Research On GPS Three-Dimensional Attitude Determination System

Nowadays in an age of rapid technological advancement, the research on high precision attitude determination becomes more and more important in military, civil applications and trade,so many measuring methods appear. Attitude determination is to acquire heading,roll and pitch and predict the future state. GPS can provide precise three-dimensional information and can navigate and locate with precision and continuity. It can accommodate adverse environmental condition, has advantages such as little culbage, cheap cost,so it is of significan meaning to determinate attitude with GPS. Use GPS carrier phase difference analysis to determinate attitude in this paper,then do research on the relational questions in GPS attitude determination and method of ambiguity resolution.At last,set up GPS attitude determination system and finish the calculation for attitude angles.In this paper, GPS attitude determination system is studied, first to introduce principle such as the architecture of GPS system, brief analysis of GPS signal, familia Coordinates and then establish GPS carrier phase measurement equation,discuess the error of attitude determination with GPS carrier phase.Creat double difference model to remove the equifinal error of satellite ephemeris, tropospheric error,multipath effect and so on. Give the calculation of carrier phase ambiguities,in order to improve the efficiency of the calculation of attitude determination,use FPGA to be the computer,two SUPERSTAR II GPS OEM bords to be the receiver.Set up a simple attitude determination system, the feasibility and applicability of the design are validated through experiments.Also do research on the three-dimensional attitude determination system, present the critical procedures on the attitude determination.The attitude determination system is composed of two parts:both hardware and software. hardware disposition is mainly about FPGA, fabricat the voltage supply circuitry, timing circuitry.Establish NiosⅡsoft kernel, Complish the design of CPU,SDRAM module and translate it,finish software in Nios II, including data processes, equation establish, design the driver of the LCD,ambiguity resolution and attituse calculation.Finally show the solution is verified by the experiment,record multiple datas and give the error analysis.