The accuracy with which meteorological elements can be measured by currently operational radiosonde equipment is examined and representative error values calculated. A method of analyzing cross-sections for missile test ranges is described. The average of two soundings is plotted at the mid-point between them and the soundings reconstructed by use of the geostrophic extrapolation. The gain in accuracy from averaging is offset by the geostrophic approximation. These opposing effects are shown by error values calculated for a fixed range distance and by distance values over which the analysis is useful.