The ADM-Aeolus mission (Credits: ESA)
Measurements of winds throughout the atmosphere are crucial for both numerical weather prediction (NWP) and climate studies. Profiling measurements of the global wind field from satellite instruments are prioritised by WMO (World Meteorological Organization) Expert Teams for global NWP. In 1999 the European Space Agency (ESA) selected the Atmospheric Dynamics Mission ADM-Aeolus to overcome the lack in global wind observations. The instrument ALADIN (Atmospheric LAser Doppler INstrument) on ADM-Aeolus provides profiles of one component of the horizontal wind vector from ground up to the stratosphere with 0.5-2 km vertical resolution and a precision of 1-3 m/s for a horizontal averaging length of 90 km. Launch is planned for mid-2015. DLR contributed to the selection of ADM-Aeolus through the development of an instrument performance simulator, supporting technology trade-offs, through impact studies in cooperation with the German Weather Service DWD, and through the development of the airborne precursor Doppler Lidar WIND (Wind INfrared Doppler lidar).
Airborne instrument demonstrator developed for ADM-Aeolus
Since 2001 DLR supports ADM-Aeolus by a project to validate the instrument concept. A development of an airborne prototype - the ALADIN airborne demonstrator A2D – was started in cooperation with space industry EADS-Astrium. The A2D is the first airborne direct-detection Doppler wind lidar for wind profile measurements worldwide and has been flown on the DLR Falcon aircraft since October 2005. In October 2006 and July 2007 the instrument performance was validated during ground campaigns at the Meteorological Observatory of DWD in Lindenberg. For the first time two different wind lidars – a coherent 2-µm lidar and the direct-detection lidar A2D – were operated aboard an aircraft in November 2007. These airborne campaigns were continued in 2008 and 2009 with flights in the vicinity of Iceland and Greenland. The pre-launch validation program was finalized in 2012 with more than 100 recommendations for the satellite mission ADM-Aeolus. Within further ESA funded activities this experience is used for algorithms and operational processors for the ADM-Aeolus ground segment, which are developed in cooperation with the DLR Institute of Remote Sensing.