scholarly journals First Results from the German Cal/Val Activities for Aeolus

2020 ◽  
Vol 237 ◽  
pp. 01008 ◽  
Author(s):  
Holger Baars ◽  
Alexander Geiß ◽  
Ulla Wandinger ◽  
Alina Herzog ◽  
Ronny Engelmann ◽  
...  
Keyword(s):  
Direct Detection ◽  
Weather Prediction ◽  
European Space Agency ◽  
High Spectral Resolution ◽  
Dual Channel ◽  
Space Agency ◽  
First Results ◽  
Global Coverage ◽  
Wind Lidar ◽  
Doppler Wind Lidar

On 22nd August 2018, the European Space Agency (ESA) launched the first direct detection Doppler wind lidar into space. Operating at 355 nm and acquiring signals with a dual channel receiver, it allows wind observations in clear air and particle-laden regions of the atmosphere. Furthermore, particle optical properties can be obtained using the High Spectral Resolution Technique Lidar (HSRL) technique. Measuring with 87 km horizontal and 0.25-2 km vertical resolution between ground and up to 30 km in the stratosphere, the global coverage of Aeolus observations shall fill gaps in the global observing system and thus help improving numerical weather prediction. Within this contribution, first results from the German initiative for experimental Aeolus validation are presented and discussed. Ground-based wind and aerosol measurements from tropospheric radar wind profilers, Doppler wind lidars, radiosondes, aerosol lidars and cloud radars are utilized for that purpose.

scholarly journals The Airborne Demonstrator for the Direct-Detection Doppler Wind Lidar ALADIN on ADM-Aeolus. Part II: Simulations and Rayleigh Receiver Radiometric Performance

2009 ◽  
Vol 26 (12) ◽  
pp. 2516-2530 ◽  
Author(s):  
Ulrike Paffrath ◽  
Christian Lemmerz ◽  
Oliver Reitebuch ◽  
Benjamin Witschas ◽  
Ines Nikolaus ◽  
...  
Keyword(s):  
Direct Detection ◽  
European Space Agency ◽  
Satellite System ◽  
Satellite Mission ◽  
Backscatter Signal ◽  
Space Agency ◽  
Expected Performance ◽  
Wind Lidar ◽  
Doppler Wind Lidar ◽  
Signal Intensities

Abstract In the frame of the Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) satellite mission by the European Space Agency (ESA), a prototype of a direct-detection Doppler wind lidar was developed to measure wind from ground and aircraft at 355 nm. Wind is measured from aerosol backscatter signal with a Fizeau interferometer and from molecular backscatter signal with a Fabry–Perot interferometer. The aim of this study is to validate the satellite instrument before launch, improve the retrieval algorithms, and consolidate the expected performance. The detected backscatter signal intensities determine the instrument wind measurement performance among other factors, such as accuracy of the calibration and stability of the optical alignment. Results of measurements and simulations for a ground-based instrument are compared, analyzed, and discussed. The simulated atmospheric aerosol models were validated by use of an additional backscatter lidar. The measured Rayleigh backscatter signals of the wind lidar prototype up to an altitude of 17 km are compared to simulations and show a good agreement by a factor better than 2, including the analyses of different error sources. First analyses of the signal at the Mie receiver from high cirrus clouds are presented. In addition, the simulations of the Rayleigh signal intensities of the Atmospheric Laser Doppler Instrument (ALADIN) Airborne Demonstrator (A2D) instrument on ground and aircraft were compared to simulations of the satellite system. The satellite signal intensities above 11.5 km are larger than those from the A2D ground-based instrument and always smaller than those from the aircraft for all altitudes.

The Airborne Demonstrator for the Direct-Detection Doppler Wind Lidar ALADIN on ADM-Aeolus. Part I: Instrument Design and Comparison to Satellite Instrument

2009 ◽  
Vol 26 (12) ◽  
pp. 2501-2515 ◽  
Author(s):  
Oliver Reitebuch ◽  
Christian Lemmerz ◽  
Engelbert Nagel ◽  
Ulrike Paffrath ◽  
Yannig Durand ◽  
...  
Keyword(s):  
Direct Detection ◽  
Weather Prediction ◽  
European Space Agency ◽  
Unmet Need ◽  
Single Frequency ◽  
Doppler Lidar ◽  
Numerical Weather ◽  
Atmospheric Observations ◽  
Wind Lidar ◽  
Doppler Wind Lidar

