Spatial ultrahigh-speed maneuvered target detection method based on RMDCFT (Radon-Modified Discrete Chirp-Fourier Transform)

Abstract

The invention relates to a spatial ultrahigh-speed maneuvered target detection method based on RMDCFT (Radon-Modified Discrete Chirp-Fourier Transform). According to the method, firstly, modification is carried out based on the conventional Radon-Fourier transform method by using prior information of spatial target motion parameters, searching is carried out in a known target motion parameter range, and thus, target echo signals are extracted along the motion trajectory of a target; meanwhile, modification is also carried out based on the conventional MDCFT method, transform processing is carried out on the extracted target echo signals, and thus, the estimation on the frequency modulation rate of the target can be obtained; secondary phase of echoes is compensated based on the estimation, coherent accumulation is carried out on the target echo signals, and target detection is realized. The method has no need of predicting or estimating the fuzzy number of speed of the target and is applicable to the circumstances of limited CPI (Coherent Processing Time) and low signal-to-noise ratio; simulation results are compared with processing results of MTD, Radon-Fourier transform, FRFT (Fractional Fourier Transform) and RFRFT (Radon-FRFT) detection methods, experimental results show that the method provided by the invention can be used for effectively detecting the target when the CPI is limited and the signal-to-noise ratio is relatively low, and thus, the effectiveness of the method provided by the invention is proved.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing and maneuvering target detection, in particular to a space ultra-high-speed maneuvering target detection method based on Radon-modified discrete chirp Fourier transform (RMDCFT). Background technique [0002] Space targets include satellites, missiles, and space debris in space. With the rapid increase in the number of space targets in recent years, they have posed serious threats to the launch of aircraft, safe operation in orbit, and homeland air defense. Therefore, it is particularly important to detect incoming space targets early and provide a longer period of early warning. Space-based radar uses satellites as a platform, which can provide possibilities for the realization of space target detection and deep space imaging. It has the characteristics of wide monitoring range, strong real-time performance, high combat effectiveness and survivability, and can detect existing rada...

AI Technical Summary

Problems solved by technology

[0006] For the method of solving Doppler walking, such as the Wigner-Ville distribution method, because it is a nonlinear operation and there is interference of cross items, it is difficult to obtain better detection performance under the condition of low signal-to-noise ratio

In addition, Fractional Fourier Transform (FRFT) and Radon-FRFT (RFRFT) are two methods used to compensate for Doppler walking phenomenon, but FRFT compensation performance is relatively limited when there is distance walking and the number of accumulated pulses is limited. , so FRFT and RFRFT cannot effectively detect space targets

[0007] The Modified Discrete Chirp Fourier Transform (MDCFT) method can eliminate the limitation of the conventional Discrete Chirp Fourier Transform (DCFT) method on the number of sampling points and frequency modulation parameters, so the practicability is improved, but when the space target speed is high , the center frequency of the echo signal will exceed the unambiguous range of the MDCFT center frequency, so it is not conducive to the subsequent accumulation and detection of target energy, so it cannot be directly used for the detection of ultra-high-speed maneuvering targets in space

However, there has not been any related research results that have been modified on the basis of the conventional Radon-Fourier transform and MDCFT methods and combined with the outstanding advantages of the two methods in space ultra-high-speed maneuvering target detection technology.

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