projections (LDP) zones designed by stakeholders consisted of +/- 20 ppm design criteria.

Dennis provided a slide depicting SPCS2022 linear distortion for all CONUS zones with a 50 ppm distortion increment as seen below. As indicated on the slide, green is +/- 50 ppm. The distortion performance is +/- 45 ppm.

As a comparison to the existing SPCS83 zones, he provided a similar slide for the CONUS SPCS83 zones. See below. As in the previous slide, green represents +/- 50 ppm. The distortion performance is +/- 159 ppm.

Now, let us look at the Alpha products. First, all zone information can be found here.

Users can click on the image below for a table of all zone definitions. The table provides the type of projection, if it was designed by NGS or the state, and the zone definition.

By clicking on the image below, users can obtain information for a point in a particular zone. The table provides northing and easting (meters and feet), scale factor, linear distortion, and convergence angle for a specific coordinate in a particular zone. It should be noted that all values that are provided in feet will be international feet units (ift).

The Alpha page provides an online option to look at all maps. The arrow in the image below highlights the link to access the online interactive maps.

When users click the link on the page, they are directed to an ArcGIS NOAA web map viewer.

To access the online map function, users need to click one of the Alpha SPCS2022 zone options.

Once users click on one of the web map buttons, another map page with a map icon appears on which users will need to click to get to the map of zones. 

After users click on the map icon, they will get another web page that contains the map zones based on their selection. In my example, I selected “all zone web map.” Once users get to this page, they can zoom into any area to find a particular zone.

I zoomed down until I located North Carolina’s map zone. The web page provides access to various layers and information. First, if users move their curser over the layer button, a list of layers pops up. Next, select one of the layers, such as Statewide Zones, then the properties of the map are placed on the map. Finally, when readers click on the map itself, the information about the SPCS2022 zone appears on the map.

North Carolina is a state that elected to have a single statewide zone. Some states decided to design several LDPs that cover certain areas or cover the entire state. Ohio is a state that designed 89 LDPs that cover the entire state. Again, by selecting the layer button, users have an option to select multizone complete zones, the properties appear on the map, and finally clicking on the map provides the zone information for that zone. In this example, I clicked on Columbus, Ohio, which is in the Ohio Franklin Zone.

Users can obtain specific information for a coordinate located in the Ohio Franklin Zone by clicking on the online interactive table of coordinates. Note that the distortion is 6.725 ppm at the coordinate in the zone. As previously stated, this was a user–defined LDP zone. 

Another Alpha site available for users to evaluate is the NGS Coordinate Conversion and Transformation Tool (NCAT). NCAT is probably the tool that most surveyors will be interested in using and providing feedback to NGS. Users can access NCAT on the Alpha SPCS2022 webpage or by clicking here.

The Alpha NCAT website has a note about the coordinates that users should provide as input to the routine. The bottom line is that the input coordinates need to be in ITRF2020 (epoch 2020.0), or readers may not get their desired zone. NGS recommends that users convert the coordinates to ITRF2020 (epoch 2020.0) using the Horizontal Time-Dependent Positioning (HTDP) tool.

Users can access HTDP here. I provided an example of HTDP for a CORS in North Carolina. I used the NAD 83 (2011) [epoch 2010.0] published coordinates of the CORS as my input values.

After using HTDP to transform the coordinates from NAD 83 (2011) to ITRF2020, I used the Alpha NCAT tool to compute the SPCS2022 values for the mark. I provided an example of the Alpha NCAT routine using the coordinates of the North Carolina CORS NCMR. The program defaults to horizontal only, so I changed it to the horizontal-height option. The user then enters the latitude, longitude, and height of the mark. Lastly, the user has an option to select the SPC zone or the program will select the zone based on the coordinates of the mark. In my example, I selected the auto pick option.

The image below provides the output of NCAT. I have highlighted a few items in the image. First, the program selected North Carolina’s Statewide Zone, the distortion is -54.554 ppm at this mark, and the UTM zone selected is Zone 17. The output also provides the scale and combined factors.

