On the Performance of Virtual Reference Stations under Disturbed Ionosphere Conditions

摘要

In this paper, first the principles of fast precise positioning using Network DGPS and the virtual reference stations (VRS) are described. Linear interpolation is used to predict the ionospheric delay at the virtual reference station. The performance of the linear interpolation method to predict the ionospheric delay is investigated using two data sets of the SCIGN GPS-network in USA, during quiet and disturbed ionosphere conditions. The user stations were simulated using two permanent GPS stations. It is found that under disturbed ionosphere conditions, the interpolation error of the double differenced ionospheric delay between virtual reference station and user station can reach several decimeters for distances between user and the closest network station of a few 10s of kilometers. Dm-level interpolation errors are not acceptable for the VRS technique, as this leads to a reduction in the actual success-rate of the ambiguity resolution and consequently performance of the VRS technique is significantly degraded.