MEASURING THE RANGE OF VISIBILITY IN DARK DIURNAL TIME BY BACKWARDS DIFFUSION (IZMERENIE DALNOSTI VIDIMOSTI V TEMNOE VREMYA SUTOK PO RASSEYANIYU NAZAD),
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
Pagination or Media Count:
Field tests have now been made of the NUOR, a nephelometric apparatus based on the backscattering principle, for determining the visibility range at night by the recording of scattering at an angle close to 180 degrees. The theory of the apparatus has been described by the author elsewhere Trudy NIIGMP, 1963, No. 13. This paper describes the construction of calibration curves for the apparatus. It was found that for the entire range of visibility measured in the network of hydrometeorological stations, the NUOR apparatus ensures an adequate degree of accuracy. The nephelometric backscattering apparatus can be used for determining the scattering coefficient at angles close to 180 degrees the scattering index should be determined independently by some other method. Data are given on the values of the relative coefficient of scattering for angles of 175--180 degrees, averaged for the entire period of observation. The comparability of the NUOR and M-37 transparency recorder is shown.