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.

scholarly journals Consistency of the Single Calculus Chain Optical Products with Archived Measurements from an EARLINET Lidar Station

2020 ◽  
Vol 12 (23) ◽  
pp. 3969
Author(s):  
Kalliopi Artemis Voudouri ◽  
Nikolaos Siomos ◽  
Konstantinos Michailidis ◽  
Giuseppe D’Amico ◽  
Ina Mattis ◽  
...  
Keyword(s):  
Lower Troposphere ◽  
Raman Lidar ◽  
Quality Requirements ◽  
Extinction Coefficients ◽  
Automated Algorithm ◽  
Operational Algorithm ◽  
Aerosol Backscatter ◽  
532 Nm ◽  
Term Analysis

A long-term analysis and climatology of aerosol backscatter and extinction coefficients profiles using a five-year study period lidar dataset derived from a multiwavelenth Raman lidar at Thessaloniki station is presented. All measurements have been processed with the latest version of the Single Calculus Chain (SCCv5.1.6) fully automated algorithm, which has been developed to provide a common lidar processing tool, within EARLINET (European Aerosol Research Lidar NETwork) stations. The optical products delivered by the SCC tool have already been compared with the optical products derived from the operational algorithm of Thessaloniki (THessaloniki Aerosol LIdar Algorithm-THALIA) and discussed in terms of inhomogeneities. In this contribution, we analyze these products for climatological purposes, in order to investigate the aerosol columnar properties over Thessaloniki lidar station, drawing conclusions about the issues to be considered when switching from the current operational algorithm to the SCCv5. The SCCv5 algorithm is evaluated for the AOD both for 355 and 532 nm. The agreement with THALIA algorithm seems promising with correlations of 0.89 and 0.84, respectively, and absolute deviations within the range of the EARLINET quality requirements. Time series of the AOD at 355 nm denote a decrease of 0.017 per year in the free troposphere, a trend that is also shown in the AOD values derived from the operational algorithm (0.014). A decrease of 0.01 per year in the lower troposphere is also noted from the SCC, whereas the corresponding AOD values derived from the operational algorithm denote a decrease of 0.017.

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.

scholarly journals Towards continuous monitoring of aerosol hygroscopicity by Raman lidar measurements at the EARLINET station of Payerne

2019 ◽  
Author(s):  
Francisco Navas Guzmán ◽  
Giovanni Martucci ◽  
Martine Collaud Coen ◽  
María José Granados Muñoz ◽  
Maxime Hervo ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
Lidar System ◽  
Remote Sensing Technique ◽  
Accuracy And Precision ◽  
Lidar Measurements ◽  
Constant Altitude ◽  
Aerosol Backscatter ◽  
Aerosol Hygroscopicity

Abstract. This study focuses on the analysis of aerosol hygroscopicity using remote sensing technique. Continuous observations of aerosol backscatter coefficient, temperature and water vapour mixing ratio are performed by means of a Raman lidar system at the aerological station of MeteoSwiss at Payerne (Switzerland) since 2008. These measurements allow us to monitor in a continuous way any change of aerosol properties as a function of the relative humidity (RH). These changes can be observed either in time at constant altitude or in altitude at a constant time. The accuracy and precision of RH measurements from the lidar have been evaluated using the radiosonde (RS) technique as reference. A total of 172 RSs were used in this intercomparison which revealed a small bias (

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 Recent Upgrades of the EOLE and AIAS Lidar Systems of the National Technical University of Athens Operating Since 2000 in Athens, Greece

2020 ◽  
Vol 237 ◽  
pp. 02030 ◽  
Author(s):  
A. Papayannis ◽  
P. Kokkalis ◽  
M. Mylonaki ◽  
R. Soupiona ◽  
C. A. Papanikolaou ◽  
...  
Keyword(s):  
Research Infrastructure ◽  
Raman Lidar ◽  
Lidar System ◽  
National Technical ◽  
Research Infrastructures ◽  
Multi Wavelength ◽  
Technical Specifications ◽  
Technical University ◽  
532 Nm

The technical specifications and advances/ upgrades of the stationary (EOLE) and mobile (AIAS) lidars located at the National Technical University of Athens (NTUA) are presented in this paper. EOLE is a multi-wavelength combined backscatter/Raman lidar system, which is part of the EARLINET lidar network since May 2000. AIAS is a mobile 532 nm elastic depolarization lidar system. Both instruments have been upgraded during 2019, in the frame of PANACEA to be part of the Greek National Research Infrastructure for aerosol research, under the umbrella of the European Strategy Forum on Research Infrastructures (ESFRI).

