The Applied Research Of The Generalized Extension Interpolation In GPS Data Processing

With the rapid development in the past ten years, GPS has extensive use in many aspects, especially playing a unique role in the field of survey and mapping.Using the precise ephemeris and precise satellite clock bias provided by IGS, we can realize the positioning and orbit determination in high precision, which makes GPS play a very important role in confirming the satellite track and monitoring ionosphere and troposphere. IGS provides precise ephemeris at 15 minute or 5 minute intervals, but in practical application, it samples by interval to be generally 15 second, 10 second, even the denser, in order to get much smaller interval, it is necessary to carry out interpolation. GPS height fits is also the important respect of GPS data processing.The generalized extended interpolation method is based on the interpolation and fitting.The generalized extended interpolation method has the advantage of simple norm of forms, not needing to increase type of degree of freedom and scale, using the original joint and degree of freedom to improve the precision.The thesis uses the generalized extended interpolation method in precise satellite ephemeris and clock bias interpolation and GPS height fits.Through the example, the thesis analyzes the relation between precision and three parameters to find the proper parameter when being most high precision of interpolation and compare the result with other methods. The thesis gets the following conclusions:1, There are close relations between the precision of the generalized extended interpolation method and three parameters. In the precise ephemeris and precise clock bias interpolation, when three parameters are 5, 11, 10 and 2, 8, 3 respectively, it can make the better precision;2, The precision of precise ephemeris interpolation of different satellites is basically identical, but the precision of precise clock bias has a verygreat difference.The change of time does not make the influence of precision; 3, When the GPS height is transformed by the generalized extended interpolation method, there is no step sudden change between each point of districts,so it does not need to deal with again;4, Through the comparison of the result of the generalized extended interpolation method and other common methods, we can find the generalized extended interpolation method has higher precision, so it is totally suitable for carrying on the satellite precise ephemeris and precise clock bias interpolation and GPS height fitting.