Use of an Artificial Snow Platform for WAM Tests

摘要

Because of the lack of a deep snow cover at the February 1991 Wide Area Mine(WAM) ground sensor tests held in Grayling, Michigan, an attempt was made there to simulate the effects of a deeper snow cover by making a pile of snow, compacting it and placing the WAM ground sensor prototype package upon the resulting platform. Recordings of moving military vehicles were then obtained with these sensors. To investigate the effects of this approach, a test was conducted in Hanover, New Hampshire, a few days later under similar snow conditions, but using a simple acoustic source (a pistol firing blank shots) rather than moving vehicles. The Hanover tests are described and reported here. The results show that the use of a small snow platform has little effect on the sensor response, and that the Grayling test procedure would be unsuccessful in simulating the effects of a deeper snow cover. The underlying cause of this failure is that the acoustic effect of a snow cover arises over a large areal extent and cannot be simulated by changing the snow properties in a small area near the sensors.