K Chakraathy Ku-band rain attenuation observations on an earth-space path in the indian region, ieee

Measurements of rain attenuation over an earth-space path at Kolkata (22°34 ' N, 88°29 ' E), India, have been carried out since June 2004 by receiving a Ku-band signal from the satellite NSS-6 (geostationary at 950 E). The instantaneous attenuations are estimated from the point rain rates measured with an optical raingauge and using the Simple Attenuation Model (SAM). The estimated values closely follow the measured attenuations for rain rates below 20 mm/h, and at higher rain rates (> 30 mm/h) the measured attenuations are significantly lower than the model estimations. Experimental data over a year reveal that occurrences of both rain rate and attenuation at Kolkata are higher than that given by the ITU-R model