Analysis of Characteristics of Atmospheric Structure Constant of Refractive Index Based on Wind Profiler Radar in Precipitation

Author(s):  
Yating Li ◽  
Debin Su ◽  
Xingang Fan
2019 ◽  
Vol 36 (4) ◽  
pp. 557-565
Author(s):  
Hua Wang ◽  
Shipeng Su ◽  
Haichuan Tang ◽  
Lin Jiao ◽  
Yunbo Li

AbstractA method of detecting atmospheric ducts using a wind profiler radar (WPR) and a radio acoustic sounding system (RASS) is proposed. The method uses the RASS to measure the virtual temperature profile and calculate the Brunt–Väisälä frequency; it also uses the WPR to measure the spectral width of the atmosphere and the atmospheric refractive index structure constant. Then the profile of the atmospheric refractive index gradient and modified refractivity are calculated using virtual temperature, spectral width, and the atmospheric refractive index structure constant. Finally, the height and intensity of the atmospheric duct are calculated to achieve continuous monitoring of the atmospheric duct. To verify the height and intensity of the atmospheric duct, comparison experiments between WPR-RASS and radiosondes were carried out from June 2014 to June 2015 in Dalian, Liaoning Province, China. The results show that the profile of modified refractivity by WPR-RASS has exactly the same trend as the radiosondes, the two methods have a good consistency, and the atmospheric duct value from WPR-RASS is in good agreement with that from radiosondes.


2012 ◽  
Vol 5 (3) ◽  
pp. 270-272 ◽  
Author(s):  
Sun Gang ◽  
Weng Ning-Quan ◽  
Xiao Li-Ming ◽  
Wu Yi

MAUSAM ◽  
2021 ◽  
Vol 64 (2) ◽  
pp. 363-370
Author(s):  
M.I. ANSARI ◽  
S.K. KUNDU ◽  
K.C. SAIKRISHNAN ◽  
RANJU MADAN

jsfM;ksa  rjax ds lapj.k dks izHkkfor djus esa jsfM;ks viorZdrk ,d egRoiw.kZ dkjd dk dk;Z djrh gSA jsfM;ks viorZdrk] ok;qeaMy dh HkkSfrd voLFkkvksa tSls & rkieku] nkc vkSj vknzZrk ij fuHkZj djrh gSA jsMkj vR;Ur NksVh vk—fr ds viorZukad fHkUurkvksa tks jsMkj ds rjax nS/;Z dh vk/kh gksrh gS] ds izfr laosnh gksrs gSA i'p izdh.kZu 'kfDr viorZukad fu;rkad Cn2 dh vk—fr ds ifjek.k ij fuHkZj djrh gSA vr% ekSle jsMkj] fo’k"k :i  foaM izksQkbyj jsMkj ds fM+tkbu ds fy, fdlh LFkku ds Cn2 ds eku mi;ksxh gksrs gSA bl 'kks/k i= esa fnYyh ds Åij ds mijhru ok;qeaMy esa ok;qeaMyh; viorZukad fu;rkad Cn2 dh :ijs[kk nSfud ,oa _rqvksa ds vk/kkj ij rS;kj djus dh dksf’k’k dh xbZ gSA The radio refractivity is an important factor which effects radio wave propagation. Radio refractivity depends upon the physical states of atmosphere, i.e., its temperature, pressure and humidity. Radars are sensitive to refractive index irregularities on scale size equal to half wavelength of Radar. Backscattered power is dependent on the magnitude of refractive index structure constant Cn2.  Hence Cn2values of a place are useful for designing weather radar specially wind profiler radars. This paper is an attempt to map the profile of refractive index structure constant Cn2 of atmosphere in the upper atmosphere, over Delhi on diurnal and seasonal basis.


2014 ◽  
Vol 7 (1) ◽  
pp. 135-148 ◽  
Author(s):  
M. Maruri ◽  
J. A. Romo ◽  
L. Gomez

Abstract. It is well known in the scientific community that some remote sensing instruments assume that sample volumes present homogeneous conditions within a defined meteorological profile. At complex topographic sites and under extreme meteorological conditions, this assumption may be fallible depending on the site, and it is more likely to fail in the lower layers of the atmosphere. This piece of work tests the homogeneity of the wind field over a boundary layer wind profiler radar located in complex terrain on the coast under different meteorological conditions. The results reveal the qualitative importance of being aware of deviations in this homogeneity assumption and evaluate its effect on the final product. Patterns of behavior in data have been identified in order to simplify the analysis of the complex signal registered. The quality information obtained from the homogeneity study under different meteorological conditions provides useful indicators for the best alternatives the system can offer to build wind profiles. Finally, the results are also to be considered in order to integrate them in a quality algorithm implemented at the product level.


Author(s):  
M. Satyavani ◽  
P. S. Brahmanandam ◽  
P. S. V. Subba Rao ◽  
M. P. Rao

This study reports diurnal variations of wind directions, wind speed of vector winds, and the evolution of boundary layer (BL) over a mid-latitude measured using a transportable 1290 MHz wind profiling radar located at Cardington (Lat. 52.10ºN; Long. 0.42ºE), Bedfordshire, UK from 17 to 28 April 2010. The horizontal winds show benign behavior during nighttime hours, while winds during daytime hours had magnitudes around, on average, 10-20 m/s, in the majority of the cases. The heights of the boundary layer (BL) varied from as low as ~1100 m to ~2600 km and BL height had shown to have evolved from 0700 universal time (UT) onwards and collapsed by 0000 UT.  Besides, a comparison made between winds measured by the 1290 MHz radar and near-by radiosonde showed a moderate similitude between them, albeit a few discrepancies are found in wind directions and speeds. The possible reasons for these discrepancies could be different volume sensing of observations of these independent observations. An attempt is, therefore, made to calculate radiosonde balloon drifts [1] for the ascending node of the balloons, which had confirmed that the balloons often drifted horizontally as long as up to 100 km. The large drifts, most probably, are the possible reasons for the mismatching of winds measured by these two independent remote sensing instruments.


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