PMCAD: Photogrammetric-Based CAD System for Traffic Accident Mapping

A low-cost, digital, three-dimensional photogrammetric mapping system has been successfully developed and implemented on a microCAD system. Code-named PMCAD, the system allows both two-dimensional line maps and three-dimensional wire-frame or solid models to be captured into CAD databases from nonmetric cameras. The mathematical algorithm is modeled on the Direct Linear Transformation (DLT) and implemented on a microcomputer. Preprocessor and postprocessor software developed to work in cooperation with the DLT algorithm, allows digital data to flow efficiently from the digitizer into a CAD system for 3D graphics display.