Thales Alenia Space, along with Viettel and MKE, have been selected by Vinamarine to provide Vietnam with a MEOLUT Next ground station. MEOLUT Next will operate as a part of the COSPAS-SARSAT global medium orbit search-and-rescue (SAR) network.
The SAR solution will enable the detection and location of distress signals from COSPAS-SARSAT beacons on land, in the air, and at sea over a radius of 2,500 km around Haiphong, Vietnam, mainly using signals from Galileo.
Thales Alenia Space’s MEOLUT Next solution employs a phased array antenna and can track more than 30 satellites, which enhances distress beacon detection and expands coverage. The solution can detect and locate distress signals from more than 5,000 km away.
MEOLUT Next is used by other COSPAS-SARSAT users including Canada, the United States, France, the European Union, Togo and Thailand.
Sharper Shape has used SimActive software’s distributed processing capabilities to complete utility corridor base maps in Montreal, Canada. In 2022, more than eight million images were collected in SimActive’s Correlator3D software to generate orthomosaics and colorized point clouds.
Correlator3D, hosted on an Amazon cloud environment, enabled quick processing of thousands of images per day over a network of virtual machines. The resulting map products covered more than 34,000 miles of utility corridor and were imported into Sharper Shape’s artificial intelligence (AI) tools to extract infrastructure information.
“The quantity of data that we capture to feed our AI tools for utility infrastructure deliverables is incredible and comes from various geographical locations at the same time,” said Petri Rauhakallio, vice president of business development at Sharper Shape. “Correlator3D allows our teams to easily import and process massive amounts of imagery for use in our digital twin production.”
Feb. 4 saw the news networks alive with sometimes wild reports about UFOs, UAVs and then a balloon. Balloons are used for weather forecasting on a regular basis, launched daily into the stratosphere with payloads gathering wind speed and direction, temperature, humidity, pressure and, of course, position.
Synchronized twice a day at about 900 locations around the world, balloons are released into the stratosphere gathering essential atmospheric data to feed our weather forecasts. Reaching altitudes of 20 miles, these balloons often drift on winds as far as 125 miles from the release point, broadcasting measurements from their onboard sensors.
At first, maybe North American Aerospace Defense Command (NORAD) thought the balloon crossing into Alaska’s airspace was just one of these high-altitude weather prediction vehicles. Aircraft were apparently scrambled, and initially it was decided there was no threat, so the balloon was allowed to continue and enter Alaskan airspace. It was detected and subsequently tracked by both the United States and Canada for some time as it continued to drift on the jet stream over the border into the lower 48. Then, people in and around Billings Montana (home to one of the nation’s three nuclear missile silo fields at Malmstrom Air Force Base) started to send in reports of a very large balloon high overhead — according to one observer with a high-resolution camera, it even seemed to be stationary for 35 minutes.
Apparently, by the time the good folks in Montana were looking up, the Pentagon had decided the balloon was a Chinese surveillance vehicle. To get this detail, one or more U-2 high altitude reconnaissance aircraft had been dispatched to investigate. The collected U-2 information spotted markings of a Chinese manufacturer on the 200-foot-tall balloon. A payload the size of a small passenger jet dangled some 20 feet below the balloon canopy. It had several antennas of various configurations. A huge solar panel was attached — presumably to power its suite of surveillance sensors.
The Federal Aviation Administration (FAA) ordered a ground stop for all aircraft traffic at the Billings airport while decisions were made about downing the balloon or allowing it to proceed.
Meanwhile, it may seem obvious that both the United States and China have developed, launched and make use of surveillance satellites. I imagined that a couple of dozen of these space vehicles would be buzzing over not only each other’s landmass, but also surveilling dozens of other countries as they orbit the whole planet.
What I found was a report that China had at least 260 such orbital observation platforms in 2022, and the United States has even more. Isn’t that enough without resorting to lower-tech balloons?
It’s possible that some electronic transmissions are short range and would not be detected by surveillance satellites operating in geosynchronous orbit (22,000 miles out), or even at 300 miles where the International Space Station (ISS) and most surveillance satellites hang out. So, a slow-moving balloon at 20 miles up might be ideal to “sniff” ground transmissions from sensitive military installations, and if you could control the balloon to hover, all the better to pick up radio signals. Could the gathering of transmission data somehow be used to geo-locate the source? It’s something the U.S. military may be working on, too, as it is reportedly also building a fleet of autonomous dirigibles and balloons.
According to press reports, the United States decided not to immediately take down the balloon, even though it subsequently discovered its surveillance capabilities. Not only was there concern over debris falling on populated areas but allowing the balloon to continue its flight over the United States provided an opportunity to observe its behavior and gather useful information. U.S. bases along its path apparently shut down all communications in sequence, as the balloon passed overhead.
The balloon was apparently found to be transmitting – presumably reporting on where it was and what it had detected. But, at some time transmissions ceased, possibly when U.S. Air Force activity was detected nearby.
The take-down off Myrtle Beach
An F-22 flew to almost the same altitude as the balloon and fired an AIM-9X Sidewinder missile into it, leaving the payload to tumble from 60,000 feet into the shallow (50-foot deep) Atlantic Ocean off Myrtle Beach, South Carolina. Recovery boats were already on hand to pick up the collapsed canopy, and to begin locating the electronics payload on the seabed. At time of writing, the U.S. recovery effort has yet to inform us on finding the key electronic payload, which would go a long way to confirming the intended mission for the balloon.
