JAXA Supercomputer System Annual Report February 2021-January 2022

Report Number: R21ER2100

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, Hidetoshi HAYASAKA(ueda.yoko@jaxa.jp;hayasaka.hidetoshi@jaxa.jp)
• Members: Masahito Arai, Takashi Goto, Makiko Hashimoto, Hidetoshi Hayasaka, Makoto Imanaka, Kenji Kowata, Fumie Kataoka, Nobuhiro Kikuchi, Mamoru Sugawara, Tomoyuki Mabuchi, Yoichi Nakamura, Ryo Nagino, Hideki Suetake, Yoko Ueda, Takehito Yoshida, Jun Yoshida

Abstract

GOSAT continues its observations for 13-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 JSS3 as one of the GOSAT Mission Operation System which processes the observation data of GOSAT. When processing algorithm is updated, JSS3 reprocesses all data observed in the past. When we calibrate products, JSS3 processes all data in the past. Also, JSS3 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 13 year TANSO-FTS data by utilizing JSS3 (10nodes) to correspond with next version-up (V230.231). It took only 35 days by JSS3, although it had taken 1.8-year by 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 2020 - Feb 2021 (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 JSS

Computational Information

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

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.09

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

*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.

ISV Software Licenses Used

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

JAXA Supercomputer System Annual Report February 2021-January 2022