CN-122017839-A - Double-base synthetic aperture radar rapid imaging method, electronic equipment and storage medium

CN122017839ACN 122017839 ACN122017839 ACN 122017839ACN-122017839-A

Abstract

The application provides a quick imaging method of a bistatic synthetic aperture radar, electronic equipment and a storage medium, wherein the method comprises the steps of receiving and acquiring echo signals based on transmitting signals sent by a transmitting station in a beam focusing mode, determining declivity parameters according to the echo signals, declivity the echo signals according to the declivity parameters to obtain declivity echo signals, carrying out interpolation transformation on the declivity echo signals to obtain interpolation echo signals, carrying out azimuth nonlinear scaling on the interpolation transformed echo signals, calculating and acquiring nonlinear scaling parameters, and carrying out azimuth Fourier transformation to obtain a final SAR image. Through declivity and interpolation change, imaging quality and imaging effect are greatly improved.

Inventors

CHEN TIANFU
ZHANG TINGXIAO
MA HONGBIN
CHEN YONGQIANG
LIU DONGHE
CHEN XUAN

Assignees

乾元国家实验室

Dates

Publication Date: 20260512
Application Date: 20260306

Claims (10)

1. A method for rapid imaging of a bistatic synthetic aperture radar, applied to a receiving station, comprising: receiving and acquiring echo signals based on transmitting signals sent by a transmitting station in a beam focusing mode; determining a declivity parameter according to the echo signal, and declivating the echo signal according to the declivity parameter to obtain a declivated echo signal; performing interpolation transformation on the de-skewed echo signals to obtain interpolated echo signals; and carrying out azimuth nonlinear scaling on the echo signals after interpolation transformation, calculating and obtaining nonlinear scaling parameters, and obtaining a final SAR image through azimuth Fourier transformation.
2. The method of claim 1, wherein the echo signal is represented as: ; Wherein, the Representing target points Is used for the diffusion coefficient of the (c), Representing the coordinates of the target point in question, And Indicating the range and azimuth antenna patterns respectively, The distance is indicated to be fast to the time, Indicating the distance-wise frequency, Indicating the slope of the range-wise chirp, The speed of light is indicated as being the speed of light, The pulse width is indicated as such, Indicating the azimuth slow time, j is the imaginary symbol in the complex number, The time of the synthetic aperture is indicated, Representing the central irradiation moment of the target point; the method further comprises the steps of after receiving and acquiring the echo signals based on the transmitting signals sent by the transmitting station in the beam focusing mode: Performing distance pulse compression on the echo signal according to a compensation phase to obtain a compensated echo signal, wherein the compensation phase is The compensated echo signal is expressed as: 。
3. The method according to claim 2, wherein the Expressed as: ; Wherein, the Representing a ground projection of the receiver station's oblique view, Representing the beam width of the receiving station, Representing the ground movement velocity of the receive station beam, , Representing the velocity of movement of the receiving station along the y-axis, Representing beam steering factors of a receiving station and rotated by azimuth of an antenna Determining; Expressed as: Wherein, the method comprises the steps of, Indicating time of day When a reference distance of the receiving station is reached, A designator representing the receive station beam imaging mode, wherein, 。
4. The method of claim 2, wherein determining a deskewing parameter from the echo signal, and deskewing the echo signal according to the deskewing parameter, to obtain a deskewed echo signal, comprises: determining the declivity parameter as according to the echo spectrum of the echo signal , Representing the first order coefficients of the doppler coefficients with respect to the azimuth center moment, wherein, , wherein, Representing the distance to first order slope; obtaining a declivity phase according to the declivity parameter ; Multiplying the echo signal with a filtering phase and the declivity phase in sequence to obtain a declivated echo signal, wherein the filtering phase is expressed as 。
5. The method of claim 4, wherein interpolating the desked echo signal to obtain an interpolated echo signal, comprises: performing interpolation transformation on the de-skewed echo signals to obtain interpolated echo signals expressed as Wherein, the interpolation mode adopted is 。
6. The method according to claim 5, wherein the performing the azimuth nonlinear scaling on the interpolated echo signal and calculating to obtain nonlinear scaling parameters, and obtaining the final SAR image through azimuth fourier transform includes: Determining azimuth scaling factors and positioning factors; According to the azimuth scaling factor and the positioning factor, performing high-order phase compensation and primary disturbance on the processed echo signal to obtain an echo signal after primary disturbance; According to the azimuth scaling factor and the positioning factor, azimuth phase compensation and secondary disturbance are carried out on the echo signal after primary disturbance, and the echo signal after secondary disturbance is obtained; And carrying out azimuth inverse Fourier transform on the echo signals after the secondary disturbance to obtain a final SAR image.
7. The method of claim 6, wherein determining the azimuth scaling factor and the positioning factor comprises: And determining the value range of the azimuth scaling factor meeting the preset condition and the value range of the positioning factor according to the preset expression.
8. The method of claim 6, wherein the performing high-order phase compensation and one disturbance on the processed echo signal according to the azimuth scaling factor and the positioning factor to obtain an echo signal after one disturbance comprises: Acquiring a phase expression corresponding to the primary disturbance according to the azimuth scaling factor and the positioning factor; Performing high-order phase compensation on the processed echo signals, and performing primary disturbance according to a phase expression corresponding to the primary disturbance; And performing azimuth phase compensation and secondary disturbance on the echo signal after primary disturbance according to the azimuth scaling factor and the positioning factor to obtain the echo signal after secondary disturbance, wherein the method comprises the following steps: Acquiring a phase expression corresponding to the secondary disturbance according to the azimuth scaling factor and the positioning factor; And carrying out azimuth phase compensation on the echo signal after primary disturbance, and carrying out secondary disturbance according to a phase expression corresponding to the secondary disturbance.
9. An electronic device comprising a processor and a memory, the memory storing machine-readable instructions executable by the processor, the processor configured to execute the machine-readable instructions to perform the method of dual-base synthetic aperture radar rapid imaging of any of claims 1 to 8.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a computer program which, when executed by a processor, performs the dual-base synthetic aperture radar rapid imaging method according to any one of claims 1 to 8.

