Near-real time product H03B (P-IN-GRU-SEVIRI Instantaneous Precipitation rate maps at ground by GEO/IR supported by LEO/MW over the full disk area) is generated by IR images from the SEVIRI instrument on-board Meteosat Second Generation (MSG) satellites “calibrated” by precipitation measurements from PMW satellite sensors in sun-synchronous orbits, processed soon after each acquisition of a new image from GEO (“Rapid Update”). The extension of the spatial coverage of the product includes the entire spatial coverage of Meteosat 0 degrees. The product is generated at the 15-min imaging rate of SEVIRI. The spatial resolution is consistent with the SEVIRI pixel, and changes across the Full Disk from 3 km near the sub-satellite point to 8 km on average over Europe. The H03B (P-IN-GRU-SEVIRI) precipitation estimates are obtained by combining IR GEO equivalent blackbody temperatures (TBB) at 10.8 ?m (Channel 9) with rain rates from PMW measurements derived from SSMIS (utilized by P-IN-OBA-SSMIS new rel.) and AMSU-A and MHS (utilized by P-IN-ONN_AMSU). The algorithm is based on an underlying collection of time and space overlapping overpasses from GEO IR imagers and Low Earth Orbit (LEO) PMW sensors, which constitutes a look up table of geolocated relationships rain rate vs TBB, updated as soon as new overlapping GEO IR and LEO PMW overpasses are available. The processing method is called “Rapid Update” (RU), which is currently the only operational algorithm enabling precipitation rate estimates with the time resolution required for nowcasting.