Global Navigation Satellite Systems Engineering, Policy, and Design
SAM PULLEN, Stanford University
A: Since at least 1997, the Global Positioning System (GPS) Control Segment (CS) has issued what are known as “Notice Advisor(ies) to NAVSTAR Users” or “NANU(s).”
By Inside GNSS
Multi-antenna carrier-phase differential GNSS (CDGNSS)-based pose (position and orientation) estimation aided by monocular visual measurements and a smartphone-grade inertial sensor form the core of a system designed for micro aerial vehicles. It can be applied generally for low-cost, lightweight, high-accuracy, geo-referenced pose estimation.
A consortium is preparing to ramp up production of Geonav IoT, a seamless indoor/outdoor positioning solution for sports applications, asset tracking and aiding drone traffic management. The GNSS module is a high-accuracy, dual-frequency system-on-chip with an integrated, low-power application processor.
One hundred days into the administration and the federal civil service crew has set the stage for the Biden team on the tough Positioning, Navigation, and Timing (PNT) issues they face: the Ligado debacle, interference concerns and a troubling lack of system redundancy or resiliency.
As stated in these pages last September, every GNSS user in every segment can benefit from the new modernized signals in the L5 band. Foremost among these are likely to be smartphone users.
By Alan Cameron
Inaccuracy in cities has been the persistent and lingering problem for GNSS, engendering many attempts at a solution and revealing deeply embedded difficulties. This article provides an overview of the Google solution, the rollout in Android phones, and before/after results.
The Department of Transportation Report on complementary and backup PNT technologies has good information but paints far from a complete picture. Several candidate technologies were not demonstrated, and market factors that will form an important consideration are not discussed.
eMobility services that provide on-demand eBikes and eScooters rentals are fast growing alternatives to traditional transportation modalities. As they are affordable, convenient, and very green, eMobility services will continue to grow in popularity. This article presents some of the challenges and useful solutions to accurately track eBike and eScooter location in the real world.
Dr. Rui Hirokawa is Deputy General Manager, Space Systems Department, at Kamakura Works, Mitsubishi Electric Corporation. A fixture in today’s GNSS community, he manages several QZSS-related projects, including the centimeter-level augmentation service (CLAS), and has recently been deeply involved in the international standardization of high-accuracy GNSS.
By Peter Gutierrez For years, both the Executive and Congress have expressed concerns over PNT vulnerabilities and clamored for solutions. Yet little has changed. Three important reports emerged at the tail end of the old regime. As new leadership takes the helm, in which direction will it take the PNT enterprise?
By Dawn M.K. Zoldi (Colonel, USAF, Ret.)
A new approach to facilitate fast and/or reliable reception and decoding of the navigation message in harsh radio propagation conditions derives from digital communications. Link-layer coding (LLC) techniques improve times-to-first-fix (TTFFs) over legacy carousel transmissions and achieve near-optimal performance with a limited complexity increase.
Innovative features of cellular fifth-generation (5G) signals enable the wireless system to play a major role in autonomous technologies. Test results of a ground vehicle navigating with signals from five 5G base stations (gNBs) over a trajectory of 773 m traversed in 110 seconds show a position root mean-squared error of 4.1 m.
The value of the GPS SPS PS goes far beyond the specific parameters that it contains. It has a great deal of information regarding how GPS operates and ideally should be read in full (including the appendices) by everyone who works with GPS at the measurement level.
