Precise GPS Positioning for Post-Mission Trajectory Estimation

Translated GPS tracking systems are frequently used to track missiles, aircraft, and other aerospace vehicle for applications requiring real-time position and velocity. The GPS/TPS tracking system provides intermediate data that is recorded during tracking and available for post-mission trajectory analysis. Greater post-mission trajectory accuracy can be achieved by using improved error models and making optimum use of the available data. This proposal outlines an error model analysis and post-processing technique directed at improving post-mission trajectory information. A method of generating accurate contiguous carrier phase measurements from the translated GPS signals is proposed. This carrier data will then be processed post-test to generate a "kinematic" solution for the trajectory. Flight test results with GPS receivers using this method have demonstrated that accuracies of better than 10 cm are possible. The degree of improvement in post-mission trajectory determination will be demonstrated using this method.