Description

Double-base synthetic aperture radar rapid imaging method, electronic equipment and storage medium Technical Field The application relates to the technical field of radars, in particular to a rapid imaging method of a double-base synthetic aperture radar, electronic equipment and a storage medium. Background The synthetic aperture radar (SYNTHETIC APERTURE RADAR, SAR for short) can realize all-day and all-weather imaging observation capability, and plays an important role in the fields of topographic mapping, resource survey, ocean current and hydrologic observation, disaster monitoring, vegetation analysis and the like. Compared with the single-base SAR, the double-base SAR has the advantages of strong concealment, strong interference resistance, high survivability and the like due to the configuration characteristics of the receiving and transmitting separation, can realize the light weight, miniaturization, low cost and diversification of the receiving station, and has the front view, side view and rear view all-round imaging capability. The beam focusing mode complex track bistatic SAR refers to a process of acquiring data by a receiving and transmitting double station, more complex motion tracks such as a satellite platform, a mobile platform and the like can be adopted, beam rotation of the receiving and transmitting platform is adopted to realize beam focusing mode imaging, long-time echo data can be acquired, a larger observation angle is provided, and therefore higher azimuth resolution is realized. However, in the research of the bistatic SAR nonlinear variable-scale imaging algorithm in the prior art, algorithm optimization is only carried out on the shift-change configuration of the bistatic SAR, and the influence of beam rotation in a beam focusing mode on frequency spectrum broadening and space-variant is not considered, so that the problem of azimuth space-variant cannot be effectively solved by a constructed disturbance function, and the problem of azimuth aliasing can be caused, so that the imaging effect is seriously influenced. Disclosure of Invention The application aims to overcome the defects in the prior art and provide a rapid imaging method, electronic equipment and storage medium of a double-base synthetic aperture radar so as to solve the problem of poor imaging effect in the prior art. In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows: In a first aspect, an embodiment of the present application provides a method for rapid imaging of a dual-base synthetic aperture radar, applied to a receiving station, the method comprising: receiving and acquiring echo signals based on transmitting signals sent by a transmitting station in a beam focusing mode; determining a declivity parameter according to the echo signal, and declivating the echo signal according to the declivity parameter to obtain a declivated echo signal; performing interpolation transformation on the de-skewed echo signals to obtain interpolated echo signals; and carrying out azimuth nonlinear scaling on the echo signals after interpolation transformation, calculating and obtaining nonlinear scaling parameters, and obtaining a final SAR image through azimuth Fourier transformation. Optionally, the echo signal is expressed as: ; Wherein, the Representing target pointsIs used for the diffusion coefficient of the (c),Representing the coordinates of the target point in question,AndIndicating the range and azimuth antenna patterns respectively,The distance is indicated to be fast to the time,Indicating the distance-wise frequency,Indicating the slope of the range-wise chirp,The speed of light is indicated as being the speed of light,The pulse width is indicated as such,Indicating the azimuth slow time, j is the imaginary symbol in the complex number,The time of the synthetic aperture is indicated,Representing the central irradiation moment of the target point; the method further comprises the steps of after receiving and acquiring the echo signals based on the transmitting signals sent by the transmitting station in the beam focusing mode: Performing distance pulse compression on the echo signal according to a compensation phase to obtain a compensated echo signal, wherein the compensation phase is The compensated echo signal is expressed as: 。 optionally, the said Expressed as: ; Wherein, the Representing a ground projection of the receiver station's oblique view,Representing the beam width of the receiving station,Representing the ground movement velocity of the receive station beam,,Representing the velocity of movement of the receiving station along the y-axis,Representing beam steering factors of a receiving station and rotated by azimuth of an antennaDetermining; Expressed as: Wherein, the method comprises the steps of, Indicating time of dayWhen a reference distance of the receiving station is reached,A designator representing the receive station beam