Kinematic and Rapid Static (KARS) GPS Positioning: Techniques and Recent Experiences

Abstract

Since the first demonstrations of airborne kinematic positioning using GPS carrier phase measurements in 1985, the ability to do practical and reliable kinematic GPS solutions in support of operational remote sensing activities has improved significantly. These improvemtns arise from a combination of factors including: GPS receivers able to track 8 or more satellites, more precise pseudorange measurements, the availability of post-processed precise satellite ephemerides, and the development of algorithms to initialize phase bias’s while in motion with a minimal amount of phase and pseudorange measurements. These factors have combined to produce an operational kinematic positioning capability accurate to centimeters while extending the range of the technique to hundreds of kilometers. The integer search algorithms used by KARS, that provide on-the-fly bias initialization and cycle slip fixing over extended range operations are described.