Imaging method for bistatic inverse synthetic aperture radar

Abstract

The invention belongs to the technical field of radar signal processing and relates to an imaging method for a bistatic inverse synthetic aperture radar. The invention provides an imaging method for the bistatic inverse synthetic aperture radar on the basis of a gradient projection algorithm and provides a constructing method of a sparse base of echo signals. By use of the imaging method, the problem of low imaging resolution caused by large bistatic included angles in the actual condition is solved, the sparsity caused by echo-signal insufficiency under the large bistatic included angles is fully utilized, sparse sampling is directly carried out on echoes of the bistatic ISAR, then reconstruction is carried out by the gradient projection algorithm, and high-accuracy estimated values for imaging points can be directly obtained. According to the imaging method, the numerous limitations of the traditional algorithm are avoided, and by utilization of the sampling bandwidth far lower than double signal bandwidth, the pressure of acquisition, transmission, processing and storage of data is relieved, simultaneously, the imaging quality is almost not influenced by the large bistatic included angles, the imaging result is not interfered by sidelobe clutters of the radar, and the super-resolution imaging can be realized when the echo signals are not complete.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing and relates to an imaging method for bistatic inverse synthetic aperture radar. Background technique [0002] Bistatic inverse synthetic aperture radar (bistatic ISAR) has a longer operating range than monostatic inverse synthetic aperture radar, and because bistatic ISAR transmits and receives radars separately, its anti-jamming ability, anti-interception ability and other safety performances are also improved. Even better, so bistatic ISAR has high civilian and military value. However, due to the separation of the transmitting and receiving radars and the existence of the bistatic angle, the resolution of the bistatic ISAR imaging is lower than that of the corresponding monostatic ISAR. As the bistatic angle increases, the resolution will drop sharply. Moreover, the bistatic ISAR target is usually a non-cooperative target, and its motion regularity is unknown, so the radar at th...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to address the deficiencies and limitations of the above-mentioned prior art, propose a bistatic ISAR imaging method based on the gradient projection algorithm, and propose a method for constructing the sparse base of the echo signal, using this method to solve the actual situation The low imaging resolution problem caused by the angle between the medium and large bistatic bases makes full use of the sparsity caused by the lack of echo signals under the large bistatic angle, directly performs sparse sampling on the echoes of the bistatic ISAR, and then uses the gradient projection algorithm Perform reconstruction to directly obtain high-precision estimation of imaging points

Images