A team of researchers has developed a low-cost sensor that can detect the changes in river height to provide wide-area flood warnings.
The Raspberry Pi Reflector (RPR) was designed by a team of scientists from the University of Bonn, the Federal University of Rio Grande do Sul, and the University of Colorado.
The solar-powered RPR is much less expensive (about US$150) than scientific-grade or geodetic GNSS instruments — the cost of which is “a limiting factor for their prompt and more widespread deployment as a dedicated environmental sensor,” the team writes in their paper.
The Raspberry Pi Reflector (RPR) prototype includes a low-cost and low-maintenance single-frequency GPS module (an Adafruit GPS FeatherWing receiver) and an unspecified GPS antenna connected to an inexpensive Raspberry Pi microcomputer. One such unit has been successfully operating since March 2020 in Wesel, Germany, next to the Rhine river.
The RPR hardware array: (a) Raspberry Pi 4 Model B (b) Adafruit Feather Adalogger microcontroller (c) Adafruit GPS FeatherWing receiver (d) GPS external antenna (e) Configuration of RPR prototype setup. (Image: Karegar, et al)
The unit on the Rhine provides sub-daily and daily water levels retrieved using spectral analysis of reflection data, or GNSS-reflectometry. The river level measurements from the RPR are compared with a co-located river gauge.
By changing the orientation of the antenna from upright to sideways facing the river, which was done in August 2021, the root-mean-square error (RMSE) was lowered to from 7.6 cm to 3 cm (sub-daily) and 6 cm to 1.5 cm (daily), the team said.
“While satellite radar altimetry techniques have been utilized to monitor water levels with global coverage, their measurements are associated with moderate uncertainties and temporal resolution,” the team states. “Therefore, such low-cost and high-precision instruments can be paired with satellite data for calibrating, validating and modeling purposes.”
The agreement will enable direct access to Xplore’s satellite tasking and archive of high-resolution data
Xplore Inc., a commercial space company providing space as a service, has signed a partnership agreement with UP42, a geospatial developer platform and marketplace. The agreement will enable direct access to Xplore’s satellite tasking and archive of high-resolution data.
Xplore’s XCRAFT satellite platform is engineered to collect data with multiple instruments including still and video imagery, hyperspectral, ultraviolet and infrared spectroscopy. Xplore’s satellite is capable of achieving user-defined video flyovers.
Data generated with Xplore’s diverse sensors will address a wide variety of use cases across the Earth observation industry including agriculture, forestry, oil and gas, maritime, change detection and intelligence, and creative media content. Additionally, customers can obtain more informative, rich layers of data from Xplore’s data-fusion products.
The combined power of bringing Xplore’s high-value imagery products to market via the UP42 platform will accelerate the commercial use of private remote-sensing data, according to Xplore.
The European Space Agency (ESA) has released a new video describing the Moonlight Initiative, part of NASA’s Artemis program.
ESA is a key partner in Artemis, which aims to return people to the Moon by the end of decade. Dozens of other international public and private missions are setting their sights on the lunar surface in the coming years.
However, to achieve a permanent and sustainable presence on the Moon, reliable and autonomous lunar communications and navigation services are required. ESA is working with industrial partners on the Moonlight Initiative, to become the first off-planet commercial telecoms and satellite navigation provider.
After launch, three or four satellites will be carried into lunar orbit by a space tug, and deployed one by one to form a constellation of lunar satellites. The number and specification of these satellites are being defined.
The constellation’s orbits are optimized to give coverage to the lunar south pole, where sustained sunlight and polar ice make it the focus of upcoming missions.
Moonlight will provide data capacities sufficient to serve these planned and future missions, with a navigation service that enables accurate real-time positioning for all lunar missions.
Taiwan will launch its first indigenously developed meteorological satellite in March 2023, reports Taiwan News.
The Triton satellite was designed and made by the National Space Organization (NSPO) over eight years. The satellite has completed testing and is undergoing review.
The 250-kg Triton carries GNSS-reflectometry equipment (GNSS-R) — independently developed by NSPO — to collect GNSS signals reflected by the Earth’s surface. Its mission is to research air-sea interaction to help predict typhoons.
Taiwan is hit by typhoons every year. Information on wave height and sea-surface wind speed, retrieved from the reflected signals, will be useful for research on typhoon intensity and path prediction.
The satellite will be transported to the Guiana Space Center in January. It is scheduled to launch in March aboard a Vega C rocket manufactured by Arianespace.
