ENTERING THE THIRD DIMENSION - AN INTEGRATED DIGITAL STEREO GEOLOGIC MAPPING WORKFLOW WITHIN ARCGIS PRO

Geologic maps serve as fundamental datasets for various derivative products and activities such as supporting the oil, gas, and mining industries; hazards assessments; and governmental decision making. The ongoing transition from paper-based mapping to an integrated GIS environment has led to the utilization of new tools and streamlined workflows designed to improve the efficiency and quality of map products. With a transition to modern technologies, incorporation of a digitally native three-dimensional (3D) aerial stereoview of the earth has lagged in most modern GIS mapping workflows. While mapping with lidar provides a greater resolution in one sense, it only gives a two-dimensional (2D) perspective. This limited viewpoint requires greater inference and can disconnect the mapping geologist from the colors and geologically controlled vegetation patterns visible in the field. A multi-method approach using both 3D stereoview and 2D lidar within the same GIS workspace can allow modern mapping workflows that replicate and improve on the stereo photo mapping of previous generations of geologists. At the Utah Geological Survey, we have a long legacy of 3D stereo mapping in GIS software and continue to develop and innovate methods to integrate the crucial third dimension into our modern mapping. Without requiring photo prints or a stereoscope, our workflow incorporates 3D stereo mapping on statewide stereo imagery within ArcPro’s Image Analyst extension. The new proposed workflow uses 3D lines that interact with lidar-derived topography and make use of a fully integrated GIS, flipping between other supporting layers and stereoview all in one working ArcGIS Pro instance. The work is ongoing to select the best workflow between active vs. passive stereoviews. Overall, this GIS-based stereo-mapping approach results in better, more geologically contextualized maps by eliminating the need to infer Earth’s natural appearance in 3D from 2D images. This work will facilitate digital stereo mapping within the broader geologic mapping community and expand and improve our methods and make better, more geologically accurate maps of the earth.