Asynchronous interference suppression method based on notch filtering processing

Abstract

The invention discloses an asynchronous interference suppression method based on notch filtering processing. The method comprises the following steps of determining an airborne radar, wherein there isa target in an airborne radar detection range, and an echo signal which is reflected by the target and is received by the airborne radar which emits the signal to the detection range is recorded as aradar original echo data matrix; according to the radar original echo data matrix, acquiring a distance-Doppler domain data matrix; then, determining a main-lobe clutter; calculating the Doppler frequency of the main-lobe clutter and obtaining a column vector g with a R length, wherein the R is a positive integer which is greater than 1;dertermining a reference threshold, successively acquiring amodified and processed result gpro, normalized power and a vector G, and then acquiring a notch filtering weight coefficient vector F; and using the notch filtering weight coefficient vector F to carry out sliding window processing on the radar original echo data matrix, and acquiring a result after the sliding window processing, wherein the result of the sliding window processing is an asynchronous interference suppression result based on limited wave filtering processing.

Description

technical field [0001] The invention belongs to the field of radar technology, in particular to an asynchronous interference suppression method based on wave-limiting filter processing, which is suitable for airborne radar echo asynchronous interference suppression. Background technique [0002] With its unique combat characteristics, airborne radar is regarded as a strategic weapon that can influence the battlefield situation by the military of various countries. Interference suppression performance is the main factor affecting the normal detection of airborne radar. Therefore, airborne radar interference suppression technology has attracted the attention of researchers from all over the world. [0003] In the radar signal environment, interference always exists; common interference can be mainly divided into four types: deceptive interference, blocking interference, point frequency (vertical stripe) interference and asynchronous interference; among them, asynchronous inter...

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Problems solved by technology

[0003] In the radar signal environment, interference always exists; common interference can be mainly divided into four types: deceptive interference, blocking interference, point frequency (vertical stripe) interference and asynchronous interference; among them, asynchronous interference (Asynchronous Interference) mainly comes from industrial The electromagnetic radiation of production equipment, communication equipment, other radars, etc., asynchronous interference is characterized by random occurrence in the form of narrow pulses, and the amplitude is much larger than the noise floor, so it is also called singular value (Singular Value); from the source, its It should have a certain periodicity, but its frequency of occurrence is inconsistent with the working pace of the radar; therefore, the time when asynchronous interference appears in the radar receiver is not fixed, showing great randomness

[0004] On the other hand, the amplitude of asynchronous interference is very large, far greater than the signal and noise level values, and sometimes even reaches the level of clutter; asynchronous interference is shown in the pulse Doppler (PD, Pulse Doppler) diagram as having a certain range in the distance domain. width, the horizontal stripes filled in the Doppler domain; in radar signal detection, because its width is similar to the echo signal of the target, it is usually detected as a target; in automatic detection, dot trace aggregation technology is usually used to Reduce the number of original traces; and because the intensity of asynchronous interference is too strong, if there is a target appearing near it, the asynchronous interference will cover the target appearing in its neighborhood due to the trace aggregation algorithm, resulting in Targets will be inexplicably lost or have errors at certain moments (specifically, the radar detects singular values), which will affect the detection performance of the radar on the target; in addition, the radar often uses the accumulation method to improve the detection probability of the target, due to the asynchronous interference signal The existence of , will significantly increase the noise floor of each channel after accumulation, which in turn will reduce the detection probability of the target

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