Seto, S., T. Iguchi, R. Meneghini, J. Awaka, T. Kubota, T. Masaki, and N. Takahashi, 2021: The Precipitation rate retrieval algorithms for the GPM Dual-frequency Precipitation Radar. J. Meteor. Soc. Japan, 99, 205-237.
Special Edition on Global Precipitation Measurement (GPM): 5th Anniversary,
Graphical Abstract Published
Plain Language Summary: New precipitation rate retrieval algorithms (version 06A) for the GPM Dual-frequency Precipitation Radar are developed. Major changes from the previous algorithms (version 03B) include the introduction of the relation between precipitation rate and mass-weighted mean diameter (R−Dm relation), non-uniform beam filling correction, DSD database (single-frequency algorithms only), and the ZfKa method (dual-frequency algorithm only).
- The R−Dm relation is used instead of the k−Ze relation for KuPR algorithm and also for the KaPR algorithm and the dual-frequency algorithm, meaning that the three algorithms share a common constraint on the DSD.
- The DSD database includes the statistics of the adjustment factor for the R−Dm relation (ε) and has been introduced to convert information obtained from the dual-frequency algorithm for application to the single-frequency algorithms.
- The dual-frequency algorithm has the advantages that it can select KuPR or KaPR for the precipitation echoes and use additional evaluation criteria such as the ZfKa method and Dual-frequency Surface Reference Technique (DSRT). For more than 90% of the precipitation pixels, either the ZfKa method or DSRT is used.