Stepped frequency signal phase compensation method for digital array radar

Abstract

The invention discloses a stepped frequency signal phase compensation method for digital array radar, and belongs to the field of digital signal processing. The method includes the steps: firstly, emitting a stepped frequency signal sub-pulse by each channel of the digital array radar to acquire video echo signals; secondly, selecting the phase of the maximum point of the video echo signal of each sub-pulse in the corresponding channel to perform linear fitting, compensating a phase value at a specified moment to realize zero deviation between a fit straight slope and an ideal slope, acquiring video echo compensation factors and performing IFFT (inverse fast Fourier transformation) for the compensated signals to output high resolution range profiles; thirdly, compensating the phase of a peak point of the high resolution range profile of each channel and enabling the phase difference Delta phi between peak points of the range profiles of the channels at the same distance to be consistent with an ideal phase difference to acquire range profile compensation factors; and fourthly, applying the acquired video echo compensation factors and the acquired range profile compensation factors to the signal processing procedure of the digital array radar. The method is applicable to signal processing of the digital array radar.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, and is particularly suitable for measuring the high-precision distance and angle of a target in a frequency modulation stepping radar system. Background technique [0002] The frequency modulation step signal is a radar signal with high resolution capability. It transmits a group of radar pulses with inter-pulse carrier frequency linear jump and intra-pulse linear frequency modulation. By performing intra-pulse pulse compression and inter-pulse The inverse Fourier transform (IFFT) process obtains the range high-resolution image of the target. The frequency modulation step signal replaces the simple pulse in the frequency step signal with a linear frequency modulation sub-pulse, so it overcomes the contradiction between the radar range and the single pulse distance resolution, and can reduce the distance while keeping the distance resolution unchanged. Increase the number of pulse...

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Problems solved by technology

[0005] In order to solve this problem, it is necessary to select the appropriate time point for phase compensation. The existing phase compensation technology for frequency step signal only performs linear phase correction for single channel, but it does not take into account the digital array radar in multi-channel In the case of correction, the slopes of the linear characteristic curves of each channel are inconsistent, which will bring errors to the angle measurement

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