Image: Screenshot of CNN news coverage
Strange, but a couple of days later over Canada, F-22s were again in action to take down a “cylindrical object” detected at 40,000 feet — an altitude posing a danger to airline traffic. Little has been released on what this object might have been — could it possibly be a re-entering piece of space debris? Again, debris recovery and analysis is underway, and we patiently wait for a public report about what this was all about.
What have we learned?
Both China and the United States operate huge fleets of surveillance satellites gathering intelligence daily about each other’s capabilities and those of other countries. Both China and United States have also invested in surveillance balloons, but China is the only country to send one over U.S. territory.
There may have been earlier balloon incursions, which are only now being reported. The U.S. response was initially to determine the configuration of the balloon and its payload, then to allow its journey along the jet stream to continue. The United States has said the balloon did not uncover anything already available by other means, but recovery and analysis of the payload would presumably confirm this announcement.
China is not happy about the U.S. takedown of a harmless, stray weather balloon. And what the heck were F-22s shooting at in Canada?
We’ll tell you more when we learn more….
Tony Murfin
GNSS Aerospace
Editor’s Note: Since the initial instance of an unidentified object floating across U.S. airspace — later identified as a Chinese surveillance balloon — three additional unidentified aerial objects were spotted in North American airspace. One was spotted in Alaska, one in northern Canada and one over the Great Lakes region. All three were shot down by U.S. fighter jets out of caution.
The Canadian Positioning, Navigation and Timing Office (PNTO) is warning stakeholders that Ligado has asked the Canadian government for access to spectrum that neighbors that of GNSS services. The request has long been a major issue in the United States because of the risk of radio frequency interference for GNSS users.
Image: da-kuk/E+/Getty Images
Innovation, Science and Economic Development’s (ISED) Spectrum Management and Telecommunications team announced on Aug. 19 a Notice of Application from Ligado Networks. The application seeks authority for providing terrestrial mobile services in the L-band (1526-1536 MHz in the MSS downlink, and 1627.5-1637.5 MHz and 1646.5-1656.5 MHz in the MSS uplink).
In its application, Ligado Canada is requesting that ISED adopt similar operational requirements and technical rules as those of the U.S. Federal Communications Commission. The rules are spelled out in 2020 FCC order 20-48, “FCC Ligado Amendment to License Modification Applications.” The operational requirements would allow Ligado Canada to provide ancillary terrestrial mobile services over specific portions of its licensed MSS spectrum.
Interested stakeholders can submit comments until Oct. 18 on ISED’s website. Respondents are requested to email their comments in Microsoft Word or Adobe PDF to [email protected].
CANSPACE Listserv is a service of Canadian Space Geodesy Forum and is administered by Dr. Richard Langley.
Canada is leveraging advanced surveillance capabilities to enhance safety and efficiency by implementing a new mandate that will require aircraft operators flying in certain domestic airspace to meet Automatic Dependent Surveillance – Broadcast (ADS-B) Out performance requirements.
ADS-B uses GNSS technology to calculate an airplane’s precise location, speed and direction. This information is transmitted twice per second, providing greater situational awareness for air traffic controllers. It also provides increased flexibility to accommodate airline and customer preferred routes.
The mandate will take effect in Class A and B Canadian airspace above 12,500 feet on Feb. 23, 2023.
“ADS-B is a foundational building block for our future airspace and operations,” said Raymond G. Bohn, president and CEO of Nav Canada. “The Canadian equipage mandate — when combined with Nav Canada’s space-based surveillance capabilities — will enhance safety and service.”
“The aviation sector plays an essential role in connecting Canadians to each other and the world,” said the Honourable Omar Alghabra, Minister of Transport. “We welcome advancements and innovation that enhance the safety and environmental sustainability of our transportation networks and supply chains.”
The equipage requirements of Canada’s ADS-B mandate are in line with a growing number of other countries in the world, and the adoption of satellite-based surveillance technology ensures long-term alignment with the global aviation system.
Space-based ADS-B is already being used and delivering safety and efficiency benefits to suitably equipped aircraft over Hudson Bay, the North Atlantic and in domestic airspace above 29,000 feet in Canada. In December 2021, Nav Canada began providing service to appropriately equipped aircraft below 29,000 feet in the Montreal Flight Information Region and plans to expand to the Edmonton and Winnipeg Flight Information Regions later this year, prior to the mandate going into effect in 2023.
Future implementation of a mandate in areas within Class C, D and E will leverage a phased approach to help achieve the maximum benefits of a performance-based mandate for Canadian airspace. Aircraft operators and owners will have adequate time to meet the equipage requirements to use space-based ADS-B technology across the country. Implementation in these classes of airspace, to occur no sooner than 2026, will be determined pending further assessment.
About the ADS-B mandate
To meet the ADS-B Out mandate, aircraft will be required to:
Be equipped with an appropriate transponder with ADS-B Out capabilities and performance with the applicable standard of Radio Technical Commission for Aeronautics (RTCA) DO-260B, “Minimum Operational Performance Standards” or newer.
