Design And Realization Of Control System For The GNSS-R Receiver

In the recent years, the technique of Ocean Remote Sensing by Using GNSS-R Signals has been paid attention to by more and more domestic and foreign scientific institutions and researchers. It is proved that GNSS-R signals can be used to extract ocean surface geophysical information, such as sea surface wind field, height and so on, which are of great importance to fisheries production, safety of navigation and weather forecast. The special equipment is needed to sample and process GNSS-R signals. So far, domestic and foreign scientific institutions have made great progress in the design of the GNSS-R receiver and developed several design solutions. In this dissertation, the design philosophies of these design solutions are combined and a new design solution of the GNSS-R receiver based on FPGA&DSP is developed.Processing theories of GNSS signals and theories of the technique of Ocean Remote Sensing by Using GNSS-R Signals are expatiated at first in this paper. The design philosophy is discussed and the system architecture and module function is described in detail. Compared with the traditional GNSS receiver, the GNSS-R receiver not only achieves the direct signals acquisition and tracking, but also receives the reflect signals from the ocean surface, finishes correlation operation and gives power spectrum. Based on FPGA&DSP the signals processing and the system control is carried out. This design solution combines features of the hardware receiver and the software receiver and meet the requirements of real-time processing and flexibility. The hardware design of FPGA and DSP is described concretely. System control and information processing program, which mainly achieves flow control, valid GNSS satellites forecast, reflection point forecast and communication with other equipment, is designed and run at DSP. Final, the testing results and analyses of the receiver are given.