The study of the mission instruments of GOSAT-2
Abstract
Greenhouse Gases Observing Satellite "GOSAT" was launched in January of 2009 and have observed the carbon dioxide and the methane almost four years. Additionally, the Level 1B algorithm has been improved based on the on board calibration and ground test using Engineering model and the accuracy of the level 1B data, that is the spectrum, has been improved. This has led to the more accurate calculation of the concentration of carbon dioxide and methane with small bias. At the same time, some issues have become clearer little by little through the on orbit operation. Especially a lot of data have been affected by the cloud, so few data have been used until now. However, the satellite has come to be recognized as an effective means of the detection of the global distribution of the greenhouse gases concentration. And in addition to the effort to resolve the issues which have become clear until now, the improvement of the observation performance have been required by a lot of users. Therefore, we researched the concrete requirements of users and set the mission requirements for GOSAT-2. Based on this mission requirement, we have studied the possibilities of these requirements. This study was implemented as premises for the usage of the Fourier Transform Spectrometer to detect the greenhouse gases as well as GOSAT. We considered the methods to increase the number of the useful data. For example, the reduction of the footprints size, increase of the number of the IFOV, the intelligent pointing and so on. It's necessary to maintain the Signal to Noise ration of the GOSAT. In addition to the method to increase the number of the useful data, we have researched the size of the aperture of the optics to maintain the signal to noise ratio corresponding to the reduction of the footprint seize. But the possibility of the corner cube used in the Fourier transform spectrometer limits the aperture size. We decided the aperture size (and corner cube size) based on the trade-off among corner cube size, footprint size and signal to noise ratio and the opinions of the scientists. In addition to the improvements of the performaces, the following requirements has been presented. To evaluate the relative matters of the anthropogenic emissions, to contribute to the MRV of REDD+ and so on. In order to meet these requirements the Fourier Transform Spectrometer on GOSAT-2 will has the additional observation channel for the carbon monoxide and Imager will has the spectrometer using the grating for Nitorgen Dioxide. Now we are investigating the possibilities of these additional functions and increase of the performances and we will decide the specifications of GOSAT-2 within one year.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A51J..08S
- Keywords:
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- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques;
- 0428 BIOGEOSCIENCES / Carbon cycling