North Carolina is a state that elected to have a single statewide zone, but, as previously mentioned, some states decided to design their own LDPs. Again, Ohio is a state that designed LDPs that cover the entire state. Once again, I entered the coordinates into the input boxes and selected the auto pick (default zone) option. As indicated in the converted coordinates section, the program selected the OH FRA-391025 zone based on the coordinates of the mark. Notice that the distortion is only +8.024 ppm.

The user has the option to select a different zone than the default zone. The image below provides the SPC values for the COLB mark when selecting the Ohio Statewide Zone. Notice that the distortion value changes from +8.024 ppm to -168.316 ppm. Also, as expected, the UTM and X, Y, and Z values have not changed.

One last option to highlight is that the user can change the default UTM zone by clicking on the up or down arrows under the UTM column. In my example, I changed the UTM zone from 17 to 16. Obviously, the values under the UTM column changed.

The concept of the NGS’s Alpha site is to provide examples of the content, format, and structure of data and products that NGS plans to release as part of the modernized NSRS. NGS states that these Alpha products are for illustrative purposes only and do not contain any authoritative NGS data or tools. It states that they are under active development and are subject to change without notice.

That said, NGS would like everyone to try these Alpha products and provide feedback to NGS, so that they can improve their products and services. I would encourage readers to try these Alpha sites and provide comments and suggestions to NGS.

In 1973, on March 1, Xerox launched the Alto, the first computer designed from its inception to support an operating system based on a graphical user interface; on April 3, Martin Cooper of Motorola made the first cellphone call, from 6th Avenue in New York City; and TCP, Ethernet, and fiber optics were created.

That same year, over Labor Day weekend, a dozen people in a small conference room on the top floor of a nearly deserted Pentagon, at a meeting called and chaired by Brad Parkinson that became known as “Lonely Halls,” made the key design choices for the Global Positioning System. None of those fundamentals have changed in the intervening half century, during which GPS was developed, launched, and modernized and became a worldwide utility underpinning many critical economic sectors — including precision agriculture, financial services, location-based services, mining, surveying and telecommunications.

At the time, Parkinson — a United States Air Force colonel with a Ph.D. in astronautical engineering from Stanford University, three years of experience in inertial guidance, and 26 combat missions in AC-130 gunships — was the first director of the GPS Joint Program Office in Los Angeles. As he and his co-authors recalled in a detailed two-part history of GPS (see the May and June 2010 issues of GPS World), the aspects of GPS that were defined at Lonely Halls included:

• Simultaneous passive ranging to four satellites in inclined orbits, ensuring user equipment would not require a synchronized atomic clock.
• A signal structure using CDMA modulation, including both a precision military code and a clear acquisition one that would be freely available to civil users worldwide.
• Two GPS broadcast frequencies in the L band.
• A family of user equipment prototypes, including a low-cost set that would demonstrate civilian use.

I recently asked Parkinson how GPS today differs from the design that came out of the Lonely Halls meeting. “The fundamental answer is that it’s identical,” he said, “in terms of design, the atomic clock, the CDMA signal, and four satellites to eliminate the need for a user clock. What has been evolving, of course, is that we’ve added another frequency and several new signals, including those for the military and L1C.”

From the very beginning, Parkinson encouraged civilians to use the system, correctly predicting that “they would apply their research and design talents to drive the size, weight and power requirements of the receivers down and the family of applications up,” he said. “That’s exactly what happened, in my opinion.”

Which applications surprised him the most? “Our revolution has been enabled by the advent of integrated circuits in terms of size and cost,” he said. For example, RTK has now given dynamic users access to centimeter accuracies.

“We were driven by visions of the many beneficial applications of GPS; visions that were not yet shared by the Air Force. GPS is a testimony to my team’s engineering competency, their tenacity, and their resourcefulness. I, and the whole world, owe them a large debt for the benevolent revolution they created.”

