Determination of Optimized Ionospheric Layer for TEC Measurement at Equatorial Region

Ionosphere layer is very important to the communication system. In Malaysia the ionosphere layer is unique because the location is near the equator where it exposed more ultraviolet radiation (UV) compared to other region. This project focuses on the determination optimized ionospheric layers for TEC measurements at equatorial region. The main parameter in this project is Total Electron Content (TEC) with elevation angle of satellite between 50 to 85 degrees. Since these satellites are in different parts of the sky and the electron content in the ionosphere varies both spatially (track) and temporally (time), the Ionospheric Pierce Point (IPP) altitude plays an important role in converting the vertical TEC from the measured slant TEC. The TEC computed from the Global Positioning System (GPS) data for different altitudes ranging from 50 km to 750km. The data from GPS dual frequency which are in Receiver Independent Exchange Format (RINEX) are supplied by Department of Survey and Mapping Malaysia (JUPEM). The data taken from two different stations located at Universiti Sains Malaysia Pulau Pinang (USMP) and Universiti Teknologi Malaysia Johor (UTMJ). The results show a variation of TEC does not significantly changes when the elevation angle is greater than 50 degrees. Therefore, the IPP altitude of 450 km to 750 km may consider as effective ionospheric layer in the equatorial region.