The rain attenuation and attenuation distribution have been obtained using the measured rain drop size distribution (DSD) and the ITU-R model of rain rate distribution over the frequency range of 10-200 GHz at three locations in the Indian region, to indicate the variability in the rain attenuation pattern in the tropical region. The prevailing DSD in the tropical region can cause very significant variability in the rain attenuation distribution indicating the need of long term and extensive measurement of DSD in the tropical region.

A MAITRA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Rain attenuation modeling from measurements of rain drop size distribution in the Indian region

IEEE Antennas and Wireless Propagation Letters

This paper studies the rain-induced propagation characteristics over a tropical location Kolkata, India, using the data collected over a 7 year period, i.e., 2004-2010. This location experiences substantial rainfall during the Indian Summer Monsoon (ISM) season which is preceded by premonsoon rainfall accompanied by strong convection. Accumulations, event duration, and fade duration statistics are presented. Long-term observations for three propagation effects, namely rain attenuation, scintillations, and depolarization, are analyzed in this paper. The seasonal patterns of these phenomena are examined to reveal the characteristic features of Kolkata. The interrelations among rain rate, rain attenuation, scintillations, and depolarization are also investigated. Propagation detriments for identical rain rates are more severe in premonsoon compared to monsoon period, mainly because of the different microphysical properties of precipitation. However, the percentage occurrences of various propagation effects are higher in monsoon than premonsoon. © 1963-2012 IEEE.

IEEE Transactions on Antennas and Propagation

Rain and rain-induced degradations of satellite links over a tropical location

Rain drop size distributions (DSD) are measured with disdrometers at five different climatic locations in the Indian tropical region. The distribution of drop size is assumed to be lognormal to model the rain attenuation in the frequency range of 10-100 GHz. The rain attenuation is estimated assuming single scattering of spherical rain drops. Different attenuation characteristics are observed for different regions due to the dependency of DSD on climatic conditions. A comparison shows that significant differences between ITU-R model and DSD derived values occur at high frequency and at high rain rates for different regions. At frequencies below 30 GHz, the ITU-R model matches well with the DSD generated values up to 30 mm/h rain rate but differ above that. The results will be helpful in understanding the pattern of rain attenuation variation and designing the systems at EHF bands in the tropical region.

Fulltext

Progress In Electromagnetics Research B

Rain attenuation modeling in the 10-100 GHz frequency using drop size distributions for different climatic zones in tropical India

Three-parameter distribution functions, gamma and lognormal, are used to describe the sizes of raindrops in Calcutta. The three parameters for a drop size distribution are obtained by solving three nonlinear equations formed with three measurements, namely rain rate and rain attenuations at millimetre and optical wavelengths. The two distribution models are compared by employing rainfall parameter estimation methods.

Journal	Data powered by TypesetIEEE Antennas and Wireless Propagation Letters
Publisher	Data powered by TypesetIEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
ISSN	1536-1225