Single-point GPS positioning accuracy using precise GPS data

Abstract Over the last few years, increased attention has been given to the use of precise GPS satellite ephemerides and clock corrections together with calibrated ionospheric models as an efficient and economical alternative to conventional differential GPS (DGPS). The advantages of such a technique include the ability of the user to perform precise absolute point positioning without the need for a base station. Also, since the satellite corrections are obtained from networks of accurately known reference sites, some of the uncertainty associated with using control data from a single base station is effectively removed. Precise satellite data and ionospheric models are being developed by various organizations across North America. Presented in this paper are some positioning test results using precise GPS satellite ephemerides and clock corrections with a single-layer ionospheric grid model obtained from the Geodetic Survey division (GSD) of Geomatics Canada. Results indicate that one-to-three metre posi...