Position location using sequential GPS measurements
Abstract
This paper reports the development of a program to derive a first order correction to initial estimates of local coordinates and local clock bias from GPS time using a single channel GPS receiver of the C/A code. The program measures sequentially the local minus GPS time via four different satellites based on an initial estimate of local coordinates. Then using these measurements along with known locations of the satellites the first order corrections to the X, Y, and Z coordinates the local time bias, from GPS time are obtained. With reasonable geometry the first order correction is theoretically good to one meter if the initial estimate of coordinates is with 3 km of the correct values. Over a very short 15 m baseline we found a 2.7 m differential position location error. Over a long baseline using a poor geometric satellite configuration the differential navigation solution was apparently within 20 m of the true values. Absolute position location relative to a first order survey point was off by only 7.2 m, and this without including ionospheric corrections to transmission delays to the satellites.
 Publication:

PLANS '82  Position Location and Navigation Symposium
 Pub Date:
 1982
 Bibcode:
 1982pln..symp..275W
 Keywords:

 Global Positioning System;
 Position (Location);
 Satellite Navigation Systems;
 SpaceTime Functions;
 Coordinates;
 Time Lag;
 Vector Analysis;
 Space Communications, Spacecraft Communications, Command and Tracking