Matteo Luccio | Editor-in-Chief
mluccio@northcoastmedia.net

Beep Inc, a provider of autonomous shared mobility solutions, and Oxa, an autonomous vehicle software developer, have partnered to deploy autonomous vehicles driven by Oxa in the United States. The collaboration marks Oxa’s entry into the U.S. market.

Under the partnership, Oxa’s autonomy software will be installed in a variety of vehicle types operated by Beep, from current passenger shuttles to future vehicle platforms.

The Oxa Driver is a software platform that combines sensor data from cameras, lidar, and radar to gain a more comprehensive view of the world around it when compared to vehicles that rely on cameras alone. This software uses AI to accurately sense and predict changes to the vehicle’s environment while learning from previous journeys.

Two of the Beep shuttles featuring Oxa software are currently operating at the recently opened SunTrax test facility in Auburndale, Florida, — the first location in the United States specifically designed for connected autonomous vehicle and standard automotive testing in a single site.

Oxa is using the facility to showcase its passenger transportation solution ahead of public availability in late 2023.

Two recent announcements showed China’s progress establishing its national “High-Precision Ground-based Timing System.” Some verbiage in the most recent announcement could indicate that the system is nearing completion.

The timing system is designed to support a vast array of scientific and technological applications as well as provide services when space-based signals are not available.

According to some Western observers, it is another example of China’s increasing lead over the United States in positioning, navigation, and timing (PNT) technology.

Its BeiDou satellite PNT system is newer and has been acknowledged superior in many ways to the U.S. Global Positioning System (GPS). This has allowed China to gain influence in some parts of the world at the expense of the United States.

Completion of the terrestrial system could have even more troubling implications for the United States.

Recent Announcements

On May 21 this year, a government affairs article in Shaanxi’s “The Paper” announced accelerated construction in Xi’an of a science center. Its centerpiece will be the country’s High-precision Ground-based Timing System. It is not entirely clear from the article whether this site will be the engineering and administrative headquarters for the system, or one of several “timing stations.”

The article also says the national system will be the largest in the world — with more than 20,000 kilometers of optical fiber and 295 time and frequency transmission sites — and will integrate space- and ground-based signals.

The network, according to the article, will supplement and improve the new eLoran (sometimes mistranslated by software as “Roland”) system in the western portion of the country. It will also support legacy eLoran “long-wave” signals in the east ensuring that the entire nation is well served.

Accuracy for the system’s fiber-optic transmissions is claimed to be less than 100 pico-seconds, with differential eLoran at less than 100 nanoseconds.

Experts in the West have confirmed that both these goals are achievable. Europe’s CERN laboratory has demonstrated picosecond level via fiber, and UK trials have shown the accuracy of differential eLoran to be within 50 nanoseconds.

A much shorter press release was issued on June 8, announcing groundbreaking for a “timing station” in Nagqu on the Tibetan plateau in China’s west. The announcement said that, once the station was complete, China will “…realize national soil coverage of long-wave [eLoran] timing signals…”

Expansion of its eLoran and fiber infrastructure to serve the entire nation gives China what some have called the “PNT resilience triad” — signals from space, from terrestrial broadcast, and over fiber. The three sources of delivery are sufficiently different that an accidental or malicious disruption of one is highly unlikely to impact the other ones. Users accessing all three should experience minimal to no impact.

Both the May and June announcements said that finishing the timing project will benefit China’s national economy and national security.

Timing is essential tech infrastructure. More precise and robust timing enables improvements to current applications and the creation of new ones. For example, better timing can enable greater spectrum efficiency with more throughput on existing frequency bands. Highly precise fiber-based timing could also support using 5G telecommunications networks for hyper-precise positioning in autonomy corridors serving self-driving vehicles, UAVs, and other systems.

China’s ground-based timing system is part of a larger plan by its National Timing Service Center for a system of systems approach to PNT. Described as a “comprehensive approach” at the Standford PNT Symposium in 2019, the architecture has satellite-based navigation at its heart and includes a wide variety of other capabilities.