Abstract The global observation of profiles of the atmospheric wind speed is the highest-priority unmet need for global numerical weather prediction. Satellite Doppler lidar is the most promising candidate to meet the requirements on global wind profile observations with high vertical resolution, precision, and accuracy. The European Space Agency (ESA) decided to implement a Doppler wind lidar mission called the Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) to demonstrate the potential of the Doppler lidar technology and the expected impact on numerical weather forecasting. An airborne prototype of the instrument on ADM-Aeolus was developed to validate the instrument concept and retrieval algorithms with realistic atmospheric observations before the satellite launch. It is the first airborne direct-detection Doppler lidar for atmospheric observations, and it is operating at an ultraviolet wavelength of 355 nm. The optical design is described in detail, including the single-frequency pulsed laser and the two spectrometers to resolve the Doppler frequency shift from molecular Rayleigh and aerosol Mie backscatter. The airborne prototype is representative of the spaceborne instrument, and their specific differences are discussed.

scholarly journals Retrieval of atmospheric backscatter and extinction profiles with the aladin airborne demonstrator (A2D)

2018 ◽  
Vol 176 ◽  
pp. 02021 ◽  
Author(s):  
Alexander Geiss ◽  
Uwe Marksteiner ◽  
Oliver Lux ◽  
Christian Lemmerz ◽  
Oliver Reitebuch ◽  
...  
Keyword(s):  
Direct Detection ◽  
European Space Agency ◽  
Backscatter Coefficient ◽  
Detection Scheme ◽  
Space Agency ◽  
Fabry Perot ◽  
Lidar Ratio ◽  
Wind Lidar ◽  
Wind Retrievals ◽  
Atmospheric Backscatter

By the end of 2017, the European Space Agency (ESA) will launch the Atmospheric laser Doppler instrument (ALADIN), a direct detection Doppler wind lidar operating at 355 nm. An important tool for the validation and optimization of ALADIN’s hardware and data processors for wind retrievals with real atmospheric signals is the ALADIN airborne demonstrator A2D. In order to be able to validate and test aerosol retrieval algorithms from ALADIN, an algorithm for the retrieval of atmospheric backscatter and extinction profiles from A2D is necessary. The A2D is utilizing a direct detection scheme by using a dual Fabry-Pérot interferometer to measure molecular Rayleigh signals and a Fizeau interferometer to measure aerosol Mie returns. Signals are captured by accumulation charge coupled devices (ACCD). These specifications make different steps in the signal preprocessing necessary. In this paper, the required steps to retrieve aerosol optical products, i. e. particle backscatter coefficient βp, particle extinction coefficient αp and lidar ratio Sp from A2D raw signals are described.

scholarly journals Development of Direct-Detection Doppler Wind Lidar for Vertical Atmospheric Motion

2020 ◽  
Vol 237 ◽  
pp. 06006
Author(s):  
Shoken Ishii ◽  
Makoto Aoki ◽  
Kanna Tominaga ◽  
Tomoaki Nishizawa ◽  
Yoshitaka Jin ◽  
...  
Keyword(s):  
Wind Profile ◽  
Direct Detection ◽  
Weather Prediction ◽  
Information And Communications Technology ◽  
Good Precision ◽  
Remote Sensing Technique ◽  
High Vertical Resolution ◽  
Wind Lidar ◽  
Atmospheric Phenomena ◽  
Doppler Wind Lidar

Wind is fundamental in many atmospheric phenomena. Global wind profile observation is important to improve numerical weather prediction (NWP) and various meteorological studies. Wind profile observations are measured mainly by radiosonde networks. A Doppler Wind Lidar (DWL) is a useful remote sensing technique for wind measurement. DWL would provide us with a wind profile having high vertical resolution, low bias, and good precision. The National Institute of Information and Communications Technology (NICT) studies DWL has been developing various DWL. In the paper, we report development of a 355-nm direct-detection DWL and describe recent results of a 2-µm coherent DWL at NICT.

scholarly journals Development of Synergetic-Active Sensor-System for Evaluation of Observations by Earthcare

2020 ◽  
Vol 237 ◽  
pp. 07011
Author(s):  
Hajime Okamoto ◽  
Kaori Sato ◽  
Masahiro Fujikawa ◽  
Eiji Oikawa ◽  
Tomoaki Nishizawa ◽  
...  
Keyword(s):  
Direct Detection ◽  
Cloud Microphysics ◽  
Sensor System ◽  
High Spectral Resolution ◽  
Horizontal Wind ◽  
Observation System ◽  
Active Sensor ◽  
Wind Lidar ◽  
Multiple Field ◽  
Doppler Wind Lidar

