JAXA Supercomputer System Annual Report April 2019-March 2020

Report Number: R19ER2100

Subject Category: Space Technology

PDF available here

• Responsible Representative: Akihiko Kuze ,Space Technology Directorate I GOSAT-2 Project Team, Project Manager
• Contact Information: Yoko UEDA(ueda.yoko@jaxa.jp)
• Members: Makiko Hashimoto, Kenji Kowata, Makoto Imanaka, Yoko Ueda, Hidetoshi Hayasaka, Mamoru Sugawara, Tomoyuki Mabuchi, Masahito Arai, Takehito Yoshida, Fumie Kataoka , Hitoshi Nagata, Jun Yoshida, Ritsuko Imatani, Nobuhiro Kikuchi, Yoichi Nakamura, Ryo Nagino

Abstract

GOSAT continues its observations for 10-years beyond its 5-year mission, providing well-calibrated high spectral resolution data. The overall functions and performances are successful and no significant degradation of SNR and spectral resolution has been observed. Several anomalies were found onboard, but they have stabilized since. The Level 1 algorithms have been updated since launch in order to correct these anomalies.

Reference URL

Please refer to ‘HOME – GOSAT – JAXA‘.

Reasons and benefits of using JAXA Supercomputer System

GOSAT mission utilizes JSS2 as one of the GOSAT Mission Operation System which processes the observation data of GOSAT. When processing algorithm is updated, JSS2 reprocesses all data observed in the past. When we calibrate products, JSS2 processes all data in the past. Also, JSS2 is used as a remote storage of all data required for its reprocessing.

Achievements of the Year

(1)GOSAT TANSO-FTS Level-1 Reprocessing

We reprocessed 10 year TANSO-FTS data by utilizing JSS2 (30nodes) to correspond with next version-up (V220.220). It took only 22 days, and we could verify speed-up more than 30 times comparing to one 1.7-year by using the conventional GOSAT L1 processing computers.

(2)Calibration and validation of GOSAT TANSO-CAI data

On-orbit sensor sensitivity change is evaluated from TANSO-CAI observation data. We expect to determine the CAI Band 1 radiometric calibration factor (or formula) by calculation of radiative transfer model using in-situ and other satellite data. The CAI Band 1 has an important information of aerosol size distribution. Hence, Band 1 radiance is optimized to agree with calibrated radiances of Band 2 and Band 3. Calibration formula of Band 2 and Band 3 are obtained as three candidates. Thus, Band 1 calibration factor is determined by calculations in these three cases. Figure 1 shows a schematic flow of the CAI radiometric calibration method. Figure 2 shows the radiometric calibration factors.

Data period: June 2019 – February 2020 (every 4 months)

Fig.1: GOSAT CAI processing flow (top) and radiometric calibration flow (bottom)

Fig.2: CAI radiometric calibration factor by inter-satellite cross calibration method

Publications

N/A

Usage of JSS2

Computational Information

• Process Parallelization Methods: N/A
• Thread Parallelization Methods: N/A
• Number of Processes: 1
• Elapsed Time per Case: 30 Minute(s)

Resources Used

Fraction of Usage in Total Resources*1(%): 0.14

Details

Please refer to System Configuration of JSS2 for the system configuration and major specifications of JSS2.

*1: Fraction of Usage in Total Resources: Weighted average of three resource types (Computing, File System, and Archiver).

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

JAXA Supercomputer System Annual Report April 2019-March 2020