The approach only requires the use of satellite stereo imagery with precise ephemeris data and is therefore not dependent on ground truth data like echo sounding or lidar depth measurements. As such time consuming and costly in-situ measurements are not required, the technique is more flexible and cost-effective than traditional approaches.
Bathymetry is the underwater topography of lakes or ocean floors and constitutes an important information layer on hydrographic charts. Traditional ways of acquiring bathymetry data include the carrying out of depth measurements using sounding lines, sonar or lidar. However, as ship-based or airborne measurements take time to prepare and perform and can only cover fairly small geographic areas in a single pass, quite significant expenditure is usually required in terms of time and money. Bathymetric information is of importance in offshore hydrocarbon exploration: knowledge of the seabed morphology and of subtle submarine features, such as so-called mud volcanoes, can provide valuable indicators to prospectors. Furthermore, accurate sea-bottom morphology facilitates the correct interpretation of 3D seismic surveys.
RWE Dea Azerbaijan tasked GAF with the performance of a bathymetric survey in its area of interest in the Caspian Sea. GAF made use of satellite remote sensing and its new stereo approach for this task and mapped an area of 230 sqkm. The bathymetric analysis was based on a stereo pair of very high resolution multispectral satellite images.