Using a Reference Vehicle for Solving GNSS Localization Challenges
VERT is a Renault Clio3, transformed into a mobile laboratory for very
precise estimation of vehicle trajectory. It’s loaded with a GNSS
receiver, inertial navigation system, encoder, and more. The authors of
this article are engineers from France’s GEOLOC Laboratory, the designer
and developer of the vehicle. They discuss the car’s architecture and
present four different methods for estimating high-precision reference
trajectory, highlighting the critical role played by navigation-grade
inertial measurement. Finally, they demonstrate and assesses VERT
performance based on newly developed navigation algorithms.
This Cátalan GNSS expert is a mathematician and a geomatics engineer. He says ''GNSS has always been present in my working life, so I never experienced the 'GNSS, aha!' moment. Rather, I never stopped thinking 'GNSS, of course!' ''
Reliability from Unreliable Peers
Guiding aircraft, tracking freight, synchronizing power grids and cellular networks, and time-stamping financial transactions — all of these civil applications require secure, reliable position and time information. This article introduces a cooperative signal authentication architecture in which civil GNSS signals and the encrypted military signals on the same frequency are sampled at the same time by a user receiver and several ad-hoc cross-check receivers. Cross-correlation of these sampled signals are used to authenticate the received signal.
World Models and Magnetic Field Maps
Our growing expectation of being able to navigate anywhere at any time leads directly to new research areas that seek accurate positioning in places where GNSS doesn’t work. But every navigation system requires a world model that enables us to make use of navigation sensor data. This article provides examples of world models in GPS and visual navigation, describes efforts to use magnetic field maps to navigate without GPS, and advocates the need for self-building world models based on data collected by the same sensors with which we navigate.
Learn from the People
Gaming GNSS is in its infancy and poses an enormous temptation to malfeasance.
Significant progress has been made in integrating two classes of small,
unmanned aircraft into the national air space, an area of considerable
interest for GNSS companies whose products provide navigation and
guidance for many of the unmanned systems.
What is the effect of user and CORS height on NRTK performance?
Indoor positioning remains both elusive and an active area of research. New services such as GPS L5 and Galileo E5 may provide a quantum leap in accuracy over earlier signal designs. Here, two engineers describe a GNSS reflectometry system to measure the correlation function of various GNSS signals received indoors. The test results indicate that L5 and E5 will improve the indoor positioning capabilities of receivers.
In this issue: Easy Riders, Collaborative Air Force, SVN 64 and Take Two for Russia
A Crucial Element
Chris Bartone talks about GNSS antennas: how multiple GNSSes and multiple
signals affect their design and operations, some common errors and their
mitigation and how phase center offsets and group delay variations
affect GNSS measurements.