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The European Space Agency (ESA)’s Earth Explorer Aeolus was launched in August 2018 carrying the world’s first spaceborne wind lidar, the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN uses a high spectral resolution Doppler wind lidar operating at 355nm to determine profiles of line-of-sight wind components in near-real-time (NRT). ALADIN samples the atmosphere from 30km altitude down to the Earth’s surface or to the level where the lidar signal is attenuated by optically thick clouds.The global wind profiles provided by ALADIN help to improve weather forecasting and the understanding of atmospheric dynamics as they fill observational gaps in vertically resolved wind profiles mainly in the tropics, southern hemisphere, and over the northern hemisphere oceans. Since 2020, multiple national and international weather centres (e.g. ECMWF, DWD, Météo France, MetOffice) assimilate Aeolus observations in their operational forecasting. Additionally, the scientific exploitation of the Aeolus dataset has started.A main prerequisite for beneficial impact and scientific exploitation is data of sufficient quality. Such high data quality has been achieved through close collaboration of all involved parties within the Aeolus Data Innovation and Science Cluster (DISC), which was established after launch to study and improve the data quality of Aeolus products. The tasks of the Aeolus DISC include the instrument and platform monitoring, calibration, characterization, retrieval algorithm refinement, processor evolution, quality monitoring, product validation, and impact assessment for NWP.The achievements of the Aeolus DISC for the NRT data quality and the one currently available reprocessed dataset will be presented. The data quality of the Aeolus wind measurements will be described and an outlook on planned improvements of the dataset and processors will be provided.

Already within the first weeks after the launch of ESA's Earth Explorer mission Aeolus on 22 August 2018, the spaceborne wind lidar ALADIN (Atmospheric LAser Doppler INstrument) provided atmospheric backscatter measurements on 5 September and wind profiles on 12 September 2018. This swift availability of observations from ALADIN after launch is considered as a great success for ESA, space industry and algorithm and processor developer teams. These teams from scientific institutes, numerical weather prediction (NWP) centres, companies and ESA continuously improved and tested the retrieval algorithms and processors using sophisticated end-to-end simulation tools and experience gained with the airborne demonstrator for Aeolus for more than 15 years before launch. This cooperation from the pre-launch phase of Aeolus was extended within a new framework for exploitation activities of Earth Explorer missions named Data Innovation and Science Cluster (DISC) starting in January 2019. The Aeolus DISC activities range from instrument monitoring including calibration to algorithm refinement resulting in updates of the complete processor chain for all product levels every 6 months. DISC teams perform continuous monitoring of the product quality and provide regular reports in supports of external validation teams and ESA. Finally, wind product monitoring and impact experiments with NWP models are building an essential activity within the Aeolus DISC in order to achieve the objective of the Aeolus mission. In order to cover the broad range of activities, a multi-disciplinary team of experts, institutes and companies was established for the Aeolus DISC coordinated by DLR with ECMWF, KNMI, CNRS/Météo-France, DoRIT, ABB, S&T and Serco. During the presentation the Aeolus instrument performance for wind products, the discovered causes of the systematic errors and their correction will be discussed. Main achievements in this area are related to the characterization and correction of enhanced dark signal levels for single "hot" pixels in June 2019, the identification of the harmonic error contribution caused by the varying telescope primary mirror temperature variation in September- October 2019, the error in the on-board computation of the satellite induced Doppler frequency shift, and finally the observed temporal drift of a constant bias caused by drifts in the internal reference path. An outlook to the implementation of these corrections for real-time and reprocessed data products will be given.

The European Space Agency (ESA)’s Earth Explorer Aeolus was launched in August 2018 carrying the world’s first spaceborne wind lidar, the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN uses a high spectral resolution Doppler wind lidar operating at 355nm to measure profiles of line-of-sight wind components in near-real-time (NRT). ALADIN samples the atmosphere from 30km altitude down to the Earth’s surface or to the level where the lidar signal is attenuated by optically thick clouds.The global wind profiles provided by ALADIN help to improve weather forecasting and the understanding of atmospheric dynamics as they fill observational gaps in vertically resolved wind profiles mainly in the tropics, southern hemisphere, and over the northern hemisphere oceans. In January 2020, the European Centre for Medium-Range Weather Forecasts (ECMWF) became the first numerical weather prediction (NWP) centre to assimilate Aeolus observations for operational forecasting.A main prerequisite for beneficial impact is data of sufficient quality. Such high data quality has been achieved through close collaboration of all involved parties within the Aeolus Data Innovation and Science Cluster (DISC), which was established after launch to study and improve the data quality of Aeolus products. The tasks of the Aeolus DISC include the instrument and platform monitoring, calibration, characterization, retrieval algorithm refinement, processor evolution, quality monitoring, product validation, and impact assessment for NWP.The achievements of the Aeolus DISC for the NRT data quality and the current status of Aeolus wind measurements will be described and summarized. Further, an outlook on future improvements and the availability of reprocessed datasets with enhanced data quality will be provided.

