The fourth Reprocessing of the ATSR L1B datasets derived from the ERS-1 and ERS-2 satellites have now been released to users by the European Space Agency (ESA).

The new ERS ATSR datasets are freely available for download to anyone with an ESA EO Sign In account via the ESA Online Dissemination Service for (A)ATSR, hosting also the latest reprocessed Envisat AATSR L1B data.

The new L1B Brightness Temperature and Radiance datasets cover the mission archives as follows:

• ERS ATSR-1 [ER1_AT_1_RBT] - from August 1991 to December 1997*
• ERS ATSR-2 [ER2_AT_1_RBT] - from June 1995 to June 2003
  
  *For ERS-1, all mission data is available except for a portion of the products acquired during the ERS-1 Phase E & F (168 days repeat orbit), which took place from April 1994 to March 1995. The affected products will be integrated at a later stage.

Users are strongly encouraged to update to the fourth Reprocessing ATSR L1B products.  

Key highlights of the release:

The datasets have been fully reprocessed into a new product format which aligns them with the format adopted by the instruments’ successors, Envisat AATSR and Sentinel-3 SLSTR, and includes the following updates from the former L1B datasets [AT1_TOA_1P / AT2_TOA_1P] generated by the ERS ATSR 3rd Reprocessing in 2013:

• Improved and extended Level 1B datasets, beginning with recovery of Level 0 data, via the reprocessing of Level 0 data to ungridded brightness temperature (UBT) scenes to Level 1A to retain extra instrument information.

• Level 1B products in a Sentinel-SAFE/NetCDF format: a product folder containing NetCDF files and an XML manifest file, holding extensive metadata. This means new information is now available, such as per-pixel uncertainty estimates, associated meteorological data from ECMWF ERA-Interim, instrument scan and pixel quality information, and channel-specific exception and flag values.

• Geolocation improvement via orthogeolocation to a Digital Elevation Model.

• Improved surface classification via use of the Sentinel-3 Land Water Masks.

• Improved cloud information via a latitude correction within cloud look-up tables.

ATSR dataset and access information:

For further details on the specific ERS ATSR-1/2 datasets, accessibility, and user registration, please visit the ATSR Data Description page.

All users are recommended to consult the accompanying documentation before using the data:

• User Documentation for (A)ATSR fourth Reprocessing
• ERS ATSR Product Notice Readme

ERS ATSR Level 2 product generation is now within the remit of the ESA Climate Change Initiative (CCI) Sea Surface Temperature/SST and Land Surface Temperature/LST project teams. Any Level 2 / Level 3 data generation will be made according to the CCI project timelines.

Dismissal of former FTP server:

The old ESA FTP service hosting the full set of the former (A)ATSR 3rd Reprocessing data will be disabled at the end of June 2024. User should complete any downloading activities in due time and start using the service for the new products instead.

Should you need any additional clarification or support please contact the ESA EO Help Desk