Research On DGPS Simulator

As the development of computer technology, marine simulators are optimized rapidly. The simulator types have finished the process that change from monotonous unit to integrated unit, which is called Full Mission Ship Handling Simulator. Lastly, the full mission ship handling simulator has become the effective method for marine training, of course, the DGPS unit is indispensable.Based on GPS Simulator using OEM board developed previously, following research works have been finished in this paper:1. Based on analyzing the advantages and disadvantages of current GPS and DGPS simulator, the paper presents a designing method and improving scheme of DGPS simulator based on OEM board.2. A new error generating algorithm for simulating ship position is presented. Through analyzing the probability distribution characteristic of GPS ship position as dropped in the CEP(Circular Error Probable), the new algorithm of errors generating considers the distribution of the ship position as three parts. In every part, the distribution of ship position is approximately considered as regular distribution. But there are differences for the probability of ship position as dropped in every part. During the generating of GPS simulator ship position and DGPS simulator ship position, different UERE(User Equivalent Range Error) are used to make the ship position approach to the real situation.3. Analyzing the method how to choose satellites in GPS position. It adopts the method that directly calculates the GDOP(Geographic Dilution of Properties) of all the satellites which can be seen to choose the satellites in order to improve the accuracy of choosing the satellites.4. Waypoints function and DGPS simulation function are finished and user interface of multi-functions of GPS simulator are improved.