Have antenna capability for broadcast toward space-based ADS-B receivers emitting 1090 MHz extended squitter. This requirement can be met either through antenna diversity (the use of a top and a bottom antenna) or with a single antenna capable of transmitting both toward the ground and up toward satellites.
In one of my previous columns, I described the National Geodetic Survey’s (NGS) plans for replacing the North American Vertical Datum of 1988 (NAVD 88) with the North American-Pacific Geopotential Datum of 2022 (NAPGD2022).
As stated in the NOAA Technical Report NOS NGS 64 Blueprint for the Modernized NSRS, Part 2: Geopotential Coordinates and Geopotential Datum, November 2017, recently revised in February 2021, orthometric heights in NAPGD2022 will be defined through ellipsoid heights and GEOID2022. This means NAPGD2022 orthometric heights will primarily be accessed through GNSS technology.
Like NAPGD2022, in the next update of the International Great Lakes Datum, denoted as IGLD (2020), the heights in the Great Lakes Region will be developed from GNSS and a gravity model. Unlike NAPGD2022, where users will be estimating GNSS-derived orthometric heights, IGLD (2020) users will be estimating GNSS-derived dynamic heights using GNSS and a gravity model.
Promote a better understanding of geodesy as a science;
Create a better appreciation of the value of geodetic surveys and thus encourage greater use of such surveys;
Promote geodetic surveys by individuals, government, and private organizations;
Foster the adoption of uniform standards and procedures for completing geodetic surveys;
Promote the processing, publishing, and disseminating of geodetic survey data and information;
Promote programs for testing, calibrating, and evaluating geodetic equipment;
Further the development and implementation of the Global Navigation Satellite System (GNSS) for geodetic, land surveying, and land information system applications;
Inform the membership of new technical developments by meetings of the association and publications in Surveying and Land Information Science (SaLIS);
Promote educational programs in geodesy, geodetic surveying, and related fields;
Cooperate with other similar organizations, both national and international, in support of the science of geodesy;
Encourage the use of geodetic surveys and mathematical coordinate systems in establishing Public Land Survey System (PLSS) corners
As stated above, AAGS cooperates with other similar organizations, both national and international, in support of the science of geodesy. AAGS is a voting member of FIG, which means AAGS has the opportunity to nominate and vote for elected officials, and develop policy that is important to all surveyors and mappers.
The theme of the FIG Working Week 2021 virtual conference was “Smart Surveyors for Land and Water Management: Challenges in a New Reality.” FIG Commission 5 focuses on meeting the highest level of accuracy for positioning and measurement (see box titled FIG Commission 5). Five 90-minute sessions described some of the efforts of FIG Commission 5.
“FIG Commission 5 focuses on meeting the highest level of accuracy for positioning and measurement. It provides the tools, techniques and procedures to educate and train surveying professionals everywhere. Appropriate methodology for data collection and processing are required to be successful in an era of global, integrated geospatial data.”
These sessions raised surveyor awareness of cutting-edge technology, techniques and procedures for using geodetic data and enhanced global cooperation and standardization in conformance with the ideals expressed by the United Nations resolution for a Global Geodetic Reference Frame. There were many good papers on positioning and measurement presented at the virtual meeting. Readers can obtain a list of presentations and papers at this website.
A paper by Jacob Heck, U.S National Geodetic Survey, and Michael Craymer, Canada Geodetic Survey titled “Updating the International Great Lakes Datum: Enabling the Integration of Water and Land Management in the Great Lakes Region” should be of interest to many U.S. and Canadian surveyors. The box below provides a link to the abstract, paper, handouts and video of the presentation.
05.1 – Managing the Land/Water Interface: WGS84 vs. the ITRS
Commission: 4 and 5
Chair: Dr. Mohd Razali Mahmud, FIG Commission 4 Chair, Malaysia
Rapporteur: Dr. Daniel Roman, FIG Commission 5 Chair, United State
Jacob Heck (U.S.) and Michael Craymer (Canada):
Updating the International Great Lakes Datum: Enabling the Integration of Water and Land Management in the Great Lakes Region (11046)
[abstract] [paper] [handouts] [video]
The International Great Lakes Datum uses dynamic heights instead of orthometric heights traditionally used for elevations on land. Figure 4 from Heck and Craymer’s FIG paper, illustrates the difference between orthometric and dynamic heights. See box titled “Figure 4 from FIG Paper by Heck and Craymer.” As described by Heck and Craymer, “The dynamic height represents the difference in potential above the reference surface and is the same at all points on a level surface. Orthometric height represents the actual physical distance above the reference surface which may change due to differences in gravity caused by the convergence of equipotential surfaces toward to the poles. Dynamic heights are therefore required for the proper management of water levels and flows in compliance with international regulations and treaties.”
Figure 4 from FIG paper by Heck and Craymer
Figure 4. Dynamic heights,HD, and orthometric heights, H. (from FIG 2021 paper by Heck and Craymer)
I would like to highlight, as described in the paper and stated in the summary, that access to the future IGLD will be primarily through GNSS techniques.
