The results of numerical estimates of the absolute error introduced in measurements of the relative humidity by atmospheric turbulence in the case of vertical two-frequency radioacoustic sounding are presented. The main interfering factors in this case are the decrease in the transverse coherence length in the sound wave and the effect of horizontal atmospheric wind.
The estimates were made for harmonic acoustic frequencies in the band 1-13.6 kHz while sounding in an atmospheric layer 50-200 m under calm conditions and in the presence of a moderate wind. The relative error in the relative humidity of 10-100% does not exceed 10%:when sounding at frequencies of 3.4-6.8 and 6.8-13.6 kHz under calm conditions and at frequencies of 6.8-13.6 kHz in the presence of wind with velocity 5m/s.
1. M.A. Kallistratova and A.I. Kon, Radioacoustic Sounding of the Atmosphere (Nauka, Moscow, 1985), 195 pp.
2. M.Yu. Orlov and B.S. Yurchak, in: Proceedings of the Institute of Experimental Meteorology, No. 38/121, 14–20 (1985).
3. S.I. Babkin and Yu.N. Ulyanov, in: Proceedings
of the 9th All-Union Symposium on Laser and Acoustic Sensing of the Atmosphere, Part II, Institute of Atmospheric Optics, Siberian Branch of the Academy of Sciences of the USSR, Tomsk (1987), pp. 145–148.
4. V.I. Tatarskii, Wave Propagation in a Turbulent
Medium, (McGraw-Hill, N.Y., 1961) [in Russian](State Publishing House of Physical and Mathematical Literature, Moscow, 1967).
5. J.C. Kaimal, J.C. Wyngaard, D.A. Haugen, et al., J. Atmos. Sci. 33, No. 11, 2151–2169 (1976).
6. O.G. Nalbandyan, Izv. Akad. Nauk SSSR, Fiz. Atmos. i Okeana 12, No. 8, 877–880 (1976).
7. V.E. Zuev, V.A. Banakh, and V.V. Pokasov, Optics of the Turbulent Atmosphere (Gidrometeoizdat, Leningrad, 1988), 270 pp.
8. I.P. Golyamin, ed., Ultrasound (Sov. Entsiklopedlya, Moscow, 1979), pp. 154–148.
9. B. Bernfeld, Journ. of Audio Engineering Soc. 28, No. 7/8, 521–524 (1980).