Photogrammetry
Photogrammetry is the science of measurement by means of photographs. Photogrammetric surveying is the application of photogrammetry to the operations of finding and delineatingthe conturs,dimensions,positioning ,etc, of parts of the earth’s surface. The principles of photogrametry are applicable to the fields of archeology, architecture,astronomy,ballistic,criminology,geology,hydraulics,radiology,and other sciences, but the gratest Development of the science isi n the field of photogrametric surveying. The realization of photogrametry is the mathematical or graphical analysis of single or overlapping photographs.
As the image of actual objects appears displaced and are of proportionate size according to their distance and relative position within the range of vision of the eye, so do the scale and the position of objects in photographs vary according to their distance and position relative to the camera stadion. Photogrammetric surveying is accomplished by the measurrement of these differences in scale and displacements in position.
Photogrammetry is not a new science, but only recently has the knowledge of photogrammetric surveying become general. It is ascience gradually developer, whose basic principles and mathematical analysis have been known for about one hundred years. Its initial Development was slow because it grew as a Branch of a science of optics and photography and came only White the Development of Aviation .
A clear understanding of the meaning of the expressions used in photogrametric surveying is essential. Following are definitions of some of the more Common terms in current use:
An anaglyph is a picture printed or projected in complementary colors combining the two images of a stereoscopic pair and giving a stereoscopic image when viewed throught spectacles having filters of corresponding compementary colors.
A camera is a Chambers or a box in which the image of eksterior objects are projected upon a sensitized surface. An aerial camera is one specially designed for use in aircraft.
