MEASUREMENT OF WINDS AT ELEVATIONS OF 30 TO 80 KILOMETERS BY THE ROCKET-GRENADE EXPERIMENT

Abstract

Thirty-two values of wind velocity between 30 and 80 kilometers have been obtained from six Aerobee rocket flights made at night at White Sands Proving Ground, New Mexico (32°N), between July 1950 and November 1951. The average wind velocity in a horizontal layer at a particular altitude was determined from the effect of the wind on a sound wave traveling downward through the layer. The sources of the sound waves were grenades, ejected and exploded along the upward path of the rocket. The positions of the grenades, the travel times of the sound waves to a point of the ground almost directly underneath the grenades, and the angles of arrival of the waves at the ground are the data required for the calculations. The wind directions were found to be easterly in summer and westerly in autumn and winter. The wind speeds were a maximum at about 55 km, the largest measured speed having been 104 meters per second.