Integration of Ground-Based Lidar and Hyperspectral Scanning - New Methods for the Remote Mapping of Geological Outcrops

Tobias H. Kurz, Simon J. Buckley, and John A. Howell
Centre for Integrated Petroleum Research (CIPR), University of Bergen, Bergen, Norway

Ground-based lidar has become a widely used method for the capture of geological data and the creation of 3D virtual outcrops. Lidar data have been used for studying reservoir analogs and building geocellular models from outcrops. These geocellular models are utilized as a means for understanding geological architectures and behaviours of reservoirs and aquifers. Lidar systems are typically linked with a high resolution digital camera which allows the lidar point cloud to be colored and also provides texture for draping the topographic surface. Hyperspectral imaging is a well developed technique for aerial and satellite remote-sensing which allows the mapping of mineralogical and lithological variations in strata based on physical interactions of electromagnetic radiation with the surface material. The reflection and absorption of certain wavelengths are controlled by the chemical and structural behaviours of the object.

The aim of the current project is to develop methods for the integration of lidar and ground-based hyperspectral data, ultimately leading to the remote mapping of lithology and petrophysics in virtual outcrops. The integration of the two datasets remains a key challenge and new methods for the registration of image data have been developed.

The methods have been tested on outcrops of dolomitized Permian limestone which crop out in NE England. Carbonates show characteristic absorption features between 2320 and 2350 nm at which calcite has an absorption minimum at 2335 nm. Dolomite causes a slight shifting of the absorption to lower wavelengths. The position of the absorption features allows the distinction between primary and altered limestone. This study indicates that a combination of geometrically accurate lidar data, combined with the spectral mapping of lithology has significant implications for the automated collection of geological data.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas