Japan Geoscience Union Meeting 2025

Presentation information

[E] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG41] Satellite Earth Environment Observation

Thu. May 29, 2025 1:45 PM - 3:15 PM Exhibition Hall Special Setting (5) (Exhibition Hall 7&8, Makuhari Messe)

convener:Riko Oki(Japan Aerospace Exploration Agency), Yoshiaki HONDA(Center for Environmental Remote Sensing, Chiba University), Tsuneo Matsunaga(Center for Global Environmental Research and Satellite Observation Center, National Institute for Environmental Studies), Nobuhiro Takahashi(Institute for Space-Earth Environmental Research, Nagoya University), Chairperson:Hiroshi Murakami(Earth Observation Research Center, Japan Aerospace Exploration Agency), Nobuhiro Takahashi(Institute for Space-Earth Environmental Research, Nagoya University)

3:00 PM - 3:15 PM

[ACG41-24] Introducing the Precipitation Measuring Mission (PMM): The next-generation precipitation observation

*Akira Yamauchi1, Tomomi Nio1, Shinichiroh Takayama1, Kazuyuki Okada1, Kinji Furukawa1 (1.Japan Aerospace Exploration Agency)

Keywords:Precipitation, Radar, Doppler, PMM, AOS

This presentation will provide a detailed overview of the Precipitation Measuring Mission (PMM). The PMM is a next-generation precipitation observation mission by the Japan Aerospace Exploration Agency (JAXA), following the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) missions. Established in June 2023, the PMM project team is developing the PMM satellite, featuring the world's first space-borne Ku-band Doppler precipitation radar (KuDPR). This mission aims to study cloud-precipitation systems to mitigate severe water-related disasters under global climate change.
The PMM satellite includes the KuDPR and a microwave radiometer developed by CNES in France. The KuDPR, operating at 13.6 GHz, uses the Displaced Phase Center Antenna (DPCA) technique to measure Doppler velocity and provide three-dimensional precipitation structures, including snowfall. This radar aims to improve precipitation measurement sensitivity compared to the GPM's Dual-frequency Precipitation Radar (DPR).
The PMM mission objectives are to elucidate global water cycle parameters, enhance weather and disaster management, and provide long-term water resource information. The data will contribute to the NASA Atmosphere Observing System (AOS) by joining an international constellation of spacecraft.
The PMM satellite's orbit is inclined at 55 degrees, operating in low earth orbit, with a mission life of five years. The spacecraft bus is based on the Global Change Observation Mission (GCOM) series. The satellite will be launched by a NASA-funded rocket and will form a constellation with other AOS mission satellites.
The KuDPR observation has three kinds of scan patterns in one scan cycle: wide swath, high-density, and Doppler. Wide swath covers over 250 km with a minimum detectable reflectivity below 15 dBZ and a vertical resolution of 250 m. High-density has a swath width of approximately 8.3 km, with a minimum detectable reflectivity below 7.3 dBZ and a vertical resolution of 500 m. Doppler observation, limited to nadir, has a swath width of approximately 5 km, measuring Doppler velocity and echo intensity with a minimum detectable reflectivity below 7.3 dBZ and a vertical resolution of 500 m.
The PMM mission advances precipitation measurement technology, building on JAXA's experience with space-borne radars. The KuDPR is expected to improve rain and snow particle discrimination, enhancing the Global Satellite Mapping of Precipitation (GSMaP) algorithm for estimating precipitation. The mission's observations, in collaboration with international partners, will provide valuable data for understanding global water cycles and addressing climate challenges. The mission operation system (MOS) for PMM, which processes data from various sensors including KuDPR and GSMaP, is planned to be built on the cloud. Additionally, the standard products for KuDPR and CNES radiometer related to PMM, from L1 to L3, are planned to be distributed through JAXA Earth Observation Satellite Data Providing System, G-portal, while research products will be handled separately.