scholarly journals Lidar Overlap Function Determination Using the Raman Lidar Signals

2020 ◽  
Vol 237 ◽  
pp. 07018
Author(s):  
Jaswant ◽  
Shishir Kumar Singh ◽  
Radhakrishnan S.R. ◽  
Devesh Shukla ◽  
Chhemendra Sharma
Keyword(s):  
Optical Properties ◽  
Simple Technique ◽  
Near Field ◽  
Lower Atmosphere ◽  
Raman Lidar ◽  
Lidar System ◽  
Field Range ◽  
The Mean ◽  
Overlap Factor

The determination of vertical distribution of optical properties of clouds and aerosols using the lidar system is affected by the incomplete overlap between the field of view of transmitter i.e. laser beam & the receiver in the near‐field range. Thus, the study of vertical profiles of aerosol optical properties in the lower atmosphere is erroneous without the correction of lidar overlap function. Here we have analysed the effect of overlap using a simple technique proposed by Ansmann and Wandinger to determine overlap function. We have determined the overlap factor for 5 different days of June 2016 and then calculated the mean overlap profile and determined the relative deviation of each day with respect to mean overlap factor. Results reveal that the complete overlap was achieved beyond 300 meters.

Optical properties of mixed aerosol layers over Japan derived with multi-wavelength Mie–Raman lidar system

2017 ◽  
Vol 188 ◽  
pp. 20-27 ◽  
Author(s):  
Yukari Hara ◽  
Tomoaki Nishizawa ◽  
Nobuo Sugimoto ◽  
Ichiro Matsui ◽  
Xiaole Pan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Raman Lidar ◽  
Lidar System ◽  
Multi Wavelength

scholarly journals Portable Raman Lidar PollyXT for Automated Profiling of Aerosol Backscatter, Extinction, and Depolarization

2009 ◽  
Vol 26 (11) ◽  
pp. 2366-2378 ◽  
Author(s):  
Dietrich Althausen ◽  
Ronny Engelmann ◽  
Holger Baars ◽  
Birgit Heese ◽  
Albert Ansmann ◽  
...  
Keyword(s):  
Laser Power ◽  
Data Retrieval ◽  
Raman Lidar ◽  
Web Page ◽  
Lidar System ◽  
Extinction Coefficients ◽  
Simultaneous Emission ◽  
Aerosol Backscatter ◽  
532 Nm

Abstract Two versions of the portable aerosol Raman lidar system (Polly) are presented. First, the two-channel prototype is depicted. It has been developed for the independent and simultaneous determination of particle backscatter and extinction coefficient profiles at 532 nm. Second, the 3 + 2 Raman lidar PollyXT (3 + 2: three backscatter and two extinction coefficients), the second generation of Polly, is described. The extended capabilities of PollyXT are due to the simultaneous emission of light with three wavelengths, more laser power, a larger main receiver mirror, and seven receiver channels. These systems are completely remotely controlled and all measurements are performed automatically. The collected data are transferred to a home server via the Internet and are displayed on a Web page. This paper describes the details of the optical setup, the housekeeping of the systems, and the used data retrieval routines. A measurement example taken close to Manaus, Brazil, on 15 August 2008 shows the capabilities of PollyXT.

Dual pure-rotational Raman channel design and implementation in a multiwavelength lidar system for the monitoring of aerosol optical properties.

2021 ◽  
Author(s):  
José-Alex Zenteno-Hernández
Keyword(s):  
Optical Properties ◽  
Cross Sections ◽  
State Of The Art ◽  
Aerosol Optical Properties ◽  
Lidar System ◽  
Separation Unit ◽  
Interference Filters ◽  
Multi Wavelength ◽  
Expected Signal

<p>Pure-rotational Raman (PRR) scattering has proven to be an efficient technique for the determination of atmospheric aerosol optical properties for lidar applications. We present the implementation of a UV-PRR and the design of a VIS-PRR in the EARLINET/UPC multi-wavelength lidar system (Barcelona, Spain). State-of-the-art computations of N<sub>2</sub> and O<sub>2</sub> differential backscatter cross-sections weighted by the optical losses inside the optical separation unit of the system allow for the theoretical estimation of the expected signal-to-noise ratios (SNR) in both UV and VIS channels. By means of customized optical interference filters UV-PRR signals from atmospheric N<sub>2</sub> and O<sub>2</sub> were detected and compared to the classical vibro-rotational Raman signals. UV-PRR detected signals have shown to possess high SNR and relative uncertainty levels lower than a tolerable 15% for daytime and nighttime measurements. The theoretical analysis of the VIS-PRR channel augurs improvements similar to those observed with the UV-PRR channel.</p>

Lamp mapping technique for independent determination of the water vapor mixing ratio calibration factor for a Raman lidar system

2011 ◽  
Vol 50 (23) ◽  
pp. 4622 ◽  
Author(s):  
Demetrius D. Venable ◽  
David N. Whiteman ◽  
Monique N. Calhoun ◽  
Afusat O. Dirisu ◽  
Rasheen M. Connell ◽  
...  
Keyword(s):  
Water Vapor ◽  
Calibration Factor ◽  
Mapping Technique ◽  
Mixing Ratio ◽  
Raman Lidar ◽  
Lidar System ◽  
Independent Determination ◽  
Water Vapor Mixing Ratio

scholarly journals Atmospheric Aerosols Detection Research with a Dual Field of View Lidar

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Lv Lihui ◽  
Zhang Tianshu ◽  
Liu Cheng ◽  
Dong Yunsheng ◽  
Chen Zhenyi ◽  
...  
Keyword(s):  
Laser Beam ◽  
Atmospheric Aerosols ◽  
Near Field ◽  
Ccd Camera ◽  
Field Of View ◽  
Detection Accuracy ◽  
Aerosol Extinction ◽  
Lidar System ◽  
Field Range ◽  
Aerosol Extinction Coefficient

A dual field of view lidar system with two independent receivers is described to realize the detection of atmospheric aerosols. A CCD camera is attached to a backscatter lidar as a receiver to complement the data in the near-field range affected by the incomplete overlap between the laser beam and the receiver field of view. The signal detected by the CCD camera is corrected and finally glued with the signal of the backscatter lidar to retrieve the aerosol extinction coefficient with Fernald algorithm. The aerosol extinction profile and visibilities measured by the dual field of lidar had been compared with the results measured by another general backscatter lidar and a surface aerosol instrument, respectively. The results suggested that the dual field of view lidar based on a CCD camera is feasible and reliable. It could obtain the data both in the near and in the far range simultaneously, improving the detection accuracy of the lidar system effectively.

scholarly journals Retrieval of Lidar Overlap Factor using Raman Lidar System

2009 ◽  
Vol 25 (5) ◽  
pp. 450-458 ◽  
Author(s):  
Young-M. Noh ◽  
Detlef Muller ◽  
Dong-Ho Shin ◽  
Kyung-Hwa Lee
Keyword(s):  
Raman Lidar ◽  
Lidar System ◽  
Overlap Factor

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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