# Multi-Sensor Precipitation Estimation from Space: Data Sources, Methods and Validation
## 7 Conclusions and Outlook
SPPs also exhibit significant uncertainties when representing light and extreme precipitation events, hailstorms, and snowfall [168; 188; 222]. Therefore, addressing these issues is imperative for enhancing global statistical postprocessing efforts. (4) The characterization and quantification of retrieval uncertainties at multiple scales should be enhanced. It has been confirmed that the performance of these precipitation estimates is influenced by underlying factors, climatic conditions, meteorological conditions, seasons, precipitation intensities, and latitudes [155; 168; 171]. Furthermore, these estimates are derived at various resolutions, and their performance is associated with spatiotemporal scales [191; 223]. Numerous evaluation studies have been conducted on this subject; however, further research is required to generalize retrieval uncertainties under diverse environmental conditions. Quantitative evaluations are expected to yield more significant results when synthesizing precipitation estimates across a wide range of environmental conditions while considering multiple factors at various scales. The GPM constellation continues to play a crucial role in supporting MPE. Notably, recent advancements in satellite systems and sensors have been made during the preparation of this paper, which hold great potential for enhancing precipitation retrievals. These include the Weather System Follow-on-Microwave (WSF-M) satellite system (launched in April 2024), as well as the Earth Clouds, Aerosol, and Radiation Explorer (EarthCare)satellite equipped with Atmospheric Lidar (ATLID) and Cloud Profiling Radar (CPR) instruments (launched in May 2024) by ESA and JAXA. Additionally, upcoming satellite systems and sensors are being planned to enhance the MPE observational capability. These include the Microwave Imager (MWI) on the Meteorological Operational-Second Generation (METOP-SG) B-series, scheduled for 2025 by ESA and EUMETSAT, as well as the ATMS on JPSS-3, planned for January 2026 by NOAA and NASA. The future utilization of infrared sensors and lightning sensors on geostationary satellites will be emphasized, such as the Meteosat Third-Generation (MTG) Imaging mission satellite-2 (MTG-I 2), expected in 2026, and MTG-Sounding 1 (MTG-S 2), anticipated in 2025 by EUMETSAT and ESA. In addition, the FY-3G satellite, China's first precipitation measurement satellite, was launched on April in 2023. It was deployed with a precipitation measurement radar (PMR) and the Microwave Radiation Imager-Rainfall Mission (MWRI-RM) [224]. It has precipitation detection capabilities comparable to the current GPMCO. It aims to accurately measure the occurrence, type, and intensity of any precipitation around the world, including over oceans and complex terrain. Many international group or projects, such as GPCP, AIP, PIP and PEHRPP, had given impetus to MPE and SPE progress. IPWG has been providing a forum to exchange information on methods for measuring precipitation and the impact of spaceborne precipitation measurements for 20 years. GPM has been tracking rain and snow around the globe for over 10 years. These existing international groups or missions or project like IPWG and GPM will continue their support of MPE. Conceptualization, R.G., X.F. and Y.L. ; writing--original draft preparation, R.G. ; writing--review and editing, X.F., Y.L. and H.Z. ; visualization, R.G. and X.F. ; supervision, Y.L. and X.F. ; funding acquisition, R.G. All authors have read and agreed to the published version of the manuscript. This research was funded by the First Class Discipline Research Special Project under Education Department of Inner Mongolia Autonomous Region, grant number YLXKZX-NSD-041; the National Natural Science Foundation of China, grant number 41901051,; the Natural Science Foundation of Inner Mongolia, grant number 2021 LHMS04006; High-level talent research start-up fund project, grant number 2020 YJRC008; and the National Natural Science Foundation of China, grant number 41961058.