For determining the elevations of terrain points, the most suitable method is convergent surveying, where the sighting beam vector is inclined at an angle from the nadir. Measurement accuracy is maximized when the optical axes of the survey zones intersect at a right angle. Stereoscopic surveying involves three main components: beam recording by a camera (sensor, scanner), the movement of the carrier’s center of mass, and changes in its angular position. The direction of the sighting beam vector in the coordinate system of the surveillance equipment is determined by the quantities defining the position of this vector. These quantities are the direction cosines of the sighting beam vector. To determine the direction cosines of the sighting beam in the coordinate systems of different cameras (sensors), analytical photogrammetric and stereophotogrammetric methods are typically used. Furthermore, it is important to consider that determining the direction cosines of the sighting beam vector in the coordinate system of cameras (sensors) with different imaging geometries requires knowledge of the scanning (shooting) method and law used in the specific surveillance system. Recently, the most commonly used method in modern surveillance systems is uniform element-by-element scanning in a plane perpendicular to the flight direction of the surveillance equipment carrier. This article offers a brief analysis of determining angular quantities (direction cosines) in the coordinate systems of frame, panoramic, slit, and optical-mechanical cameras.
Evgeniy Kozin (Fri,) studied this question.