Abstract

Synthetic aperture radar (SAR) is widely known as one of the most successful applications of optical processing techniques. However, as use of SAR has expanded to include more and varied applications, optics has not continued to play a central role in the processing architectures. This has been due to technological limitations and restrictions inherent in the original coherent processing technique. In recent years several hybrid optical SAR processing approaches have been proposed which address the new processing issues while still exploiting the processing power of optics. These techniques fall into three groups: space-integrating, where the image is formed via a 2-D spatial integration of light after a frame of data has been received; time-integrating, where the image is formed with a temporal integration of light along each coordinate axis; and time-and-space-integrating, in which a 1-D spatial integration is performed after each line of data is received and the results are temporally integrated along the other dimension to complete the imaging process. We compare the fundamental limitations of these approaches in key performance aspects such as resolution, dynamic range, real-time operation, and flexibility. The results provide guidelines in matching the various hybrid architectures with the diverse SAR applications.

© 1987 Optical Society of America