GEOLOGICAL STUDY OF SEDIMENTARY BASINS USING SPOT DATA

This paper illustrates the benefits of DTMs created from SPOT images f or the exploration of sedimentary basins. We chose an example located in the Ebro sedimentary basin in Spain, characterized by good outcropp ing conditions and slight deformations. The data used consist of a pai r of SPOT panchromatic images and a SPOT XS image. The work consists o f making up a 3D database, followed by interpretation of stereo pairs computed from orthoimages and the DTM. This interpretation is made on a stereoscopic desk and results in a digital file containing in the fo rm of vectors all the observed faults and lithology. These vectors are then used to make calculations on the geometry of the objects they re present: we demonstrate that we can accurately measure layer direction s and dips, sediment thicknesses and fault throws. Synthesis of perspe ctive views made at the same time provide a good understanding of the structures and help to test their geometric consistency. Thus knowledg e about relief given by DTMs helps to interpret remote detection image s in 3D space, and particularly to accurately quantify the results of this interpretation.