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Atmospheric structure measurements from accelerometer instrumented falling spheres

Document ID: 53

Philbrick, C. Russell¹
McIsaac, J. P.¹
Fryklund, D. H.²
Buck, R. F.³

¹ USAF, Geophysics Laboratory, Hanscom AFB, Bedford, MA, U.S.A.
² Accumetrics Corporation, Cambridge, MA, U.S.A.
³ Oklahoma State University, Stillwater, OK, U.S.A.
 

Abstract

A three-axis piezoelectric accelerometer, mounted in a 25 cm diameter sphere has been used to measure the atmospheric density and winds and obtain a temperature profile in the altitude range of 50 to 150 km. The sphere with its own telemetry system, beacon transponder and associated support electronics was released from a Nike-Orion boosted payload at an altitude of about 70 km on the up-leg of the flight. The drag acceleration measured by the accelero­meter can be used to directly calculate the atmospheric density with a vertical resolution of about 100 meters. The wind field is calculated under the assumption of a uniform distribution in the horizontal plane between the up-leg and down-leg regions which are separated by about 30 km. The atmospheric temperature profile is determined by integrating along the density profile under the as­sumptions of the ideal gas law and hydrostatic equilibrium. The profiles obtained from the density, temperature and wind profiles can be used to describe those regions of the atmosphere which would be expected to be statically and dynamically unstable. A prototype of the high frequency accelerometer which should be able to measure the drag acceleration component associated with structure scales as small as 2 meters was also included in the payload. The purpose of this high frequency accelerometer is to measure the structure associated with the inertial subrange of turbulence layers in the mesosphere. Data were obtained at 0447 UT on 16 November and 0009 UT on 1 December 1980. The measurements were made in conjunction with many other experiments during the two salvos for disturbed geomagnetic conditions as part of the Energy Budget Campaign.

 

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Keywords: mesosphere, thermosphere, density, temperature measurements, wind velocity, turbopause

Citation:

"Atmospheric structure measurements from accelerometer instrumented falling spheres", Philbrick, C. R., J. P. McIsaac, D. H. Fryklund, R. F. Buck, Forschungsbericht W; 81-052, Bundesministerium fur Forschung und Technologie, Bonn, Germany, 1980, pp. 352 - 361

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Accelerometer

Accelerometer