GNSS

ESA plans for low-orbiting navigation satellites

ESA’s Navigation Directorate is planning an in-orbit demonstration with new navigation satellites that will orbit just a few hundred kilometres up in space, supplementing Europe’s 23 222-kmdistant Galileo satellites. Operating added-value signals, these novel so-called ‘LEO-PNT’ satellites will investigate a new multi-layer satnav system-of systems approach to deliver seamless Positioning, Navigation and Timing services that are much more accurate, robust and available everywhere.

Simply by virtue of physics, with less of a distance to cover down to Earth, the signals from these LEO-PNT satellites can be more powerful, able to overcome interference and reach places where today’s satnav signals cannot reach.

And by adopting novel navigation techniques and a wider range of signal bands the satellites can address particular user needs: for instance at lower orbits the satellites themselves move more rapidly relative to Earth’s surface – think of the International Space Station at 400 km that orbits the Earth every 90 minutes – which offers possible advantage in the time needed to reach very accurate positions. Also some bands could offer greater penetration in difficult environments while other bands could offer higher robustness and precision.

The purpose of ESA’s plan to perform an in-orbit demonstration of low Earth orbiting satnav satellites is precisely to consolidate the types of signals, enabling technologies and their potential for future services.

The plan is to build and fly an initial mini-constellation of at least half a dozen satellites to test capabilities and key technologies, as well as demonstrating signals and frequency bands for use by a follow-on operational constellation, in the same way that Europe’s GIOVE test satellites paved the way for Galileo. www.esa.int

Russia, China sign contracts on mutual deployment of navigation stations

Russia and China have signed contracts for the deployment of Russia’s GLONASS stations in China and China’s Beidou system stations in Russia, the state corporation Roscosmos said in a news release.

Roscosmos CEO Yury Borisov and the chairman of the China Satellite Navigation System Committee, He Yubin saw contracts signed for the deployment of Russian GLONASS stations in China and Chinese stations of the Beidou system in Russia, the news release says.

At the meeting, a statement was also signed by the Information and Analytical Center for Coordinate, Time and Navigation Support of the Central Research Institute for Machine Building (TsNIIMash, an affiliate of Roscosmos) and the Test and Assessment Research Center at the China Satellite Navigation Office on jointly providing information support services to GLONASS and Beidou customers. https://english.almanar.com

GPS interference caused the FAA to reroute Texas air traffic

The Federal Aviation Administration is investigating the cause of mysterious GPS interference that prompted the closure of one runway at the Dallas Fort Worth International Airport and some aircraft in the region had to be rerouted to areas where signals were working properly.

The interference first came to light in the early October this year, when the FAA issued an advisory over ATIS (Automatic Terminal Information Service). It warned flight personnel and air traffic controllers of GPS interference over a 40-mile swath of airspace near the Dallas-Fort Worth airport. The advisory read in part: “ATTN ALL AIRCRAFT. GPS REPORTED UNRELIABLE WITHIN 40 NM OF DFW.”

An advisory issued around the same time by the Air Traffic Control System Command Center, meanwhile, reported the region was “experiencing GPS anomalies that are dramatically impacting” flights in and out of Dallas Fort Worth and neighboring airports. It went on to say that some of the airports were relying on the use of navigation systems that predated GPS. Then, around 11 pm Dallas time, the interference ended. As mysteriously as the interference began, it had stopped.

Civilian GPS relies on low-power satellite signals broadcast in the L band, a radio frequency range that’s also used by civilian terrestrial radio sources, including 5G mobile devices. That makes GPS susceptible to unintentional interference from the rollout of this nextgeneration technology. Equipment used on military bases is also a frequent cause.

Typically, however, when unintentional interference occurs, authorities can pinpoint the cause within a few hours. With no known cause, experts can only speculate.

“We don’t know if there are malicious actors behind this incident, or if it’s a result of interference,” Josh Lospinoso, co-founder and CEO of aircraft and transportation security company Shift5 and a former US Cyber Command official said. “Interference is a timely issue for airports and airlines right now. There was a big push by wireless carriers to roll out 5G in airports a few months ago that was a terrible idea from the perspective of how many legacy devices in aircraft rely on the wireless bands that are impeded by 5G.”

Lospinoso also noted the susceptibility of civilian GPS to intentional spoofing and jamming. North Korea used GPS jamming in 2012. Three years ago, the Center for Advanced Defense Studies reported that Russia had performed extensive spoofing of signals used by GPS and other GNSS in Syria and other combat zones.

In 2012, for instance, researcher Brad Haines reported that he was able to spoof the ADS-B signals surveillance technology aircraft rely on to determine their position via satellite navigation. The researcher demonstrated how attackers could use these spoofed signals to create “ghost planes” that would appear on air traffic controllers’ screens. Researchers have also devised a low-cost hack that spoofs the instrument landing systems that planes rely on to safely land.

GPS interference isn’t life threatening. But as noted, episodes like these do cause cancellations, delays, and other inconveniences. https://arstechnica.com

Australia’s SouthPAN early Open Services now live

Early Open Services delivered by the Southern Positioning Augmentation Network (SouthPAN) are now live in Australia and New Zealand, improving location-based capabilities for the Australasia region.

SouthPAN provides accurate, reliable and instant positioning services across all of Australia and New Zealand’s land and maritime zones without the need for mobile phone or internet coverage. It will improve positioning from 5-10 meters, to as little as 10 centimeters — a 50-fold increase in accuracy.

This satellite-based augmentation system (SBAS) test-bed project took place between 2017 and 2019, demonstrating the value of SouthPAN to Australian and New Zealand economies and communities. Economic analysis indicates that it is more than $6.2 billion for Australia alone.

In February 2020, Geoscience Australia and Toitū Te Whenua Land Information New Zealand (LINZ) began a joint collaboration on SouthPAN under the Australia New Zealand Science, Research and Innovation Cooperation Agreement (ANZSRICA). A comprehensive procurement process followed, awarding an AUD$1.18 billion, 19- year contract on Sept. 16 to Lockheed Martin Australia. www.ga.gov.