scholarly journals Development and Test of a Fringe-Imaging Direct-Detection Doppler Wind Lidar for Aeronautics

2020 ◽  
Vol 237 ◽  
pp. 07008
Author(s):  
Patrick Vrancken ◽  
Jonas Herbst
Keyword(s):  
Direct Detection ◽  
Michelson Interferometer ◽  
Laser Pulses ◽  
High Rate ◽  
Control Loops ◽  
Wind Speeds ◽  
Gust Alleviation ◽  
Close Range ◽  
Wind Lidar ◽  
Doppler Wind Lidar

DLR currently investigates the use of Doppler wind lidar as sensor within feedforward gust alleviation control loops on fast-flying fixed-wing aircraft. Such a scheme imposes strong requirements on the lidar system such as sub-m/s precision, high rate, high spatial resolution, close measurement ranges and sensitivity to mixed and pure molecular backscatter. We report on the development of a novel direct-detection Doppler wind lidar (DD-DWL) within these requirements. This DD-DWL is based on fringe-imaging of the Doppler-shifted backscatter of UV laser pulses in a field-widened Michelson interferometer using a fast linear photodetector. A prototype for airborne operation has been ground-tested in early 2018 against a commercial coherent DWL, demonstrating its ability of measuring close-range wind speeds with a precision of 0.5 m/s, independent of the actual wind speed.

Frequency stabilization method in direct detection Doppler wind lidar under field experiment conditions

2016 ◽  
Vol 45 (9) ◽  
pp. 0906004
Author(s):  
王国成 Wang Guocheng ◽  
张飞飞 Zhang Feifei ◽  
钱正祥 Qian Zhengxiang ◽  
杜 跃 Du Yue ◽  
舒志峰 Shu Zhifeng ◽  
...  
Keyword(s):  
Field Experiment ◽  
Direct Detection ◽  
Frequency Stabilization ◽  
Stabilization Method ◽  
Wind Lidar ◽  
Doppler Wind Lidar

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.

A method of frequency-locking in Direct Detection Doppler Wind LIDAR

2014 ◽  
Author(s):  
Yuan Yao ◽  
Xin Gao ◽  
Ziru Sang ◽  
Kun Hu ◽  
Futian Liang ◽  
...  
Keyword(s):  
Direct Detection ◽  
Frequency Locking ◽  
Wind Lidar ◽  
Doppler Wind Lidar

Design on the readout electronics for the mobile direct detection Doppler wind LIDAR

2013 ◽  
Author(s):  
Xin Gao ◽  
Fei Wen ◽  
Yuan Yao ◽  
Zi-ru Sang ◽  
Ge Jin
Keyword(s):  
Direct Detection ◽  
Readout Electronics ◽  
Wind Lidar ◽  
Doppler Wind Lidar

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.

scholarly journals Intercomparison of wind observations from the European Space Agency's Aeolus satellite mission and the ALADIN Airborne Demonstrator

2020 ◽  
Vol 13 (4) ◽  
pp. 2075-2097 ◽  
Author(s):  
Oliver Lux ◽  
Christian Lemmerz ◽  
Fabian Weiler ◽  
Uwe Marksteiner ◽  
Benjamin Witschas ◽  
...  
Keyword(s):  
Direct Detection ◽  
Ultra Violet ◽  
Wind Data ◽  
Random Errors ◽  
Satellite Mission ◽  
High Coverage ◽  
Wind Speeds ◽  
Dual Channel ◽  
Wind Lidar ◽  
Cassegrain Telescope

Abstract. Shortly after the successful launch of the European Space Agency's wind mission Aeolus, co-located airborne wind lidar observations were performed in central Europe; these observations employed a prototype of the satellite instrument – the ALADIN (Atmospheric LAser Doppler INstrument) Airborne Demonstrator (A2D). Like the direct-detection Doppler wind lidar on-board Aeolus, the A2D is composed of a frequency-stabilized ultra-violet (UV) laser, a Cassegrain telescope and a dual-channel receiver to measure line-of-sight (LOS) wind speeds by analysing both Mie and Rayleigh backscatter signals. In the framework of the first airborne validation campaign after the launch and still during the commissioning phase of the mission, four coordinated flights along the satellite swath were conducted in late autumn of 2018, yielding wind data in the troposphere with high coverage of the Rayleigh channel. Owing to the different measurement grids and LOS viewing directions of the satellite and the airborne instrument, intercomparison with the Aeolus wind product requires adequate averaging as well as conversion of the measured A2D LOS wind speeds to the satellite LOS (LOS*). The statistical comparison of the two instruments shows a positive bias (of 2.6 m s−1) of the Aeolus Rayleigh winds (measured along its LOS*) with respect to the A2D Rayleigh winds as well as a standard deviation of 3.6 m s−1. Considering the accuracy and precision of the A2D wind data, which were determined from comparison with a highly accurate coherent wind lidar as well as with the European Centre for Medium-Range Weather Forecasts (ECMWF) model winds, the systematic and random errors of the Aeolus LOS* Rayleigh winds are 1.7 and 2.5 m s−1 respectively. The paper also discusses the influence of different threshold parameters implemented in the comparison algorithm as well as an optimization of the A2D vertical sampling to be used in forthcoming validation campaigns.

Results of the pre-development of ALADIN, the direct detection Doppler wind lidar for ADM/Aeolus

2004 ◽  
Author(s):  
Yannig Durand ◽  
Roland Meynart ◽  
Alain J. Culoma ◽  
Didier Morancais ◽  
Frederic Fabre
Keyword(s):  
Direct Detection ◽  
Wind Lidar ◽  
Doppler Wind Lidar
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