The Ariane 6 launch vehicle program has taken a dramatic step towards first flight with the start on Oct. 5 of hot-fire tests of the rocket’s upper stage and its all-new Vinci engine, according to the European Space Agency (ESA).
The tests are a significant step forward. They are being conducted using the specially built P5.2 test bench for engine and stage testing at the German Aerospace Center (DLR) in Lampoldshausen. The P5.2 test bench subjects the entire upper stage to operating conditions representative of a flight from Europe’s Spaceport in French Guiana, with the exception of vacuum and microgravity.
New Vinci Engine
Vinci, the upper stage engine of Ariane 6 fed by liquid hydrogen and oxygen, can be stopped and restarted multiple times — a critical capability for the complex missions demanded by launch customers today.
The rocket can place several satellites into different orbits and de-orbit the upper stage, leaving a minimum of hazardous debris in space. Vinci also has been developed for reliability, simplicity and lower costs.
Replacement Heavy Launcher
This test series is a critical milestone on a development path that will soon see Ariane 6 replace Ariane 5 as ESA’s heavy launcher.
For more than a quarter century, Ariane 5 has been a reliable partner for commercial, institutional and scientific clients. One of its most notable missions was the Dec. 25, 2021, flight that carried the NASA/ESA/CSA James Webb Space Telescope to its operational outpost in deep space.
But Ariane 6 will be an even more versatile vehicle, strengthening Europe’s autonomy in accessing space.
Auxiliary Power Unit
The tests being run at Lampoldshausen are also evaluating an innovative auxiliary power unit (APU) that works in tandem with the Vinci engine and is instrumental to Ariane 6 upper-stage performance.
To restart in space, earlier engines relied on large quantities of tanked helium to generate the necessary pressure and temperature in the propellant tanks and to ensure there are no bubbles in the fuel lines. However, the APU delivers these conditions using only small amounts of the cryogenic hydrogen and oxygen already carried in the main tanks.
Heading to ESTEC
The test series is being run by DLR and ArianeGroup, the Ariane 6 launcher prime contractor. When the test series is complete, the upper stage — integrated by ArianeGroup at its facility in Bremen, Germany — will be shipped to ESA’s ESTEC technical center in the Netherlands for stage separation and acoustic tests.
Ultimately, the Lampoldshausen tests will investigate hardware behavior and system function of the complete stage with its tanks, engines and avionics.
“The preparation for these hot firing tests is even more complex than for an actual launch,” said Ariane 6 launcher program manager Guy Pilchen. “Our colleagues in Lampoldshausen have decades of experience in rocket propulsion with extremely advanced test facilities. With ArianeGroup colleagues to control the upper stage and DLR people operating the test bench, we couldn’t ask for a better team.”
Space independence for Europe
ESA Director of Space Transportation Daniel Neuenschwander said that this new engine and the upper stage it powers are indispensable components of Ariane 6 and its objective — to guarantee that Europe maintains independent, competitive and sustainable access to space.
“It’s a fact in the 21st century that Europeans depend on space for safety, prosperity and security,” Neuenschwander said. “Europe needs to work toward complete autonomy in accessing and operating in space. Ariane 6 is key to this, and we are eager to see the liftoff from Europe’s Spaceport in French Guiana.”
Ariane 6 Vinci engine testing at DLR Lampoldshausen. (Photo: ESA)
The European Space Agency (ESA) is looking for companies interested in helping create a constellation of lunar satellites to connect and guide missions to the Moon. Creating lasting telecommunications and navigation links with the Moon will enable sustainable space exploration for the hundreds of lunar missions that are due to launch within the next few decades, ESA stated.
The companies would provide telecommunications and navigation services to these lunar missions, under its Moonlight initiative.
ESA is completing two studies with two consortia of space companies based in Europe that assess the business case and the technical solutions for building and operating a constellation of lunar satellites. ESA is asking any space firms to indicate whether they would like to become involved in the ambitious project — or simply to develop lunar telecommunication and navigation technologies and products. The deadline is Oct. 28.
Artist’s rendering: NASA
On Sept. 19, ESA Director General Josef Aschbacher and NASA Administrator Bill Nelson signed a joint statement on lunar exploration cooperation at the International Astronautical Congress in Paris.
The lunar Gateway will be an outpost in orbit around the Moon. It will serve as the staging point for both robotic and crewed exploration of the lunar south pole.