We develop the synergetic ground-based active-sensor-system for the evaluation of observations by space-borne lidars. The system consists of second version of multi-field-view multiple-scattering polarization lidar (MFMSPL-2), multiple-field-of-view high spectral resolution polarization lidar, direct-detection Doppler wind lidar, coherent Doppler wind lidar and 94GHz cloud profiling radar. The system can simulate observed signals from sensors onboard the joint Japanese/European mission Earth Clouds, Aerosols and Radiation Explorer (EarthCARE). The observation system can provide unique opportunity to study interaction of cloud microphysics, aerosol microphysics, vertical air motion and vertical distribution of horizontal wind and it will lead to evaluate cloud-convective parameterization and to reduce uncertainties in climate change predictions.

Validation of Aeolus aerosol and wind products with sophisticated ground-based instruments in the Northern and Southern Hemisphere

2020 ◽  
Author(s):  
Holger Baars ◽  
Alina Herzog ◽  
Ronny Engelmann ◽  
Johannes Bühl ◽  
Martin Radenz ◽  
...  
Keyword(s):  
United Arab Emirates ◽  
Weather Forecasting ◽  
Eastern Mediterranean ◽  
European Space Agency ◽  
Chem Phys ◽  
High Spectral Resolution ◽  
Backscatter Coefficient ◽  
Range Resolution ◽  
Space Agency ◽  
First Results

<p>The European Space Agency (ESA) has launched the Earth Explorer Mission Aeolus on 22 August 2018. Within the German initiative EVAA (Experimental Validation and Assimilation of Aeolus observations), Cal/Val activities for Aeolus started immediately after the instrument was turned on in space. The aim is to validate the wind and aerosol products of Aeolus and to quantify the benefits of these new measurements for weather forecasting and aerosol and cloud research. <br>For this purpose, ground-based aerosol and wind lidar observations have been performed at the Leibniz Institute for Tropospheric Research (TROPOS) in Leipzig, Germany, and at Punta Arenas (53.13 S, 70.88 W), Chile, in the frame of the DACAPO-PESO campaign (dacapo.tropos.de). Radiosondes have been launched during the Aeolus overpasses each Friday at Leipzig in addition since mid of May 2019. In Punta Arenas, we also used Doppler cloud radar observations with respect to the validation of Mie and Rayleigh winds of Aeolus.  </p><p>Aerosol-only observations with multiwavelength-Raman polarization lidar were made at the PollyNET (Baars 2016) stations in Haifa (Israel), Dushanbe (Tajikistan), Tel Aviv (Israel), and in the United Arab Emirates (UAE) - the latter two are hosted by PollyNET partner institutions (Baars, 2016). These locations are close to the desert with frequent dense, lofted aerosol layers and are thus of particular interest for Aeolus Cal/Val. Considering the long averaging length of Aeolus (87 km) and the distance to the lidars (max. 100 km), a good agreement with respect to the co-polar backscatter coefficient is found between Aeolus and the ground-based lidars at these locations.</p><p>We will present results from the above-mentioned Cal/Val activities with respect to, both, wind and aerosol products of Aeolus. It will be shown, that one of the mission goals, namely the demonstration that wind observations from space by active remote sensing are possible, have been already achieved. Furthermore, it will be demonstrated that the spaceborne HSRL (high spectral resolution lidar) technique applied for Aeolus can provide independent backscatter and extinction measurements of aerosols – a spaceborne novelty as well. Since September 2019, also an aerosol-optimized range resolution, the so-called Mediterranean range-bin setting (MARS), is operational for Aeolus in the Eastern Mediterranean. First results show a significantly improved aerosol retrieval for this adapted instrumental setting and will be presented as well.</p><p> </p><p>Reference:</p><p>Baars, H., et al. (2016), An overview of the first decade of PollyNET: An emerging network of automated Raman-polarization lidars for continuous aerosol profiling, Atmos. Chem. Phys., 16(8), 5111-5137, doi:10.5194/acp-16-5111-2016.</p>

ESA’s Wind Lidar Mission Aeolus – Instrument Performance and Stability

2020 ◽  
Author(s):  
Thomas Kanitz ◽  
Benjamin Witschas ◽  
Uwe Marksteiner ◽  
Thomas Flament ◽  
Michael Rennie ◽  
...  
Keyword(s):  
Incidence Angle ◽  
Weather Prediction ◽  
European Space Agency ◽  
Positive Outcome ◽  
Doppler Lidar ◽  
Energy Redistribution ◽  
Space Agency ◽  
Explorer Mission ◽  
Wind Lidar ◽  
The Impact