The International Great Lakes Datum provides a framework for water level management in the world’s foremost resource of surface freshwater. The current datum, IGLD (1985), is being updated and replaced by IGLD (2020). This updated datum will be fundamentally different in terms of definition and access to the datum. The datum will be identical to the new NAPGD2022 North American geopotential datum and will be compatible with the existing CGVD2013 (if not identical as well) at the reference epoch of 2020. IGLD (2020) is expected to be released in 2025 at about the same time as NAPGD2022. Access to both frames will be primarily through GNSS techniques. This will lead to more consistent heights across the entire Great Lakes region. Further information about the IGLD update can be found on the Coordinating Committee website.
This new paradigm is important for anyone who works in the Great Lakes region. Actually, it is important to anyone that surveys in the United States, because this new paradigm will also be used to access the North American-Pacific Geopotential Datum of 2022 (NAPGD2022). Anyone following my columns knows this is the future, and that the National Geodetic Survey (NGS) is leading the way in the United States by modernizing the National Spatial Reference System (NSRS).
Another section that I’d like to highlight is in the box titled “Excerpt from Heck and Craymer Paper on IGLD.”
For IGLD (2020), the geoid height, N, will be provided by GEOID2022 which will be used to define NAPGD2022 and the expected update to CGVD2013. IGLD (2020) dynamic heights will therefore be equivalent to dynamic heights in NAPGD2022 and CGVD2013 at the 2020 reference epoch. For IGLD (2020) heights of water levels, hydraulic correctors may also need to be applied.
An important advancement in the development of the new IGLD and North American datums will be the availability of an accurate crustal velocity model that can propagate ellipsoidal heights between different reference epochs. This will enable heights determined at any epoch to be propagated back to the adopted 2020 reference epoch used for IGLD (2020). This will effectively obviate the need to update the entire IGLD datum for the effects of GIA for a much longer period of time, except for incremental improvements to the velocity model and updates to the reference epoch.
It’s important for users to know that the IGLD (2020) dynamic heights will be equivalent to dynamic heights in NAPGD2022, and an accurate crustal velocity model will be used at any epoch to propagate back to the adopted 2020 reference epoch. The box titled “Determining Heights in IGLD (2020)” is an excerpt from Heck and Craymer’s FIG paper that describes the process that will be implemented for estimating GNSS-derived dynamic heights in the updated IGLD (2020).
In previous realizations of IGLD, spirit leveling was used to determine geopotential numbers which were converted directly to orthometric heights that could then be converted to dynamics heights using equation 4 (𝐻𝐷 =𝐶/𝛾45).
In the geoid-based IGLD (2020), heights will be primarily determined through GNSS techniques which provide a direct measure of ellipsoidal height. Although spirit leveling is more accurate over shorter distances, GNSS methods combined with an accurate geoid model are capable of providing more accurate heights over moderate to longer distances at a small fraction of the cost of leveling.
An orthometric height, H, above the geoid is obtained from a GNSS-derived ellipsoidal height, h, above the reference ellipsoid using the geoid height or undulation, N, of the geoid above the reference ellipsoid. This is represented by the simple equation:
𝐻 = ℎ − 𝑁 (5)
Using equations (2) – (5), the dynamic height can be obtained from the GNSS-derived ellipsoidal height using:
𝐻𝐷 =(𝑔̅ ∗ (ℎ − 𝑁))/𝛾45 (6)
For IGLD (2020), the geoid height, N, will be provided by GEOID2022 which will be used to define NAPGD2022 and the expected update to CGVD2013. IGLD (2020) dynamic heights will therefore be equivalent to dynamic heights in NAPGD2022 and CGVD2013 at the 2020 reference epoch. For IGLD (2020) heights of water levels, hydraulic correctors may also need to be applied.
An important advancement in the development of the new IGLD and North American datums will be the availability of an accurate crustal velocity model that can propagate ellipsoidal heights between different reference epochs. This will enable heights determined at any epoch to be propagated back to the adopted 2020 reference epoch used for IGLD (2020). This will effectively obviate the need to update the entire IGLD datum for the effects of GIA for a much longer period of time, except for incremental improvements to the velocity model and updates to the reference epoch.
As stated by Heck and Craymer, hydraulic correctors may also need to be applied to meet IGLD (2020) International policies, procedures and regulations. Information on IGLD (1985) hydraulic correctors can be found on NGS Geodetic Tool Kit Page.
Another paper presented at FIG Working Week that would be of interest to surveyors is a paper on establishing a geoid-based vertical datum given by Dan Roman, Chief Geodesist at NGS (see the box below). Again, the abstract, paper, handouts and video can be downloaded from the link.
05.1 – Managing the Land/Water Interface: WGS84 vs. the ITRS
Commission: 4 and 5
Chair: Dr. Mohd Razali Mahmud, FIG Commission 4 Chair, Malaysia
Rapporteur: Dr. Daniel Roman, FIG Commission 5 Chair, United State
Roman Daniel (USA): Determining an Optimal Geoid-Based Vertical Datum (10876)
[abstract] [paper] [handouts] [video]
Roman discusses the concept of establishing an International Height Reference System (IHRS) so all countries could provide physical heights across their boundaries and over the oceans (see the boxes titled “Excerpt from FIG Paper by Dan Roman” and “Summary from FIG Paper by Dan Roman “). I’ve highlighted several sections that are important to establishing a IHRS.
