Development and Testing of a Multiple Filter Approach for Precise DGPS Positioning and Carrier-Phase Ambiguity Resolution

Paul E. Henderson and John F. Raquet

Abstract:	Precise relative positioning obtained using differential GPS depends on accurately fixing carrier phase ambiguities. In order to achieve acceptable precision, many current static and kinematic surveying algorithms use a floating-point solution until enough information becomes available to accurately fix the carrier phase ambiguities. However, in dynamic environments or in situations where many brief measurement outages or cycle slips are possible, these algorithms may never gain enough information to fix the ambiguities with the confidence required for a fixed point solution. A new method is presented that starts with the floating point results, yet smoothly and rapidly attains the precision of the correct fixed integer solution. Use of this method eliminates the need to decide when to switch from the floating to the fixed integer solution at a discrete point in time. This method is based on a theoretically correct blending of solutions from multiple filters, each of which hypothesizes a different ambiguity set. When coupled with efficient ambiguity resolution algorithms and implemented in a parallel architecture, this new filtering technique is computationally efficient, and has a wide range of applications. This paper describes the new algorithm and explains its differences and advantages over current approaches. Computational and implementation concerns are discussed and finally, results from real world data sets are presented.
Published in:	Proceedings of the 2000 National Technical Meeting of The Institute of Navigation January 26 - 28, 2000 Pacific Hotel Disneyland Anaheim, CA
Pages:	806 - 815
Cite this article:	Henderson, Paul E., Raquet, John F., "Development and Testing of a Multiple Filter Approach for Precise DGPS Positioning and Carrier-Phase Ambiguity Resolution," Proceedings of the 2000 National Technical Meeting of The Institute of Navigation, Anaheim, CA, January 2000, pp. 806-815.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In