Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588505
Title: Design and construction of widebeam riometer system
Author: Bogdanov, Anton
Awarding Body: Lancaster University
Current Institution: Lancaster University
Date of Award: 2011
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Abstract:
Ionospheric absorption is a controlling factor in accurate prediction of medium to high frequency signal levels that are passing through ionosphere. Particularly at high latitudes ionospheric storms are the main problem, causing unreliable communication. Sometimes these storms can lead HF radio signals to "polar blackouts" (reducing the signal in-time by 20 % or more) or they can even be completely absorbed by ionosphere. [Ware and Owren, 1958] This project report presents the design, construction and testing of a device that is used to measure ionospheric cosmic noise absorption, which is called riometer. During the project development different methods of filter design (all-pole and coupled capacitor resonator filters), impedance matching (L, pi and capacitor tapped matching) and signal attenuation calculation (impedance mismatch, pi attenuator and potential divider) are showed and described. The need for new riometer design had arisen, because some discrete components used in previous riometer designs are obsolete [LIS Riometers] and therefore the new riometers cannot be made based on the old designs, so the new design had to be invented. This new riometer design also includes the new feature of controlling the switching between antenna and calibration using the computer control inputs and mechanical override switch, thus providing higher system flexibility.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.588505  DOI: Not available
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