Contents

01 July 1977
Vol 197, Issue 4298

About The Cover

Sonic booms from supersonic transports such as the Concorde may be used to probe the upper atmosphere. Acoustic signals of relatively high amplitude and low frequency, generated by the sonic booms, are reflected from both the stratosphere and the thermosphere and can be used to determine temprature and wind conditions at the reflection levels. See page 47. [British Aircraft Corp./Aerospatiale France]