Global Navigation Satellite Systems Engineering, Policy, and Design
Federal Communications Chairman Ajit Pai’s step this week toward approving Ligado Networks’ request to use its satellite frequencies for a terrestrial 5G service comes after nearly a decade of testing that showed both versions of their proposal would interfere with GPS users.
By Dee Ann Divis
We stand at an existential crossroads while someone else decides our future. I don’t mean the choice of direction, currently roiling the front pages, that pits the national health against the national economy. No, this one doesn’t get the attention it deserves, outside of the PNT and the telecom communities, though arguably it could have equally long-running and widespread, perhaps catastrophic effects.
By Alan Cameron
“Ligado’s planned usage will likely harm military capabilities, particularly for the U.S. Space Force, and have major impact on the national economy,” two ranking Senators and a Representative wrote. The timing could not be worse, they said to allow what “is fundamentally a bad deal for America’s national and economic security.”
By Dee Ann Divis
Thirteen agencies responsible for much if not most of the nation’s military, civil, security and economic activity say Ligado Networks’ plan to use satellite frequencies for 5G communications would interfere with GPS users in general and DOD use in particular.
By Dee Ann Divis
JNC 2020, the largest U.S. military Positioning, Navigation and Timing (PNT) and GPS conference, has been rescheduled for September 8–11, 2020 at the same two locations near Cincinnati, Ohio.
By Inside GNSS
GPS keeps a digital twin sequestered in El Segundo, California. Galileo has an Earth-bound space vehicle in Noordwijk, the Netherlands, straining at its bonds, yearning to break free and fly with its brethren. Both constellation “ghosts” exist in an eerie testing twilight, being made to replicate the movements and reactions of their free-flying families. Their sacrifices could lead to better, more robust satellites in future generations.
By Alan Cameron
Knowledge gained in close study of post-processed GNSS/INS data from very high-dynamic aerial maneuvers can improve position monitoring in machine control, precision agriculture and other industrial applications.
The Space Force’s Space and Missile Systems Center (SMC) announced Tuesday it would reschedule the launch of the GPS III SV03 satellite “to minimize the potential of COVID-19 exposure to the launch crew and early-orbit operators.”
Originally scheduled for late April 2020 on a SpaceX Falcon 9 rocket, the launch is now projected to go up no earlier than June 30.
By Dee Ann Divis
Readers of this website are familiar—perhaps overly familiar!—with the threats to resilient positioning and navigation that are posed by interference, intentional and unintentional. Timekeeping applications for critical infrastructure using GNSS must also protect themselves against jamming and spoofing.
Though the pandemic impacts federal workers and contractors across the country, the early-March testing of GPS backup technologies finished on time and the analysis is expected to be completed on schedule.
By Dee Ann Divis
A new API for GNSS simulators enables greater accuracy, integrity and control for growing sensor-fusion testing needs. Spirent Communications’ SimHIL, an integrated hardware-in-the-loop (HIL) testing software API for Spirent GNSS simulators, brings high-fidelity GNSS signal simulation with low latency to automotive industry HIL testbeds.
By Inside GNSS
A new methodology targets sub-meter GNSS accuracies in the consumer realm for applications such as augmented reality and visually impaired navigation. Recent Android RTK smartphone services in a real-time environment achieve accuracies below 50 cm. Can these be matched with PPP?
By Joshua Critchley-Marrows, et al.
An assisted GPS direct positioning estimation (DPE) technique for urban environment copes with a full spectrum of direct-line-of-sight and non-line-of-sight or multipath conditions. A new approach using signal visibility and specular reflection predictions within the DPE shows the potential to reduce positioning error from approximately 30 to 10 meters.
