Design and development of coherent data logging system for offline SAR processor

Synthetic Aperture Radar (SAR) is an imaging system which can produce very high-resolution images from data collected by a relatively small antenna mounted onto a moving, airborne or spaceborne platform. SAR images are formed from the reflection of coherent signals. Therefore, a SAR system requires a high end data collection system which preserves coherent Doppler phase information in order to reconstruct image properly. In this paper a coherent data logging system is presented that acquires and stores the radar echoes as it moves along its path, preserving the signal characteristics and phase changes. Both the In-phase (I) and Quadrature (Q) signals are acquired through distinct channels. The speed of the platform is also recorded at known interval as speed information is significant for SAR signal processing.