Comparative Analysis of FY-3G and GPM Observations on Precipitation Structure and Microphysical Characteristics: A Case of Super Typhoon Krathon

China's first precipitation measurement satellite, FY-3G, became operational in April 2024. This study presents the first comparison of Level-2 Ku-band precipitation products from FY-3G and Global Precipitation Measurement (GPM), focusing on the three-dimensional precipitation structure and microphysical characteristics of Super Typhoon Krathon (2418). Both FY-3G and GPM observed that convective precipitation dominated the eyewall and stratiform precipitation prevailed in the inner and outer rainbands. However, FY-3G reported higher overall precipitation intensities than GPM. In the eyewall, both satellites observed that high concentrations (dBN_w > 40) of large raindrops (D_m > 2 mm) led to intense precipitation, where droplet concentration was the primary determining factor. FY-3G exhibited a broader drop size distribution (DSD) for convective precipitation than GPM, while for 10–20 mm/hr stratiform precipitation, both D_m and lgN_w had a narrower distribution. The inner rainbands exhibited the most distinct DSD differences, with FY-3G observing D_m from 0.6 to 2.6 mm, while GPM detected 1.3–2.3 mm with lower lgN_w. In the outer rainbands, both satellites observed large raindrops (D_m > 2.1 mm), driven by the super typhoon's radial circulation dynamics. For most stratiform precipitation, FY-3G showed 1.5–2.0 mm raindrops as the main contributors, while GPM also had a high proportion of 1.0–1.5 mm drops. Both satellites consistently observed 1.5–2.0 mm drops as the main contributors in convective precipitation. Additionally, FY-3G detected relatively higher number of raindrops smaller than 1.0 mm across various precipitation intensities, which may be primarily attributed to the higher sensitivity of the FY-3G Precipitation Measurement Radar compared to the GPM Dual-frequency Precipitation Radar.