Weighting and Mitigation of Multipath Effects in GPS Range Measurements in an Urban Environment for Pedestrian Navigation

M. Langer, C. Ascher, J. Bauer, G.F. Trommer

Abstract:	In this paper we will show how to process range measurements in a high sensitive GPS receiver in an urban environment by mitigating multipath effects in a real world scenario. We will compare a c/n0 weighting of range measurements approach to a maximum likelihood approach where multipath effects are identified and mitigated. A previous approach of a maximum likelihood estimator is evaluated and enhanced for use in a pedestrian navigation system. These enhancements include a higher robustness in severe multipath environments and a gain in position accuracy by applying weightings to the range measurements corrected by the maximum likelihood estimator in respect of satellite geometry and c/n0. Such a high sensitive GPS receiver is adapted to our Dual-IMU pedestrian navigation system where a tight integration of an Inertial Measurement Unit (IMU), a barometric sensor, a magnetic compass and the GPS sensor is implemented. The Dual-IMU comprises a foot mounted and a torso mounted IMU. Furthermore Zero Velocity Updates (ZVUs) during the stance phase of the foot mounted IMU reduce the drift of the MEMS based inertial system. For the Tightly Coupled GPS/INS data fusion the obtained GPS range measurements have to be weighted properly in the measurement step of the Kalman filter.
Published in:	Proceedings of the 2012 International Technical Meeting of The Institute of Navigation January 30 - 1, 2012 Marriott Newport Beach Hotel & Spa Newport Beach, CA
Pages:	928 - 939
Cite this article:	Langer, M., Ascher, C., Bauer, J., Trommer, G.F., "Weighting and Mitigation of Multipath Effects in GPS Range Measurements in an Urban Environment for Pedestrian Navigation," Proceedings of the 2012 International Technical Meeting of The Institute of Navigation, Newport Beach, CA, January 2012, pp. 928-939.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In