The IHRS is relatively recent compared to the ITRS. Ihde et al. (2017) discussed plans for unification of heights globally, which were updated more recently in Sanchez et al (2021). Just as ITRF realizations are made within the ITRS, there will be IHRF realizations made within the IHRS. The key concept here is that positions will first be realized in the ITRS and then expressed in the IHRS. This means that GNSS-accessed geodetic coordinates will determine your position in a realization of the ITRF. Using those ITRF coordinates, geopotential values will be determined from an equivalent IHRF model based above a datum of W0 = 62,636,853.4 m2 s-2. This effectively gives your position in the Earth’s gravity field, which is a physical height. In adopting such a model then, all countries might provide consistent physical heights across their national boundaries and over the oceans.
There is a great deal of activity in modernizing how geospatial data are collected, processed and maintained globally. International agreements are in place to have everyone adopt the Global Geodetic Reference Frame to facilitate geospatial data transfer. The approach will be to realize coordinates in the International Terrestrial Reference Frame and then obtain physical heights from the International Height Reference Frame. Countries may adopt any realization of the ITRF but are restricted to a single geopotential value in the IHRF – W0 = 62,636,853.4 m2 /s2. If comparisons to local tide gauges demonstrate this is not optimum for national definitions of a vertical datum, then an alternate geopotential datum can be determined based on an approach that requires supplemental information.
GNSS-observations on multiple tide gauges will establish local Mean Sea Level and any variations due to Topography of the Sea Surface. A model of the TSS would be required to remove TSS effects at tide gauges to determine the geodetic coordinates of MSL. Use of a geopotential model enhanced by locally obtained gravity data would yield the geopotential number(s) at tide gauge(s). Assuming multiple tide gauges, then an average or some statistical analysis might be made to determine the optimal geopotential value to select as a geoid.
NGS’s new modernized NSRS will be compatible with the concept of an International Height Reference Frame. As stated in Roman’s paper, a recent article by Laura Sanchez, et.al, describes a strategy for the realization of the IHRS (see box below.)
Authors: Laura Sánchez, Jonas Ågren, Jianliang Huang, Yan Ming Wang, Jaakko Mäkinen, Roland Pail, Riccardo Barzaghi, Georgios S. Vergos, Kevin Ahlgren and Qing Liu1
Abstract
In 2015, the International Association of Geodesy defined the International Height Reference System (IHRS) as the conventional gravity field-related global height system. The IHRS is a geopotential reference system co-rotating with the Earth.
Coordinates of points or objects close to or on the Earth’s surface are given by geopotential numbers C(P) referring to an equipotential surface defined by the conventional value W0 = 62,636,853.4 m2 s−2, and geocentric Cartesian coordinates X referring to the International Terrestrial Reference System (ITRS). Current efforts concentrate on an accurate, consistent, and well-defined realisation of the IHRS to provide an international standard for the precise determination of physical coordinates worldwide. Accordingly, this study focuses on the strategy for the realisation of the IHRS; i.e. the establishment of the International Height Reference Frame (IHRF). Four main aspects are considered: (1) methods for the determination of IHRF physical coordinates; (2) standards and conventions needed to ensure consistency between the definition and the realization of the reference system; (3) criteria for the IHRF reference network design and station selection; and (4) operational infrastructure to guarantee a reliable and long-term sustainability of the IHRF. A highlight of this work is the evaluation of different approaches for the determination and accuracy assessment of IHRF coordinates based on the existing resources, namely (1) global gravity models of high resolution, (2) precise regional gravity field modelling, and (3) vertical datum unification of the local height systems into the IHRF. After a detailed discussion of the advantages, current limitations, and possibilities of improvement in the coordinate determination using these options, we define a strategy for the establishment of the IHRF including data requirements, a set of minimum standards/conventions for the determination of potential coordinates, a first IHRF reference network configuration, and a proposal to create a component.
I have highlighted several statements in the box titled “FIG Working Group 5.3.” This working group is focused on issues associated with implementing vertical control based on an International Height Reference Frame (IHRF). NGS is working with these groups to ensure that the United States height system will be compatible with the rest of the world.
I encourage everyone to visit the FIG website and explore the papers given during 2021 FIG Working Week. Here is a list of the FIG Commissions. For more information can be obtained on each commission by clicking on the Commission’s title.
Before the American Congress on Surveying and Mapping (ACSM) disbanded, the four-member organization collaborated to convene annual surveying and mapping conferences in the United States. Topics similar to those presented at FIG Working Week were presented at these conferences. I became a member of ACSM in 1972 and learned a lot from attending and participating in these conferences.
Since these ACSM conferences are no longer being held, I encourage users of geospatial data and GNSS technology to participate in professional societies such as AAGS to enhance their understanding and knowledge of new technical developments in the field of geospatial positioning and measurement. As the current president of AAGS, I am biased, but a benefit of AAGS membership is access to the Surveying and Land Information Science (SaLIS)journal that publishes new technological developments related to geodesy, surveying, and mapping.
“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.
Screenshot: Missing Children Society of Canada
Network Tool Helps Find Children
Microsoft and Esri Canada have developed the Child Search Network to enhance Canada’s national strategy for missing children. The network provides police services with a quick way to share information and collaborate with others, as well as with the general public, to find missing children faster and reunite them with their families. Police can put out information on a missing child via a website and smart-phone app. Members of the public can then offer tips by downloading the MCSC rescue app to register to receive alerts and share any information they may have regarding a missing child or youth. The tool helps meet the “gap of response” for high-risk cases of missing children that do not meet the strict criteria for the AMBER Alert.