ESA’s European Service Modules will power all Artemis Orion spacecraft to the Moon and back. ESA will also provide refueling elements for Gateway and a communications module that will pave the way for Moonlight.
ESA has already initiated the Lunar Pathfinder project to provide initial communications services to early lunar missions, which will also help to prepare for the next stage with Moonlight. The Lunar Pathfinder will also include a navigation payload demonstrator, which will allow positioning in lunar orbit using GPS and Galileo systems for the first time, and is due to launch in 2025.
Space companies in Europe and Canada will be invited to tender for the initial Moonlight work in December.
The Hawaiian Volcano Observatory (HVO) of the U.S. Geological Survey has been working to rebuild its geodesic monitoring network after lava consumed several GNSS stations in 2018.
The work began following the 2018 Kīlauea lower East Rift Zone eruption and summit collapse, with funding from the Additional Supplemental Appropriations for Disaster Relief Act of 2019 (H.R. 2157).
Teams are rebuilding and improving HVO’s geodetic monitoring network to better detect, assess and respond to volcanic hazards related to Hawaiian volcanoes. The main geodetic datasets used by HVO scientists to measure surface deformation (ground movements) are GNSS, tilt and satellite radar (InSAR) imagery.
HVO’s geodetic network includes more than 70 GNSS stations and 15 tiltmeters on the Island of Hawai’i that continuously record and transmit data. These instruments require routine maintenance, must be upgraded periodically due to age, and must be replaced if destroyed by volcanic activity such as in 2018.
Network upgrades include replacing out-of-date instruments and improving HVO’s network of near real-time monitoring instruments at critical areas on Kīlauea’s summit and rift zones to support early detection of magma movement and associated hazards.
Lava takes out stations
In 2018, lava flows destroyed three GNSS stations in the lower East Rift Zone. Another three GNSS stations were destroyed in the caldera collapses at Kīlauea’s summit.
HVO staff rapidly deployed new GNSS stations at nearby locations to allow for continued monitoring during the eruption. These rapidly deployed sites included GNSS smart antennas mounted on surveys tripods — a setup typically only used for temporary deployments of several days to weeks.
Many of these rapidly deployed sites were decommissioned and removed after 2018. However, 13 of them are still being used for critical monitoring and remain on temporary tripods. These sites will be upgraded and hardened using engineered fixed monuments and masts. New sites will also be installed to replace sites destroyed in 2018.
A temporary GNSS monitoring site in the Kīlauea caldera was part of the rapid response to the December 2020 Halema‘uma‘u eruption. The site will be upgraded into a continuously operating reference station with state-of-the-art instrumentation and a hardened antenna mast. (Photo: USGS/A.P Ellis)
Emergency monitoring ongoing
GNSS receivers acquired by supplemental funds already have supported emergency monitoring of active eruptions and other volcano-related activity. Data from these instruments help HVO detect volcanic activity and inform partners at Hawai’i Volcanoes National Park (HAVO), Hawai’i County Civil Defense (HCCD) and Hawai’i Emergency Management Agency (HI EMA).
For example, HVO rapidly deployed three new semi-continuous GNSS stations in response to the December 2020 Kīlauea eruption. These stations gave scientists a more complete view of magma returning to Kīlauea’s summit.
Similarly, HVO deployed rapid-response GNSS equipment at two pre-existing benchmarks during the Kīlauea south caldera intrusion event in August 2021, allowing scientists to track the migration of magma from the south caldera to farther south. New instruments give HVO a more detailed understanding of and ability to monitor Kīlauea’s volcanic processes.
HVO’s geodesy program plays a critical role in monitoring Hawaiian volcanoes. HVO’s updated geodetic network ensures that scientists can monitor changes in the shape of volcanoes, respond to eruptions, and understand magma storage and movement underground.
“Thanks to supplemental funding, HVO is in the best position ever to leverage our state-of-the-art geodetic network to gain insights into the active volcanoes in Hawai’i, assess their hazards, issue warnings, and advance scientific understanding to reduce the impacts of volcanic eruptions,” stated Volcano Watch, HVO’s weekly newsletter.
The satellite company spoke to 20,000 people in 11 countries across the globe to uncover their perceptions of space, what happens “up there” and how they think it impacts life here on Earth.
The survey found that most people have no idea about the benefits of space. Only one third are excited about space, with 47% concerned about space junk and just 8% associating space with communications and connectivity.
Just 8% of respondents associate space with communications and connectivity.
