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dc.contributor.authorLaPean, James Williamen_US
dc.date.accessioned2014-03-14T21:39:16Z
dc.date.available2014-03-14T21:39:16Z
dc.date.issued1993-11-05en_US
dc.identifier.otheretd-06302009-040304en_US
dc.identifier.urihttp://hdl.handle.net/10919/43483
dc.description.abstract

In 1987 a NASA panel recommended the creation of the Mission to Planet Earth. This mission was intended to apply to remote sensing experience of the space community to earth remote sensing to enhance the understanding of the climatalogical processes of our planet and to determine if, and to what extent, the hydrological cycle of Earth is being affected by human activity. One of the systems required for the mission was a wide scanning, high gain reflector antenna system for use in radiometric remote sensing from geostationary orbit.

This work describes research conducted at Virginia Tech into techniques for beam scanning offset Cassegrain reflector antennas by subreflector translation and rotation. Background material relevant to beam scanning antenna systems and offset Cassegrain reflector antenna system is presented. A test case is developed based on the background material. The test case is beam scanned using two geometrical optics methods of determining the optimum subreflector position for the desired scanned beam direction. Physical optics far-field results are given for the beam scanned systems. The test case system is found to be capable of beam scanning over a range of 35 half-power beamwidths while maintaining a 90% beam efficiency or 50 half-power beamwidths while maintaining less than 1 dB of gain loss during scanning.

en_US
dc.format.mediumBTDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartLD5655.V855_1993.L365.pdfen_US
dc.subjectBeam opticsen_US
dc.subject.lccLD5655.V855 1993.L365en_US
dc.titleBeam scanning offset Casegrain reflector antennas by subreflector movementen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical Engineeringen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-06302009-040304/en_US
dc.date.sdate2009-06-30en_US
dc.date.rdate2009-06-30
dc.date.adate2009-06-30en_US


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