Greenhouse Gases Measurement Instruments on GOSAT-2

Paper number

IAC-15,B1,3,9,x30659

Author

Mr. MASAKATSU NAKAJIMA, JAXA, Japan

Coauthor

Dr. Hiroshi Suto, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Yoshiyuki Ishijima, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. YASUTOSHI HYAKUSOKU, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Kazuhiko Yotsumoto, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Masashi Abe, JAXA, Japan

Coauthor

Dr. Takehiro Miyakawa, JAXA, Japan

Coauthor

Dr. Kei Shiomi, JAXA, Japan

Coauthor

Mr. TAKESHI HIRABAYASHI, JAXA, Japan

Year

2015

Abstract

Greenhouse gases Observing SATellite (GOSAT) is the satellite dedicated to measure the greenhouse gases, and has been operated on orbit over six years since it was launched on 23rd, January, 2009.
GOSAT is loaded with two mission instruments, Fourier Transform Spectrometer (FTS) is the main instrument to observe the carobon dioxide and methane, and Cloud and Aerosol Imager (CAI) is the pushbloom imager to detect the clouds and aerosols for the  compensation of the FTS data. This FTS has been observing at four spectral bands from 760nm to 14.3$\mu$m. And the CAI measures at four bands from 380nm to 1.6$\mu$m.
To improve the performance of the greenhouse gases observation from space, GOSAT-2 development had been started.
The principal requirements on GOSAT-2 are measuring the CO2 concentration with the accuracy of 0.5 ppm at 500km and 2,000km mesh spatial resolution over the land and ocean, respectively and 1 month average and estimating the net flux with the error of 100 percents.
The mission instruments on GOSAT-2 are TANSO-FTS-2 and TANSO-CAI-2. And in conjunction with the starting of the GOSAT-2 mission, it was requires to measure the new molecule, carbon monoxide, as the correlated matter of the anthropogenic emission of the greenhouse gases to estimate the anthropogenic emission of the carbon dioxide. Therefore,the observation range of 2.0$\mu$m band was extended to 2.3$\mu$m. The observation performance of the TANSO-CAI will be improved to estimate PM2.5. including the adoption of the additional observation band, 343nm, 443nm and 550nm, and the two viewing angles, +/- 20 degrees. The three bands, 674nm, 869nm and 1.6$\mu$m, are allocated in both viewing angles.
The design of GOSAT-2 were defined based on the feasibility studies and lessons and learned obtained through the development and on-orbit operation.
The modulator in the FTS-2 has two corner cubes on the both edges of the swing arm with a “V” shape as with the FTS on GOSAT. But the effective aperture of FTS-2 will be expanded to 73mm from 64mm of the FTS to increase the signal to noise ratio to improve the measurement accuracy.
And to increase the number of the useful data, GOSAT-2 will equip the function to avoid the clouds during the observation using the images obtained by the monitor camera in FTS-2.
In this presentation, the GOSAT-2 mission, lessons and learned of GOSAT and the design of the GOSAT-2 mission instruments will be shown as well as the satellite system.

Abstract document

IAC-15,B1,3,9,x30659.brief.pdf

Manuscript document

(absent)