“From connecting rural communities to helping solve climate change, we know the enormous potential space holds to improve life on Earth, and what it has already brought us,” Inmarsat said in a statement. “Now, both the magnificent possibilities and the potential risks of space, which Inmarsat is working hard to address, need to be showcased to the world.”
The report also features contributions from renowned figures in the sector including Scott Kelly, former astronaut and commander of the International Space Station, and Josef Aschbacher, director general of the European Space Agency.
“The research findings mark a real wake-up call for the space industry,” Inmarsat said. “It’s clear that people have a low understanding of the breadth and richness of the work being done in space today. Perhaps because the technology deployed is essentially invisible, people do not appear to understand the role space is already playing in their everyday lives, nor its potential to deliver a brighter future for our planet.”
In a world where GPS and other GNSS signals can be easily denied or, worse, spoofed, interest in other forms of navigation has rebounded.
Imagine being able to locate yourself within a couple of centimeters with just your cellphone – deep underground. Or inside a metal structure. Or underwater (assuming you can keep your equipment dry).
No satellite signals, no Wi-Fi ranging, no inertial system. Just the ambient magnetic flux that constantly surrounds us all. Everywhere.
Animals have used the Earth’s magnetic field to find their way for millions of years. People have been using magnetic compasses for over a thousand. Until the advent of GPS, magnetic compasses were foundational tools for aircraft and ship navigation, especially when out of sight of easily recognized landmarks.
Then GPS came along, and almost everyone’s eyes turned to space.
But in a world where GPS and other GNSS signals can be easily denied or, worse, spoofed, interest in other forms of navigation has rebounded. And because GPS helped demonstrate the efficiencies geospatial services provide, users also want those services to be more resilient and to work in places signals from space just can’t reach.
According to Neill, “Our solution builds upon inexpensive magnetometers, smartphones, machine learning, edge computing, and some incredibly complex math to convert raw magnetic data into a source of ultra-precise location data. These relatively recent tech developments allow us to bring things together for a major update to a centuries-old way of navigation and positioning.”
Describing AstraNav as a software tech company, Neill said that the company’s system is “hardware agnostic.” It can work on “just about anything that has a magnetometer. No additional hardware or external connectivity is required, and we can run on any existing operating system.”
The company has partners in retail, automotive and telecom validating the technology. They have also been working with a U.S. Department of Defense (DOD) combatant commander to demonstrate the product, as well as Virginia Tech and its National Security Institute (VTNSI.) “This is not a case of ‘here’s an idea that we hope will materialize,” said Neill. Describing two real-world trials and use cases to the board, he said, “This technology is a reality, and we’re doing it.”
Most previous magnetic navigation efforts relied upon relatively low-resolution maps. An airplane could find its way safely across the ocean using the maps that were available and likely end up within a mile or two of an airport. Much higher resolution maps built through surveys and artificial intelligence are critical to AstraNav’s centimeter-level accuracy with systems that continue to learn on their own.
Intellectual property is AstraNav’s biggest asset. “We have multiple patents filed and pending,” said Neill. “Our IP is what allows us to sense and analyze magnetic fields so finely, develop maps, and make use of very low-cost magnetometers, such as the ones in cell phones.”
Several people at the advisory board presentation expressed surprise that they had not heard of the company and this capability before. “We have been busy getting established as a company, supporting our first commercial clients, and doing demonstrations for various folks within DOD,” Neill explained. “This presentation is by way of our coming out party. We are very eager to become better known and are looking forward to explaining our capabilities one-on-one with potential users.”
Citing an abundance of proprietary material, Neill was unwilling to discuss a lot of technical detail at the public meeting. His short presentation, he said, was to raise awareness and stimulate interest.
The number of those in attendance who after the presentation said they were eager to learn more showed that he was successful.
Dana A. Goward is President of the Resilient Navigation and Timing Foundation
The launch of Xona’s test satellite begins a new era of innovation in assured PNT, with NovAtel receivers demonstrating early support of Xona’s signals
Hexagon | NovAtel has signed a memorandum of understanding with Xona Space Systems to collaborate in the positioning, navigation and timing (PNT) development of Xona’s new low-Earth orbit (LEO) constellation.
LEO constellations offer a new avenue of assuring PNT by providing stronger signals with satellites closer to Earth and improved positioning accuracy with rapidly changing geometry, NovAtel explained. Additional constellations and a larger number of available satellites improve visibility in cases where parts of the sky are obstructed by buildings and other obstacles.