<p>The European Space Agency, ESA deployed the first Doppler wind lidar in space within its Earth Explorer Mission Aeolus in August 2018. After the initial commissioning of the satellite and the single payload ALADIN, the mission has started to demonstrate the capability of Doppler lidar to measure wind from space. In order to provide the best Aeolus wind product possible, detailed monitoring of the instrument is crucial for analysis of system health, but also for the assessment of measurement performance and data product calibration. Within the last 1.2 years the different instrument modes to assess instrument and laser health, as well as the nominal wind processing indicated longterm instrument drifts. The laser beam profile has been monitored and showed an energy redistribution within the beam. The line of sight has slowly drifted, resulting in a change of incidence angle at spectrometer level. The impact of these observed drifts on the wind product are compensated on demand by updates of dedicated ground processing calibration files. This contribution will provide an overview about the Aeolus instrument modes and the observed stability that are needed to provide the Aeolus wind product. The current Aeolus performance has been assessed by various Numerical Weather Prediction centers. The positive outcome is represented by ECMWF’s decision to start using Aeolus data operationally on 9<sup>th</sup> January 2020.</p>

scholarly journals 0.355-micrometer direct detection wind lidar under testing during a field campaign in consideration of ESA's ADM-Aeolus mission

2013 ◽  
Vol 6 (12) ◽  
pp. 3349-3358 ◽  
Author(s):  
S. Lolli ◽  
A. Delaval ◽  
C. Loth ◽  
A. Garnier ◽  
P. H. Flamant
Keyword(s):  
Direct Detection ◽  
Weather Prediction ◽  
European Space Agency ◽  
Geostrophic Wind ◽  
Lower Atmosphere ◽  
Wind Data ◽  
High Spectral Resolution ◽  
Horizontal Wind ◽  
Field Campaign ◽  
Remote Sensors

Abstract. The atmospheric wind field information is a key issue to numerical weather prediction (NWP) and climate studies. The Atmospheric Dynamic Mission-Aeolus is currently developed by the European Space Agency (ESA) to launch a wind sensing Doppler lidar in mid-2015. The high spectral resolution lidar concept is using backscattered laser signals from molecules and particles to provide accurate horizontal wind velocity measurements in the depth of atmosphere. The Aeolus lidar, so-called ALADIN, will operate in UV at 0.355 μm. The combination of air molecules and UV laser light is intended to provide wind data evenly distributed everywhere in the lower atmosphere (below 30 km altitude). The goal of the ESA's Aeolus mission is to enhance the present meteorological observations system over sparse wind data regions, and more importantly to provide direct wind information in the tropics where no geostrophic wind can be derived from mass fields obtained from passive radiometer satellite. The 0.355 μm lidar concept was under testing during a field campaign conducted at the Haute-Provence Observatory, France, in 1999. Several active remote sensors were deployed on the site, and it was the opportunity to address the self-consistency of wind measurements made by different lidars, a 72 MHz radar, and conventional balloon radio soundings. The paper presents the comparison of different remote sensors using two criteria: Pearson cross-correlation coefficient and root mean square error. The methodology discussed here may be useful in future ESA Aeolus validation campaigns involving different kinds of instruments.

scholarly journals Airborne direct-detection and coherent wind lidar measurements over the North Atlantic in 2015 supporting ESA’s aeolus mission

2018 ◽  
Vol 176 ◽  
pp. 02011 ◽  
Author(s):  
Uwe Marksteiner ◽  
Oliver Reitebuch ◽  
Christian Lemmerz ◽  
Oliver Lux ◽  
Stephan Rahm ◽  
...  
Keyword(s):  
Direct Detection ◽  
European Space Agency ◽  
The North ◽  
Space Agency ◽  
Lidar Measurements ◽  
Wind Measurements ◽  
Measurement Principle ◽  
Wind Lidar ◽  
First Time ◽  
Prototype Instrument

The launch of the Aeolus mission by the European Space Agency (ESA) is planned for 2018. The satellite will carry the first wind lidar in space, ALADIN (Atmospheric Laser Doppler INstrument). Its prototype instrument, the ALADIN Airborne Demonstrator (A2D), was deployed during several airborne campaigns aiming at the validation of the measurement principle and optimization of algorithms. In 2015, flights of two aircraft from DLR & NASA provided the chance to compare parallel wind measurements from four airborne wind lidars for the first time.

Sign in / Sign up

Export Citation Format

Share Document