Photo: Kroger
S’more Delivery Options
Grocery chain Kroger and Drone Express have launched a pilot delivery program in Centerville, Ohio, filling orders in as quickly as 15 minutes. Orders are sent to the customer’s smartphone location, which could include sending picnic supplies to a park or sunscreen to a beach. As part of the project, Kroger is selling bundled products within the payload weight — about five pounds, such as a S’mores bundle with graham crackers, marshmallows and chocolate.
One of the largest Adélie penguin colonies in the world was surveyed with multiple UAVs in March. Survey time was reduced from three days (with a single drone manually piloted) to under three hours. The work was led by a team of experts from Stanford University, Point Blue Conservation Science and Conservation Metrics. UgCS software by SPH Engineering was used to develop a system to autonomously survey the penguins. Thousands of high-resolution images were taken on each survey. An artificial intelligence model by Conservation Metrics is under development that will automatically identify and count adult penguins and their chicks. Using UgCS with a Stanford-provided planning algorithm, the survey team efficiently photographed more than 300,000 breeding pairs at Cape Crozier, Antarctica. The surveys will contribute to large-scale assessments of penguin populations and breeding success, key metrics for monitoring the health of the Antarctic marine ecosystem.
Photo: Bryngelzon/E+/Getty Images
Seeing Sinkholes with Satellites
Synspective Inc. is offering a sinkhole-detection prediction tool using satellite imagery analysis. Part of the company’s Land Displacement Monitoring service, an algorithm uses data science and machine learning to detect spatial and temporal variations. It can identify areas where sinkholes are likely to occur, areas where cave-ins have occurred, and areas where cave-ins are in progress. The input data is automatically updated, and the platform handles the processing and analysis of the complex satellite imagery.
Effective Sept. 1, Tallysman Wireless Inc. was acquired by Calian Group Ltd. to expand Calian’s reach in the satcom industry to markets requiring smaller antennas used in end-user devices that need a different range of fidelities, according to Patrick Thera, president, Advanced Technologies, Calian.
Calian is a publicly owned Canadian company listed on the Toronto Stock exchange. Its solutions include satellite gateways and infrastructure for RF communications, telemetry, tracking and control systems, space science and earth observation. Calian also provides leading-edge communication products for terrestrial and satellite networks.
Based in Ontario, Canada, Tallysman designs, manufactures and sells a wide range of GNSS, Iridium and Globalstar antennas and related products into a market with a broad range of vertical applications that include precision reference systems, survey, timing, precision agriculture, unmanned and autonomous vehicles, marine and more. The company also produces cloud-based wireless tracking systems over two-way radio systems and 4G category M cellular systems, for applications ranging from school buses to municipal public works.
The company is widely recognized as a technology leader and is the supplier of high-precision antennas to precision GNNS systems providers. Under the Calian umbrella, Tallysman will continue to operate as it has been, with no changes in product availability, fulfilment, support, management or engineering services.
Tallysman will also continue to invest in research and development, and bring new and innovative GNSS products to the market, the company said.
The definitive agreement is valued at up $24.5 million. Amount paid on closing is $15.7 million (net of cash received) and contains two earnout periods of $4M and $4.8M based on the achievement of a certain level of EBITDA performance over the next 30 months. Tallysman’s results will be consolidated and reported with Calian’s Advance Technology segment.
“This important acquisition supports both customer diversification and service line innovation, two key pillars within our four-pillar growth strategy,” stated Kevin Ford, Calian president and CEO. “The Tallysman acquisition demonstrates Calian continued our focus on innovation and growth. The wide range of products and applications Tallysman brings to Calian expands our product line and entry into new markets. We are excited with the opportunity to support innovation in exciting growth industries such as autonomous vehicles, precision agriculture and wearables. We could not be more pleased to welcome Tallysman to the Calian team.”
Sampford Advisors acted as exclusive M&A advisor to Tallysman.
“We are extremely pleased to join the Calian team,” said Gyles Panther, Tallysman president and CTO states. “We look forward to continuing, profitable growth of our core GNSS businesses with products that we sell to a broad customer base. As a member of the Calian family, we also look forward to leveraging additional resources, new technologies and markets deriving from Calian’s deep expertise in satellite communications.”
“Calian welcomes Tallysman to our team,” Thera said. “The Tallysman product line and services add a complementary component to our ground-based satellite communications business. GNSS is one of the fastest growing markets for satellite ground systems and we are excited to join forces with a leader in this field.”
MVT Geo-solutions, in partnership with Iris Automation, has been granted the first beyond-visual-line-of-sight (BVLOS) Special Flight Operations Certificate (SFOC) by Transport Canada using only onboard detect-and-avoid (DAA) systems.
The approval was granted based on the utilization of Iris Automation’s DAA system, called Casia, which provides commercial drones with automated collision avoidance maneuvers.
The waiver permits flights within the Unmanned Aircraft Systems (UAS) Center of Excellence’s controlled airspace Remotely Piloted Aircraft System (RPAS) test range in Alma, Quebec. This is the first BVLOS flight at the location leveraging only onboard DAA for air risk mitigation, and does not require ground-based observers or radar.
