Geolocation Techniques Research Articles

Geo-location in urban areas using signal strength repeatability

We propose a new approach to geo-location of cellular mobile subscribers that exploits the structure and repeatability of certain patterns of measured signal strength. With careful selection of the locations of the patterns, and appropriate training measurements, geo-location in urban areas could be based on pattern recognition. Simulation results lead to the conclusion that very reliable geo-location techniques could be developed based on this approach.

Satellite Laser Altimetry. On-Orbit Calibration Techniques for Precise Geolocation.

In the thirty years since the launch of the Skylab radar altimeter, satellite-based altimetry has proven to be a powerful tool to map the Earth and other planets. In order to fully exploit an orbiting altimeter, it is necessary to calibrate certain parameters not only before launch, but also after the altimeter is in orbit. Over the years, techniques have been worked out for on-orbit calibration of radar altimeters. Our use of Earth-orbiting satellite laser altimetry began in 1996 with the Shuttle Laser Altimeter. Although laser altimetry presents unique opportunities, it also requires new on-orbit calibration techniques. These techniques are still evolving and include the integration of multiple tracking data types with planned pointing maneuvers over oceans and waveform analysis. This paper describes on-orbit calibration techniques for the several missions that have flown laser altimeters to date and for laser altimeter missions which will launch in the near future.