Flight route boundaries are planned on the basis of topographic maps and with the assistance of IGI’s (Kreuztal) specialist software ‘World Wide Mission Planning (WWMP/WinMP) are also simulated.

Required parameters such as photo scale, end-and-side-lap, and flight direction are input into the program. After interactive checks and corrections of the software generated flight lines, the data is stored on a PCMCIA card. During aerial photography this data is transferred to the on board computer. The aircraft navigation is carried out with the assistance of CCNS4 (Computer Controlled Navigation System) which is supported by GPS (Global Positioning System) a satellite navigation system.

To date 25 American military Navstar satellites are orbiting the earth at approximately 20,000 km above the earth’s surface. At the precise moment that an aerial photo is taken the position of the aircraft can be determined by evaluating the signals from, at a minimum, four satellites. In addition to computer controlled navigation, aircraft position at the precise moment of shutter release can be determined by a ground station using kinematic GPS (DGPS). After aerial photography missions recorded co-ordinates of the camera’s projection centres are read into Bentley’s MicroStation CAD software using a standard interface and then plotted out as flight line indices.