APPLICATIONS OF IMAGING RADAR TO GEOLOGY (REMOTE SENSING, IMAGE PROCESSING, LANDSAT)

Imaging radar is a complex, recently-developed sensor whose potential in geologic applications remain largely unexplored. In vegetated, cloud-covered regions, imaging radar may be the single most important reconaissance tool available; in better-exposed areas, it may provide valuable data complementary to those provided by optical systems.; This thesis is a collection of nine studies examining tone, texture, and features imaged by radars. A variety of computer image processing techniques were developed to reveal characteristics of these scenes. Field checking of sites suggests links between the geology and the images.; Tonal studies examine the effects of varying frequency polarization, and illumination geometry. Most surficial geologic units in Death Valley, California, are distinguishable by use of multifrequency, multipolarization radar data. Quaternary basalt flows in Idaho are separable by changing illumination geometry in the vertical plane, whereas desert fans and dunes show little tonal variation as function of changing illumination azimuth.; Topographic texture is strongly enhanced by radar's unusual imaging physics. Computer image processing techniques developed in this study prove useful in classifying and enhancing image texture. The classification technique, applied to areas in Tennessee and the Dominican Republic, yield results in good agreement with those of human interpreters. The enhancement technique resolves a plunging anticline that was not evident on unprocessed imagery.; Identification of features such as lineaments and large topographic highs is critically dependent on radar system parameters. Case studies and simulations from a variety of sites serve to clarify these phenomena. A mathematical model of topography-induced distortion provides insight into the relationship between a radar image and the illuminated terrain.; Imaging radar is shown to be a useful sensor for geologic mapping, especially when complementary data are present. Careful image processing, field checking of interpretations, and an understanding of radar imaging physics are critical to effective utilization of this unusual sensor.