Study of GPS instrumental bias and TEC estimations from GPS stations in Thailand

Abstract

The Total Electron Content (TEC) or satellite delay can be derived from the dual-frequency of Global Positioning System (GPS). The error of TEC accuracy suffers seriously from the GPS instrumental biases, including satellite bias and receiver bias. In this paper, we apply the singular value decomposition (SVD) to derive TEC, GPS satellite and receiver biases from the 11 GPS receiver stations in Thailand, which are operated by DPT. From the results, the daily satellite bias range between −8 ns and 10 ns. The estimated receiver bias varies from −5.03 ns to 1.88 ns. The biases in TEC are removed. The TEC estimation by SVD method is a good agreement level at each locations. The TEC of SVD estimation is compared with a TEC of general calculation by a GPS receiver from DPT9. The estimated TEC by SVD method at Bangkok area is used. The trend of both TEC are concurrence. Thus, the SVD method can be used to estimate the TEC, GPS satellite and receiver biases in Thailand area.