Determination of Orthometric Height of NJI2 CORS Station

Abstract

Many surveyors use the network of global positioning system (GPS) Continuously Operating Reference Stations (CORS) as accurate “free” control monuments in their projects. The National Geodetic Survey (NGS) publishes and maintains coordinates for these stations in terms of X, Y, Z, and latitude, longitude, and ellipsoidal heights. This information is very useful for horizontal positioning but not for vertical positioning. Establishing the orthometric heights of a CORS station will enhance its usefulness to surveyors and geodesists. In this paper, a method for determining orthometric heights for CORS is described and evaluated. The implementation of the proposed procedure at the NJI2 CORS station produced an orthometric height with a standard deviation of ±1 mm.