Some observers trace China’s national PNT efforts to an incident in 1996 during the Third Taiwan Strait Crisis. Chinese forces fired three missiles toward a point in the sea offshore of Tiawan’s Kee Lung naval base. Two of the missiles were lost. According to the People’s Liberation Army this was because the United States denied or altered GPS signals that the missiles were using for guidance.

Known by China’s military as “The Unforgettable Humiliation” the incident sparked decades of effort to ensure China would never again be dependent upon another nation or space for PNT. The BeiDou global navigation satellite system and the High-precision Gound-based Timing System are the two most noteworthy accomplishments in this regard.

Implications for the United States

China’s ever-increasing lead in essential PNT technology and infrastructure is of great concern to many in the United States.

China’s global navigation satellite system, Bei Dou, is newer and, according to a presidential advisory board, substantially superior to GPS in many ways. Using it as an instrument of “soft power,” China is offering other nations BeiDou signals, along with discounted user and support equipment, as part of its Belt and Road, and Digital Silk Road initiatives. Where successful, these efforts erode both GPS usage and U.S. influence.

Of greater concern to many are the “hard power” implications of China’s PNT dominance.

While China has and continues to develop multiple and resilient sources of PNT, in the United States “GPS is still a single point of failure,” according to a member of the National Security Council.

As a result, if China were to interfere with GPS in some way, a U.S. response in-kind against BeiDou would have much less impact. This strategic asymmetry has been described by former CIA senior analyst George Beebe as “an open invitation” for mischief or attack. One that could easily lead to an escalating series of responses ending in an armed conflict no one wants.

At a more tactical level, China’s eLoran system extends 1,000 miles offshore covering Taiwan, the Strait, and all approaches. In a conflict to capture the island and make it subject to the Communist regime, China could block all signals from space while preserving its forces’ ability to maneuver and communicate. Already at a disadvantage having to deploy far from their support bases, this would further hamper U.S., Japanese, and other forces hoping to help Taiwan maintain its independence.

The U.S. Department of Defense boasts it can operate well in GPS-denied environments and says it is also working on alternative means of navigation for deployed forces.

This begs the strategic question, though, of whether the United States would be willing to come to the aid of Taiwan or another ally if the homeland were threatened with a prolonged and crippling disruption of GPS services.

Prior to Russia’s invasion of Ukraine, the Kremlin destroyed a defunct satellite and boasted it would shoot down all 32 GPS satellites and “blind NATO” if the alliance intervened. Many observers have wondered whether that has played into subsequent U.S. and NATO policy toward the conflict.

Unfortunately, little has been done to eliminate the possibility of a belligerent adversary holding the U.S. homeland hostage through GPS.

For two decades narrow government and industry interests in GPS production have successfully opposed any effort they see as possibly “competing” for space in limited budgets. Appeals that such projects would increase system security by “taking the bullseye off” GPS satellites and signals have been to no avail.

However, this may be changing. Several years ago the National Guard began development of a national timing architecture and network, called NITRO. The project supports the Guard’s own requirements to be able to operate without GPS and to aid state first responders. It is already in use in 7 states.

The future of NITRO is unclear, though, as the Department of Defense sees it as a civil defense rather than a national defense project and is no longer supporting it in the budget. Yet, the National Guard’s funding flows through defense appropriations.

As of this writing, the National Guard and NITRO remain stuck in a bureaucratic and budgetary no-man’s land with no clear path forward.

Qualcomm has entered a technology agreement with Hyundai Motor Group to integrate its Snapdragon Automotive Cockpit Platform into Hyundai Motor Group’s purpose-built vehicles (PBV).

The infotainment systems on the PBVs will use Snapdragon Automotive Cockpit Platforms for a “holistic, seamlessly connected and smart user experience,” Qualcomm said.

The PBVs are designed to deliver transportation, comfort, logistics, commercial and healthcare services. The latest generation of Qualcomm’s Snapdragon platform benefits from optimized power consumption, high-definition graphics and immersive multimedia and audio.

