Japan Geoscience Union Meeting 2018

Presentation information

[EE] Poster

A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG36] Satellite Earth Environment Observation

Thu. May 24, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Riko Oki(Japan Aerospace Exploration Agency), Yoshiaki HONDA(Center for Environmental Remote Sensing, Chiba University), Yukari Takayabu(東京大学 大気海洋研究所, 共同), Tsuneo Matsunaga(Center for Global Environmental Research and Satellite Observation Center, National Institute for Environmental Studies), Allen HL Huang (University of Wisconsin Madison)

[ACG36-P10] Dependence on Spectral Reflectance of Surface Properties at Railroad Valley Playa for GOSAT/GOSAT-2 Vicarious Calibration

*Takehiko Arai1, Tsuneo Matsunaga1 (1.National Institute for Environmental Studies)

Keywords:Green house gas, GOSAT, Railroad Valley, Vicarious calibration

GOSAT and the next generation GOSAT-2 satellites estimate the concentration of greenhouse gases, and distribution of aerosol and cloud by observing solar light reflection and radiation from surface and atmosphere of the Earth. A bidirectional reflectance distribution function (BRDF) is required for the estimation because the surface reflectance of solar light varies with the observation geometry and the surface condition. The purpose of this study is to search for an appropriate BRDF model of Railroad Valley playa, Nevada (RRV) for the sensor calibration of GOSAT. We measured the radiance factor of RRV by varying with solar incident angles and observed angles using a spectroradiometer (FieldSpec4, ASD Inc.) mounted on a one-axis goniometer. The surface sands were shifted to several sizes of grain (75, 125, 250, 500, and 1000 μm). We determined the Hapke parameters (Hapke, 2012) as the BRDF for the observed radiance factor of the sands by the least squares fitting with the free parameters of a single scattering albedo, an asymmetric factor, a shadow hiding opposition effect parameter, and a mean slope angle. This result indicates that the albedo was varied with the grain size and its physical state of the surface. Therefore, detail measurements of the surface properties at local sites, such as a filling factor, are significant to determine the precise albedo of the calibration site.