Opio, Phillip. Determination of ionospheric variation along the different lattitude s of the African sector using GPS tec data for the year 2011 / Phill ip Opio. - Kampala, 2014. - xi, 95 p. ; 30 cm. Unpublished thesis (MSc. PHYSICS)- Makerere University, 2014 Includes bibliographical references. Subjects--Topical Terms: Ionosphere ----Africa.----Ionospheric drift.----Africa.---- Dewey Class. No.: 538.767