基于动力学轨道外推的星载辅助GPS快速搜索方法

发布时间：2018-08-01 12:51

【摘要】：星载GPS接收机广泛应用于卫星实时导航定位、定时。只要捕获到至少4颗可见GPS卫星,GPS接收机就能完成一次定位。但由于星载GPS接收机处于高动态运动状态,无法接收外界辅助信息,因此大部分星载GPS接收机仍然采用轮询搜索方法对所有GPS卫星进行捕获,导致定位时间长。在此背景下,提出一种星载辅助GPS(AGPS)快速搜索方法,通过减少捕获次数来缩短定位时间。方法以卫星轨道运动规律为辅助信息,基于动力学轨道外推预测星载GPS接收机的概略位置,然后通过计算俯仰角实时判断GPS卫星对星载GPS接收机是否可见。星载GPS接收机可以优先捕获可见的GPS卫星,从而减少捕获次数,缩短定位时间。仿真结果表明,相比于轮询搜索、决策树搜索方法,为搜索到相同颗可见GPS卫星,星载辅助GPS快速搜索方法需要的捕获次数最少;并且,随着轨道高度增加,星载辅助GPS方法需要的捕获次数增加得最慢。
[Abstract]:Spaceborne GPS receivers are widely used in satellite real-time navigation and positioning. At least four visible GPS receivers can be captured once. However, because the spaceborne GPS receiver is in a high dynamic state, it is unable to receive the external auxiliary information, so most of the space-borne GPS receivers still use the polling search method to capture all GPS satellites, resulting in a long positioning time. Under this background, a fast search method for spaceborne aided GPS (AGPS) is proposed, which can reduce the time of location by reducing the number of times of acquisition. Methods based on dynamic orbit extrapolation, the general position of spaceborne GPS receiver was predicted with satellite orbit motion rule as auxiliary information, and then the visibility of GPS satellite to spaceborne GPS receiver was determined by calculating the pitch angle in real time. Spaceborne GPS receivers can preferentially capture visible GPS satellites, thus reducing the number of captures and shortening the positioning time. The simulation results show that, compared with the polling search, the decision tree search method requires the least number of acquisition times to search the same visible GPS satellite, and with the increase of orbit altitude, the space-borne auxiliary GPS fast search method requires the least number of acquisition times. The acquisition times required by the spaceborne auxiliary GPS method are the slowest.
【作者单位】：中国科学院上海微系统与信息技术研究所;上海微小卫星工程中心;
【基金】：国家863计划(NO.2011AA12A101)
【分类号】：P228.4

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