Research On Flight Pattern Oriented Real-time Massive Terrain Data Scheduling Service Algorithm

The distributed 3-D terrain data service is one of the most important development aspects in the 3-D terrain environment research, but the real-time 3-D terrain model construction based on distributed massive terrain data service can't be achieved in some conditions. Through analyzing the key technologies in the 3-D terrain construction and service, new algorithms are proposed to improve the efficiency of massive terrain data service, so as to construct and refurbish real-time 3-D terrain model in some flight activities. At last, the algorithms are implemented on World Wind that is a NASA's open-source geography software. The research includes the following parts:(1) The key technologies of the 3-D terrain data service, which affect the efficiency of distributed massive terrain data service, including organizing and scheduling of massive data and real-time interaction based on massive terrain data, are analyzed. And the difficulties of these technologies are indicated. A solution based on data preload and data buffer is proposed to overcome these difficulties.(2) According to the impact of different flight activities on data preload and data buffer, this thesis mainly considers three main flight patterns: satellite pattern, cruise pattern and random pattern and then data service models for all the three patterns are built.(3) Based on the flight patterns'data service models, data service algorithms are presented separately, and the complexity of algorithms, time efficiency and storage efficiency are analyzed and compared with the current algorithm.(4) Finally, the three data request algorithms are implemented in World Wind which is a NASA's open-source geography software. The validity of the new algorithms is proved through their comparison with the current algorithm based on the criterion of FPS.