Evaluation of precise kinematic on-the-fly relative GPS positioning for a rocket sled test

Abstract

This paper evaluates the use of the Global Positioning System (GPS) to perform kinematic relative positioning for a rocket sled moving at a maximum speed of 525 ft/s. The test demonstrates precise positioning accuracy in the well-controlled environment of the High-Speed Test Track at Holloman AFB, New Mexico. Application of this procedure determines the miss distance vector between a target and interceptor missile at or near the moment of intercept, where both missiles are far from a land reference site. Other potential applications include the autonomously controlled docking of space vehicles and high-speed aircraft landing on aircraft carriers. Results are presented that use the Remondi Kinematic On-The-Fly (OTF) relative positioning procedure. The procedure uses L1 and L2 frequency pseudorange and phase measurements of GPS to precisely determine dynamic relative position. This particular algorithm is capable of subdecimeter positioning accuracy with respect to a moving platform. The position of the sled antenna is determined with respect to a fixed antenna located about 6 m away from the test track. A truth miss distance comparison is made at the point of closest approach. Centimeter level agreement is obtained. In addition, positioning of the fixed antenna with respect to the moving sled antenna is obtained to demonstrate the capability to use a moving platform as a reference. Sled test trajectories are presented and evaluated.