Estimation method for motion parameter of stepped frequency radar target

Abstract

The invention discloses an estimation method for a motion parameter of a stepped frequency radar target, and belongs to the field of radar signal processing. The stepped frequency radar signal is verysensitive to the target motion, therefore the motion speed of the target needs to be accurately estimated before a high resolution range profile is synthesized. The method comprises the steps of firstly, analyzing radar echo signal characteristics of a uniform-speed motion target, and eliminating a secondary phase term of the echo through Keystone transform; and secondly, performing IFFT (InverseFast Fourier Transform) operation on a group of stepped frequency echo signals and then performing FFT (Fast Fourier Transform Algorithm) operation to obtain a two-dimensional distance-speed parameter spectrum, and obtaining accurate estimation values of the target speed and the initial distance according to the peak position. However, when noise interference exists, the target parameter estimation is not accurate, therefore, the distance dimension parameter spectrum is denoised by using a maximum likelihood estimation threshold-based Morlet wavelet denoising method so as to obtain the accurate parameter estimation of the target in low signal to noise ratio. The estimation method for the motion parameter of the stepped frequency radar target disclosed by the invention has popularization and application values in the field of stepped frequency radar signal processing.

Description

technical field [0001] The invention belongs to the field of frequency step radar signal processing engineering, and in particular relates to a method for estimating motion parameters of a frequency step radar target. Background technique: [0002] The frequency step signal is a kind of synthesized wideband radar signal, which has become a hot spot in the research of radar signal processing in recent years. However, since the frequency step signal is a Doppler sensitive signal, the movement of the target will cause problems such as inaccurate ranging, waveform divergence, and amplitude loss. Therefore, how to perform velocity estimation and motion compensation becomes the key to high-resolution range imaging of moving targets in frequency stepping radar. [0003] At present, the commonly used frequency stepping radar signal target motion detection methods mainly include the following categories: The first type of method is to use the coherent detection method to estimate th...

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Problems solved by technology

[0003] At present, the commonly used frequency stepping radar signal target motion detection methods mainly include the following categories: The first type of method is to use the coherent detection method to estimate the target’s motion speed first, and then perform motion compensation on the echo signal, but this method is difficult to obtain in the signal-to-noise The speed estimation error is relatively large under the condition, which affects the accuracy of the speed estimation, and then causes the blurring of the target imaging

The second type of method is to eliminate high-order phase items and realize motion compensation through signal parameter design, but this method requires precise design of signal parameters, and the transmitter is more complicated

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