TRMM Precipitation Radar Surface Cross-Section L2 1.5 hours  V7 (TRMM_2A21) at GES DISC
The new version of these data is in GPM-like format (consistent with the GPM Dual-frequency Radar data format), and can be found under the name GPM_2APR.

This is the sigma zero algorithm, which inputs the PR power (1B21) and computes estimates of the path attenuation and its reliability by using the surface as a …