The spherical geometry of weather radar scans results in a data distributio
n wherein datapoint separation in one coordinate direction and/or in one pa
rt of the analysis domain can differ widely from that in another. Objective
analysis of the nonuniform radar data to a uniform Cartesian grid is desir
able for many diagnostic purposes, For the benefit of the diagnostic data a
nalyst as well as of users of these analyses, the authors evaluate properti
es of techniques typically used for such objective analysis. This is done p
artly through theoretical consideration of the properties of the schemes. b
ut mostly by empirical resting. In terms of preservation of the phase and a
mplitude of the input data, predictability of th; degree of smoothing and f
iltering, and relative insensitivity to input data unsteadiness or spatial
characteristic, the isotropic Gaussian or Barnes-type weight function with
constant smoothing parameter appears to be the most desirable of the scheme
s considered. Modification of this scheme so that the weight function varie
s spatially, with the datapoint spacing, results in an improved analysis, a
ccording to some commonly used measures of error. Interpretation of analyse
s based on such a modified scheme can be affected, however. For example, an
alyses of unsteady input fields suffer from a convolution of the temporal e
volution of the data with spatial variations of the weight function. As a c
onsequence, unambiguous assessment of physical evolution is precluded.