HIGH-RESOLUTION INTERFEROMETRIC SAR FOR DISCOVERER II High-Resolution Interferometric Synthetic Aperture Radar for Discoverer II

New requirements have recently emerged for high-resolution digital terrainelevation data. Such data are required for critical applications such as intelligent preparation of the battlefield and precision engagement. The recent development of high-resolution interferometric synthetic aperture radar (IFSAR) has made meeting these requirements a possibility. Because studies have shown that a space-based IFSAR mission is feasible, a high-resolution terrain-mapping mode has been included as an important part of the Discoverer II Technology Demonstration Program. This article presents a survey of the current state of research for space-based high-resolution IFSAR. Research and development have focused on key technical challenges such as phase unwrapping, baseline-tilt estimation, motion contamination, vegetation and urban-area effects, synchronization, and error minimization. The application of high-resolution terrain-elevation data to tactical targeting is also discussed. (