Already within the first weeks after the launch of ESA´s Earth Explorer mission Aeolus on 22 August 2018, the spaceborne wind lidar ALADIN (Atmospheric LAser Doppler INstrument) provided atmospheric backscatter measurements on 5 September and wind profiles on 12 September. This swift availability of observations from ALADIN after launch is considered as a great success for ESA, space industry and algorithm and processor developer teams. These teams from scientific institutes, numerical weather prediction (NWP) centres, companies and from ESTEC and ESRIN continuously improved and tested the retrieval algorithms and processors using sophisticated end-to-end simulation tools and experience gained with the airborne demonstrator for Aeolus. ALADIN as the first wind-lidar in space is not only based on new technologies for lasers, optical interferometers and detectors, but also the retrieval algorithms had to be developed without any heritage from earlier space-borne wind lidars. This cooperation from the development phase of Aeolus will be continued and extended within a new framework for exploitation activities of Earth Explorer missions named Data Innovation and Science Cluster (DISC) during the phase E2 starting after completion of the commissioning phase activities. The Aeolus DISC activities range from instrument monitoring including calibration and characterization to algorithm refinement, and towards a continuous evolution of the processors for all product levels. Product quality monitoring plays an essential role including validation of products from external validation teams, whose results will be synthesised by DISC experts and eventually will lead to further algorithm updates. The DISC consortium will provide support to ESA ranging from anomaly resolving for the payload data ground segment to support in decisions for instrument operation, calibration and providing support to the Aeolus Quality Working Group (QWG). Also support to Aeolus users from the validation teams, science and NWP communities will be provided by DISC experts. The aim of the Aeolus mission is to provide global observations of vertical profiles of one component of the horizontal wind vector with sufficient accuracy and precision to demonstrate a positive impact on NWP analysis and forecasts. All activities within the DISC are targeted towards supporting this overall objective. Therefore impact experiments with NWP models are building a major activity within DISC. These impact experiments, the product monitoring activities, or the feedback from the user community will eventually guide further recommendations for algorithm and processor evolution. Both forward-engineering (or bottom-up) approaches as well as complementary reverse-engineering (or top-down) approaches will be practiced. The monitoring of the Aeolus data product quality and instrument performance, the refinement of retrieval algorithms or the evolution of the processors strongly benefit from monitoring of Aeolus data with NWP models. This NWP monitoring provides temporally continuous comparisons of Aeolus observations with NWP models for all altitudes and over all geographical regions, and this with almost immediate feedback on the data quality. The large potential of this approach was already successfully demonstrated during the commissioning phase, where a systematic error in Rayleigh winds for one specific range gate was spotted by comparison of several orbits of Aeolus data with the ECMWF model. This bias in Rayleigh winds could be traced back to one suspicious pixel on the Rayleigh ACCD. Investigations for correcting these effects on pixel level are on-going. This clearly demonstrates the successful approach of combining the expertise on the instrument, retrieval algorithms, and NWP monitoring. An overview of the DISC activities as well as first results from instrument performance and data product quality will be discussed.

Soon after its successful launch in August 2018, the spaceborne wind lidar ALADIN (Atmospheric LAser Doppler INstrument) on-board ESA's Earth Explorer satellite Aeolus has demonstrated to provide atmospheric wind profiles on a global scale. Being the first ever Doppler wind lidar instrument in space, ALADIN contributes to the improvement in numerical weather prediction by measuring one component of the wind vector along the instrument's line-of-sight from ground throughout the troposphere up to the lower stratosphere. The measurements are performed with the single payload ALADIN, which is a direct-detection Doppler wind lidar operating at an ultraviolet wavelength of 354.8 nm. ALADIN uses a frequency-tripled Nd:YAG laser, a large 1.5 m Cassegrain telescope, and 2 interferometers for detection of the Doppler frequency shift from molecules and particles. Challenges during the development of the ALADIN instrument are highlighted and first results are discussed including validation with an airborne instrument demonstrator.

VirES is a Virtual workspace for Earth-observation Scientists, a service provided by the European Space Agency (ESA). VirES has firstly been established for ESA's magnetic field mission Swarm as "VirES for Swarm" and has been extended to ESA's atmospheric dynamics mission Aeolus, which is scheduled for launch in August 2018. The service is developed by the Austrian IT company EOX in strong collaboration with missions' scientists. VirES is a web-based service (https://vires.services) that enables scientists to discover, visualize, select and download data of Earth-observation missions through an easy to operate graphical user interface. "VirES for Aeolus" will provide access to Aeolus L1B, L2A, L2B, L2C products and auxiliary data. The first version 1.0 passed acceptance tests in April 2018 and developments towards Version 1.1 (launch version) are in progress. The service is planned to be accessible for public use as soon as the mission's commissioning phase is completed and first data products are released by ESA.

The ADM-Aeolus is primarily a research and demonstration mission flying the first Doppler wind lidar in space. Flexible data processing tools are being developed for use in the operational ground segment and by the meteorological community. We present the algorithms developed to retrieve accurate and representative wind profiles, suitable for assimilation in numerical weather prediction. The algorithms provide a flexible framework for classification and weighting of measurement-scale (1 10 km) data into aggregated, observation-scale (50 km) wind profiles for assimilation. The algorithms account for temperature and pressure effects in the molecular backscatter signal, and so the main remaining scientific challenge is to produce representative winds in inhomogeneous atmospheric conditions, such as strong wind shear, broken clouds, and aerosol layers. The Aeolus instrument provides separate measurements in Rayleigh and Mie channels, representing molecular (clear air) and particulate (aerosol and clouds) backscatter, respectively. The combining of information from the two channels offers possibilities to detect and flag difficult, inhomogeneous conditions. The functionality of a baseline version of the developed software has been demonstrated based on simulation of idealized cases.