کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1234871 968838 2011 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mie lidar observations of lower tropospheric aerosols and clouds
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Mie lidar observations of lower tropospheric aerosols and clouds
چکیده انگلیسی

Mie lidar system is developed at Laser Science and Technology Centre, Delhi (28.38°N, 77.12°E) by using minimal number of commercially available off-the-shelf components. Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser operating at 1064 nm with variable pulse energies between 25 and 400 mJ with 10 Hz repetition rate and 7 ns pulse duration is used as a transmitter and off-axis CASSEGRAIN telescope with 100 mm diameter as a receiver. Silicon avalanche photodiode (Si-APD) module with built-in preamplifier and front-end optics is used as detector. This system has been developed for the studies of lower tropospheric aerosols and clouds. Some experiments have been conducted using this set up and preliminary results are discussed. The characteristics of backscattered signals for various transmitter pulse energies are also studied. Atmospheric aerosol extinction coefficient values are calculated using Klett lidar inversion algorithm. The extinction coefficient, in general, falls with range in the lower troposphere and the values lie typically in the range 7.5 × 10−5 m−1 to 1.12 × 10−4 m−1 in the absence of any cloud whereas this value shoots maximum up to 1.267 × 10−3 m−1 (peak extinction) in the presence of clouds.

Figure optionsDownload as PowerPoint slideHighlights
► This system has been developed for the studies of lower tropospheric aerosols and clouds.
► Nd:YAG laser operating at 1064 nm with variable pulse energies between 25 and 400 mJ with 10 Hz repetition rate and 7 ns pulse duration is used as a transmitter and off-axis CASSEGRAIN telescope with 100 mm diameter as a receiver.
► Silicon avalanche photodiode (Si-APD) module with built-in preamplifier and front-end optics is used as detector.
► Mie lidar can be used for routine measurements of distribution and variation of clouds and aerosols at sites of interest.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 84, Issue 1, 15 December 2011, Pages 32–36
نویسندگان
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