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Emission, absorption and group delay of microwaves in the atmosphere in relation to water vapour content over the Indian subcontinentThe advent of satellite communication for global coverage has apparently indicated a renewed interest in the studies of radio wave propagation through the atmosphere, in the VHF, UHF and microwave bands. The extensive measurements of atmosphere constituents, dynamics and radio meterological parameters during the Middle Atmosphere Program (MAP) have opened up further the possibilities of studying tropospheric radio wave propagation parameters, relevant to Earth/space link design. The three basic parameters of significance to radio propagation are thermal emission, absorption and group delay of the atmosphere, all of which are controlled largely by the water vapor content in the atmosphere, particular at microwave bands. As good emitters are also good absorbers, the atmospheric emission as well as the absorption attains a maximum at the frequency of 22.235 GHz, which is the peak of the water vapor line. The group delay is practically independent of frequency in the VHF, UHF and microwave bands. However, all three parameters exhibit a similar seasonal dependence originating presumably from the seasonal dependence of the water vapor content. Some of the interesting results obtained from analyses of radiosonde data over the Indian subcontinent collected by the India Meteorological Department is presented.
Document ID
19860018334
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Sen, A. K.
(Calcutta Univ. India)
Gupta, A. K. D.
(Scottish Church Coll. Calcutta, India)
Karmakar, P. K.
(Saint Andrew's High School Calcutta, India)
Barman, S. D.
(Bajkul Milani Coll. West Bengal, India)
Bhattacharya, A. B.
(Serampore Coll. West Bengal, India)
Purkait, N.
(Calcutta Univ. India)
Gupta, M. K. D.
(Calcutta Univ. India)
Sehra, J. S.
(Department of Electronics New Delhi, India)
Date Acquired
August 12, 2013
Publication Date
December 1, 1985
Publication Information
Publication: International Council of Scientific Unions Handbook for MAP, Vol. 18
Subject Category
Geophysics
Accession Number
86N27806
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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