Photogrammetric Resection and Associated Techniques

This document introduces fundamental photogrammetric techniques such as resection, intersection, relative orientation, absolute orientation, and bundle adjustment. These methods play vital roles in surveying and mapping applications. Photogrammetric resection involves calculating 3D coordinates of image feature points, which serve as foundational data for generating Digital Elevation Models (DEMs) and Digital Surface Models (DSMs). In code implementation, resection typically uses collinearity equations with iterative least-squares solutions to determine camera exterior orientation parameters.

Intersection refers to the process of determining 3D ground coordinates using overlapping images from multiple camera positions. Algorithmically, this employs forward intersection calculations based on known camera parameters and corresponding image points. Relative orientation establishes the geometric relationship between stereo image pairs by recovering relative camera positions, often implemented through coplanarity condition equations and essential matrix computations.

Absolute orientation transforms the model coordinate system to the ground coordinate system using control points, typically implemented via 3D similarity transformations (helmert transformation) with rotation, translation, and scaling parameters. Finally, bundle adjustment represents the optimal estimation method that simultaneously refines all camera parameters and 3D point coordinates. Modern implementations use sparse matrix techniques with Levenberg-Marquardt optimization to minimize reprojection errors across entire photogrammetric networks.