A novel sampling method for GBAS availability assessment based on multi-constellation

In the future, there will be many navigation satellite constellations ( GPSinverted commas GLONASSinverted commas Galileo and so on ) and multi-constellation will be used for most applications^[1-3]. Selecting an optimal sampling method for availability assessment is very important to decrease computing time for many applications whose processing capability and time are limited such as aviation and intelligent transport system. The sampling intervals in the conventional sampling methods mentioned above are all constants, without considering the temporal and spatial domain correlation characteristics of both the satellites geometry and the measurement errors. If using the full-frequency sampling method, the computing burden will be intolerance. In the paper, the constants sample method and the full-frequency sampling method is compared. After discussing the sample interval, the relationship between the difference availability and the sample proportion is obtained. Moreover, the critical sample points where the number of the visible satellites is changed are analyzed. In the method proposed in the paper, the constant sample and the critical point are all considered. Simulation results show that the new sample method is feasible.