Status of the GCOM mission and the important role of scatterometer Haruhisa Shimoda 1, 2, Keiji Imaoka 1, and Akira Shibata 1 1 Japan Aerospace Exploration Agency 2 Tokay University Research and Information Center Satellite Measurements of Ocean Vector Winds: Present Capabilities and Future Trends Miami, FL February 7-9, 2005

Overview After the Midori-II loss on October 2003, JAXA and science teams have been discussing desired follow-up activity of Midori-II. After the Midori-II loss on October 2003, JAXA and science teams have been discussing desired follow-up activity of Midori-II. Global Change Observation Mission (GCOM) is being proposed to contribute climate change portion of the GEOSS framework. Global Change Observation Mission (GCOM) is being proposed to contribute climate change portion of the GEOSS framework. Combination of AMSR and SeaWinds-type scatterometer is highly desired for GCOM-W. Combination of AMSR and SeaWinds-type scatterometer is highly desired for GCOM-W. JAXA is proposing NASA to provide scatterometer for GCOM-W satellite. JAXA is proposing NASA to provide scatterometer for GCOM-W satellite.

Note: This chart includes NOT authorized plan Legend Symbol Planned Project Approved Project After Operation Period

A plan of advanced low Earth orbit satellites To develop advanced low Earth orbit satellites →to aim cutting edge system and mutual complementary system to the operational system such as WWW, NPOESS Sea surface wind vector AMSR F/O, Scatterometer (GCOM-W) SST SST AMSR F/O (GCOM-W) Cloud structure Cloud Profiling Radar (EarthCARE) Aerosol GLI F/O (GCOM-C) CO 2 concentration Greenhouse Gas Observation Sensor (GOSAT) Precipitation Dual-frequency Precipitation Radar (GPM) Disaster monitoring SAR/disaster monitoring satellites, Optical Sensor/ Geo-stationary EO satellite To develop and operate an Earth Observation Network for GEOSS 1330 GCOM-W GOSAT CPR/EarthCARE GCOM-C With NASA With ESA DPR/GPM With NASA Optical Sensor/ Geo-stationary EO satellite SAR/disaster Monitoring satellites

Earth Observation Summit, GEOSS, and GCOM The 2 nd Earth Observation Summit The 2 nd Earth Observation Summit –Held in Tokyo on April, 2004 –The Framework for a 10-Year Implementation Plan –The Communique of the 2 nd Earth Observation Summit The 10-Year Implementation Plan The 10-Year Implementation Plan –Gives guidance for establishing new Global Earth Observation Systems of Systems (GEOSS) by strengthen existing observation systems, establishing successor international mechanism. JAXA will propose a series of satellites for establishing GEOSS mainly focused on observations of climate change for loss of ADEOS-II, in addition to ALOS for disaster, GPM for water cycle, GOSAT for carbon cycle. JAXA will propose a series of satellites for establishing GEOSS mainly focused on observations of climate change for loss of ADEOS-II, in addition to ALOS for disaster, GPM for water cycle, GOSAT for carbon cycle.

Global Change Observation Mission GCOM consists of 2 satellite series: GCOM consists of 2 satellite series: –Sea surface observation mission, so called GCOM-W, will have AMSR F/O and a scatterometer. –Atmospheric and terrestrial observation mission, so called GCOM-C, will have GLI F/O. Each series will have 3 satellites with 5 years mission: totally covers 13 years (1-year overlap between consecutive satellites). Each series will have 3 satellites with 5 years mission: totally covers 13 years (1-year overlap between consecutive satellites). Middle size common bus system to improve reliability. Middle size common bus system to improve reliability. –Being developed for GOSAT. –Common basic design with specific modules to fit each mission and improve the basic design. –Basically 1 mission (and/or sensor) as risk management.

