Direct Geo-Referencing is a new technique in photogrammetry, especially in the aerial photogrammetry. Unlike the Aerial Triangulation “AT”, this method does not require Ground Control Points “GCPs”, to process aerial photographs into desired ground coordinates systems. Compared with the old method, this method has four main advantages: faster field work, faster data processing, simple workflow and less cost. Generally, direct geo-referencing using two systems, Global Navigational Satellite Systems “GNSS” and Inertial Navigational System “INS”. GNSS recording the camera coordinates “X, Y, Z”, and INS recording the camera orientation angles “w, φ, k” at the time of exposure. These parameters merged and are provided to each photograph in the processing stage. |
