Abstract:
Apart from geodesy and geophysical interest, GPS has great importance in scientific
applications. For many years GPS has played a major role in determining ionospheric
characteristics, including TEC and electron density profiles. The ionospheric effects in
the propagation of Global Positioning System (GPS) signal is one of the main sources of
error in GPS precise positioning. Therefore, it is important to have a precise estimation
of the ionospheric delays. The developed model is a function of elevation angle and
TEC. Then ionospheric correction model has been developed to accurately determine
the difference in ionospheric delay so that a more accurate differential GPS correction
can be made. A good model for the low-latitude region has become more and more
important because of the need for high accuracy GPS positioning. An ionospheric error
correction model should be made applicable to any location including the low-latitude
region. The model has been validated and it gives the differential (between spaced
receivers) ionospheric error to sub-centimetre accuracy.