Phase synchronization method and system for satellite-bone double-base SAR system based on two-way synchronization

Abstract

The invention provides a phase synchronization method for a satellite-bone double-base SAR system based on two-way synchronization. When the system works in phase synchronization mode, a double star synchronous clock unit provides high-precision time synchronization information, reference second pulse signal and high-precision reference frequency source for the system. The phase synchronization method comprises the following steps of: S1, a transmitting star transmits a phase synchronization pulse signal through a synchronous antenna, the phase synchronization pulse signal is received by a receiving star, and the receiving star obtains an intermediate frequency signal by frequency mixing, and performs A / D conversion and FFT spectrum analysis to extract a carrier phase difference of the transmitting end; S2, after receiving the phase synchronization pulse signal of the transmitting star, the receiving star transmits the phase synchronization pulse signal through the synchronous antenna,and the phase synchronization pulse signal is received by the transmitting star after the system delay, and the transmitting star obtains the intermediate frequency signal by the frequency mixing, and performs the A / D conversion and the FFT spectrum analysis to extract the carrier phase difference of the receiving end; and S3, the transmitting star and the receiving star transmit the respective carrier phase difference to the ground, and after performing the difference, the carrier phase difference can be used as an echo phase compensation value to compensate for the received star echo signalto complete phase synchronization.

Description

technical field [0001] The invention relates to the technical field of bistatic SAR systems, in particular to a phase synchronization method and system for a spaceborne bistatic SAR system based on two-way synchronization. Background technique [0002] The spaceborne bistatic synthetic aperture radar (SAR) system (abbreviated as bistatic SAR system) is a new radar system in which the transmitter and receiver are placed on two satellites respectively. Compared with the single-base SAR system, the dual-base SAR system can achieve high-resolution and large-scale imaging; it can obtain the front-view or rear-view imaging of the target or scene; it can be used for interferometric imaging to obtain the target or scene. Three-dimensional images; with good "four anti-" capabilities, namely anti-radiation missiles, anti-electronic jamming, anti-low-altitude invasion, and anti-invisibility, it plays an important role in modern electronic warfare and future information warfare. The se...

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Problems solved by technology

[0008] At present, most of the research on the synchronization of bistatic SAR systems focuses on time and space synchronization, and there are relatively few studies on phase synchronization, and they have not been jointly discussed with other synchronization issues.

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