光波測量における気象補正について ―音波速度による気温の推定―

Abstract

In the distance measurements by a Geodimeter, making the proper correction for the atmosphericindex of refraction, the experiments to estimate the temperature from the velocity of sound travellingbetween both ends of base line have been tried. The result of the experiment on the paved road(length: 500 m) is 2ｰC lower, whose effect on the corrected distances is comparable to the accuracyof the Geodimeter, than direct measurements with thermometer. On the propagation of sound, the effect of refraction on the travel time is practically negligible in consideration of the accuracyof the Geodimeter. But attenuation is too high to propagate over a few kilometers.