Research On Synthetic Aperture Radar Real-time Signal Processing Algorithms And Application

Synthetic Aperture Radar (SAR) is a kind of new imaging radar, it hasthe characteristic of all-weather, day and night and long range, it is of great valueto study on SAR imaging in both civilian and military applications, This dissertationhave a deep research on Airborne real-time imaging technology in accordance withthe project from Institute of Electronics, Chinese Academy of Sciences.Firstly,analysis on the principle of high-resolution SAR imaging are reviewed,pointing out that SAR range resolution is depended on signal bandwidth, while SARazimuth resolution is depended on the bandwidth of the LFM-featured Doppler signalgenerated from the relative movement between aircraft carrying the radar and thefixed ground target, the high azimuth resolution can be realized through pulsecompression. We use the R-D algorithm in the image processing. As for the phase errorscaused by aircraft's motion errors, accurate motion compensation should be appliedin order to get high resolution, high contrast and low geometric distortion SARimages. In this dissertation, the clutter lock algorithm is expounded in order toestimate Doppler centroid, which is integrated with the preprocessing. And thenAutofocus algorithm and Range Cell Migration Correction (RCMC) are emphasized inthe dissertation.The signal processor is composed of six TS201 DSPs, which takes on eachparticular function. The main factor for the algorithm design are using thephase-variant FIR filter for preprocessing, special FFT architecture design,optimal interpolation, feasible matrix transpose manipulation,and image processingusing Gaussian Filter. Both fixed-pointed data and floating-pointed data are usedin the processing. Pay more attention to cooperation between the DSPS and codeoptimization.