The SPOT imaging system, launched in 1986 by the French National Space Agency (CNES), provides two significant advances for mapping geological structures from satellite imagery: increased spatial resolution of key structural and stratigraphic elements, and stereoscopic capabilities for making strike-and-dip measurements. Quantitative stereo mapping with SPOT data may be done using hard-copy images and conventional equipment, such as stereo plotters, or by displaying images on a video monitor in stereo-viewing format. The latter method is a new remote-sensing technique particularly relevant to the exploration community. This technique allows development, with minor expenditure and training, of an effective stereo mapping capability on existing image-processing systems or o stand-alone personal computers.

SPOT stereo data is particularly useful for mapping low-amplitude and highly deformed structures. Surface structure maps generated from stereo imagery data can be applied to exploration at two levels. At early stages, such maps can be used to establish the style, trend, size, and spatial distribution of structures in a basin, and to investigate key tectonic elements. At more advanced prospecting stages, these maps can be used to constrain subsurface mapping of structures located in areas of poor seismic data quality. This latter technique, however, may require the support of higher resolution stereo aerial photography.