According to Qualcomm, the latest generation of Snapdragon Automotive Cockpit Platforms offer optimal power consumption while providing top-tier graphics as well as top immersive multimedia and audio experiences.

The platforms offer location services, emergency calling, noise reduction, and dual SIM capability as well as cloud-based monitoring and management systems. Using Qualcomm’s artificial intelligence (AI) engine and machine learning (ML) capabilities for intuitive and intelligent systems, Snapdragon can support digitally advanced applications, including in-vehicle virtual assistance and adaptive human interfaces. It can also facilitate natural communication between the vehicle and passengers for added safety and comfort.

The platform also employs dynamic configuration management to ensure vehicles are kept up to date. Reliable cloud-based vehicle monitoring and management also is possible through cloud service solutions.

Qualcomm and Hyundai Motor Group have been collaborating since 2011 on in-vehicle mobile communications using Snapdragon Automotive Connectivity Platforms.

GNSS researchers presented hundreds of papers at the 2022 Institute of Navigation (ION) GNSS+ conference, which took place Sept. 19-23, 2022, in Denver, Colorado, and virtually. The following four papers focused on the use of GNSS in urban environments. The papers are available here.

GPS World will be attending this year’s ION conference in Denver, Colorado, on Sept. 11-15.

FGO-based GNSS/INS integration improves performance in urban canyons in Hong Kong

The integration of GNSS and inertial navigation systems (INS) has the potential to improve performance due to their complementariness. In this paper, the authors investigated positioning based on the integration of GNSS and INS using factor graph optimization (FGO). This ultimately showed improved performance in urban canyons in Hong Kong. The effectiveness of the proposed method was verified using challenging datasets collected using two automobile-level GNSS receivers in the urban canyons of Hong Kong.

For the experiment conducted in this paper, only the GNSS pseudorange measurement was utilized in the existing FGO-based GNSS/INS integration. The overall potential of the Doppler frequency and carrier-phase measurements has yet to be explored by the authors. To fill this gap, the authors proposed a tightly coupled GNSS/INS integration, using FGO, by exploiting the potential of diverse raw GNSS measurements. The GNSS pseudorange, Doppler frequency, and time-differenced carrier-phase measurements were integrated with the INS, using FGO.

The authors believe the improved performance using FGO-based GNSS/INS integration positioning was due to the global optimization property and the increased measurement redundancy of FGO, compared with the method based on extended Kalman filtering.

Weisong, Hsu; “Factor Graph Optimization for Tightly-Coupled GNSS Pseudorange/Doppler/Carrier Phase/INS Integration: Performance in Urban Canyons of Hong Kong.”

3D mapping in urban environments aided by surround mask GNSS/lidar SLAM

Automatic driving with coupled GNSS/INS and lidar sensors has been implemented in many urban environments successfully over the years. However, this technology is still prone to errors. These potential errors are especially evident in challenging environments, such as urban canyons with several moving objects and building layouts that provide unexpected and abnormal features for lidar sensors and multi-path for GNSS signals.

To address these error challenges in urban environments, the authors of this paper proposed a surround mask that explores error sources from surrounding environments, which could subsequently improve the performance of an integrated mapping system. The surround mask in this experiment extracted a two-layer factor, including non-line-of-sight detection and static objects detection, to collectively compensate for the specific drawbacks of the lidar-based SLAM and the navigation system.

The authors explain that the surround mask eliminated the need to apply complex post-processing to eliminate the accumulated error for each observing unit.

The experimental results demonstrated that the proposed surround mask detected the represented error sources in the local coordinate and provided environment-awareness information for the integrated mapping system.

Ai, Luo, El-Sheimy; “Surround Mask Aiding GNSS/LiDAR SLAM for 3D Mapping in the Dense Urban Environment.”