BVLOS flights unlock autonomous drone use for economically beneficial commercial applications including infrastructure inspection, mining, mapping, agriculture, emergency response and package delivery.
“Achieving the first BVLOS approval in Canada further validates our technology alongside multiple permissions we have already received from regulators in the U.S. and South Africa,” said Iris Automation CEO Alexander Harmsen. ”This technology is critical to safely integrate drones into the airspace along with manned-aircraft, and we look forward to unlocking commercial operations for our customers in Canada.”
Iris Automation’s onboard computer-vision DAA system is an effective, scalable and cost-effective technology to enable commercial BVLOS operations.
“The UAS Center of Excellence is looking forward to leveraging Iris Automation’s DAA system and existing flight expertise within our network to conduct BVLOS flights with MVT Geo-solutions,” said UAS Center of Excellence Director William de Keiser. “We will continue to develop our partnership with Iris Automation to provide training to local operators and enable BVLOS flights in Canada.”
The first BVLOS flights are scheduled to take place within weeks. The resulting data will inform more complex BVLOS operations in the future.
The 18,000-container-capacity CMA CGM Kuergelen. (Photo: CMA CGM)
Of the 273 papers researchers presented this year at the Institute of Navigation’s annual ION GNSS+ conference, which took place in Miami on Sept. 16–20, the following five focused on maritime issues. Papers are available at www.ion.org/publications/browse.cfm.
Automating the Sharing of Ocean Weather Data
The Automatic Identification System (AIS) — mandatory for large ships and used by many mid-sized ones — was designed to help avoid collisions, enable shore authorities to provide vessel traffic services, and allow coastal states to monitor their waters. It also may be used to transmit other information between AIS stations onboard and ashore.
In the aftermath of the sinking of the container ship El Faro in 2015, the U.S. National Transportation Safety Board (NTSB) and U.S. Coast Guard found a contributing factor was lack of reliable weather forecasts. The NTSB then recommended to the National Oceanic and Atmospheric Administration (NOAA) that it determine whether AIS could be used to share weather data collected by ships, to supplement the Voluntary Observing Ship (VOS) program where ships voluntarily submit weather observations to NOAA. The paper describes a successful test of this concept.
Citation. Gregory Johnson, Ken Dykstra, Gaurav Dhungana and Brian Tetreault, “Sharing Ships’ Weather Data via AIS.”
EGNOS for Maritime Navigation
The European Geostationary Navigation Overlay System (EGNOS), which has been providing guidance to civil aviation since 2011, also can support maritime, railway and road applications. This paper assesses its use for maritime navigation compliant with International Maritime Organization (IMO) requirements for harbor entrances, harbor approaches and coastal waters: 99.8% of signal availability, 99.8% of service availability, 99.97% of service continuity, and 10 meters of horizontal accuracy. A kinematic test campaign was conducted in the waters of the Canary Islands using a geodetic multi-frequency, multi-constellation receiver-antenna pair installed aboard two vessels. The EGNOS Maritime Service met all IMO requirements by achieving a signal availability of 99.999%, a service availability in 99.9% of a predefined rectangular region, and 1.06 meters of horizontal accuracy at the 95th percentile. The service continuity requirement, however, was met in only 62.50% of the predefined region. Therefore, the paper concludes that the continuity risk is the most limiting factor for expanding the EGNOS Maritime Service along the coastal waters of the Canary Islands.
Citation. Deimos Ibáñez Segura, Adria Rovira Garcia, Jaume Sanz, José Miguel Juan, Guillermo González Casado, María Teresa Alonso, José A. López Salcedo, Huamin Jia, Francisco Javier Pancorbo Garcia, Carlos Garcia Daroca, Irene Martin Calle, Santos Rodrigo Abadía Heredia and Manuel López Martínez, “A Kinematic Campaign to Evaluate EGNOS 1046 Maritime Service.”
Options for Integrity
Many maritime authorities are considering how to maintain the integrity of navigation systems as their infrastructure ages, especially given that the need for integrity in the user position is expected to increase with e-navigation services and for autonomous vessels. In harbor entrances, harbor approaches and coastal waters, the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) prescribes an absolute horizontal accuracy of ≤10 meters 95% of the time, with an integrity risk of 99.99999%. Today’s GNSS more than meets that accuracy requirement, so the driver is integrity. Options for integrity are marine radiobeacon DGPS/DGNSS, the primary augmentation system in use today; receiver autonomous integrity monitoring (RAIM); satellite-based augmentation systems (SBAS); and others (such as commercial services or inertial.). The European MarRINav project is investigating resilient PNT options to support UK Critical National Infrastructure. Part of this work is comparing EGNOS and marine radiobeacon DGPS performance to inform international discussions and receiver standardization.
Citation. Alan Grant, George Shaw and Martin Bransby, “Considering SBAS and marine radiobeacon corrections to support safe maritime operations.”
