Bistatic SAR Signal Synchronization via Phase Compensation
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Solution Overview
Problem
Bistatic Synthetic Aperture Radar (SAR) systems face phase errors due to oscillator frequency differences between primary and secondary satellites, affecting imaging focus and interferometry phase accuracy.
Innovation Solution
A signal synchronization system that includes an acquisition module to receive synchronous signals, a determination module to calculate a compensation phase, and a compensation module to perform phase compensation on radar echo signals, ensuring phase synchronization between signals from primary and secondary satellites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If primary and secondary satellites use different oscillators for signal transmission, then the bistatic SAR system achieves flexible configuration and rich information acquisition, but phase errors are introduced due to oscillator frequency errors
Solution Approach 1:
A phase reference signal is introduced as an intermediary between the primary and secondary satellites. This reference signal serves as a common timing基准 that both satellites use to synchronize their oscillators, thereby eliminating phase errors while preserving the flexible bistatic configuration
Solution Approach 2:
The system implements feedback by continuously monitoring the phase difference between signals from primary and secondary satellites, then adjusting the oscillator frequencies based on this feedback to maintain phase coherence throughout the observation period
2Duration of action of moving object
If observation time is extended to improve imaging coverage, then more comprehensive ground information is acquired, but phase errors accumulate over time
Solution Approach 1:
The phase reference signal is established in advance before the extended observation period begins. This preliminary synchronization ensures that both satellites start with coherent phases and maintain synchronization throughout the entire extended observation time, preventing phase error accumulation
Solution Approach 2:
Continuous feedback mechanisms adjust oscillator frequencies in real-time during the extended observation period, compensating for drift and preventing phase error accumulation over time
3Measurement precision
If oscillator frequency is increased to improve signal resolution, then imaging detail is enhanced, but phase instability increases due to frequency errors
Solution Approach 1:
The phase reference signal acts as a mediator that decouples the relationship between high oscillator frequency and phase stability. By referencing both high-frequency signals to a common stable reference, the system achieves both high resolution and phase stability
Solution Approach 2:
The system changes the parameter of oscillator frequency to high values for improved resolution, while simultaneously using the phase reference signal to control and stabilize the phase parameter, allowing independent optimization of both resolution and stability
Data Source
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AI summary
A device and system for signal synchronization are provided. The device includes an acquisition module, a determination module and a compensation module. The acquisition module acquires a first synchronous receiving signal received by a first communication device and a second synchronous receiving signal received by a second communication device. The first communication device synchronously receives a first radar echo signal and the first synchronous receiving signal by using a first delayer. The second communication device synchronously receives a second radar echo signal and the second synchronous receiving signal by using a second delayer. The determination module determines a compensation phase for the second synchronous receiving signal based on the acquired first synchronous receiving signal and second synchronous receiving signal. The compensation module performs, according to the compensation phase, phase compensation on the second radar echo signal to obtain a compensated second radar echo signal.