Airborne direct-detection and coherent wind lidar measurements along the east coast of Greenland in 2009 supporting ESA’s Aeolus mission Uwe Marksteiner a , Oliver Reitebuch a , Stephan Rahm a , Ines Nikolaus b , Christian Lemmerz a , Benjamin Witschas a a Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, 82234 Wessling, Germany; b Physics Solutions, Oberdorfer Str. 20, 82278 Althegnenberg ABSTRACT The Aeolus mission of the European Space Agency (ESA) will send the first wind lidar to space to fulfill the utmost need for global wind profile observations. Before the scheduled launch in late 2013, pre-launch campaigns have to be performed to validate the measurement principle and to optimize retrieval algorithms. Therefore, an airborne prototype instrument has been developed, the ALADIN Airborne Demonstrator (A2D). In September 2009 an airborne campaign over Greenland, Iceland and the Atlantic Ocean was conducted using two instruments: the A2D and a well established coherent 2-µm lidar for aerosol and cloud backscatter. Thus, two wind lidar instruments measuring Mie and Rayleigh backscatter in parallel were operated on the same aircraft. This paper describes the analysis of wind measurement data gathered during a flight segment on 26.09.2009. A dedicated aerial interpolation algorithm is introduced taking into account the different resolution grids of the two lidar systems. Via a statistical comparison of line of sight (LOS) winds the systematic and random error of the direct-detection wind lidar A2D was assessed, yielding -0.7 m/s and 1.9 m/s for the Rayleigh and 1.1 m/s and 1.3 m/s for the Mie channel, respectively. Keywords: ADM-Aeolus, wind lidar, ALADIN 1. INTRODUCTION In 1999 the Atmospheric Dynamics Mission ADM-Aeolus was selected as the 2 nd Earth Explorer Core Mission within the European Space Agency’s (ESA) Living Planet Programme and it is considered as a technology demonstrator for future operational wind lidar missions. After launch in late 2013 Aeolus will be the 1 st European lidar and the first wind lidar worldwide in space. The measurement of wind is considered to be a preferential objective by the World Meteorological Organisation (WMO) [1]. A spaceborne Doppler lidar is considered to be the only candidate to provide a global coverage of wind profile observations essential for the improvement of Numerical Weather Prediction (NWP) and advancement of climate studies. Currently a lack of coverage is present especially over the oceans which contribute with about two thirds to the earth surface. With its global vertical wind measurements Aeolus will contribute to closing this gap which has been identified as one of the main deficiencies of the Global Observing System (GOS). In impact studies it was shown that wind measurements can considerably improve medium-range weather forecast [2]. Due to their small representativeness and instrumental errors, measurements from wind lidars have high potential to reduce the analysis error of NWP models in data-sparse regions [3]. Aeolus will revolve the earth at an altitude of 400 km in a sun-synchronous dawn-dusk orbit with a 35° off-nadir and across track viewing geometry [4]. During its planned three-year life time the satellite will measure wind from 0-27 km in troposphere and lower stratosphere with an adaptable resolution. The single layers of the measurement grid can be commanded from 250 to 2000 m vertical thickness aiming at the extraction of the most valuable data from the occurring atmospheric conditions, e.g. in case of high cirrus clouds, varying ground elevation or in order to distinguish dust layers from the underlying planetary boundary layer. The satellite carries the Atmospheric Laser Doppler Instrument (ALADIN), an active instrument firing laser pulses towards the atmosphere. ALADIN is equipped with two interferometers sensitive to molecular and aerosol or cloud backscatter, assuring optimal coverage within the whole altitude range. Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing VII, edited by Upendra N. Singh, Gelsomina Pappalardo, Proc. of SPIE Vol. 8182, 81820J © 2011 SPIE · CCC code: 0277-786X/11/$18 · doi: 10.1117/12.897528 Proc. of SPIE Vol. 8182 81820J-1 Downloaded from SPIE Digital Library on 02 Nov 2011 to 129.247.247.239. Terms of Use: http://spiedl.org/terms