Airborne Doppler Wind Lidar Technology Demonstration for Aeolus - from Pre-launch Campaigns to Mission Performance Validation

• Published in: International Conference on Space Optics — ICSO 2022
• Main Authors: Lemmerz, Christian, Lux, Oliver, Witschas, Benjamin, Rahm, Stephan, Marksteiner, Uwe, Geiss, Alexander, Weiler, Fabian, Reitebuch, Oliver
• Format: Conference Object
• Language: English
• Published: SPIE, the international society for optics and photonics 2022
• Subjects: Lidar; North Atlantic
• Online Access: https://elib.dlr.de/202193/; https://elib.dlr.de/202193/2/32-Presentation_Aeolus_Airborne_Tech_Demo-ICSO_2022-10-03_CL.pdf; https://elib.dlr.de/202193/3/Airborne%20Doppler%20wind%20LIDAR%20technology%20demonstration%20for%20Aeolus_ICSO-2022_SPIE-1277707.pdf

The Atmospheric LAser Doppler Instrument (ALADIN) on-board Aeolus was the first European lidar and the first direct-detection Doppler wind lidar (DWL) in space. To support the processor development and operational preparation of the ESA mission, for the first time an airborne technology demonstrator was implemented in parallel. The ALADIN Airborne Demonstrator (A2D) was developed, featuring the complex receiver optics including the spectrometers of the ALADIN pre-development model. A2D also consists of a frequency-stabilised ultra-violet laser, a Cassegrain telescope and the same dual-channel optical and electronical receiver design to measure wind speeds along the instrument’s line-of-sight by analysing particulate (Mie) and molecular (Rayleigh) backscatter signals. The A2D has been deployed by DLR for studies in the optical laboratory as well as during various ground and airborne field campaigns since 2005. A scanning, high-accuracy coherent DWL operating at 2-µm wavelength acted as a reference by providing wind vector profiles for the A2D and Aeolus validation. The combination of both DWLs enabled to explore the ALADIN-specific wind measurement technology under various atmospheric conditions. The two instruments were operated in parallel on the DLR Falcon research aircraft in a downward looking configuration similar to Aeolus, but offered higher horizontal resolution as well as the possibility to influence and monitor all relevant system parameters. Resulting from these pre-launch activities, the operational experience and algorithm development for Aeolus grew to a level, which paved the way for the fast commissioning and quick success of the mission after its launch in August 2018. With ESA support, DLR conducted four airborne validation campaigns during the first three years of the Aeolus mission, performing coordinated underflights along the Aeolus track in different geographical regions and operational states of the mission. After three campaigns in Central Europe and the North Atlantic region around ...