HR: 15:25h
AN: G33D-08    [Abstracts]
TI: Acquisition, Visualization and Analysis of Photo Real 3D Virtual Geology at High Accuracy: Oblique, Close Range Data Acquisition From the Ground With Digital Cameras, Terrestrial Laser Scanners and GPS
AU: * Xu, X
EM: xuxue@utdallas.edu
AF: Dept. of Geosciences,University of Texas at Dallas, 2601 N. Floyd Rd, Richardson, TX 75083 United States
AU: Aiken, C L
EM: aiken@utdallas.edu
AF: Dept. of Geosciences,University of Texas at Dallas, 2601 N. Floyd Rd, Richardson, TX 75083 United States
AB: For almost seven years we have been mapping geology digitally using a combination of laser rangefinding and GPS. We have extended that concept to add unique real photo texture mapping. This is a unique method combining computer visualization and photogrammetry and has been used to build 3D photo real models at millimeter to centimeter accuracy and resolution of a variety of 3D features especially extensive geologic outcrops in the US, Spain, Ireland, United Kingdom, and Mexico. Although the method is independent of the type of laser rangefinder being used we presently are using fast laser scanners for faster and more detailed models although these data sets are then extremely large resulting in hardware and software problems for users. These models are globally oriented so they can be integrated with other globally positioned data sets such as drill holes, geophysical surveys (seismic and ground penetrating radar), and conventional geologic mapping (stratigraphic sections, outcrop mapping of contacts and orientations.) etc. Three dimensional measurements such as strikes, dips and thicknesses are extracted by fitting surfaces to digitized lines in 3D space defining the intersection of a boundary or fracture/fault with the surface, allowing quantitative measurements with associated statistics. The models have incorporated data from as many as one hundred close range oblique photos (taken from the ground or helicopters etc.) and 60 terrestrial scans over a single site, and laterally over several kilometers. We have also applied the method to processing air photos, using the terrestrial scanners for the terrain model ( at a few centimeters), control from GPS and the commercially acquired air photos for the real photo texture mapping for a fully realized 3D orthophoto. We use the term "real photos" rather than "photorealistic" because the latter has been used for models with texture surfaces that are "like the real" but not the "real" photo surface whereas our approach uses real photos for the surfaces. Petroleum companies have been the major user of these models utilizing them in 3D stereo in their CAVE (CAVE Automatic Visualization Environment) systems for virtual field trips and integrated analysis of reservoir characterization analogs. They are also being incorporated in short courses and UTD courses such as structural geology before, during and after field trips to the sites. One of our models has been used by a visual effects group for a film for television. We will display several examples of these models at this meeting in a Geowall 3D stereo system using powerful and cost effective open source software.
UR: http://www.utdallas.edu/~xuxue
DE: 1294 Instruments and techniques
DE: 1295 Integrations of techniques
DE: 1299 General or miscellaneous (1709)
SC: Geodesy [G]
MN: Fall Meeting 2005