Simplified GNSS positioning performance analysis

The aim of this study is to develop a simplified analytic method to assess the performance of GNSS navigation and to analyze the impact of erroneous measurements. The method uses the mathematical description of continuous satellite distributions in order to simplify and generalize the equation for covariance and systematic error propagation. Its results shall bring a general insight into the navigational conditions, especially in rough terrain. In the frame of the Swiss-wide Implementation Program for SESAR-oriented objectives (CHIPS) a number of applied research and development efforts are undertaken in order to solve specific problems related to the peculiarities of Swiss air space. Especially the rough terrain in the Alpine region is often cause of different limitations for aviation and puts severe constrains on procedures at low flight levels. The assessments of GPS performance in rough terrain is presently mainly based on real satellite positions as well as on real terrain data. Our method will deliver a first, rough assessment of the GPS performance complementing simulations and field measurements. On the other hand it permits an early decision on the feasibility of flight procedure implementation while admitting an insight into possible satellite-based navigation solutions. We present the mathematical model, which allows assessing the GPS performance by avoiding simulations or real measurements as far as possible.