Bistatic SAR Phase Synchronization via Coded Signal Interpolation
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Solution Overview
Problem
Bistatic synthetic aperture radar (SAR) systems face challenges in phase synchronization due to oscillator frequency errors and low-frequency phase noise, affecting imaging focusing and interferometric phase accuracy, which are not effectively addressed by existing methods.
Innovation Solution
A method for processing non-interrupted phase synchronization signals using coded signals, where phase synchronization signals are sent during the time slot between radar signal transmission and reception, and echo signals are processed through matched filtering and phase compensation to improve imaging quality in bistatic SAR systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase synchronization signals are transmitted using traditional methods, then phase synchronization can be achieved, but the imaging quality and signal-to-noise ratio are degraded due to oscillator frequency errors and low-frequency phase noise
Solution Approach 1:
The patent applies preliminary action by transmitting the phase synchronization signal during the time slot between radar signal transmission and reception, before the actual imaging process. This allows the synchronization signal to be captured and processed in advance, enabling phase error compensation to be applied before imaging, thereby improving both phase synchronization accuracy and imaging quality without interference from oscillator frequency errors and low-frequency phase noise
Solution Approach 2:
The patent introduces an intermediary approach by using a dedicated phase synchronization signal that is transmitted separately from the radar signal. This intermediary signal serves as a reference for phase compensation, allowing the system to measure and correct phase errors introduced by oscillator frequency errors and low-frequency phase noise, thereby improving imaging quality while maintaining phase synchronization accuracy
2Measurement precision
If phase synchronization is implemented in bistatic SAR systems, then interferometric phase accuracy can be improved, but the system complexity increases due to the need for separate transmission and reception phases
Solution Approach 1:
The patent applies merging by combining the phase synchronization signal transmission with the existing radar signal transmission and reception process. The phase synchronization signal is transmitted during the time slot between radar signal transmission and reception, utilizing the existing system infrastructure without requiring separate dedicated transmission and reception paths. This reduces system complexity while still achieving improved interferometric phase accuracy through phase error compensation
3Reliability
If the phase synchronization signal is transmitted during the time slot between radar signal transmission and reception, then non-interrupted synchronization can be achieved, but the signal processing complexity increases
Solution Approach 1:
The patent applies periodic action by transmitting the phase synchronization signal periodically during each time slot between radar signal transmission and reception. This periodic transmission ensures continuous phase synchronization without interruption, allowing the system to continuously measure and compensate for phase errors. The regular timing of these synchronization signals simplifies the processing logic compared to continuous transmission, as the system can expect and process synchronization signals at predictable intervals
Data Source
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AI summary
A method for processing a non-interrupted phase synchronization signal of a bistatic synthetic aperture radar (SAR) based on a coded signal includes that: when a first receiving signal of a first SAR does not contain a first received synchronization signal, the first receiving signal is determined as a first echo processing signal, when a first receiving signal contains the first received synchronization signal, a peak phase of a synchronization signal is extracted, and the synchronization signal is separated to obtain a first echo processing signal; when a second receiving signal of a second SAR does not contain a second received synchronization signal, a second receiving signal is determined as a second echo processing signal, when the second receiving signal contains the second received synchronization signal, a peak phase of a synchronization signal is extracted, and the synchronization signal is separated to obtain a second echo processing signal; a compensation phase is calculated according to the peak phases, and is compensated into the second echo processing signal after interpolation, and imaging is performed on the obtained first and second echo processing signals.