摘要
Beginning in 2006, four ground stations located at Chung-Li (25.136 degrees N, 121.539 degrees E), TasoTun (23.981 degrees N, 120.697 degrees E), CheCheng (22.725 degrees N, 120.544 degrees E), and tropical Itu Aba Island (10.06 degrees N, 114.350 degrees E) were set up to receive beacon signals from six FORMOSAT-3/COSMIC (Bernhardt et al. 2000) and other NNSS-like satellites. By applying differential Doppler technique on three quadrature components of the three-band beacon signals, we were able to obtain total electric contents (TEC) values and scintillation along the radio path through the ionosphere. Such measurements can be used to derive regional ionospheric irregularity and tomography. In this paper, we have confirmed the power patterns contributed from the transmitting antennas on board FS3/COSMIC and the ground-based receiving antennas. The multiplicative algebraic reconstruction technique (MART) algorithm has also been implemented to reconstruct ionospheric tomography images. Observations of the diurnal variations and the dynamics of equatorial anomaly showed that the equatorial anomaly appeared at 0800 LT, and then subsequently moved toward the Earth's poles. The north crest was strongest at similar to 1300 LT and its core was located at about 10 degrees N of the magnetic latitude (similar to 20 degrees N geographic latitude). Afterwards, the crest moved toward the equator after sunset and disappeared after midnight.