Segmental variable repeat frequency model sampling uniformity digital processing method and device

Abstract

The invention discloses a segmental variable repeat frequency model sampling uniformity digital processing method and a segmental variable repeat frequency model sampling uniformity digital processingdevice. The method includes steps of step S1, confirming every sampling position after uniformity sampling according to the working time and sampling rate under every sampling state; step 2, performing short-time cutting on echo data according to the sampling rate and an instant Doppler bandwidth to obtain every sub-section echo data; step S3, resampling every sub-section echo data after short-time cutting to the uniform equivalent sampling position through a special interpolation treatment; step S4, performing distance and time alignment on the data after orientation resampling. According tothe feature of the segmental variable repeat frequency signal, a signal uniformity pretreatment plan is designed, so as to transform non-uniform sampling to uniform equivalent sampling signal, thus the observing target property is acquired by means of analysis algorithm of subsequent uniform sampling signal.

Description

technical field [0001] The invention belongs to the field of signal processing, and in particular relates to a method and a device for sampling and homogenizing digital processing in a subsection variable repetition frequency mode. Background technique [0002] In the application of spaceborne SAR for ground imaging military reconnaissance, in order to obtain high resolution and long azimuth scene coverage at the same time, it is necessary to turn the antenna beam through a large angle to ensure a large synthetic aperture bandwidth in azimuth and a long azimuth mapping zone . In this case, when ultra-high-resolution spaceborne SAR is imaging a certain area, the range migration of the scene echo during the entire working process will be very large, and this phenomenon will make it impossible to use fixed echoes during the entire working process. Receive window to receive complete echo. In order to ensure the effective reception of the entire echo, different from the traditi...

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Problems solved by technology

[0003] "Segmentation variable repetition frequency" is a brand-new sampling working mode. Since the system does not maintain a constant sampling frequency during the working process, the signal no longer satisfies the Nyquist sampling theorem, and the signal will generate frequency domain aliasing at this time. phenomenon, it is impossible to use mature signal analysis methods to obtain target observation results

[0004] At present, there is no system with segmental variable PRF working mode at home and abroad, so there is no public literature on the preprocessing of segmental variable repetition frequency signals. Direct use of existing signal processing methods will cause periodic aliasing of signals, making the frequency domain algorithm failure

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