Calibration/Validation
HISUI Calibration and Data Processing Flow
The results of the pre-launch laboratory test, post-launch onboard lamp and ground observation data are comprehensively analyzed and compiled into calibration parameters (onboard correction table, radiometric DB, and geometric DB), and the raw data are corrected by using these calibration parameters during product processing.
HISUI Calibration
The quality of HISUI Level1 products depends on the version of the radiometric or geometric DB. Please refer to the version listed in the product metadata and the quality information below.
| Radiomatric DB Version (Release) |
Wavelength shift from specification | Smile *1 | Radiance deviation between pixels |
|---|---|---|---|
| HSHRDB_20220625170000_301_001*4 (2023/08/03) | Now investigation | VNIR:very small SWIR:<2nm |
There are radiance deviation of crosstrack pixels (vertical stripes) in lower VNIR radiance. (Now investigation) |
| HSHRDB_20220330080000_301_001*4 (2023/08/03) | |||
| HSHRDB_20210927000000_301_003 (2023/08/03) | Now investigation | VNIR:very small SWIR:very small in cirtain period SWIR<2nm *3 |
|
| HSHRDB_20210524000000_301_003 (2023/08/03) | Now investigation | VNIR:+0.2~+1.7nm SWIR:+2.8~+7.1nm |
|
| HSHRDB_20201023000000_301_003 (2023/08/03) | |||
| Old Radiomatric DB Version (Release) |
Wavelength shift from specification | Smile *1 | Radiance deviation between pixels |
| HSHRDB_20210927000000_300_002 (2022/08/03) | Now investigation | VNIR:very small SWIR:<2nm *3 |
There are radiance deviation of crosstrack pixels (vertical stripes) in lower VNIR radiance. (Now investigation) There remains an offset in SWIR that depends on sensor temperature. |
| HSHRDB_20210524000000_300_002 (2022/08/03) | Now investigation | VNIR:+0.2~+1.7nm SWIR:+2.8~+7.1nm |
|
| HSHRDB_20201023000000_300_002 (2022/08/03) | |||
| HSHRDB_20210927000000_200_001 (2021/10/20) | Now investigation | VNIR:very small SWIR:<2nm *3 |
There are radiance deviation of crosstrack pixels (vertical stripes). The level is mostly lower than 0.1% in reflectance. There are radiance deviation of alongtrack pixels (horizontal stripes). |
| HSHRDB_20210524000000_200_001 (2021/10/20) | Now investigation | VNIR:+0.2~+1.7nm SWIR:+2.8~+7.1nm |
|
| HSHRDB_20201023000000_200_001 (2021/10/20) |
*1 Smile: Wavelength shift in crosstrack pixels
*3 There are <2nm smile in SWIR between 2022/09/30 and 2023/01/04.
*4 New versions added due to sensor status changes on 2022/03/30 and 2022/06/25
| Geomatric DB Version (Release) |
Keystone *2 | Comment about geolocation error | ||
|---|---|---|---|---|
| HSHGDB_20191205000000_202_003 (2023/03/24) | <0.05pixel | <200m error in nominal case There are possiblity of <7km error in alongtrack in the case of homogeneous image such as cloud, desert and sea. Now investigatiiton. |
||
| HSHGDB_20191205000000_201_002 (2022/02/28) | <0.1pixel | |||
| HSHGDB_20191205000000_200_001 (2021/12/16) | VNIR:-0.2~+0.4pixel SWIR:-0.7~+0.5pixel |
|||
*2 Keystone: Crosstrack location shift in wavelength pixels