The Correction Model of Tropospheric Delay of GPS Network RTK Considering Altitude Factors

In GPS network RTK, the tropospheric delay is a major error source. The troposheric delay of rove station is obtained through certain interpolation algorithm when the tropospheric delay of base stations is calculated. However, conventional interpolated algorithms depend on the plane, neglecting the altitude factors. And the traditional lay out of GPS reference stations should consider only the plane distribution without the consideration of the altitude distribution. The paper firstly analyzes the variation tendency of the zenith tropospheric delay at stations along with elevation changes and the author submitted that for a larger relief area, the base station network layout should be laid in accordance with the terrain, not only to consider the plane-shaped structure, but also consider on the structure of GPS altitude graphics. A change to the linear interpolation method (LIM) improve the accuracy of the interpolation algorithms better, either in a flat terrain or in the undulating terrain. And the practical examples prove this conclusion.