| With the rapid development of satellite communication, Global Navigation Satellite System are improving constantly. No matter in the field of civilian and military use, related research about high precision and high efficiency of GNSS receiver are more and more, its demand is also increasing.This paper in view of the PVT algorithm of space-borne GNSS receiver, through the almanac prediction algorithm of GPS, BD and GLONASS, emulates and implements the calculation of satellite position,velocity and doppler frequency shift according to the almanac data. This paper also put forward a kind of interpolation calculating scheme.Implements and compares calculating results of PVT interpolation under different interpolation orders. The main research contents are as follows:First of all, it introduces the composition of GNSS system, analyzes the structure of signal and frame under different GNSS system. It also describes a feasible receiver scheme under the principle of space-borne GNSS receiver and introduces the architecture of hardware and software and the module of main function.Secondly, it studies the algorithm about calculation of satellite position, velocity and doppler frequency shift using almanac data of different GNSS system. It also analyzes the determination method of satellite’s visibility according to the characteristics of space-borne GNSS receiver.Thirdly, it studies three startup modes of space-borne GNSS receiver and introduces the PVT calculation module in detail. It also proposed an interpolation scheme which optimizes the PVT calculation process.Lastly, it lists the implementation process and part of the code of almanac prediction module and PVT interpolation module. It also implements the almanac prediction module and PVT interpolation module of GPS, BD and GLONASS through online debugging. Finally, it verifies the PVT interpolation results of different order. |
