Photogrammetry is the science of obtaining reliable information and measurements about the properties of surfaces and objects without physical contact with the objects through photographs, for mapping and surveying.
The German geographer Otto Kersten first introduced the term in 1867 in the title of an article that was published in the Architectural Society Weekly Journal. The word “photogrammetry" is derived from the three Greek words phos or phot, meaning light; gramma, which means letter or something drawn, and metrein, the noun of measure.
Photogrammetry is commonly used in mapping, architecture, geology and engineering. Meteorologists can also use it as a way to determine the actual wind speed of a tornado.