Identification of window frequency at different places of India

International audienceMillimeterwave window frequencies between the two successive absorptionmaxima of 60 GHz and 120 GHz respectively, play a significant role inthe context of radar and communication applications. Atmosphericparameters like temperature, water vapour and oxygen play major rolesfor determination of window frequencies which are latitude dependent.Radiosonde data were analyzed to identify a frequency at which minimumsignal attenuation occurs in the millimeterwave band, between 60 GHz and120 GHz, at various places in India. The data are taken from BritishAtmospheric Data Centre (BADC, U.K). Analysis shows that water vapourplays a dominant role for determining window frequency during themonsoon season. On the other hand, temperature dominates water vapour inshifting window frequency during the winter and summer seasons. Theresults obtained also show that minimum attenuation occurs at 73 GHz andmaximum at 83 GHz over the chosen places in India during January toDecember depending on the latitudinal position. Another salient resultobtained from our analyses is that water vapour is mainly responsiblefor lowering the window frequency from its conventionally acceptedvalue, over certain places in India. Hence, these climatologicalparameters play a major role in determining window frequency overcertain places of choice in India throughout the year