What is Photogrammetry

Photogrammetry is the technique of measuring objects(2D or 3D)from photo-grammes. We say commonly photographs but it may be also imagery stored electronically on tape or disk taken by video or CCD cameras or radiation sensors such as scannerst

Brief History of Photogrammetry

1851: Only a decade after the invention of the "Daguerrotypie" by Daguerre and Niepce, the french officer Aime Laussedat develops the first photogrammetrical devices and methods. He is seen as the initiator of photogrammetry.

1858: The German architect A. Meydenbauer develops photogrammetrical techniques for the documentation of buildings and installs the first photogrammetric institute in 1885 (Royal Prussian Photogrammetric Institute).

1866: The Viennese physicist Ernst Mach publishes the idea to use the stereoscope to estimate volumetric measures.

1885: The ancient ruins of Persepolis were the first archaeological object recorded photogrammetrically.

Photographing Devices

hey have stable and precisely known internal geometries and very low lens distortions. Therefore, they are very expensive devices. The principal distance is constant, which means, that the lens cannot be sharpened when taking photographs. As a result, metric cameras are only usable within a limited range of distances towards the object. The image coordinate system is defined by (mostly) four fiducial marks, which are mounted on the frame of the camera. Terrestrial cameras can be combined with tripods and theodolites. Aerial metric cameras are built into aeroplanes mostly looking straight downwards. Today, all of them have an image format of 23 by 23 centimeters