Background suppression method based on radar image statistical characteristics

Abstract

The invention discloses a background suppression method based on radar image statistical characteristics, and belongs to the technical field of radar image processing. The method comprises the following steps: carrying out linear frequency modulation pulse pressure processing on a large-time wide-bandwidth linear frequency modulation continuous wave signal of a radar to form pulse pressure data; arranging the data frames of the pulse pressure data according to the corresponding azimuth angles, and splicing the data frames into a radar image; adopting an inter-frame non-coherent processing method to carry out sliding window average processing of the window length on the radar image; removing distance attenuation of the radar image; and removing direction attenuation of the radar image. According to the invention, the far and near echo energy difference of the FOD radar image caused by signal propagation attenuation can be effectively compensated, the expansibility interference signal inthe distance direction can be suppressed, and the FOD radar image with complex distribution characteristics originally is converted into a general gray scale image with uniform background fluctuation.

Description

technical field [0001] The invention belongs to the technical field of radar image processing, and in particular relates to a background suppression method based on statistical characteristics of radar images. Background technique [0002] FOD (Foreign Object Debris, airport runway foreign object) monitoring radar (hereinafter referred to as FOD radar) is mainly equipped in civil aviation airports to actively detect objects that should not exist on the airport runway and may cause damage to aircraft take-off and landing, including metal parts (Nuts, bolts, etc. left by aircraft or vehicles on duty), gravel, etc. Compared with the traditional manual regular inspection method, FOD radar has the following advantages: wide observation range, all-weather and all-weather work, good real-time performance, etc. Due to the small size of FOD, in order to meet the high-resolution detection requirements, FOD radar generally adopts the millimeter-wave LFMCW (Linear Frequency Modulated C...

AI Technical Summary

Problems solved by technology

This type of method can achieve good detection performance with a relatively low false alarm rate under the condition of relatively uniform clutter distribution characteristics, but when the background clutter is relatively complex, the detection performance of this type of method decreases, and the false alarm rate is high

[0005] "IEEE Transactions on Aerospace and Electronic Systems" published an article titled "Clutter map CFAR analysis", which disclosed a CA-CFAR method based on clutter maps. Wave average power, reducing the false alarm caused by the background clutter changing with the distance unit, the disadvantage is that when the interference exists, the method will cause the target to be missed, which will affect the detection performance

[0006] Due to the limited height of the FOD radar (generally within 3 meters), the antenna beam basically scans downward at a small horizontal angle, and the scattering characteristics of ground objects are relatively complicated. Using the above method will lead to a high false alarm rate of the system, which will increase Difficulty in optical identification or manual inspection, resulting in waste of time and resources

[0007] To sum up, how to solve the problem of high false alarm rate in FOD radar detection due to the scattering characteristics of complex ground objects is a hot issue in this research field, and it is also one of the key technologies of FOD radar low false alarm tiny stationary target detection system

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