Global Positioning System (GPS) autonomous navigation

A system description, a discussion of design issues, and performance results obtained from the Aerospace Corporation simulation of the GPS autonomous navigation system (ANS) concept are given. Analysis methods, physical models, and pertinent equations are presented. Measurement data are realistically simulated and include the effects of all known environmental and hardware phenomena affecting performance. Performance under nominal and anomalous conditions (satellite failures) and in nuclear environments is described. Unobservable errors which degrade performance are discussed. Preliminary studies show that the full constellation system is measurement rich. A simple scheme such as rejecting low signal-to-noise ratio or high delay measurements will probably be a satisfactory design response to distortion due to scintillation in the enhanced environment.<
>