JMA Geostationary Meteorological Satellite System for Himawari-8/9
Outlines and Activities.
The Himawari-8/9 satellite and their ground stations are operated by Himawari Operation Enterprise Corporation (HOPE) — a special-purpose company (SPC) established under JMA's Private Finance Initiative (PFI) project. Observation data from the Advanced Himawari Imager (AHI) and Data Collection Platform (DCP) data are transmitted through HOPE to JMA, which process the information and disseminate products to users. The figure below gives an overview of the Himawari-8/9 ground segment.
a) Site diversity
Himawari-8/9 use the Ka band for AHI and DCP data downlink frequency, and adopts the Ku band for telemetry, tracking and command (TT&C). To minimize the potential for negative data impacts from these bands, which both tend to be affected by rain attenuation, site diversity is introduced by establishing two antenna sites (ASs). One is in the Kanto region (the primary station) and the other is in the Hokkaido region (the secondary station), meaning that their locations are around 800 km apart and in different weather conditions. The two data centers (DCs) for processing data received are also located in the Kanto and Hokkaido regions.
b) Operation by HOPE
HOPE operates the ASs and DCs. The ASs are house transmitting/receiving equipment including antennas with a diameter of 9 meters, and the DCs have equipment for satellite control and AHI/DCP data processing. AHI and DCP data received at ASs are transmitted to DCs, where the former is processed to create level 1a data (raw data with calibration/navigation parameters attached) and the latter is converted for use with JMA's telecommunications system. The processed data are transmitted to JMA's Meteorological Satellite Center (Tokyo) and its Osaka Regional Headquarters (Osaka). In the event that the primary station becomes dysfunctional, the secondary station takes over its operations.
c) Operation by JMA
The Meteorological Satellite Center (MSC) receives data from both the primary and secondary stations for preprocessing, and Himawari Standard Data, HRIT files and edited DCP data are then produced and provided to users. The Osaka Regional Headquarters receives data from the secondary station only. In the event that the MSC system becomes dysfunctional (e.g., due to a malfunction caused by a natural disaster), data/products are provided from Osaka.
Himawari-8/9 don't carry equipment for direct dissemination. Instead, all imagery derived from the satellites is distributed to NMHSs via an Internet cloud service (see (a) in the figure). Full sets of data also are provided to researchers via archive servers operated by the Japanese Science Group on a best-effort basis (b). The HimawariCast service additionally disseminates primary sets of imagery via a communication satellite using Digital Video Broadcasting — Satellite — Second Generation (DVB-S2) technology (c). Further details of the HimawariCast service are available here. More information on the cloud service to be used are available here.