Global Daily 23GHz Brightness Temperature from AMSR2 Satellite

Brightness temperature data at 23GHz is derived from the AMSR2 sensor onboard the JAXA GCOM-W satellite. The Level 3 product provides daily and monthly statistical means, including brightness temperature, standard deviation, and data counts, on a global 0.25-degree grid. The dataset is produced by the Japan Aerospace Exploration Agency from observations beginning after the satellite's launch in May 2012.

Use Cases

• Retrieving sea surface temperature or soil moisture by analyzing the `Brightness_Temperature_(H)` and `Brightness_Temperature_(V)` values at 23GHz.
• Assessing data quality and uncertainty for each grid cell using the `Standard_Deviation` column available in monthly products.
• Identifying valid observation coverage by filtering pixels using the `Average_Number` and `Total_Number` count columns.
• Separating analysis for satellite ascending and descending tracks to study diurnal effects on the observed brightness temperature.
• Masking invalid data outside the observation swath by identifying error values (65531 to 65534) and missing values (65535).

Strengths

• Global spatial coverage with a consistent 0.25-degree grid resolution.
• Provides separate data products for daily and monthly temporal aggregation.
• Includes quality metrics like `Standard_Deviation`, `Average_Number`, and `Total_Number` for each pixel.

Limitations

• Specific temporal coverage and total row count are not provided in the description.
• The 23GHz frequency is sensitive to atmospheric water vapor, which can complicate surface signal isolation.
• Data outside the sensor's 1450 km swath is marked as error values, creating gaps in global daily maps.

Provenance

Source

Japan Aerospace Exploration Agency (JAXA).

Collection Method

Satellite remote sensing via the AMSR2 microwave radiometer onboard the GCOM-W spacecraft, with Level 3 processing calculating arithmetic means of Level 1B and Level 2 data.

Time Range

Observations began after the satellite launch on May 18, 2012. Specific end date not provided.

Freshness

Daily and monthly generation frequency. The current product version is Version 2.

Geography

Global.