SAR radio frequency interference suppressing method

Abstract

The invention provides an SAR radio frequency interference suppressing method. The technical scheme is that a range line echo signal of SAR data is taken as the input, a phase space matrix is constructed according to the echo signals and a phase space matrix of a reference signal is obtained by utilizing a space projection method; restoring a one-dimensional reference signal from the phase space matrix of the reference signal by adopting an opposite angle equalizing method; determining the judgment threshold of an interference signal according to the reference signal; determining interference frequency points in echoes according to the determined interference judgment threshold and implementing the radio frequency interference suppression of the range line by using the amplitude mean value of the reference as a substitute. By adopting the method provided by the invention, the SAR image quality can be improved effectively after interference suppression.

Description

technical field [0001] The invention belongs to the intersecting technical field of aerospace and microwave remote sensing, in particular to a method for suppressing RFI (Radio Frequency Interference, radio frequency interference) in SAR (Synthetic Aperture Radar, synthetic aperture radar) data. Background technique [0002] SAR (Synthetic Aperture Radar) obtains target information by actively emitting electromagnetic waves. It is an all-weather, all-time high-resolution imaging system and has great potential in target reconnaissance and earth remote sensing applications. However, SAR (especially low-band SAR) is easily affected by RFI in a complex electromagnetic environment, thereby reducing image quality and affecting image recognition and applications. [0003] Due to its good penetration characteristics, the SAR system has unique advantages in concealed target detection and forest vegetation surveying and mapping. However, there are a large number of broadcasting, TV si...

AI Technical Summary

Problems solved by technology

These interfering signals can cause severe degradation of SAR image performance

[0004] The notch method and the subspace projection method are currently widely used RFI suppression methods, but the traditional notch method is easy to cause the loss of useful information, and the limitation of the subspace projection method is that it relies too much on the orthogonality of the subspace. When the signal power is large, it will cause subspace misjudgment and introduce false alarms in undisturbed areas of the image

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