Publications
Aravind Kilaru, Sarat K Kotamraju, Nicholas Avlonitis, K.Ch. Sri Kavya, Rain rate intensity model for communication link design across the Indian region, Journal of Atmospheric and Solar-Terrestrial Physics, Volume 145, 2016, Pages 136-142, ISSN 1364-6826, http://dx.doi.org/10.1016/j.jastp.2016.05.001.
(http://www.sciencedirect.com/science/article/pii/S1364682616301201)
Abstract: A study on rain statistical parameters such as one minute rain intensity, possible number of minute occurrences with respective percentage of time in a year has been evaluated for the purpose of communication link design at Ka, Q, V bands as well as at Free-Space Optical communication links (FSO). To understand possible outage period of a communication links due to rainfall and to investigate rainfall pattern, Automatic Weather Station (AWS) rainfall data is analysed due its ample presence across India. The climates of the examined AWS regions vary from desert to cold climate, heavy rainfall to variable rainfall regions, cyclone effective regions, mountain and coastal regions. In this way a complete and unbiased picture of the rainfall statistics for Indian region is evaluated. The analysed AWS data gives insight into yearly accumulated rainfall, maximum hourly accumulated rainfall, mean hourly accumulated rainfall, number of rainy days and number of rainy hours from 668 AWS locations. Using probability density function the one minute rainfall measurements at KL University is integrated with AWS measurements for estimating number of rain occurrences in terms of one minute rain intensity for annual rainfall accumulated between 100mm and 5000mm to give an insight into possible one minute accumulation pattern in an hour for comprehensive analysis of rainfall influence on a communication link for design engineers. So that low availability communications links at higher frequencies can be transformed into a reliable and economically feasible communication links for implementing High Throughput Services (HTS).
Keywords: Rain rate model; Attenuation; Probability of rain; Satellite link attenuation; One minute rain intensity; Automatic Weather Station (AWS)
A. Kilaru, N. Avlonitis, S. K. Kotamraju and I. Otung, "Rain integration time and percentage probability of rain in Indian subcontinent for satellite communications," 2014 International Conference on Electronics and Communication Systems (ICECS), Coimbatore, 2014, pp. 1-7.
Abstract: The study of rain statistics, including average and extreme conditions, plays a significant role in predicting link availability and in calculating required tradeoff margins for the designing of a ground to space RF link. In this paper the cumulative distribution of average rainfall measured for 15 years is used in order to obtain probabilities of exceedance of rainfall rates using cumulative time statistics and empirical models for the Indian subcontinent. The results are compared with the rain rates extracted from the ITU-R model for the locations under study. The calculated rainfall rates suggest significant variances in the climatic features such as probability of heavy rain and number of rainy days in a year. The analysis shows that the ITU-R model underestimates the rainfall intensity rates by 32.6%, 26.2% and 40.7%, 19% at higher and lower percentage of time when compared with measured rain rate data from Indian Metrological department. It is shown that the discrepancy between the empirical model and ITU-R model at higher percentage of time results in a 15 to 5 dB difference in predicted signal attenuation depending on the region, percentage of time and frequency. Adaptive Power Control is proposed as a means to improve the link availability during period of higher intensity rainfall.
keywords: {probability;rain;satellite links;statistical analysis;ITU-R model;Indian Metrological department;Indian subcontinent;adaptive power control;average rainfall;climatic features;cumulative distribution;cumulative time statistics;empirical models;ground to space RF link;link availability;predicted signal attenuation;rain statistics;rainfall intensity rates;satellite communications;tradeoff margins;Analytical models;Availability;Data models;Predictive models;Rain;Size measurement;Time measurement;Adaptive Power Control;attenuation;probability of rain;rain integration time;rain rate;satellite link attenuation},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6892541&isnumber=6892507