The introduction of new GNSSs requires updating the AGPS-only solution to add support for new GPS bands, new GNSSs, and to enhance accuracy, sensitivity, and availability.

Innovation: Opportunistic Navigation Finding Your Way with AM Signals of Opportunity Jul 1, 2007 By: Jonathan McEllroy, John F. Raquet, Michael A. Temple

The signals from AM stations can be used to determine the position of a mobile receiver with respect to a reference receiver using time difference of arrival (TDOA) measurements and a supplementary link between the two receivers. A team from the U.S. Air Force Institute of Technology describe simulations and real-world experiments they carried out using a software-defined radio receiver to test the feasibility of AM radio TDOA measurements for positioning and navigation.

Innovation: Any Questions? The International GNSS Service Jan 1, 2007 By: Angelyn W. Moore

The IGS was established in 1994 in order to provide the highest quality GNSS data and products in support of Earth science research, multidisciplinary applications, and education. It was and is still the aim of the IGS to advance scientific understanding of the Earth system components and their interactions, as well as to facilitate other applications benefiting society.

Approach with Precision Ground Augmentation Proves Out Sep 1, 2006 By: Tim Murphy, John Ackland, Tom Imrich, Tiffany Lapp, Roger Friedman

New ground-based augmentation systems at or near airports offer the potential of new or improved capabilities, as well as cost reduction for existing airspace system infrastructure. The authors tested a prototype using a multimode GPS receiver that converts differentially corrected signals to the airplane's instrument system, enabling more precise autolandings.

EGNOS Takes Flight Aviation Trials Signal Benefits in Difficult Approach Environments Apr 1, 2006 By: Henk Veerman, Patrick Rosenthal, Olivier Perrin

Tests of the European Geostationary Navigation Overlay Service (EGNOS) indicate the system's future capabilities as a navigation aid for the aeronautical community, particularly in approaches to mountain-based airports and other challenging environments.

Assistance When There's No Assistance Long-Term Orbit Technology for Cell Phones, PDAs Oct 1, 2005 By: David Lundgren, Frank van Diggelen

Long-Term Orbit data, obtainable over the Internet, can enable a locatable cell phone or PDA to position itself accurately for as long as four days without further assistance.

Myths and Realities of Anywhere GPS High Sensitivity versus Assisted Techniques Sep 1, 2005 By: Chris Carver

AGPS does not mean works "Anywhere" GPS. Accurately determining what will work for any given application requires a properly designed test procedure.

Low-cost sensors and a Horizontal Trust Level (HTL) enable mobile-terminal applications requiring continuous quality of service in positioning and integrity.