航海模拟器中星空视景的建模与仿真

Modeling and simulation of celestial scene in shiphandling simulator

为了完善航海模拟器视景库,提高三维视景的逼真度,在视景系统中添加对星空天体运动的仿真.采用FK5星表数据进行数学建模,以航海模拟器中实时获取的系统时间和观测经纬度为参数,计算天体在第二赤道坐标系中的位置;根据球面天文学的知识,进行坐标转换,获得天体相对于观测者所在空间直角坐标系中的坐标;由太阳和月球间的相对位置决定月相,利用得到的计算结果进行星空视景的绘制,并将程序集成到航海模拟器视景系统中,实现场景漫游.仿真结果表明,该方法实现的星空视景符合航海模拟器的精度要求和虚拟场景中漫游的实时性要求.

The use of celestial scene in shiphandling simulator can greatly improve the fidelity of 3D scene. Based on FK5 ephemeris, the paper presented an approach for modeling and simulating the celestial ,scene in the shiphandling simulator. The basic idea of the method is that the coordinates of the celestial bodies in the 2nd coordinates of equinoctial system was calculated by the mathematical model which took the system time and the position of observer as the parameter that was obtained dynamically. Then the star position is converted into the observation coordinate with a series of coordinates conversion. The phase of moon was determined by the relative position between the sun and the moon. Consequently the celestial ,scene can be rendered dynamically by using the modeling result. A real-time rendering program of celestial bodies in visual system of shiphandling simulator was built adopting OpenGL codes. Simulation results show that the method can meet the real-time requirement in the shiphandling simulator.