NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Natural noise above 50 MHZ from terrestrial and extraterrestrial sourcesThis paper offers a brief overview of natural radio noise for frequencies above 50 MHz in terms of brightness temperature as observed from two vantage points. The first is from an Earth station located at 40 degrees north latitude and observing at elevation angles from 0 to 90 degrees with an ideal antenna. The second is a satellite in geostationary orbit communicating with the Earth. Earth station noise at VHF and UHF is dominated by galactic and solar noise. Emission from the atmosphere, gases and hydrometeors, are dominant at EHF and SHF. Radiative transfer theory is invoked in the calculation of brightness temperature from the atmosphere. The situation is not vastly different from geostationary orbit if communications is with the Earth. Emission from the land and sea, even under idealized conditions, enters significantly. Land is a much more effective emitter than sea water, but at frequencies above 30 GHz the differential becomes much less due to the increasing significance of atmospheric emission.
Document ID
19930066851
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Smith, E. K.
(NASA Headquarters Washington, DC United States)
Flock, W. L.
(NASA Propagation Information Center; Colorado Univ. Boulder, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1991
Publication Information
Publication: In: Environmental and space electromagnetics (A93-50826 21-46)
Publisher: Springer-Verlag
Subject Category
Communications And Radar
Accession Number
93A50848
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available