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本文提出了一种利用GPS信号确定航天器姿态的全新敏感器方案。这一定姿敏感器方案要利用布置在单个敏感器探头上的多个GPS信号天线接收单元来捕获尽量多的GPS卫星。文中探讨了几种敏感器单元的布局结构。敏感器阵除可提供导航功能外,还可用来跟踪处于每个天线单元视场内的GPS卫星。利用被发现的GPS卫星的视线矢量与各个天线单元的固定基线矢量即可确定平台姿态。这种定姿方案较之标准的差分载波相位定姿法有明显的优点。首先,它可以大大降低或全部消除由于多路径效应所引起的误差。此外,它既不要求判定整周模糊解,也无需通过麻烦而昂贵的自检来确定路线偏差。进而,这种新敏感器不需要将各个天线物理上隔开来构成定姿的干涉测量基线。最后,这种新型敏感器发展潜力仅受天线和接收机技术发展的制约,而不像目前干涉姿态确定方法那样有种种物理上的局限性。初步仿真结果表明,这种敏感器可能实现约1°(3σ)的定姿精度。
In this paper, we propose a new sensor scheme that uses GPS signals to determine the attitude of the spacecraft. This attitude-sensitive approach uses as many GPS satellites as possible on a single sensor head to capture as many GPS satellites as possible. This paper discusses the layout of several sensor units. In addition to providing navigation capabilities, the sensor array can also be used to track GPS satellites in the field of view of each antenna element. The platform attitude can be determined by using the fixed baseline vectors of the line-of-sight vectors of the discovered GPS satellites and the respective antenna elements. This positioning scheme than the standard differential carrier phase positioning method has obvious advantages. First, it can greatly reduce or eliminate all the errors caused by multipath effects. In addition, it does not require the determination of full-blown ambiguities nor the need to go through cumbersome and expensive self-tests to determine the course deviation. Furthermore, the new sensor need not physically separate the individual antennas to form a set of interferometric baselines. Finally, the potential of this new type of sensor is limited only by the development of antenna and receiver technologies, unlike the physical limitations of current methods of attitude determination. Preliminary simulation results show that this sensor may achieve about 1 ° (3σ) attitude accuracy.