scholarly journals Lidar Innovations for Technologies and Environmental Sciences (LITES) – An Remote Sensing Infrastructure Facility: Setup and Measurements Examples

2020 ◽  
Vol 237 ◽  
pp. 07017
Author(s):  
Boyan Tatarov ◽  
Detlef Müller ◽  
Matthias Tesche ◽  
Sung-Kyun Shin
Keyword(s):  
Remote Sensing ◽  
Spectral Resolution ◽  
High Energy ◽  
High Spectral Resolution ◽  
Ultra High Energy ◽  
Lidar Signal ◽  
Environmental Sciences ◽  
Time Resolved ◽  
The University

At the University of Hertfordshire, we have been developing a new remote sensing facility (LITES) to explore the feasibility of using Raman and/or fluorescence backscattering for chemical aerosol profiling. This paper provides an overview of the instruments of the facility and measurement examples. LITES includes a ultra-high-energy Nd:YAG/OPO setup, spectroscopic equipment with high spectral resolution, several imaging and single detectors that allow for time-resolved (lidar) signal detection, a Raman/fluorescence microscope, and a suite of gas and aerosol chambers. We present examples of elastic, rotational and vibrational spectroscopic lidar signals, as well as in-situ microscopic spectrums of dust and bio-aerosol compounds.

scholarly journals A global compilation of in situ aquatic high spectral resolution inherent and apparent optical property data for remote sensing applications

2019 ◽  
Author(s):  
Kimberly A. Casey ◽  
Cecile S. Rousseaux ◽  
Watson W. Gregg ◽  
Emmanuel Boss ◽  
Alison P. Chase ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Organic Matter ◽  
Optical Property ◽  
Dissolved Organic Matter ◽  
Spectral Resolution ◽  
Infrared Imaging ◽  
High Spectral Resolution ◽  
Colored Dissolved Organic Matter ◽  
Sensing Applications

Abstract. Light emerging from natural water bodies and measured by remote sensing radiometers contains information about the local type and concentrations of phytoplankton, non-algal particles and colored dissolved organic matter in the underlying waters. An increase in spectral resolution in forthcoming satellite and airborne remote sensing missions is expected to lead to new or improved capabilities to characterize aquatic ecosystems. Such upcoming missions include NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Mission; the NASA Surface Biology and Geology observable mission; and NASA Airborne Visible/Infrared Imaging Spectrometer – Next Generation (AVIRIS-NG) airborne missions. In anticipation of these missions, we present an organized dataset of geographically diverse, quality-controlled, high spectral resolution inherent and apparent optical property (IOP/AOP) aquatic data. The data are intended to be of use to increase our understanding of aquatic optical properties, to develop aquatic remote sensing data product algorithms, and to perform calibration and validation activities for forthcoming aquatic-focused imaging spectrometry missions. The dataset is comprised of contributions from several investigators and investigating teams collected over a range of geographic areas and water types, including inland waters, estuaries and oceans. Specific in situ measurements include coefficients describing particulate absorption, particulate attenuation, non-algal particulate absorption, colored dissolved organic matter absorption, phytoplankton absorption, total absorption, total attenuation, particulate backscattering, and total backscattering, as well as remote-sensing reflectance, and irradiance reflectance. The dataset can be downloaded from https://doi.pangaea.de/10.1594/PANGAEA.902230 (Casey et al., 2019).

scholarly journals A global compilation of in situ aquatic high spectral resolution inherent and apparent optical property data for remote sensing applications

2020 ◽  
Vol 12 (2) ◽  
pp. 1123-1139
Author(s):  
Kimberly A. Casey ◽  
Cecile S. Rousseaux ◽  
Watson W. Gregg ◽  
Emmanuel Boss ◽  
Alison P. Chase ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Organic Matter ◽  
Optical Property ◽  
Dissolved Organic Matter ◽  
Spectral Resolution ◽  
Infrared Imaging ◽  
High Spectral Resolution ◽  
Colored Dissolved Organic Matter ◽  
Sensing Applications

Abstract. Light emerging from natural water bodies and measured by radiometers contains information about the local type and concentrations of phytoplankton, non-algal particles and colored dissolved organic matter in the underlying waters. An increase in spectral resolution in forthcoming satellite and airborne remote sensing missions is expected to lead to new or improved capabilities for characterizing aquatic ecosystems. Such upcoming missions include NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission; the NASA Surface Biology and Geology designated observable mission; and NASA Airborne Visible/Infrared Imaging Spectrometer – Next Generation (AVIRIS-NG) airborne missions. In anticipation of these missions, we present an organized dataset of geographically diverse, quality-controlled, high spectral resolution inherent and apparent optical property (IOP–AOP) aquatic data. The data are intended to be of use to increase our understanding of aquatic optical properties, to develop aquatic remote sensing data product algorithms, and to perform calibration and validation activities for forthcoming aquatic-focused imaging spectrometry missions. The dataset is comprised of contributions from several investigators and investigating teams collected over a range of geographic areas and water types, including inland waters, estuaries, and oceans. Specific in situ measurements include remote-sensing reflectance, irradiance reflectance, and coefficients describing particulate absorption, particulate attenuation, non-algal particulate absorption, colored dissolved organic matter absorption, phytoplankton absorption, total absorption, total attenuation, particulate backscattering, and total backscattering. The dataset can be downloaded from https://doi.org/10.1594/PANGAEA.902230 (Casey et al., 2019).

