In order to develop regional scale geological maps for use in small-scale survey, scheduling ground activity for large-scale surveying and to study the field geological features together with their geographical locations and association of various geological units on surface, remote sensing has been in use extensively. In order to have a comprehensive understanding of lithostratigraphy, multiple data sources are required to be integrated.
Three-dimensional view of the local relief will be provided by stereo imagery to facilitate delineation and identification of units. For field analysis and ground truth, aerial photographs and satellite imageries are carried along with for use in the form of base maps in the field. Aerial photographs generally provide high-resolution information (like weathering, drainage patterns, etc.) for site-specific analysis. Large coverage area and moderate resolution are required for regional overview. In geological exploration, since the various elements of concern are not dynamic, frequency of imaging has been never an issue.
One of the biggest problems faced in the application of remote sensing are the thick vegetation canopy. For such cases, the technique of remote sensing is of great aid to geologists for indicating rock type on the basis of the growth of the vegetation type on it (geobotany). The growth of particular type of vegetation is controlled by specific type of mineral and rock constituents on which it grows. A study involving natural association of various geological units with the growth of specific type of vegetation on them acts as good indicators and is of much use in geological mapping. By integrating different source of image data (optical, radar) at an appropriate scale, remote sensing is optimally used. Worldwide data are readily available in imageries captured through satellites and are of reasonable price (price per km).
