Geometric Rules for Terrestrial Radionavigation Multipath Mitigation by Averaging

Abstract

In this contribution, we present a method to analyze the effectiveness of multipath mitigation by extended averaging in the context of terrestrial radionavigation. We derive the requirements of extended averaging on the geometry between a ground station and an aircraft. Using that knowledge, we are able to analyze the effectiveness of extended averaging for real‐world flight trajectories. Copyright © 2017 Institute of Navigation.

Characterization and Mitigation of Multipath for Terrestrial based Aviation Radionavigation

“…A third method is to use modeling to identify potential areas of multipath for inspection. A model for identifying critical areas causing MPCs with critical delays and relative Doppler velocity that are both significant and difficult to mitigate was developed . For these latter two methods, flight inspection can then be used judiciously to verify and precisely determine the region and level of multipath.…”

“…Scenario 1 is very typical: A lateral MPC with P M,rel < 1, which is usually the case for lateral MPCs, is degrading the range estimation. Given a suitable geometry, which should usually be the case , its influence on the range estimation can be averaged out and the error significantly reduced without a requirement for upgraded avionics clocks.…”

“…Scenario 3 is very similar to scenario 1. However, it is expected to appear with a significantly lower probability than scenario 1, as it requires a geometry unsuitable for averaging . The most economic way is to avoid the situation by operational changes.…”

“…The most economic way is to avoid the situation by operational changes. Those changes could be a slight change of the flight path or removing reflecting objects from the surroundings of the ground station, as outlined in .…”