scholarly journals EARLINET dust observations vs. BSC-DREAM8b modeled profiles: 12-year-long systematic comparison at Potenza, Italy

2014 ◽  
Vol 14 (16) ◽  
pp. 8781-8793 ◽  
Author(s):  
L. Mona ◽  
N. Papagiannopoulos ◽  
S. Basart ◽  
J. Baldasano ◽  
I. Binietoglou ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Saharan Dust ◽  
Raman Lidar ◽  
Dust Layer ◽  
Systematic Comparison ◽  
Dust Extinction ◽  
Lidar Measurements ◽  
Order Of Magnitude ◽  
Lidar Ratio ◽  
532 Nm

Abstract. In this paper, we report the first systematic comparison of 12-year modeled dust extinction profiles vs. Raman lidar measurements. We use the BSC-DREAM8b model, one of the most widely used dust regional models in the Mediterranean, and Potenza EARLINET lidar profiles for Saharan dust cases, the largest one-site database of dust extinction profiles. A total of 310 dust cases were compared for the May 2000–July 2012 period. The model reconstructs the measured layers well: profiles are correlated within 5% of significance for 60% of the cases and the dust layer center of mass as measured by lidar and modeled by BSC-DREAM8b differ on average 0.3 ± 1.0 km. Events with a dust optical depth lower than 0.1 account for 70% of uncorrelated profiles. Although there is good agreement in terms of profile shape and the order of magnitude of extinction values, the model overestimates the occurrence of dust layer top above 10 km. Comparison with extinction profiles measured by the Raman lidar shows that BSC-DREAM8b typically underestimates the dust extinction coefficient, in particular below 3 km. Lowest model–observation differences (below 17%) correspond to a lidar ratio at 532 nm and Ångström exponent at 355/532 nm of 60 ± 13 and 0.1 ± 0.6 sr, respectively. These are in agreement with values typically observed and modeled for pure desert dust. However, the highest differences (higher than 85%) are typically related to greater Ångström values (0.5 ± 0.6), denoting smaller particles. All these aspects indicate that the level of agreement decreases with an increase in mixing/modification processes.

scholarly journals One year of Raman lidar observations of free-tropospheric aerosol layers over South Africa

2015 ◽  
Vol 15 (10) ◽  
pp. 5429-5442 ◽  
Author(s):  
E. Giannakaki ◽  
A. Pfüller ◽  
K. Korhonen ◽  
T. Mielonen ◽  
L. Laakso ◽  
...  
Keyword(s):  
South Africa ◽  
Optical Properties ◽  
Biomass Burning ◽  
Mean Value ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Tropospheric Aerosol ◽  
Wide Range ◽  
Significant Difference ◽  
532 Nm

Abstract. Raman lidar data obtained over a 1 year period has been analysed in relation to aerosol layers in the free troposphere over the Highveld in South Africa. In total, 375 layers were observed above the boundary layer during the period 30 January 2010 to 31 January 2011. The seasonal behaviour of aerosol layer geometrical characteristics, as well as intensive and extensive optical properties were studied. The highest centre heights of free-tropospheric layers were observed during the South African spring (2520 ± 970 m a.g.l., also elsewhere). The geometrical layer depth was found to be maximum during spring, while it did not show any significant difference for the rest of the seasons. The variability of the analysed intensive and extensive optical properties was high during all seasons. Layers were observed at a mean centre height of 2100 ± 1000 m with an average lidar ratio of 67 ± 25 sr (mean value with 1 standard deviation) at 355 nm and a mean extinction-related Ångström exponent of 1.9 ± 0.8 between 355 and 532 nm during the period under study. Except for the intensive biomass burning period from August to October, the lidar ratios and Ångström exponents are within the range of previous observations for urban/industrial aerosols. During Southern Hemispheric spring, the biomass burning activity is clearly reflected in the optical properties of the observed free-tropospheric layers. Specifically, lidar ratios at 355 nm were 89 ± 21, 57 ± 20, 59 ± 22 and 65 ± 23 sr during spring (September–November), summer (December–February), autumn (March–May) and winter (June–August), respectively. The extinction-related Ångström exponents between 355 and 532 nm measured during spring, summer, autumn and winter were 1.8 ± 0.6, 2.4 ± 0.9, 1.8 ± 0.9 and 1.8 ± 0.6, respectively. The mean columnar aerosol optical depth (AOD) obtained from lidar measurements was found to be 0.46 ± 0.35 at 355 nm and 0.25 ± 0.2 at 532 nm. The contribution of free-tropospheric aerosols on the AOD had a wide range of values with a mean contribution of 46%.

