Slant Range Analysis and Compensation of Radar Altimeter Flight Test Data

This paper introduces a high detailed radar altimeter simulation model, considering geometric and signal processing aspects. On the one hand, the simulation model is deployed in a simulation environment for a better understanding of the different error sources of radar altimeters, on the other hand, it is used inflight to compensate those errors. To evaluate the radar simulation model, the results are compared to recorded altimeter flight test data to show the strengths and weaknesses of the simulation model and the following applicability. Afterwards, the inflight use of a radar altimeter simulation model is introduced in a compensation algorithm, using the real flight test data to improve the height measurement compared to a classical radar height processing. The aiding of a compensated radar height measurement in an integrated navigation system is introduced. Finally, the performance of the algorithm is shown on an approach trajectory of a small aircraft on an airfield in hilly environment.