Petroleum and mineral resources play a major role in the daily lives of the global population. Resource exploration and geological research is important to maintain and enhance the quality of life to the global population through the provision of materials for infrastructure, fuel for heat, cooking and transportation, and through the insurance of protection from geological hazards.

Traditionally geological information for mapping at local and regional scales has been acquired through field work by qualified geoscientists. Optical remote sensing from air- and spaceborne platforms provide a synopic view of the terrain which allows geological information to be collected over a larger region. Geological information from optical sensors are however, hindered by cloud cover, identification of features restricted by illumination conditions, and the delineation of geological structure dependent on the angle and elevation of the sun. However, over the past decades, radar remote sensing has proven to be an effective tool for the extraction of geological information, unhindered by external illumination and weather conditions.

The geological interpretation of radar imagery at a regional scale is based on the analysis of surface morphology at the terrain and landform level. The use of radar data for topographic mapping has been well documented (Simonett and Davis 1983; Williams 1983). The side-looking configuration of spaceborne SARs highlight relief; the use of shallow incidence angles produces a shading effect or shadowing which can emphasize even subtle slopes in the landscape. These are often attributable to underlying geological units and structures.

Other remotely sensed data can be integrated with SAR data to provide additional information for an imaged area, thus creating an enhanced image map for interpretation. Landsat TM optical data adds vegetation information which allows for geobotanical correlations to be developed. Information about underlying soil, sediment, and bedrock conditions can be inferred from surface vegetation, although the successful application of this technique requires extensive, study area-specific background information. Another valuable combination is with the varied data sets generated by modern geophysical surveying--widespread in mineral exploration. Combined with radar imagery it provides a means of correlating, or at least locating, inferred subsurface mineral horizons, structural features, or lithologies with respect to surface relief.

Radar-derived geological information is used by experts involved in a wide range of geological applications including geological and quaternary mapping, mineral and hydocarbon exploration, and geologic hazard identification.

Radar is particularly well suited for geological mapping because of the terrain texture information it provides which are often related to geological structures and surficial deposits. These features are often manifested topographically at the Earth's surface; the side-looking configuration of radar enhances differences in relief which may aid in the delineation of such features.

Quaternary mapping in glaciated terrain, which involves the delineation of landforms together with the assessment of surficial material, has been successfully demonstrated using radar alone and in combination with optical remotely sensed data. The radar data provides information on topography of landforms, from which many Quaternary features can be identified through their characteristic morphology. The optical data provides information on natural vegetation cover which may be related to conditions such as soil/sediment drainage, clay content, etc. In combination with conventionally derived Quaternary maps, radar data can allow regional extrapolations of surficial deposits which can then be used for infrastructure route planning and aggregate resource assessments.

Radar has also proven to be a promising tool for mineral and hydrocarbon exploration. Certain types of mineralization and hydrocarbon resources are often associated with specific geological structures thus, the mapping of these structures when topographically expressed can assist in the identification of areas of high mineral and hydrocarbon potential. Often radar data are merged with geophysical data. The radar data allows the delineation of topographically expressed structures, while the geophysical data aids in the identification of strong magnetic signature. Resulting composites show the correlation between geological structure and magnetic anomalies which aid in the planning of detailed ground surveys.

Geologic hazard identification is an important part of geological research as it pertains to the safety of humans, as well as to the protection of the environment they inhabit. The identification of seizmic zones, and the assessment of landslide hazards and coastal erosion has been successfully demonstrated using radar.