Himawari-8/9 are new-generation geostationary meteorological satellites developed by Japan's Japan Meteorological Agency (JMA). These satellites feature advanced optical sensors with significantly higher radiometric, spectral, and spatial resolution compared to previous geostationary satellites. They have 16 observation bands, with spatial resolutions of 0.5 or 1 km for visible and near-infrared bands and 2 km for infrared bands. Combined with short revisit times (around 10 minutes for Full Disk and 2.5 minutes for sectored regions), these capabilities enable improved identification and tracking of rapidly changing weather phenomena and the derivation of quantitative products. For example, fundamental cloud products are operationally retrieved from Himawari-8 data. These products are used to generate Clear Sky Radiance and Atmospheric Motion Vector data for numerical weather prediction, and volcanic ash and Aeolian dust products for disaster monitoring and environmental assessment. Satellite imagery is distributed to users via multiple channels, including Internet cloud services and communication satellite services. Himawari-8 was launched in 2014 and began operations in 2015, while Himawari-9 is scheduled for launch in 2016 for in-orbit standby and will eventually replace Himawari-8. Both satellites will operate for seven years, with Himawari-9's observations continuing until 2029. JMA's Himawari-8/9 will be operational ahead of other third-generation satellites such as NOAA/NASA's GOES-R and EUMETSAT's Meteosat Third Generation (MTG). The satellites are three-axis attitude-controlled, with a length of approximately 8 meters and a mass of about 3,500 kg each. They are equipped with the Advanced Himawari Imagers (AHIs), which have capabilities comparable to the Advanced Baseline Imager (ABI) on the GOES-R satellite. The AHIs use the Ku-band for telemetry and command operations and the Ka-band for downlinking AHI data. Each satellite also carries a transponder to relay meteorological and tide/tsunami data from earth-based observing stations to sustain the Data Collection System (DCS) of the GMS and MTSAT series. The ground segment for Himawari-8/9 is operated by Himawari Operation Enterprise (HOPE), a special-purpose company established under a Private Finance Initiative (PFI) project. HOPE controls the satellites, receives data from their AHI/DCP units, and sends the data to JMA, which processes the information and provides related products to users. The Ku-band is used for telemetry, tracking, and command, while the Ka-band is used for data downlinks from their AHI and DCP units. To minimize the adverse effects of rain attenuation, antenna sites approximately 800 km apart are situated in the Kanto and HokkaidoHimawari-8/9 are new-generation geostationary meteorological satellites developed by Japan's Japan Meteorological Agency (JMA). These satellites feature advanced optical sensors with significantly higher radiometric, spectral, and spatial resolution compared to previous geostationary satellites. They have 16 observation bands, with spatial resolutions of 0.5 or 1 km for visible and near-infrared bands and 2 km for infrared bands. Combined with short revisit times (around 10 minutes for Full Disk and 2.5 minutes for sectored regions), these capabilities enable improved identification and tracking of rapidly changing weather phenomena and the derivation of quantitative products. For example, fundamental cloud products are operationally retrieved from Himawari-8 data. These products are used to generate Clear Sky Radiance and Atmospheric Motion Vector data for numerical weather prediction, and volcanic ash and Aeolian dust products for disaster monitoring and environmental assessment. Satellite imagery is distributed to users via multiple channels, including Internet cloud services and communication satellite services. Himawari-8 was launched in 2014 and began operations in 2015, while Himawari-9 is scheduled for launch in 2016 for in-orbit standby and will eventually replace Himawari-8. Both satellites will operate for seven years, with Himawari-9's observations continuing until 2029. JMA's Himawari-8/9 will be operational ahead of other third-generation satellites such as NOAA/NASA's GOES-R and EUMETSAT's Meteosat Third Generation (MTG). The satellites are three-axis attitude-controlled, with a length of approximately 8 meters and a mass of about 3,500 kg each. They are equipped with the Advanced Himawari Imagers (AHIs), which have capabilities comparable to the Advanced Baseline Imager (ABI) on the GOES-R satellite. The AHIs use the Ku-band for telemetry and command operations and the Ka-band for downlinking AHI data. Each satellite also carries a transponder to relay meteorological and tide/tsunami data from earth-based observing stations to sustain the Data Collection System (DCS) of the GMS and MTSAT series. The ground segment for Himawari-8/9 is operated by Himawari Operation Enterprise (HOPE), a special-purpose company established under a Private Finance Initiative (PFI) project. HOPE controls the satellites, receives data from their AHI/DCP units, and sends the data to JMA, which processes the information and provides related products to users. The Ku-band is used for telemetry, tracking, and command, while the Ka-band is used for data downlinks from their AHI and DCP units. To minimize the adverse effects of rain attenuation, antenna sites approximately 800 km apart are situated in the Kanto and Hokkaido