NILAI TAMBAH PENGOLAHAN KANGKUNG HIDROPONIK MENJADI KANGKUNG RENDANG

2020 ◽  
Vol 2 (2) ◽  
pp. 95-106
Author(s):  
Indrawaty Sitepu ◽  
Nurmely Violeta Sitorus
Keyword(s):  
Raw Materials ◽  
Value Added ◽  
Data Retrieval ◽  
Rice Flour ◽  
Production Costs ◽  
Added Value ◽  
Water Spinach ◽  
A Value ◽  
Chicken Eggs

Kangkung hidroponik menjadi kangkung rendang merupakan kegiatan yang dapat meningkatkan nilai tambah, menghasilkan produk yang dapat dikonsumsi, serta menambah pendapatan dan keuntungan produsen.Tujuan penelitian untuk menguraikan apa saja tahapan pengolahan kangkung hidroponik menjadi kangukung rendang, menganalisis biaya produksi, penerimaan, dan pendapatan, menganalisis nilai tambah pengolahan kangkung hidroponik menjadi kangkung rendang, menganalisis apakah usaha pengolahan kangkung hidroponik menjadi kangkung rendang layak diusahakan. Penelitian ini dilakukan di Jalan Bromo lorong Amal Medan Denai Kota Medan. Penentuan daerah penelitian dilakukan secara purposive, Metode pengambilan sampel secara sensus yaitu usaha Syifa Hidroponik dengan pengambilan data ulangan selama 2,5 bualan sebanyak 10 kali ulangan. Hasil penelitian: 1) Tahapan  pengolahan kangkung hidroponik menjadi kangkung rendang yaitu:  Penyediaan bahan baku kangkung hidroponik, kangkung dihaluskan, pengadonan kangkung, telur ayam, tepung beras dan garam, kangkung dikukus, kangkung didinginkan, dipotong-potong, digoreng, pemasakan bumbu rendang, pencampuran kangkung yang digoreng dengan bumbu rendang dan pemasaran. Total biaya pengolahan kangkung hidroponik menjadi kangkung rendang untuk sekali produksi sebesar Rp 545.291,83, penerimaan sebesar Rp 1.500.000,00, per sekali produksi dan pendapatan sebesar Rp 954.708,17 per sekali produksi. Nilai tambah yang dihasilkan dari pengolahan kangkung hidroponik menjadi kangkung rendang tergolong tinggi dengan rasio nilai tambah 75,31% > 50%.Usaha pengolahan kangkung hidroponik menjadi kangkung rendang layak untuk diusahakan dengan nilai R/C rasio 2,75 > 1.  Abstract  Hydroponic water spinach into rendang water spinach is an activity that can increase added value, produce edible products, as well as increase producer income and profits. The purpose of the research is to describe what are the stages of processing hydroponic water spinach into rendang kangukung, analyze production costs, revenue, and income, analyze added value of processing hydroponic water spinach into rendang water spinach, analyzing whether the business of processing hydroponic water spinach into rendang water spinach is worth the effort. This research was conducted in Jalan Bromo Amal Medan Denai alley Medan City. Determination of the study area was done purposively, census sampling method that is Syifa Hydroponic business with retrieval data retrieval for 2.5 boasting as many as 10 replications. The results of the study: 1) The stages of processing hydroponic water spinach into rendang water spinach, namely: Provision of raw materials for hydroponic water spinach, crushed water spinach, stirring water spinach, chicken eggs, rice flour and salt, steamed water spinach, water spinach water spinach, cut into pieces, fried, fried spicy water spinach, cooking water spinach kale, chicken egg, rice flour and salt, steamed water spinach, water spinach kangkung cooled, cut, fried, cooking spices, rendang, mixing fried kale with spicy rendang and marketing. The total cost of processing hydroponic water spinach into rendang water spinach for one production is Rp. 545,291.83, revenue is Rp. 1,500,000.00, per production and income is Rp. 954,708.17 per production. The added value generated from the processing of hydroponic water spinach into rendang water spinach is classified as high with a value added ratio of 75.31%> 50%. The business of processing hydroponic water spinach into rendang water spinach is feasible to be cultivated with an R / C ratio of 2.75> 1.  

scholarly journals A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter
Keyword(s):  
Acetic Acid ◽  
Optical Density ◽  
Extinction Coefficient ◽  
Spectrophotometric Method ◽  
Extinction Coefficients ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Given

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.

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