Remote temperature inversion sensor. [For correcting aerial survey measurements for uranium; using spectral radiance measurements in 15. mu. CO/sub 2/ band]

In conducting aircraft surveys for uranium, it is found that temperature inversions can give spurious results because they promote accumulation of radon gas in the atmosphere. The /sup 214/Bi (daughter product of radon) gamma-rays detected from the atmosphere-borne radon are difficult to separate from the /sup 214/Bi gamma-rays originating from the ground, and providing a signature for uranium deposits. The purpose of the present study was to examine the feasibility of making remote temperature soundings of the atmosphere below a low-flying aircraft (140 m or less above ground) by the inversion of radiance measurements taken in the 15-micron carbon dioxide absorption band. Such measurements would identify those temperature inversion conditions possibly leading to an unacceptably large background of gamma-rays from the atmospheric radon. Thus, the incidence of spurious aerial survey data could be greatly reduced. An atmospheric model was set up and the selection of layers and frequencies for radiance measurements was optimized. An error study was then made to determine the accuracy of the temperature profiles. It was concluded that the uncertainties in the temperature profile resulting from expected realistic errors of measurement were too large to consider further study of this approach. Other alternative approaches were considered, e.g.,more » spatial, rather than spectral scanning, and determined not to be feasible.« less