Photogrammetry is the art, science, and technology of obtaining geometric information on the 3-dimensional shape and orientation of objects from photographs and other imaging sensors. Geophysical quantities and textural information may be extracted additionally. We focus on digital photographs, range images, and point clouds in general. These are acquired from terrestrial, airborne and spaceborne platforms, using photogrammetric and amateur cameras as well as laser scanners. By investigating the measurement process, appropriate geometric and radiometric calibration methods are developed and, consequently, insight into the properties and the quality of geodata is obtained. Subsequently, models of our three dimensional environment are reconstructed automatically. This approach is seen as fundamental prerequisite for successful application of Earth Observation in topography, hydrology, forestry and related sciences which are studied together with experts in those fields.