A stereoscopy acquisition mode collects remotely sensed data where each location on the ground (or the imaged objects) is covered multiple times (at least twice), from different perspectives. Stereopairs and stereoscopic coverage enable the extraction of 3D representations of the environment from remotely sensed imagery.
A stereoscopy acquisition mode collects remotely sensed data where each location on the ground (or the imaged objects) is covered multiple times (at least twice), from different perspectives. Stereopairs and stereoscopic coverage enable the extraction of 3D representations of the environment from remotely sensed imagery. Most aerial photographs are taken with frame cameras along flight lines, or flight strips. [...] Successive photographs are generally taken with some degree of endlap [, i.e. overlap]. Not only does this lapping ensure total coverage along a flightline, but an endlap of at least 50 percent is essential for total stereoscopic coverage of a project area. Stereoscopic coverage consists of adjacent pairs of overlapping vertical photographs called stereopairs. Stereopairs provide two different perspectives of the ground area in their region of endlap [overlap]. When images forming a stereopair are viewed through a stereoscope, each eye psychologically occupies the vantage point from which the respective image of the stereopair was taken in flight. The result is the perception of a three-dimensional stereomodel. As an input to photogrammetry analysis procedures, stereopairs from flight strips enable the extraction of digital elevation models (DEM), orthophotos, thematic GIS data, and other derived products through the use of digital raster images and relatively sophisticated analytical techniques. With the availability of close-range UAV and terrestrial hand-held camera data, 3D reconstructions of buildings (even indoors) and other objects on the terrain surface become possible.