Minimize ERS News

ERS-2 Scatterometer L2 dataset processing with ASPS v. 10.04 completed

14 May 2015

The re-processing campaign of ERS-2 Scatterometer Level 2.0 products has been completed, adopting the latest Advanced Scatterometer Processing System (ASPS) version 10.04. Data from Cycle 10 to Cycle 165 (26 March 1996 - 07 March 2011) and from the 3 days repeat cycles at the end of the mission (07 March 2011 - 05 July 2011) is now available to the user community.

  • Data from Cycle 01 to 09 has not been reprocessed, due to the limited availability of the AMI in Wind Scatterometer mode
  • Data from Cycle 69 to 74 has not yet been reprocessed, due to degraded calibration performances in the Aft beam antenna measurements. As a consequence of this issue, the Aft beam measurements for those specific cycles will be re-calibrated and the affected cycles will be reprocessed at a later stage

Detailed information related to the ERS-2 Scatterometer consolidated Level 2.0 products availability can be found here.

The new ASPS Level 2 data set includes significant quality improvements with respect to the previous near-real time UWI data version:

  • re-fined calibration of the three backscattering measurements (sigma noughts)
  • four aliased wind vector solutions (Rank 1-4) and de-aliased wind vector flag
  • the sea-ice probability and sea-ice flag
  • the YAW error angle flag to be used as quality indicator filter during the Zero Gyro Mode (ZGM) period from 2001 till the end of the ERS-2 mission

In addition, the long-term ERS-2 dataset has also been characterised in terms of CMOD5N geophysical forward model derived by ECMWF in order to retrieve the neutral winds from the backscattering measurements.

The ASPS Level 2 products are available in nominal resolution of 50km (ASPS20_N) and in high resolution of 25 Km (ASPS20_H). In addition, the ERS data reprocessed with the ASPS v 10.04 facility is also available in the UWI format in order to maintain the compatibility with the previous operational data format. The detailed description of the product format is reported in the Product Specification document.

Data Access

The latest reprocessed data is made available online via FTP together with the previously released products. For new users, access can be provided through Fast Registration.

The ERS-2 Scatterometer ASPS data will be moved to the ESA centralised dissemination server within 2015. Users will be informed about the change of credentials in due time.


More detailed information on all changes implemented for the reprocessing campaign with ASPS version 10.04 is available on the ESA Sensor Performance and Product Algorithm portal:

  • Products Quality Readme File
  • Products Specifications
  • Algorithm Theoretical Baseline Document (ATBD)
  • ASPS Product Handbook