Novel process noise model helps GNSS Kalman filter degradation in busy cities

Improving the accuracy of GNSS positioning in urban environments is difficult, especially when using low-cost GNSS receivers. In this paper, the authors showed that if the process noise covariance is turned up in a “naïve” manner for poor satellite geometry, the estimation-error covariance could become unintentionally large in a certain direction.

The unintentional inflation of estimation-error covariance could cause the degradation of accuracy. The authors also proposed a fictitious process noise covariance based on an extension of a novel process noise model, which was proposed in their previous work.

The authors stated that in Kalman filter for GNSS positioning, the process noise covariance is often bumped up to avoid the filter divergence in the presence of unknown model errors, by assuming there is a fictitious process noise in addition to the nominal process noise. In this study, the fictitious noise covariance is determined based on the observation matrix, step-by-step, and it reduced the estimation errors without causing the unintentional inflation of estimation-error covariance.

The effectiveness of the derived process noise model is demonstrated for the data sets that simulate GNSS signals from the antenna that moves from open sky areas to urban areas. The estimation errors with the derived process noise model were significantly reduced, compared to the ones with other two process noise models.

Ai, Luo, El-Sheimy; “Surround Mask Aiding GNSS/LiDAR SLAM for 3D Mapping in the Dense Urban Environment.”

3D lidar-aided GNSS RTK positioning for increased accuracy mapping in urban canyons

The GNSS real-time kinematic (RTK) positioning technique has shown centimeter-level absolute results in open-sky areas; however, it can suffer from polluted GNSS measurements and poor satellite geometry in urban environments. This is due to the non-line-of-sight (NLOS) and multipath reception caused by signal blockage and reflection.

In this paper, the authors stated that lidar sensors integrated with odometry systems that include an inertial measurement unit (IMU) provided a precise environment description and short-term accurate relative positioning capabilities that could be utilized for aiding GNSS-RTK to obtain better performance.

While 3D lidar-aided GNSS RTK positioning methods detect the GNSS NLOS receptions via an incrementally built map and improve the satellite geometry using the low-lying virtual satellite from lidar features, the high-elevation angle NLOS receptions cannot be fully detected, and the multipath signals cannot be effectively mitigated.

In response to this, the authors proposed a 3D lidar-aided GNSS RTK positioning method with iterated coarse to fine batch optimization by a global 3D NLOS exclusion aided by a point cloud map, which enables the detection of high-elevation angle NLOS receptions. Additionally, the authors proposed iterated batch optimization based on a devised, tightly coupled, factor graph that fully exploited the global consistency among the constraints of lidar, IMU and GNSS RTK to exclude potential multipath signals.

The proposed method aimed to achieve lifelong accurate positioning performance in deeply urbanized areas. The effectiveness of the proposed method has been proved by the evaluation conducted on the author’s open-source challenging dataset, UrbanNav, which contains various sequences collected by automobile-level low-cost GNSS receivers in urban canyons of Hong Kong.

Liu, Wen, Hsu; “3D LiDAR Aided GNSS Real-time Kinematic Positioning via Coarse-to-fine Batch Optimization for High Accuracy Mapping in Dense Urban Canyons.”

BAE Systems has been awarded an £89 million contract by the Ministry of Defense (MOD) to enhance front-line connectivity for military personnel, UAVs, combat vehicles, fighter jets, aircraft carriers and military commands.

The contract will be dedicated to the research and development phase of BAE Systems’ deployable tactical wide area network (WAN), Trinity. Trinity is due to be delivered in December 2025.

Under the contract, BAE Systems will lead an alliance of trusted partners, including Kellogg, Brown and Root (KBR), PA Consulting and L3Harris, to design and manufacture Trinity. The companies aim to deliver a highly secure battlefield internet capability to UK forces, which will sustain battlefield awareness and intelligence sharing through a myriad of adversarial attacks.

Trinity’s resilience is based on its composition, the company said. It is made up of a series of nodes, each able to add, access and move data in a secure network. If several nodes are damaged in warfare, the remaining automatically re-route to maintain optimum network speed and flow of information.