Himawari-8 and 9
Himawari-8 and -9 Meteorological Missions
JMA (Japanese Meteorological Agency) has operated the GMS (Geostationary Meteorological Satellite) and MTSAT (Multifunction Transport Satellite) series of satellites around the 140º east longitude to cover the East Asia and Western Pacific regions since 1977, and makes related contributions to the WMO’s World Weather Watch (WWW) Program. As a follow-on to the MTSAT series, the Agency plans to operate next-generation satellites called Himawari-8 and Himawari-9 (himawari means “sunflower” in Japanese). Unlike the current MTSAT series, which performs both meteorological and aeronautical functions, to include air-traffic control communications and position information, Himawari-8 and -9 will have a dedicated meteorological mission. 1) 2) 3) 4) 5) 6)
Currently (2014), MTSAT-2 (Himawari-7) is operational, while MTSAT-1R (Himawari-6) is on standby in orbit. MTSAT-2, which took over the earth observation mission of MTSAT-1R on July 1, 2010, is scheduled to complete its observation operation in around 2015. In order to provide continuous observation services, JMA plans to launch Himawari-8 in the summer 2014 and commence its operation in 2015, when MTSAT-2 is scheduled to complete its period of operation. The Agency also plans to launch Himawari-9 in 2016.
Figure 1: Schedule for the follow-on satellites to the MTSAT series (image credit: JMA)
Figure 2: Artist's rendition of the deployed Himawari-8 spacecraft (image credit: MELCO)
In July 2009, JMA completed contract arrangements with MELCO (Mitsubishi Electric Corporation) for the manufacture of Himawari-8 and -9, which have identical specifications.
Spacecraft parameters: 7)
• The Himawari spacecraft is 3-axis stabilized with momentum bias. It features a MELCO DS-2000 bus. The overall size of the deployed spacecraft is: 5.2 m (X-axis), 8.0 m (Y-axis), 5.3 m (Z-axis).
• The launch mass is ~3500 kg, the dry mass is 1300 kg.
• The design life is 8 years (including In-Orbit-Test) for AHI, 15 years for the spacecraft bus.
• ADCS (Attitude Determination and Control Subsystem)
- Attitude sensors: Coarse Sun Sensor, Star Tracker, IRU (Inertial Reference Unit), Gyroscope
- Actuation device: RWA (Reaction Wheel Assembly)
• EPS (Electrical Power Subsystem): The power generated is 2.6 kW, the bus voltage is 100 V, use of a Li-ion battery.
• MDHS (Mission Data Handling Subsystem): MDHS connects with the AHI instrument using SpaceWire I/F and processes the data from the instrument into telemetry, based on the CCSDS recommendations. The processed data are sent to the Ka-band transmission system. MDHS also connects with a satellite control system by SpaceWire and sends commands to AHI.
Figure 3: Schematic view of the Himawari-8/9 satellite (image credit: JMA)
• RF communications:
- Ku-band for TT&C services. The uplink rate is 500 bit/s, the downlink data rate is 15.36 kbit/s with a modulation PCM-PSK/PM
- Ka-band for payload data transmission. The data rate is 66 Mbit/s for AHI and 100 bit/s/300 bit/s for DCS. The modulation is QPSK, PCM-PSK, no encryption.
- UHF for DCS: The data rate is 100 bit/s/300 bit/s with a modulation of PCM-PSK.
For AHI data, compression is performed according to CCSDS Recommendation for Space Data System Standards. Lossless Data Compression, CCSDS 121.0-B-1 Lossless, May 1997.
Launch: A launch of Himawari-8 is scheduled for 2014 on an H-IIA vehicle from the TNSC (Tanegashima Space Center) of JAXA, Japan.
The launch of Himawari-9 is scheduled for 2016.
Orbit: Geostationary orbit, altitude of ~35,800 km, longitude of ~140º east, covering the East Asia and Western Pacific regions, succeeding the GMS and MTSAT series.
Data Distribution / Dissemination plan for HIMAWARI-8/9 8)
Both Himawari-8 and -9 spacecraft do not carry any equipment for direct data broadcasting. Hence, JMA is discussing the utilization of ICS (Internet Cloud Service) and CTS (Commercial Telecommunication Satellite) as data distribution services (Figure 4). JMA will substitute the CTS broadcasting for current MTSAT direct broadcasting. On the other hand, the Internet Cloud Service will be newly introduced as a means of data distribution for the National Meteorological and Hydrological Services (NMHSs) and for EUMETSAT. The agency will also introduce an Archive Server that is operated by the Japanese Science Group. Users of this server will be able to obtain all types of imagery from this server. Table 1 shows the receivable imagery products via the Internet Cloud Service / the CTS broadcasting. However, the types of imagery are limited for CTS broadcasting.