GCOM satellites GCOM-W satellite – –Sensors Advanced Microwave Scanning Radiometer (AMSR) F/O Scatterometer (under discussion) – –Sun-Synchronous polar orbit, orbit height: 800km, swath 1400km, LTN: 13:30 (tentative) – –2009 first launch is proposed GCOM-C satellite – –Sensor Second generation Global Imager (SGLI) – –Sun-Synchronous polar orbit, orbit height: 1000km, swath 1200km, LTN: 13:30 (tentative) – –2010 first launch is proposed

AMSR on Midori-II Non-deployable, offset parabolic antenna with effective aperture size of 2.0 m. Non-deployable, offset parabolic antenna with effective aperture size of 2.0 m. Total power microwave radiometers. Total power microwave radiometers. High Temperature noise Source (HTS) and Cold Sky Mirror (CSM) for onboard two-point calibration. High Temperature noise Source (HTS) and Cold Sky Mirror (CSM) for onboard two-point calibration. Two feed horns for 89GHz to keep enough spatial sampling in along track direction. Two feed horns for 89GHz to keep enough spatial sampling in along track direction. Center Frequency (GHz) AB Bandwidth (MHz) PolarizationVertical and HorizontalVerticalVertical and Horizontal 3dB Beam Width (degrees) IFOV (km)40x7027x4614x2517x298x146x10 3x6 Sampling Interval (km)10x105x5 Temperature Sensitivity (K) Incidence Angle (degrees) Dynamic Range (K) Swath Width (km)Approximately1600 Integration Time (msec) Quantization (bit)1210 Scan Cycle (sec)1.5

AMSR Sea surface temperature

Oceanic geophysical parameters by AMSR Total precipitable waterCloud liquid water Sea surface wind speed Precipitation Global Monthly Mean in April 2003

GCOM satellites GCOM-W satellite – –Sensors Advanced Microwave Scanning Radiometer (AMSR) F/O Scatterometer (under discussion) – –Sun-Synchronous polar orbit, orbit height: 800km, swath 1400km, LTN: 13:30 – –2009 first launch is proposed GCOM-C satellite – –Sensor Second generation Global Imager (SGLI) – –Sun-Synchronous polar orbit, orbit height: 1000km, swath 1200km, LTN: 13:30 – –2010 first launch is proposed

San Francisco ● chl a (1km) 250m ocean GLI 250m RGB:22/21/20 ，

Continuous observation by AMSR Continue unique AMSR observation (high-res and global) and construct long-term dataset. Continue unique AMSR observation (high-res and global) and construct long-term dataset. Reliable long-term time series of SST, sea surface winds, water vapor, precipitation, and ocean flux to contribute to the understanding, monitoring, and forecast of climate change. Reliable long-term time series of SST, sea surface winds, water vapor, precipitation, and ocean flux to contribute to the understanding, monitoring, and forecast of climate change. Operational benefits include continuous measurement of cloud-through SST, frequent and quantitative measurements of storms to maintain precipitation forecast accuracy. Operational benefits include continuous measurement of cloud-through SST, frequent and quantitative measurements of storms to maintain precipitation forecast accuracy. Overlapping period of consecutive sensors aids cross- calibration to establish stable long-term records. Overlapping period of consecutive sensors aids cross- calibration to establish stable long-term records. Contribution to the GPM constellation. Contribution to the GPM constellation.

Basic requirements for AMSR F/O Minimum modifications from AMSR on ADEOS-II to reduce risks/cost and keep the earliest launch date. Minimum modifications from AMSR on ADEOS-II to reduce risks/cost and keep the earliest launch date. However, several essential improvements will be indispensable. However, several essential improvements will be indispensable. –Improvement of calibration system including warm load calibration target. –Consideration to C-band radio frequency interference (RFI). Combination with SeaWinds-type scatterometer is highly desired. Combination with SeaWinds-type scatterometer is highly desired.

