First Airborne Wind Lidar Campaign for the Validation of Aeolus

Kurzfassung

Already three weeks after the successful launch of Aeolus in August 2018, atmospheric return signals and wind profiles were detected by the first ever Doppler wind lidar instrument in space, ALADIN (Atmospheric LAser Doppler INstrument). For an experimental validation of Aeolus, the ALADIN Airborne Demonstrator (A2D) was developed at DLR and deployed during several field campaigns in the last decade. As the A2D is based on the ALADIN predevelopment model, it features a high degree of commonality with the satellite instrument (e.g. a highly representative optics and electronics receiver design and the same laser wavelength of 355 nm). Hence, it is a key instrument for calibration and validation activities and surely helps to increase the understanding of Aeolus instrument characteristics. A first airborne campaign for the comparison with Aeolus data in the commissioning phase was conducted in the period between 5 November and 5 December 2018. From the operation base at DLR in Oberpfaffenhofen, four satellite underflights in Central Europe featuring both the A2D and the DLR 2-µm coherent Doppler wind lidar (DWL) onboard the Falcon research aircraft could be performed. This payload allowed addressing the campaign objectives to compare atmospheric and ground returns from air- and spaceborne DWLs as well as to test airborne Cal/Val strategies and procedures with respect to Aeolus characteristics like e.g. horizontal and vertical sampling settings. Data analysis is currently ongoing and first qualitative comparative results are available. Based on the lessons learned from this campaign, the upcoming airborne deployments of the DLR DWL payload onboard Falcon during the operational phase E2 of Aeolus will be conducted in May and September 2019 in Central Europe and Iceland respectively, followed by a tropical campaign in the first half of 2020. An overview of the conducted airborne campaigns and specific results from instrument comparisons will be presented together with an outlook on future airborne ALADIN performance assessment campaigns focusing on the validation of wind and aerosol products.