Initial Assessment of the Performance of the First Wind Lidar in Space on Aeolus

Oliver Reitebuch,Tommaso Parrinello,Michael Rennie,Jos De Kloe,Hugo Stieglitz,Benjamin Witschas,Denny Wernham,Stephan Rahm,Markus Meringer,Jonas Von Bismarck,Alain Dabas,Christian Lemmerz,Ad Stoffelen,Fabian Weiler,Oliver Lux,Uwe Marksteiner,Thomas Flament,Ines Nikolaus,Rune Floberghagen,Anne-Grete Straume,Dorit Huber,Thomas Kanitz,Lars Isaksen,K Sebastian Schmidt ,M Vaughan ,T Fehr ,Gert‐Jan Marseille ,Alexander Geiß

doi:10.1051/epjconf/202023701010

Abstract

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 (DWL) instrument in space, ALADIN contributes to the improvement in numerical weather prediction (NWP) by measuring one component of the horizontal wind vector. The performance of the ALADIN instrument was assessed by a team from ESA, DLR, industry, and NWP centers during the first months of operation. The current knowledge about the main contributors to the random and systematic errors from the instrument will be discussed. First validation results from an airborne campaign with two wind lidars on-board the DLR Falcon aircraft will be shown.

Highlights

The Aeolus satellite was successfully launched from Kourou (French Guiana) on August 22, 2018
The lidar ALADIN is based on a direct-detection Doppler Wind Lidar (DWL) operating at an ultraviolet (UV) wavelength of 354.8 nm [3]
Nine days after launch on August 31st ALADIN was switched-on and first backscattered light from the atmosphere was sampled on September 5th showing typical lidar signals including molecular returns, cloud tops and extinction below the clouds (Fig. 1)

Summary

INTRODUCTION

The Aeolus satellite was successfully launched from Kourou (French Guiana) on August 22, 2018. Its single payload ALADIN is the first European lidar and the first DWL in space [1]. It is considered as a technology demonstrator for future operational wind lidar missions. Aeolus provides profiles of one component of the horizontal wind vector along the laser line-ofsight (LOS, projected to the horizontal HLOS) from ground up to the lower stratosphere (20 km to 30 km) with 250 m to 2 km vertical resolution. A wind profile is obtained from horizontal averaging along track in order to achieve the precision requirement (random error) of 1 m/s to 2.5 m/s (HLOS) depending on altitude [2]. The requirement for the maximum bias of 0.7 m/s (HLOS) is more stringent than the random error requirement

THE ALADIN LIDAR

RESULTS

Random error performance

CONCLUSIONS