Also, as the threat of unintentional or malicious jamming and spoofing increases, it becomes important to consider alternative sources of PNT and resiliency methods, the companies said.
“Precise and robust PNT forms the foundation for safe operation of modern applications such as automotive and autonomy,” said Brian Manning, CEO of Xona. “We are thrilled to be collaborating with NovAtel to demonstrate the benefits that our combined technologies can bring to these markets and many more.”
Xona’s new constellation will transmit encrypted signals on two frequencies, both offering authentication, further building new levels of resilience against malicious interference. NovAtel is an early adopter of Xona’s signals and an industry leader in resilient assured PNT.
“This agreement accelerates the future of alternative PNT,” said Sandy Kennedy, vice president of innovation at Hexagon’s Autonomy & Positioning division. “Our collaboration will demonstrate the complete assured PNT ecosystem that Xona has envisioned, and of which NovAtel is very excited to be part.”
Xona and NovAtel will be presenting innovations in assured PNT and the future of GNSS at the Autonomy & Positioning Reality Summit during HxGN LIVE Global in Las Vegas, June 20-23.
Three HawkEye 360 radio-frequency geolocation microsatellites were launched May 25. The satellites, launched aboard SpaceX Transporter-5 mission, were built by Space Flight Laboratory (SFL) of Toronto. Three SFL-built satellites for greenhouse gas monitoring were also launched.
The HawkEye 360 constellation detects and geolocates RF signals for maritime situational awareness, emergency response, national security and spectrum analysis applications.
Once Cluster 5’s on-orbit checkout is complete, the HawkEye 360 constellation will be expanded to 15 satellites, doubling capacity and revisit rates. This significantly boosts the constellation’s ability to serve global customer demand and to monitor activity across places such as Ukraine.
“Every enhanced satellite cluster we launch helps us deliver a higher density of valuable data to our government, commercial and humanitarian customers and partners – advancing our efforts to monitor global activities for a safer and more secure world,” said HawkEye 360 John Serafini. “Launch by launch, these space-based innovations are analyzing the knowns and uncovering the unknowns of the RF spectrum across the globe.”
Cluster 5 includes enhanced antenna functions introduced with Cluster 4, which allow greater flexibility in geolocating signals across a wide range of frequencies important to customers.
Cluster 4, launched April 1, has been completing checkout and moving into final formation to begin collecting data in late June. Cluster 5 is slated to achieve initial operating capability in August.
Cluster 4 on orbit. (Image: HawkEye 360)
HawkEye 360 plans to continue to grow the constellation to achieve revisit rates of about 15 minutes to support timely defense, national security and commercial applications.
SFL has now developed 15 microsatellites for HawkEye 360 of Herndon, Virginia. SFL was selected for these missions due to the importance of formation flying by multiple satellites for successful RF geolocation.
Other missions developed by SFL in the past two years include 16 communications CubeSats and three microsatellites designed for Earth observation, maritime tracking and atmospheric monitoring.
In its 24-year history, SFL has developed cubesats, nanosatellites and microsatellites that have achieved more than 191 cumulative years of operation in orbit.
Two Belgian adventurers are crossing Greenland on a triathlon including ski, kayak and a vertical rock climb. On the ride, they are using Septentrio’s AsteRx-SB receiver, collecting valuable data for climate research in collaboration with the Royal Observatory of Belgium.
The data will help build a precise elevation profile of the Greenland Ice Sheet as well as to calibrate existing elevation models, which are based on satellite altimetry. In addition, the multi-frequency capability of the AsteRx-SB receiver will enable monitoring of ionospheric activity as well as Galileo signals at high latitudes.
“The AsteRx-SB receiver provides accurate and reliable positioning data even in the world’s harshest environments,” said Nicolas Bergeot of the Time-Ionosphere section, Royal Observatory. Data collected will help research of arctic ice caps, ionospheric activity and other topics.
The expedition is called Nanok, which is an Inuit word for polar bear. Adventurers Gilles Denis and Nathan Goffart started the triathlon with a 600-km ski with a pulk sled along the Arctic Circle. The second part of the triathlon is a 1,000-km sea kayak along the Greenland east coast, and finally a 1-km vertical rock climb.
Gilles Denis shows the AsteRx-SB receiver and the PolaNt-x MF antenna that are accompanying the explorers for the entire journey, so that data can be collected at various locations along the way. The receiver is powered by solar panels. (Photo: Nanok Expedition)
