photogrammetric

Photogrammetric refers to photogrammetry, the science of obtaining reliable measurements from photographs. It involves deriving accurate three-dimensional coordinates of surface points from overlapping images, typically using stereo pairs or image blocks, to create spatial representations of objects, terrain, and built environments.

Historically, photogrammetry developed from methods to measure parallax in the 19th and early 20th centuries, advancing to analytical and digital forms that enable automated orientation and 3D reconstruction.

Technical workflow includes image capture with sufficient overlap and known camera parameters, indirect and direct orientation using ground control or self-calibration, followed by bundle adjustment to refine positions. Once oriented, stereo intersection yields measurements, and dense matching produces point clouds. Outputs commonly include orthophotos, digital elevation models, and textured 3D models for analysis or visualization.

Applications span topographic mapping, civil and architectural engineering, urban planning, forestry, archaeology, geosciences, disaster response, environmental monitoring, and cultural heritage documentation. In recent decades, drone-based photogrammetry has expanded capabilities and accessibility.

Accuracy depends on image geometry, overlap, scale, and control data, while limitations include occlusion, textureless surfaces, lighting variability, and the need for calibration and error management.

Modern practice integrates photogrammetry with GIS, and increasingly relies on digital sensors and software, including structure-from-motion approaches, to streamline production of geospatial data.