PROJECT PRE-GONDOLA II : AIRBORNE LIDAR OBSERVATIONS

摘要

Lidar (laser radar) observations from an aircraft of the cloud of debris resulting from the Pre-GONDOLA II explosion at Fort Peck, Montana, are described. With the neodymium (near infrared) lidar pointing horizontally at 45 aft of the aircraft beam, the aircraft made a series of flights past the cloud position at a height of approximately 225 meters above ground level and the lidar was fired at intervals of approximately 6 seconds. Since the cloud rapidly became invisible, these flights were positioned with reference to the lidar observations using a Doppler navigation system. Fror the lidar observations the location, shape, and internal structure (in terms of variations of density) of the cloud at the flight level were determined at five successive times, extending some 37 minutes after the explosion and some 17 kilometers downwind. While this technique is thus shown to be immediately available (with minor improvements) for limited operational application, the developments necessary to realize its full potential are identified and described. In particular, significant improvements in the data handling system are proposed.