stereophotogrammetric

Stereophotogrammetric is a branch of photogrammetry that derives three-dimensional measurements from stereo photographs or stereo image blocks. By capturing two or more images from slightly different viewpoints, it exploits parallax to reconstruct the coordinates of points in space relative to a defined camera model, yielding accurate 3D data for surfaces and volumes.

In practice, stereophotogrammetry relies on solving the geometry that relates image points to object points through camera orientation and calibration. Photogrammetric work often uses epipolar geometry to constrain correspondences, and measurements are refined by bundle adjustment to minimize reprojection errors across all images.

The typical workflow includes image acquisition with overlapping views, camera calibration, determination of exterior orientation, matching of corresponding points between images, and triangulation to compute 3D coordinates. Digital systems commonly perform dense stereo matching to produce point clouds and digital surface models, which may be post-processed into meshes or contours.

Equipment ranges from analogue stereo plotters and stereoscopes used with film cameras to modern digital cameras, calibrated lenses, and software that performs automated or semi-automated image matching. Data sources include aerial photographs, close-range architectural or industrial imagery, and UAV-based collections.

Applications are widespread in topographic mapping, civil engineering, archaeology, cultural heritage documentation, geology, and industrial metrology, where precise measurements of shape, volume, and alignment are required. Limitations include occlusions, textureless or repetitive areas, lighting effects, and dependence on accurate camera calibration and ground control for georeferencing.