Close-range geophotogrammetric mapping of trench walls using multi-model stereo restitution software.

摘要

Methods for mapping geologic features exposed on trench walls have advanced from conventional gridding and sketch mapping to precise close-range photogrammetric mapping. In our study, two strips of small-format (60 (times) 60) stereo pairs, each containing 42 photos and covering approximately 60 m of nearly vertical trench wall (2-4 m high), were contact printed onto eight 205 (times) 255-mm transparent film sheets. Each strip was oriented in a Kern DSR15 analytical plotter using the bundle adjustment module of Multi-Model Stereo Restitution Software (MMSRS). We experimented with several systematic-control-point configurations to evaluate orientation accuracies as a function of the number and position of control points. We recommend establishing control-point columns (each containing 2-3 points) in every 5th photo to achieve the 7-mm Root Mean Square Error (RMSE) accuracy required by our trench-mapping project. 7 refs., 8 figs., 1 tab. (ERA citation 16:021832)