KDP estimation
From Lrose Wiki
The LROSE procedure to estimating KDP from PHIDP
Basics
KDP is estimated from the range derivative of PHIDP. PHIDP accumulates along a radar beam as it passes through a precipitating medium and estimating KDP can identify regions of large phase shifts.
The LROSE method for estimating KDP is based on an updated version of the technique developed by Hubbert and Bringi (1995).
An Iterative Filtering Technique for the Analysis of Coplar Differential Phase and Dual Frequency Radar Measurements'. J. Hubbert and V.N.Bringi. JTech Vol 12, No3, June 1995. Link