Aircraft Carrier Multipath Modeling forSea-Based JPALS

摘要

This paper provides an overview of multipath modelingfor the Sea-Based Joint Precision and Landing System(JPALS). The model integrates a detailed structuralmodel of the aircraft carrier USS Eisenhower, receivingantenna gain and phase patterns, receiver tracking loopmodels, and satellite motions to simulate both code andcarrier phase tracking errors due to multipath. Theseefforts complement analysis of actual shipboard test data[2] and use one dockside data set for model validation.For this purpose, a top-level yardarm antenna/receiversystem is simulated and the multipath results arecompared to actual test data. Comparisons are given inthe form of code multipath time histories and elevationdependent error statistics. The statistical comparisonsshow that the model accurately captures elevationdependentelevation error magnitudes and trends.Simulated carrier phase multipath results show 1-σmagnitudes of under 0.5 cm and maximum errors of lessthan 1.5 cm.The Advanced GNSS Multipath Model is also used toevaluate expected performance of fixed and beamsteeringcontrolled radiation pattern antennas located onboth the top and middle levels of the yardarm structure.The results show higher levels of multipath at the middle