Figure 4: Schematic diagram of the data distribution/dissemination plan for HIMAWARI-8 and -9 (image credit: JMA)
Table 1: Receivable imagery via the CTS broadcasting / the Internet Cloud Service
Legend to Table 1: The types of imagery are limited for CTS broadcasting. The imagery which will be disseminated via CTS broadcasting is HRIT and LRIT only (indicated by Bold and Italic characters).
The specification list of receiver for the CTS broadcasting is shown in Table 2. To receive imagery, the specification of equipment is needed. Note that the equipment for the current MTSAT direct broadcasting is not available for the CTS broadcasting.
Table 2: The receiver specification list
Sensor complement: (AHI, SEDA, DCS)
The functions and specifications of the Himawari-8 and -9 sensor complement are notably improved from those of the on-board imager of MTSAT. The Himawari-8 and -9 spacecraft carry the AHI (Advanced Himawari Imager) instrument to enable enhanced nowcasting, NWP (Numerical Weather Prediction) and environment monitoring. 9)
Figure 5: Enhancement of the observation function of Himawari-8/9 when compared to that of MTSAT-1R/2 (image credit: JMA)
AHI (Advanced Himawari Imager):
AHI is an ABI (Advanced Baseline Imager) class instrument, designed and developed at Exelis Inc. of Rochester, N.Y., and similar to the one that will be integrated onto the GOES-R spacecraft series of NASA/NOAA.
In November 2009, MELCO selected Exelis (former ITT Space Systems) of Rochester, N.Y. to build the imaging systems for two geostationary satellites, Himawari-8 and -9, of JMA. 10)
ABI and AHI both have 16 spectral channels in the visible and infrared spectrum, which is a significant increase in the number of spectral channels in comparison to heritage instruments. The two instruments have similar spectral bands with two main differences: ABI includes a 1.38 µm channel (for cirrus cloud detection), while this channel is replaced with a 0.51 µm channel (green band – to produce color composite imagery) on AHI. 11)
The AHI instrument provides the following general characteristics:
• Multi-purpose imagery for weather watch, NWP utilization and environment monitoring; and wind derivation by tracking clouds and water vapor features
• 16 channels operating in the VIS, NIR, SWIR, MWIR and TIR spectral bands, i.e. from ~ 0.43 to ~13.4 µm.
• AHI is replacing JAMI flown on Himawari-6 (MTSAT-1R) and IMAGER on Himawari-7 (MTSAT- 2)
• Scanning technique: Mechanical, 3-axis stabilized satellite, E-W continuous, S-N stepping
• Spatial resolution: From 0.5 km to 2 km, depending on spectral band
• Coverage/cycle: Full disk in 10 minutes, limited areas in proportionally shorter intervals.
Table 3: Characteristics of the AHI instrument
Figure 6: SRF (Spectral Response Functions) of AHI in the VNIR bands (image credit: JMA)
Figure 7: SRF (Spectral Response Functions) of AHI in the IR bands (image credit: JMA)
Figure 8: Photo of the AHI instrument (image credit: ITT Exelis, JMA)
Figure 9: Photo of the cryocooler electronics (image credit: ITT Exelis, JMA)
Figure 10: Photo of the electronics unit (image credit: ITT Exelis, JMA)
Figure 11: A sequence of AHI observations in 10 minutes time frame (image credit: JMA)
Status: In December 2013, ITT Exelis delivered the AHI instrument to Mitsubishi Electric Corporation. 12)
SEDA (Space Environment Data Acquisition Monitor)
SEDA will measure the radiation to which Himawari-8/-9 satellites are exposed in their geostationary Earth orbits. SEDA’s design is basically identical to the EMU (Environmental Monitoring Unit) developed for the European satellite navigation system Galileo.
- Protons: 15 MeV ~ 100 MeV
- Electrons: 0.2 MeV ~5 MeV.
DCS (Data Collection Subsystem)
The Himawari-8/-9 missions support the collection of surface-based observation data obtained by ground segments with corresponding on-board DCSs (Data Collection System) in the same manner as provided by the MTSAT series. DCP channels relay their data from the DCPs through a UHF transponder, which outputs the Ka-band signal.
