Abstract: One embodiment of the system is implemented as an aircraft comprising a rotor. For example, the aircraft may be a helicopter. This embodiment also comprises an acoustic source, wherein this acoustic source comprises an acoustic signature of the aircraft. This particular embodiment also comprises an acoustic collection device affixed to the aircraft. The acoustic collection device preferably comprises an array of microphones. Finally, this embodiment also has a data processing device, such as a computer, for collecting the data detected by the microphones and processing this data. In operation, the aircraft is flown for a distance along a path while the aircraft emits acoustic energy. Then, the microphones detect the acoustic energy that is reflected off the terrain. Optionally, the detected energy may be stored as data and processed, so that noise may be reduced and a terrain image may be formed.