Airborne meteorological radar ground clutter suppression method

Abstract

The invention discloses an airborne meteorological radar ground clutter suppression method, which comprises the following steps of 1) determining priori knowledge such as radar system parameters, ground clutter and meteorological target distribution geometrical relationship by adopting an area array antenna, 2) obtaining a ground clutter pitch angle, a ground clutter azimuth angle, a meteorological target pitch angle and a meteorological target azimuth angle through distance circulation and azimuth circulation, thereby respectively obtaining respective time domain guide vectors and spatial domain two-dimensional guide vectors of the ground clutter pitch angle, the ground clutter azimuth angle, the meteorological target pitch angle and the meteorological target azimuth angle, 3) obtaining aground clutter and a meteorological target three-dimensional space-time guide vector according to the time domain dimension guide vector, the azimuth dimension guide vector and the pitch dimension guide vector, 4) obtaining snapshot signals and a covariance matrix of the ground clutter and the meteorological target according to the three-dimensional guide vector, and 5) after obtaining the covariance matrix, carrying out full-dimensional optimal processing to obtain a weight vector, and filtering the snapshot signal by using the weight vector. The method can improve the estimation precision and convergence rate, can effectively improve the detection performance of the system in a non-uniform environment, and also has a good clutter suppression effect.

Description

technical field [0001] The invention belongs to the technical field of airborne weather radar ground clutter suppression and the technical field of array signal processing, in particular to a method for airborne weather radar ground clutter suppression Background technique [0002] Airborne weather radar is an important electronic device of the aircraft, which can detect and warn in real time of thunderstorms, turbulence, wind shear and other disastrous weather ahead of the flight path, thereby guiding pilots to avoid dangerous areas. At present, there are two main manufacturers of airborne weather radars, Collins and Honeywell. The airborne weather radar usually works in the downward-looking mode. At this time, the echo of the airborne weather radar not only contains meteorological targets, but also noise and ground clutter. It is necessary to effectively suppress the main lobe and side lobe ground clutter in order to Identify weather targets and reduce the probability of ...

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Problems solved by technology

[0004] Among the technical solutions disclosed above, solution 1) is easily limited by flight conditions, and the mid-range clutter suppression effect is not obvious; solution 2) due to the movement of the carrier aircraft will cause the frequency shift and broadening of the echo spectrum, resulting in the meteorological target spectrum and The ground clutter spectrum is not very different, so the suppression effect is not obvious compared with ground radar; in scheme 3), due to the existence of uncertain factors such as channel amplitude and phase errors and antenna direction pointing errors, the estimated airspace cancellation The weight coefficient often deviates from the actual value, which affects the effect of clutter suppression; in scheme 4), it is difficult to obtain the original data, and the polarization information processing generally requires a high degree of clutter polarization, and the movement of the carrier aircraft makes the clutter spectrum expand. It is very difficult to apply polarization information alone to the application of airborne weather radar

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