Noniterative Method of Solving the GPS Double-Differenced Pseudorange Equations

Abstract

The global positioning system (GPS) is a constellation of 24 navigation satellites developed and deployed by the U.S. Department of Defense to provide worldwide real-time positioning capability to its numerous users around the globe. When two or more GPS receivers operate simultaneously, the use of differential GPS positioning has been widely adopted in many engineering applications to improve the positioning accuracy by reducing common errors contained in the concurrent GPS signals. The currently adopted approach to solve the GPS double-differenced pseudorange equations is based on the least-squares principle and requires the use of an iterative procedure. In this study, an algebraic, direct solution of the double-differenced pseudorange equations is introduced. It is demonstrated by experimental data that this noniterative method provides highly compatible positioning results with the traditional least-squares approach.