Basic requirements for AMSR F/O Antenna : 2.0m, offset parabolic antenna Antenna : 2.0m, offset parabolic antenna Channel sets Channel sets –Identical to AMSR-E (no O 2 band channels) –6.925(TBD), 10.65, 18.7, 23.8, 36.5, 89.0GHz –Dual polarization Calibration Calibration –Improvements of hot load etc. –Enhance pre-launch calibration testing Orbit Orbit –Afternoon orbit with 700~800km altitude Mission life Mission life –5 years goal

On-going discussion RFI mitigation at C-band RFI mitigation at C-band –Considering appropriate center frequency around 6.9GHz (hardware mitigation may be difficult due to tight schedule). Polarimetric channel for 36.5GHz Polarimetric channel for 36.5GHz –Only U or V stokes for 36.5GHz due to the limitation of feed and receiver packaging (difficult for 18.7GHz). Redundancy of important channels Redundancy of important channels –Lessons learned from 89GHz problem of AMSR-E. –36.5GHz V/H channels are used in many retrievals. Relationship to GCOM-C/SGLI orbit Relationship to GCOM-C/SGLI orbit

SeaWinds/AMSR combination Scatterometer/Radiometer combination since SeaSat. Scatterometer/Radiometer combination since SeaSat. Unique combination still in NPOESS+METOP era. Unique combination still in NPOESS+METOP era. Advantages Advantages –SeaWinds : Rain flagging and attenuation/scattering correction. –AMSR : Improvement of Tb model as a function of wind vector. Application to Meteorology/Physical Oceanography Application to Meteorology/Physical Oceanography –Ocean surface heat flux : needs simultaneous observation. –Simultaneous measurements of water vapor, SST, precipitation, and sea surface winds are effective for investigating various time-space scale phenomenon (MJO, typhoon, monsoon, ENSO, water-energy cycle, ocean circulation in surface mixed layer) Synergism of active/passive measurement in other research areas are also expected. Synergism of active/passive measurement in other research areas are also expected. –Ice drift monitoring, detection of snow and ice melting, land surface sensing including vegetation and soil moisture.

↑ Provided by Dr. Frank Wentz of Remote Sensing Systems

↑ Wind vector dependence of AMSR brightness temperatures by using AMSR and SeaWinds. Horizontal axis indicates relative wind direction by SeaWinds (0 degree corresponds to up-wind case), vertical axis indicates deviations of AMSR 37GHz Tb from that under calm ocean condition. Data of September 2003 were used. ↑ Provided by Dr. M. Konda of Kyoto University. 2- 4m/s 4- 6m/s 6- 8m/s 8-10m/s10-12m/s 12-14m/s SST: 25-30C PW : 36-38mm CLW: Kg/m2

Simultaneous measurements Snapshots of AMSR level2 standard product of (a) the latent heat flux, (b) the SST, (c) wind speed, and (d) the water vapor pressure in the East China Sea on December 20, Wind direction observed by SeaWinds scatterometer on QuikSCAT is superimposed by black arrows. (a) (b) (d) (c) ↑ Provided by Dr. M. Konda of Kyoto University.

Continuity of Scatterometer Ocean wind vector measurement continues for over 10-years since ERS-1/AMI launch in Ocean wind vector measurement continues for over 10-years since ERS-1/AMI launch in METOP/ASCAT will be available in near future. Combination with GCOM-W scatterometer will increase time resolution (or coverage). METOP/ASCAT will be available in near future. Combination with GCOM-W scatterometer will increase time resolution (or coverage). Wind vector retrieval by polarimetric radiometer is epoch making, but may need validation phase with simultaneous observation by scatterometer. Wind vector retrieval by polarimetric radiometer is epoch making, but may need validation phase with simultaneous observation by scatterometer. Scatterometer data are valuable in operational use. Scatterometer data are valuable in operational use.

Summary GCOM is being proposed as the follow-on mission of Midori-II. GCOM is being proposed as the follow-on mission of Midori-II. Combination of AMSR and SeaWinds-type scatterometer is highly desired for GCOM- W satellite. Combination of AMSR and SeaWinds-type scatterometer is highly desired for GCOM- W satellite. JAXA is proposing NASA to provide scatterometer for GCOM-W satellite. JAXA is proposing NASA to provide scatterometer for GCOM-W satellite.

Backup Slides

AMSR Follow-on Sensor Team In alphabetic order (FY15 members) : Kazumasa Aonashi (Meteorological Research Institute) Kazumasa Aonashi (Meteorological Research Institute) Kohei Cho (Tokai University) Kohei Cho (Tokai University) Naoto Ebuchi (Institute of Low Temperature Science, Hokkaido University) Naoto Ebuchi (Institute of Low Temperature Science, Hokkaido University) Yasuhiro Fujimoto (Fuji. Tech) Yasuhiro Fujimoto (Fuji. Tech) Keiji Imaoka (Earth Observation Research and application Center, JAXA) Keiji Imaoka (Earth Observation Research and application Center, JAXA) Toshio Koike (The University of Tokyo) Toshio Koike (The University of Tokyo) Harunobu Masuko (National Institute of Information and Communications Technology) Harunobu Masuko (National Institute of Information and Communications Technology) Masashige Nakayama (Earth Observation Research and application Center, JAXA) Masashige Nakayama (Earth Observation Research and application Center, JAXA) Tetsuo Nakazawa (Meteorological Research Institute) Tetsuo Nakazawa (Meteorological Research Institute) Fumihiko Nishio (Chiba University) Fumihiko Nishio (Chiba University) Katsuya Saito (Japan Fisheries Information Service Center) Katsuya Saito (Japan Fisheries Information Service Center) Akira Shibata (Earth Observation Research and application Center, JAXA) Akira Shibata (Earth Observation Research and application Center, JAXA) Shuji Shimizu (Earth Observation Research and application Center, JAXA) Shuji Shimizu (Earth Observation Research and application Center, JAXA) Haruhisa Shimoda (Tokai University) Haruhisa Shimoda (Tokai University) Nobuhiro Takahashi (National Institute of Information and Communications Technology) Nobuhiro Takahashi (National Institute of Information and Communications Technology) Yoshiaki Takeuchi (Japan Meteorological Agency) Yoshiaki Takeuchi (Japan Meteorological Agency)

Necessity of finer spatial resolution Particularly for lower frequency channels. Particularly for lower frequency channels. Spatial resolution of SST by 6.9GHz to resolve mesoscale eddies (10-100km) that affect maritime variation and are important for fisheries. In fishery applications, ships can move about 1-100km during a day. Goal of microwave radiometer would be 10km, but practical target is 25km. Spatial resolution of SST by 6.9GHz to resolve mesoscale eddies (10-100km) that affect maritime variation and are important for fisheries. In fishery applications, ships can move about 1-100km during a day. Goal of microwave radiometer would be 10km, but practical target is 25km. 10GHz Tb are necessary to retrieve heavy precipitation. Finer resolution is desired comparing to the grid size of near future global model (20km). 10GHz Tb are necessary to retrieve heavy precipitation. Finer resolution is desired comparing to the grid size of near future global model (20km). Resolving smaller scale phenomena is needed for land use by using 6.9GHz Tb and retrieved soil moisture. Resolving smaller scale phenomena is needed for land use by using 6.9GHz Tb and retrieved soil moisture. Decrease errors due to coarse resolution (e.g., beam filling proglem). Decrease errors due to coarse resolution (e.g., beam filling proglem). Promote cross-utilization with optical and infrared instruments by narrowing spatial resolution discrepancy. Promote cross-utilization with optical and infrared instruments by narrowing spatial resolution discrepancy.

SST from GLI and AMSR Detectable size of oceanic eddies are approximately 50km by AMSR observation. Ideal goal for AMSR spatial resolution is 10km, but practical requirement is 25km. This resolution will resolve finer scale eddies (e.g., areas A and B) and provide useful information to fishery. 50km A B