ESA’s Aeolus mission continues to advance weather forecasting with further data improvements, thanks to a third reprocessing campaign.

Enhancements from this campaign include seamless delivery of low wind bias products from the mission’s beginning to present day and corrections in hot pixel fluctuations.

Part of ESA’s Earth Explorer family of research missions, Aeolus is the first satellite mission to profile Earth’s wind globally.

Launched in 2018, the mission uses one sensor – called the Atmospheric Laser Doppler Instrument (ALADIN) – to provide data to advance research in atmospheric dynamics.

The recent reprocessing campaign covered 31 August 2018 to 16 June 2019 – focusing on the initial operation period of the first Flight Model laser (FM-A).

Results from the campaign have been published and are now available for browsing and download.

The data generation is based on processor versions used for operational Near-Real Time (NRT) generation of baseline 14 (B14) data products.

The reprocessing covers the preliminary wind (L1B), scientific wind (L2B) and aerosol/cloud optical (L2A) product types. It also covers the respective auxiliary files for these products and for the first-time provides low wind bias data products for ALADIN’s initial FM-A period of operation.

The secondary operation period of Aeolus occurred following the switch-over from the first FM-A laser to the second FM-B laser in June 2019, until August 2022.

In combination with the second reprocessing campaign for this secondary operation period and the NRT baselines, the third reprocessing campaign completes the seamless data availability of low wind bias products from the beginning of the mission to this day.

One of the main improvements with respect to the original processing baseline is the correction of hot pixel fluctuations. This was achieved with an algorithm, which detects hot pixel induced steps in the backscattered signal.

No regular dark signal measurements were performed at the beginning of the first operational period. However, an advanced detection and correction approach newly developed by the Aeolus Data Innovation and Science Cluster (DISC) ensures the correction of hot pixel induced steps even in this period.

In contrast to previous reprocessing campaigns, the third reprocessing campaign featured a more sophisticated detection algorithm, which also allows for the correction of illuminated hot pixels located within the two Rayleigh spots.

Detailed information about all major processing improvements and quality analysis can be found in the recently published Summary Reprocessing document.

Continued reprocessing of Aeolus data ensures the mission continues to deliver useful, high-quality data. The next reprocessing campaign will use B16 processor versions and will cover the complete data period from September 2018, to the release of NRT baseline B16 in spring 2023.

Data from Aeolus are already being used by many meteorological centres across the world to inform better weather forecasts, climate models and other research. This third reprocessing campaign improves Aeolus data further, so that the mission continues to exceed its original objectives.