Research On GPS Carrier Phase Real Time Kinematic Precise Positioning System

With the rapid development of economy, the demand for precision positioningtechnology has become more and more urgent in areas such as urban planning andconstruction, precision agriculture, transportation and water conservancy facilitiesconstruction. In recent years, RTK technology, based on the development of the GPStechnology and communication technology, with the advantages of a high degree ofautomation, low operating conditions, and high precision attracts more and moreattention. RTK measurement is based on carrier phase measurements. After real-timeaccess to other receivers’ data by using radio technology, the receiver can realize cm-level positioning through the difference operation to eliminate the error. Due tohandling multiple receiver reference data, RTK technology has a higher requirementfor the performance of the receiver. After did a research on RTK positioningprinciple and algorithm, this paper put a RTK receiver design which has properties ofhigh performance, low cost, low power consumption. Then a RTK vehicle navigationapplication is designed and tested.First of all, the theoretical research of the RTK includes carrier phase differentialpositioning model, integer ambiguity solving model, cycle slip detection andprocessing, etc., and the ambiguity least squares search algorithm and the principle ofcycle slip detection have been carried on the MATLAB simulation.Secondly, this paper proposes a hardware circuit principle design. The designincludes three parts: RF-front-end module, baseband signal processing module andapplication processing module. RF-front-end’s main chip is MAX2796supplementedby peripheral device. Baseband signal processing part adopts FPGA to realize thereal-time tracking capture operation of multi-channel signals. Application processingmodule uses STM32F4series MCU with DSP functions to achieve solver and datatransmission.Finally, a RTK vehicle navigation application model is designed. This model ismainly composed of RTK module, three-axis magnetometer and other peripheral modules. Through the test, the model is proved that it can realize autonomousnavigation.