Measurement of Attenuation by a Dual-Radar Method: Concept and Error Analysis

Abstract The authors describe a method for the measurement of specific attenuation using two radars operating at virtually the same wavelength at which the attenuation is desired. Use of the same wavelength avoids confounding between differences in received powers due to attenuation and wavelength dependence of reflectivity factors. A governing equation for the specific attenuation and an analytical solution of the equation are derived. The analytical solution gives an explicit expression for the specific attenuation in terms of the specific attenuation at an initial point and the second derivative of estimates of the difference between ensemble average received powers for the two radars along and near the characteristics of the governing equation. An error analysis shows that error in the computed attenuation is due to error in the attenuation coefficient at the initial point and errors in the estimates of the ensemble average received powers. Unless the initial point is poorly chosen, the error due to t...