Update on GOSAT TANSO-FTS performance, operations, and data products after more than six years in space
Atmospheric Measurement Techniques Discussions
A dataset containing more than six years (February 2009 to present) of radiance-spectra for carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) observations has been acquired by the Greenhouse gases Observing SATellite (GOSAT), nicknamed "Ibuki", Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS). This manuscript provides updates on the performance of the satellite and TANSO-FTS sensor and describes important changes to the data product,
... the data product, which has recently been made available to users. With these changes the typical accuracy of retrieved column-averaged dry air mole fractions of CO<sub>2</sub> and CH<sub>4</sub> (X<sub>CO<sub>2</sub></sub> and X<sub>CH<sub>4</sub></sub>) are 2 ppm or 0.5 % and 13 ppb or 0.7 %, respectively. Three major anomalies of the satellite system affecting TANSO-FTS are reported: a failure of one of the two solar paddles in May 2014, a switch to the secondary pointing system in January 2015 and most recently, a cryo-cooler shutdown and restart in August 2015. The Level 1A (L1A) (raw interferogram) and the Level 1B (L1B) (radiance spectra) of version V201.201 (V201) described here have long-term uniform quality and provide consistent retrieval accuracy even after the satellite system anomalies. In addition, we discuss the unique observation abilities of GOSAT, made possible by an agile pointing mechanism, which allows for optimization of global sampling patterns.