scholarly journals Aerosol optical and microphysical retrievals from a hybrid multiwavelength lidar data set – DISCOVER-AQ 2011

2014 ◽  
Vol 7 (9) ◽  
pp. 3095-3112 ◽  
Author(s):  
P. Sawamura ◽  
D. Müller ◽  
R. M. Hoff ◽  
C. A. Hostetler ◽  
R. A. Ferrare ◽  
...  
Keyword(s):  
Remote Sensing ◽  
In Situ Measurements ◽  
Index Of Refraction ◽  
High Spectral Resolution ◽  
Lidar Data ◽  
Data Set ◽  
Microphysical Properties ◽  
Lidar Measurements ◽  
Multiwavelength Lidar

Abstract. Retrievals of aerosol microphysical properties (effective radius, volume and surface-area concentrations) and aerosol optical properties (complex index of refraction and single-scattering albedo) were obtained from a hybrid multiwavelength lidar data set for the first time. In July 2011, in the Baltimore–Washington DC region, synergistic profiling of optical and microphysical properties of aerosols with both airborne (in situ and remote sensing) and ground-based remote sensing systems was performed during the first deployment of DISCOVER-AQ. The hybrid multiwavelength lidar data set combines ground-based elastic backscatter lidar measurements at 355 nm with airborne High-Spectral-Resolution Lidar (HSRL) measurements at 532 nm and elastic backscatter lidar measurements at 1064 nm that were obtained less than 5 km apart from each other. This was the first study in which optical and microphysical retrievals from lidar were obtained during the day and directly compared to AERONET and in situ measurements for 11 cases. Good agreement was observed between lidar and AERONET retrievals. Larger discrepancies were observed between lidar retrievals and in situ measurements obtained by the aircraft and aerosol hygroscopic effects are believed to be the main factor in such discrepancies.

scholarly journals Operation of the Airborne 355-nm High Spectral Resolution and Doppler Lidar LNG

2020 ◽  
Vol 237 ◽  
pp. 06011
Author(s):  
D. Bruneau ◽  
J. Pelon ◽  
F. Blouzon ◽  
Q. Cazenave ◽  
H. Collomb ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
High Energy ◽  
High Spectral Resolution ◽  
Doppler Lidar ◽  
Backscatter Coefficient ◽  
Relative Precision ◽  
Airborne Measurements ◽  
Wind Measurements ◽  
High Spectral Resolution Lidar ◽  
Better Than

High spectral resolution lidar (HSRL) are known to offer capabilities of separating attenuated aerosol and molecular backscattering so that particle extinction and backscattering can be separately retrieved. UV operation provides high energy in eye-safety conditions. Further to that, it could be important for most meteorological or environmental studies to get wind measurements at the same time. LNG is now the only HSR Doppler Lidar (HSRDL) system capable of this. Results obtained during ground-based and airborne measurements show that the backscatter and extinction coefficients at 355 nm can be measured with a relative precision better than 10% (adjusting altitude and time resolution from 60 m to 240 m and 30s to 2mn, respectively) in aerosol layers of 0.5 10−6 m−1 sr−1 backscatter coefficient from ground and aircraft. The same relative precision is obtained in cirrus clouds of a 10−5 m−1 sr−1 backscatter coefficient. The capacity of the system to perform wind velocity measurements has also been demonstrated with precisions in the range of 1 to 2 ms−1 in same conditions. We present the main characteristics and illustrate observational capabilities from ground-based and airborne measurements.

scholarly journals Time-resolved mid-infrared dual-comb spectroscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Muhammad A. Abbas ◽  
Qing Pan ◽  
Julien Mandon ◽  
Simona M. Cristescu ◽  
Frans J. M. Harren ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Vibrational Excitation ◽  
High Spectral Resolution ◽  
Acquisition Time ◽  
Time Resolved ◽  
Short Acquisition Time ◽  
Mid Infrared ◽  
Infrared Wavelength ◽  
Potential Applications ◽  
Kinetics Of

AbstractDual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this “fingerprint” region. Here we report time-resolved mid-infrared dual-comb spectroscopy, covering ~300 nm bandwidth around 3.3 μm with 6 GHz spectral resolution and 20 μs temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/combustion analysis.

Photoluminescence of Eu-doped GaN

2011 ◽  
Vol 1342 ◽  
Author(s):  
K.P. O’Donnell
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Pressures ◽  
Vapour Phase ◽  
High Energy ◽  
Photoluminescence Excitation ◽  
Vapour Phase Epitaxy ◽  
The University

ABSTRACTThis talk reviews work on the optical properties of Eu-doped GaN at the Semiconductor Spectroscopy laboratory of the University of Strathclyde. The principal experimental technique used has been lamp-based Photoluminescence/Excitation (PL/E) spectroscopy on samples produced mainly by high-energy ion implantation and annealing, either at low or high pressures of nitrogen, as described by Lorenz et al. [1]. These have been supplemented by samples doped in-situ either by Molecular Beam Epitaxy or Metallorganic Vapour Phase Epitaxy. Magneto-optic experiments on GaN:Eu were carried out in collaboration with the University of Bath.

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