Determination of GPS Total Electron Content using Single Layer Model (SLM) Ionospheric Mapping Function

The ionosphere layer is very important to the communication system. The ions produced from the striking process of the ultra violet light have an active role in reflecting and observing the earth radio waves. This layer also is an unstable medium because it is vulnerable to several distortions which affect its physical condition. Studies of Total Electron Content (TEC) have given important relationship to the ionospheric layers due to high density of electron concentration at F region. Total Electron Content (TEC) measurements from ground stations to Global Positioning System (GPS) satellite provide a rich source of information about the Earth's ionosphere. This research involves the determination of TEC content in ionosphere based on single layer model in order to determine the appropriate TEC value for Malaysia. This research assessing the errors translated from the code-delay to the carrier-phase ionospheric observable by the so-called "Levelling Process" which is applied to reduce carrier phase ambiguities from the data.