Apples to Apples Standardized Testing For High-Sensitivity Receivers Jan 1, 2008 By: Alexander Mitelman, Per-Ludvig Normark, Martin Reidevall, Stuart Strickland

Many products have similar performance specifications, but specified performance and measured performance can vary widely. Here, the authors describe how a standard methodology precisely defines acquisition, tracking, and reacquisition, using specific input signals to test each quantity.

The growing need for ubiquitous positioning and navigation to service the anywhere, anytime needs of the consumer location-based services (LBS) markets will strongly influence future receiver architectures. In particular, the need to operate with a multiplicity of GNSS systems, but also with other positioning techniques such as Wi-Fi access-point mapping and radio frequency identification (RFID) tagged locations, points towards increased use of software-defined radio (SDR) architectures.

GNSS Accuracy: Lies, Damn Lies, and Statistics Jan 1, 2007 By: Frank van Diggelen

This update to a seminal article first published here in 1998 explains how statistical methods can create many different position accuracy measures. As the driving forces of positioning and navigation change from survey and precision guidance to location-based services, E911, and so on, some accuracy measures have fallen out of common usage, while others have blossomed. The analysis changes further when the constellation expands to ombinations of GPS, SBAS, Galileo, and GLONASS. Software scripts, provided online, help bridge the gap between theory and reality.

Innovation: Spacecraft Navigator Autonomous GPS Positioning at High Earth Orbits Apr 1, 2006 By: William Bamford, Luke Winternitz, Curtis Hay

A receiver specially designed to function in high Earth orbit goes through a series of tests with a GPS signal simulator to validate its performance of the receiver on the ground, well before it debuts in orbit.

PDF: A receiver specially designed to function in high Earth orbit goes through a series of tests with a GPS signal simulator to validate its performance of the receiver on the ground, well before it debuts in orbit.

OpenSource GPS — A Hardware/Software Platform for Learning GPS: Part II, Software Feb 1, 2006 By: Clifford Kelley, Douglas Baker

As we mentioned in last month's "Innovation" column, the OpenSource GPS Project began in 1995 as a noncommercial alternative to the pioneering GPS Builder product introduced by GEC Plessey Semicon-ductor in Swindon, United Kingdom. (GEC Plessey was acquired by Mitel Semiconductor, Ottawa, Canada, in 1998 and reborn in 2001 as Zarlink Semicon-ductor.) Based on the same family of GPS chipsets, OpenSource GPS provides students an opportunity to learn about GPS by experimenting with the hardware and software of a GPS receiver.

OpenSource GPS, Part I A Hardware/Software Platform for Learning GPS: Part I, Hardware Jan 1, 2006 By: Clifford Kelley, Douglas Baker

The OpenSource GPS project has developed an economical hardware and software platform specifically for educational purposes. In this month’s column, two of the project’s leaders, present part one of a two-part article on the project. This month, they will discuss the hardware component, built around the Zarlink GP2015/GP2021 chipset.

Early Results Are In Nov 1, 2005 By: Neil Gerein, Michael Olynik, Michael Clayton, Jonathan Auld, Tony Murfin

The Galileo Test Receiver will enable developers to add other frequencies and services in the future, and a new single-channel L1/E5a Galileo transmitter lets designers perform in-lab demonstrations and signal-in-space testing.

A Single-Chip GPS Receiver And the Steps to Mass-Market Galileo Oct 1, 2005 By: Philip G. Mattos

As GPS chip volumes per manufacturer reach millions for the automotive market and tens of millions for consumer GPS, the market map for a single-chip GPS changes considerably. The advent of Galileo will bring out the full benefits of sensitivity, creating an opportunity for low-cost, high-integration one-chip solutions.