Comparison of observed tropospheric refraction with values computed from the surface refractivity

Radar elevation-angle errors observed in the Tularosa Basin of New Mexico are compared with values predicted from the surface value of the radio refractive index. Although this method of prediction is not particularly efficacious under the conditions of this experiment, encouraging agreement nevertheless was obtained between predicted and observed: a) mean value of elevation angle error, b) variation of elevation angle error with
N_{s}
, and c), the degree of reduction in the uncertainty of prediction gained over the use of a single-standard atmosphere.