A Ground Clutter Removal Method for Airborne Weather Radar Based on Terrain Elevation Data

Abstract

The invention provides a method for eliminating terrestrial clutters of an airborne weather radar based on terrain altitude data. The method provided by the invention comprises the following steps of: reading airplane position and radar parameters, establishing a local rectangular coordinate system, calculating longitudes and latitudes of ground sampling points in a beam direction, reading DEM (Digital Elevation Model) data, calculating a lower view angle sequence of the sampling points relative to an airplane, analyzing a tendency of the lower view angle sequence, judging a monotonically decreasing sequence, eliminating a non-monotonically-decreasing lower view angle value, determining a beam grounding range, editing echo signals and replacing by a background, updating the airplane position and an antenna azimuth angle, judging whether the scanning is finished, displaying complete scanning echo signals by a radar display screen and the like. According to the method provided by the invention, by utilizing the characteristics that the terrestrial clutters of the airborne weather radar echoes and weather targets are respectively located at units with different distances and can be separated in the distance and adopting the discipline characteristics of the lower view angle, the grounding position of the radar beam is analyzed, and the terrestrial clutters is eliminated by utilizing and utilizes the terrain altitude data; and the method has the advantages of simple method, calculation accuracy, good inhibition effect, capability of effectively eliminating terrestrial cluttersof the airborne weather radar in a time domain and the like.

Description

technical field [0001] The invention belongs to the technical field of airborne radar clutter suppression, in particular to an airborne weather radar clutter elimination method based on terrain elevation data. Background technique [0002] Since the airborne weather radar is placed on the aircraft and generally works in a down-looking mode, it faces more serious ground (sea) clutter than the ground-based weather radar, and the clutter has a wide distribution and high intensity. In addition, the frequency shift of the main lobe clutter and the increase of the scanning azimuth angle caused by the movement of the carrier aircraft also broaden the frequency band of the clutter. This clutter Doppler broadening makes conventional frequency-domain filtering methods invalid and cannot separate it from the frequency domain. But at this time, ground clutter and meteorological targets are usually separable in space. [0003] At present, the ground clutter suppression technology of ai...

AI Technical Summary

Problems solved by technology

Among them, the determination of the depression angle range of the beam is very important. Once there is an error in the depression angle, it will have a very large impact on the calculation of the subsequent clutter position.

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