A novel, high resolution temperature sensor for balloon applications Original Research Article

The speed of sound is to a very good approximation proportional to the square root of the temperature. A temperature sensor based on that principle was flown from ESRANGE, Sweden, in September 1999 together with a temperature sensor of an ozone sonde. The new sensor provided data comparable to the conventional sensor up to the apogee of 19 km of that particular balloon flight. The high—resolution variations of the acoustically derived temperatures are analysed relative to the radiosonde data, but also as frequency spectra. Explanations for differences from the theoretical behaviour are put forward and conceivable improvements are presented.