Accession Number : ADA118774

Title :   Development of an Airborne Sonic Thermometer.

Descriptive Note : Final rept. 1 Jul 80-30 Sep 82,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROPHYSICS LAB

Personal Author(s) : Christiansen,Tore R

PDF Url : ADA118774

Report Date : Sep 1982

Pagination or Media Count : 122

Abstract : An airborne sonic thermometer has been developed and is now ready for flight testing. The designed instrument uses a specially developed electromagnetic transmitter, a sensitive condenser microphone and integrated circuit components. The air temperature is determined by measuring the phase difference between the transmitted and received signals across an acoustic path in the medium. The phase information is delivered as a changing dc-level voltage, as a digital signal and in the form of two phase shifted squarewaves. Improvements of the present design are needed to exclude the effect of wind speed on the temperature measurement, and in the accuracy of the calibration of the signal outputs. Once these are included, however, temperature measurements to an accuracy of plus minus one tenth of a degree centrigrade, over a temperature range from plus 25 C to minus 80 C, should be available. (Author)

Descriptors :   *SOUND TRANSMISSION, *THERMOMETERS, *AIRBORNE, FLIGHT TESTING, DIGITAL SYSTEMS, ATMOSPHERIC TEMPERATURE, TRANSMITTERS, INTEGRATED CIRCUITS, SONAR TRANSDUCERS, MEASUREMENT, WIND VELOCITY, ACCURACY, MICROPHONES, SIGNALS

Subject Categories : Test Facilities, Equipment and Methods
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE