The Enhancement Of Inertial-Aided GNSS Carrier Phase Double Differenced Attitude Determination Algorithms

Attitude determination through the use of Global Navigation Satellite System(GNSS)signals is one of the many applications of satellite-based navigation.Multiple GNSS antennas installed on a given platform are used to provide orientation estimates,thus adding attitude information to the standard positioning service.It is a common treatment that utilizing information from multiple sensors to improve the performance of attitude determination.This thesis proposes a new filter design that uniformly treat all constraints and observations to provide better float solution for ambiguity resolution,hence improve the performance of attitude determination.This thesis starts from basic GNSS observation models,including the single differenced model and double differenced model,and the model of error sources.The model of attitude determination through a baseline is then given.Tactics of resolving integer ambiguities are discussed.A new filter which treats different constraints and observations in a uniform way is put forward to provide a better float estimation for integer ambiguity resolution algorithm,which in this case is the LAMBDA algorithm.The method is implemented in C on the basis of the open source platform RTKLIB.The original RTKLIB is used to provide results of traditional method for comparison.Multiple experiments are carried out using low cost devices like the ?blox receiver.The new method is proved to get the first fixed solution faster and have a higher success rate then the tradtional method.The method is analyzed from a theoretical standpoint,and tested with a series of settings,which proves the method to be valid and robust.