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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/195

Authors: Fekadu, Admass
Advisors: Dr.Baylie Damtie
Copyright: 2007
Date Added: 11-Oct-2007
Publisher: Addis Ababa University
Abstract: This thesis aims on the methods how one measures the impulse response of a pulsation magnetometer using the data collected from Ethio-Finno observatory at Entoto Mountain located in Addis Ababa. Our pulsation magnetometer measures the fluctuation(perturbation) of the three components of the Earth’s magnetic field happening due to diurnal variations, magnetic storms, ultra low frequency waves in the ionosphere and ionospheric currents. To extract useful information from the measurements, it is useful to determine the impulse response of the instrument. The thesis describes on how to infer about the impulse response from the measurement(the output signal) which represents the variation of the three components of the Earth’s magnetic field (H, D and Z-components). The measurement contains short lived peaks which are believed to be the results of lightening flashes. Basically, among the different phenomena that takes place in the ionosphere, ionospheric currents resulted in lightening phenomena. By approximating the lightening effect represent Dirac-Delta function and considering as an input to our system, we can measure impulse response of the pulsation magnetometre by carefully investigating many days of data. Analysis of four day data for different hours showed that our modelling(method) works convincingly. Once impulse response of a given system is known, we can increases our knowledge about the upper atmosphere by knowing how the system modifies any input signal to give as an output signal.
Description: Academic thesis to be presented for the partial fulfillment of the requirements for the degree of Master of Science in Physics
URI: http://hdl.handle.net/123456789/195
Appears in:Thesis - Physics

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