Regional ionosphere maps over Malaysia during solar minimum

The regional ionosphere maps over Malaysia were studied during the minimum phase of solar cycle 23. Fifty-seven GPS RTK reference stations for the network covering the whole of Malaysia managed by JUPEM were used in this analysis. TEC is the measure of the number of electrons along the path from the satellite and is reported as TEC Units (1 TECU = 1×1016 electrons). The observations of oblique TEC can be obtained from the delays of GPS signals on the carrier frequencies of L1=1575.45 MHz and L2=1227.6 MHz under the assumption of infinitesimal single-layer ionospheric model. For this study, the data on 5th May 2007 and 23rd May 2007 was used. Results show that TEC maps derived from GPS RTK vary with all the geomagnetic activity indices.