This is how I envision the system being used. A citizen complained that an aircraft coming in for a landing at 2:00 AM was too noisy because it was flying low. The investigating person would take out the two VCR tapes that were recorded between midnight and 6:00 AM. The investigator would fast-forward the tape two hours to the time of the 2:00 AM flight. The investigator would listen to the tape's recorded radio traffic to get the aircraft's N-number. (When coming in for a landing pilots are required to call in their aircraft's N-number even when the control tower is closed.) The investigator would play the videotape until the aircraft passes through the viewing area of the screen. (Being it is nighttime you would watch for the aircraft's navigation lights passing through the viewing area.) The picture of the aircraft would then be paused and moved frame by frame to the center of the TV screen. A calibrated template would be placed over the screen to measure the number of degrees the aircraft is above the camcorder's site. This information would be used to determine the aircraft's height above the camcorder's site.