Evaluation of WAAS for Use in Canadian Waters
Mariners navigating in Canadian waters use a ground-based augmentation system (GBAS) that provides differential corrections and integrity monitoring of GPS. This GBAS has been provided since 1994 by the Canadian Coast Guard (CCG) in the form of a differential GPS (DGPS) broadcast service. The service is only provided south of latitude 60°N in collaboration with the U.S. Coast Guard. Before embarking on a recapitalization program of its 24-year-old DGPS, and given that the U.S. Coast Guard is progressively shutting down its National Differential GPS sites, the CCG is evaluating options for its own DGPS network. Options include the wide-area augmentation system (WAAS), originally developed by the U.S. Federal Aviation Administration for civil aviation. This paper describes the authors’ evaluation for the CCG to determine the expected accuracy, integrity and availability of WAAS throughout Canadian waters, concluding that the current WAAS provides acceptable accuracy and integrity for most of Canada, excluding the higher latitudes.
Citation. Gregory Johnson, Gaurav Dhungana and Jean Delisle, “An Evaluation of WAAS 2020+ to Meet Maritime Navigation Requirements in Canadian Waters.”
GNSS + INS for Attitude Determination
Attitude determination (AD) is an important navigation component for ships and spacecraft. GNSS enables resolving their orientation in a precise and absolute manner, by employing multiple antennas rigidly mounted on the vessel. This requires carrier-phase observations, with the consequent added complexity of resolving integer ambiguities. Inertial aiding has been extensively exploited for AD, because it enables tracking fast rotation variations and bridging short periods of GNSS outage. In this paper, the fusion of inertial and GNSS information is exploited within the recursive Bayesian estimation framework, applying an Error State Kalman Filter, which, unlike common Kalman filters, tracks the error or variations in the state estimate, posing meaningful advantages for AD. The results show that the inertial aiding, along with a constrained attitude model for the float estimation, significantly improve the performance of attitude determination compared to classical unaided baseline tracking.
Citation. Daniel Medina, Vincenzo Centrone, Ralf Ziebold, and Jesús García, “Attitude Determination via GNSS Carrier Phase and Inertial Aiding.”
Trimble has acquired Cansel Survey Equipment’s Can-Net and AllTerra New Zealand’s iBase networks. The acquisitions significantly increase the global footprint of Trimble-owned Virtual Reference Station (VRS) networks by adding key geographies in North America and New Zealand.
Subscription-based VRS correction services are now accessible to more customers around the world who rely on high-accuracy corrections to increase productivity and reduce operational costs. The correction services are designed for professionals in agriculture, geospatial and construction as well as emerging high-accuracy applications, such as on-road positioning for passenger vehicles. Financial terms were not disclosed.
The Can-Net and iBase acquisitions add over 1.1 million square kilometers (over 425,000 square miles) to Trimble’s correction services coverage that has grown robustly over the past eight years, contributing to Trimble’s shift toward software, services and subscription business emphasis.
Can-Net Network. The Can-Net network comprises multiple VRS networks and single-base solutions offering GNSS corrections across Canada. The acquisition provides Trimble with the largest VRS footprint in Canada, covering more than one million square kilometers (386,000 square miles).
Subscribers primarily work in the agriculture, survey and construction industries. In addition, the Can-Net network enables Trimble corrections technology to be used by automotive stakeholders deploying ADAS systems along the Trans-Canadian Highway.
iBase Network. The iBase network expands Trimble’s VRS footprint across both the north and south islands of New Zealand, totaling more than 100,000 square kilometers (39,000 square miles).
“The high-accuracy precision provided by VRS technology is a powerful tool in driving operational and financial efficiency for industries that require easy access to positioning services,” said Patricia Boothe, vice president of Trimble’s Advanced Positioning Division. “We are aggressively expanding the accessibility of VRS corrections around the globe. Our vision is to make high-accuracy positioning available to the broadest base of commercial users worldwide for applications in agriculture, construction, automotive, autonomy and others where precise positioning is a critical part of the solution. Trimble will continue to invest in technology and infrastructure to push the boundaries of performance and accessibility for our portfolio of services.”
Trimble networks are supported by a global network operations team made up of GNSS system engineers, geodesy experts and IT professionals. The team monitors the networks 24/7 from operation centers located on three continents, ensuring consistent and reliable service uptime and performance integrity.
A cockpit equipped with ADS-B controls. (Photo: FAA)
Canada will be delaying the implementation dates for Phases 1 and 2 of its ADS-B Out Performance Requirements Mandate, according to a report by the Canadian Owners and Pilots Association.
ADS-B stands for Automatic Dependent Surveillance – Broadcast. Deadline for aircraft in the United States to be equipped with ADS-B Out capability is Jan. 1, 2020.
The original deadline for implementation in Canada was set for Feb. 25, 2021, for Phase 1-Class A airspace and Class E airspace above FL600, and Jan. 27, 2022 (Phase 2-Class B airspace).
Because numerous industry operators have stated they will not be able to meet those deadlines, new Phase 1 and 2 implementation dates will be set.
Transport Canada-Civil Aviation (TCCA) has also stated that some regulatory matters must be dealt with before implementation can take place.
There is no word yet on how this might affect the implementation of remaining phases — C, D and E), according to the report. Nav Canada’s performance requirements mandate document states that implementation of the different phases will be a minimum of one year apart.
ADS-B Out. ADS-B Out broadcasts information about an aircraft’s GPS location, altitude, ground speed and other data to ground stations and other aircraft once per second.
Air traffic controllers and aircraft equipped with ADS-B In can immediately receive this information.
Tbe ADS-B offers more precise tracking of aircraft compared to radar technology, which sweeps for position information every 5 to 12 seconds.
