The current status of GOSAT and the concept of GOSAT-2

GOSAT which is dedicated to monitor the column concentration of carbon dioxide and methane was launched almost 3 and half years ago, and the data processing algorithm have been improved a few times based on the calibration and validation, and the precision of the concentration data have been increased. These data gave us a realization of the availability of the GHG observation from space. And it has been required to expand this mission to make it useful for mankind. So we have investigated the requirements for the next generation greenhouse gases observations from space and have defined the mission requirements for GOSAT-2. The measurement accuracy target of Carbon Dioxide concentration defined in this mission requirement is 0.5 ppm at 500km and 2,000km mesh spatial resolution over the land and ocean, respectively and 1 month average. To achieve this target, GOSAT-2 will adopt the Fourier Transform Spectrometer (FTS) and the imager along with GOSAT, but the functions and performances will be improved. For example, the CO observation band will be added and the grating spectrometer for UV band of CAI will be adopted to measure NO2 and to improve the aerosol retrievals. Following the presentation of the GOSAT observation results, the concept of GOSAT-2 will be shown.