The Himawari-8 and -9 ground segment, designed, built and installed by MELCO, consists of antennas of 9 m diameter and radio frequency and satellite control equipment installed at the main unit in Hiki-gun, Saitama Prefecture, and the sub unit in Ebetsu, Hokkaido. 13)
In August 2010, Himawari Operation Enterprise was established as Special Purpose Company to operate the Himawari series spacecraft. This consortium is composed of Mitsubishi UFJ Lease & Finance Company Limited (representative company, management of office), NS Solutions Corporation (development of ground facilities, systems and maintenance work), and Space Engineering Development Co., Ltd. (service delivery), and has contracted this project with JMA in 2010 for the duration of 20 years until the end of March 2030 ((4 year and 7 month development period, 15 year maintenance and service delivery period).
2) Tatsuya Kimura, “Up?to?date Information on the Japanese Next?Generation Himawari?8/9 Satellites for Users’ Preparedness,” May 13, 2013, URL: http://www.wmo.int/pages/prog/sat/meetings/documents/EC-65-SideEvent-UserPrep_Doc_02_JMA.pdf
3) Francis P. Padula, “Using S-NPP VIIRS as a Transfer Radiometer to Inter-compare GOES-R ABI and Himawari-8 AHI,” https://ams.confex.com/ams/94Annual/webprogram/Paper235594.html
4) Satoru Tsunomura, “Current Status and Future Plan of Japanese Meteorological Satellite Program,” URL: http://jma-net.go.jp/sat/data/web/aomsuc-2/Session1/1-3_STsunomura.pdf
5) Yasushi Izumikawa, “Update of JMA’s Status Report (2012),” Geneva, Switzerland, April 17-19, 2012, URL: http://www.wmo.int/pages/prog/sat/meetings/documents/ET-SAT-7_Doc_05-05_JMA-update.pdf
6) Masaya Takahashi, “Status of Next Generation Japanese Geostationary Meteorological Satellites - Himawari-8/9 and their Products,” NOAA Satellite Science Week: GOES-R AlgorithmWorking Group (AWG), Proving Ground, and Risk Reduction annual meetings, Kansas City,MO, USA, Apr. 30 - May 4, 2012, URL: http://www.goes-r.gov/downloads/2012-Science-Week/posters/tues/05_Takahashi.pdf
7) Information provided by Keiko Yamamoto of the Satellite Program Division, Japan Meteorological Agency (JMA).
8) Hiroaki Tsuchiyama, Toshiyuki Kurino, Masaya Takahashi, “Progress on development of new products expected from Japanese follow-on geostationary meteorological satellites HIMAWARI-8/9,” Proceedings of the Joint EUMETSAT /AMS Meteorological Satellite Conference to address issues on Weather, Climate, Oceans and the Environment, Vienna, Austria, Sept. 16-20, 2013, , URL: http://www.eumetsat.int/website/home/News/ConferencesandEvents/PreviousEvents/DAT_2027670.html
9) “Himawari-8/9 and MTSAT-1R/2 imagery channels and file sizes,” URL: http://www.jma.go.jp/jma/jma-eng/satellite/news/2013_Questionnaire/Annex1_ImageryChannelsAndFileSizes.pdf
10) ITT picked to build the imaging systems for Japanese weather satellites,” ITT, Nov. 2, 2009, URL: http://www.itt.com/News/Releases/2009/ITT-Picked-to-Build-Advanced-Imaging-Systems-for-J/
11) “Exelis delivers advanced weather satellite payload to commercial customer in Japan,” Exelis, Dec. 17, 2013, URL: http://www.exelisinc.com/news/pressreleases/Pages/Exelis-delivers-advanced-weather-satellite-payload-to-commercial-customer-in-Japan-.aspx
12) “Exelis delivers advanced weather satellite payload to commercial customer in Japan,” Exelis, Dec. 18, 2013, URL: http://www.exelisinc.com/news/pressreleases/Pages/Exelis-delivers-advanced-weather-satellite-payload-to-commercial-customer-in-Japan-.aspx
13) “Himawari Operation Enterprise and Mitsubishi Electric Complete Ground Facilities for Weather Satellite Operations,” MELCO, October 7, 2013, URL: http://www.mitsubishielectric.com/news/2013/1007.pdf
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates.