The Japan Aerospace Exploration Agency (JAXA) will launch the Global Change Observation Mission Climate (GCOM-C) satellite. We developed the algorithms for retrieving the Leaf Area Index (LAI) and the fraction of Absorbed Photosynthetically Active Radiation (fAPAR), which will be produced and distributed as one of the GCOM-C standard land products by JAXA. In this document, we introduce the methods for retrieving them.

Japan Aerospace Exploration Agency (JAXA) will launch an Earth observing satellite for climate studies named "Global Change Observation Mission – Climate (GCOM-C)" in 2017 which carries a multi-spectral optical sensor named Second-Generation Global Imager (SGLI). The GCOM-C satellite will observe various geophysical variables such as vegetation, land surface temperature, aerosol, clouds, ocean color, sea surface temperature, snow cover extent, snow grain size and so on. The objectives of the SGLI observations are to elucidate the roles of the geophysical variables in the recent changing Earth's climate system and to establish long-term satellite data record of the variables. Three kinds of target accuracies to be achieved for the SGLI observations are defined for evaluating the success of the GCOM-C satellite mission. First one is the minimum thresholds to be achieved for the first SGLI data release at one year after the launch of GCOM-C. Second and third thresholds are the standard and goal accuracies to be achieved at five years after the launch for evaluating the full and extra success of the mission. The target accuracies for individual SGLI products are available at the GCOM-C web site (http://suzaku.eorc.jaxa.jp/GCOM_C/index.html). The quality and accuracies of SGLI products are planned to be evaluated and maintained through validation activities organized by the SGLI validation team consisting of JAXA and SGLI principal investigators (PIs). Uncertainties of the SGLI data products will be characterized through the comparison with in-situ observations, similar products derived from other satellites, climatological data, and/or numerical model simulations. This paper summarizes the overall validation plan for the SGLI geophysical variable products.

The “Global Change Observation Mission-Climate”(GCOM-C) is a project of Japan Aerospace Exploration Agency (JAXA) for the global and long-term observation of the Earth environment. The GCOM-C is expected to play an important role in monitoring and understanding global climate change. The GCOM-C is a part of the JAXA's GCOM mission which consists of two satellite series, GCOM-C and GCOM-W (Water). Whereas GCOM-W carries a multi-frequency, dual-polarized, passive microwave radiometer named Advanced Microwave Scanning Radiometer 2 (AMSR2) to observe water-related targets such as precipitation, sea surface temperature, soil moisture, and snow depth, GCOM-C carries a multi-spectral optical radiometer named Second Generation Global Imager (SGLI), which has special features of wide spectral coverage from 380nm to 12μm, a high spatial resolution of 250m, a swath width exceeding 1000km, two-direction simultaneous observation, and polarization observation. The GCOM-C mission aims to contribute to improving our knowledge and prediction of the global carbon cycle and radiation budget through high-accuracy observation of global vegetation, ocean color, temperature, cloud, aerosol, and snow and ice through the SGLI observations.

GCOM-C (Global Change Observation Mission -Climate) project aims to observe a global, long-term climate change and environmental change of the Earth, to implement Global Change Observation Mission (GCOM) as with GCOM-W (-Water). GCOM-C satellite, carrying a SGLI (Second generation Global Imager) sensor, is scheduled to be launched in the end of Japanese Fiscal Year 2016 and is designed to conduct optically-based measurements related to the atmosphere, ocean, cryosphere and land. 29 geophysical parameters are defined as GCOM-C/SGLI standard products, which are essential for achieving the goals of GCOM mission. The accuracies of each SGLI product are divided in 3 phase for the observation project: release threshold accuracy, standard accuracy and target accuracy. The ’release threshold accuracy’ is the minimum level for the first data release at 1 year after launch. The ’standard’ and ’target’ accuracies correspond to fulland extra success criteria of the mission within 5 years after launch respectively. The release threshold accuracies of the standard products are basically evaluated through the comparison with those derived from other satellite sensors at same spatial coverage and temporal periods and/or with groundbased observation network such as flux tower site data, AERONET, buoy data and so on. For the evaluation of the standard and target accuracies, several field campaigns are also being prepared. In this presentation, we are going to introduce an outline of validation plan for GCOM-C/SGLI standard products and discuss the possible collaboration of in-situ data and validation methods between atmosphere, ocean, cryosphere, and land category of GCOM-C and between other satellite such as EarthCARE and GOSAT.