【作者】 黄胜；

【导师】 吴斌；

【作者基本信息】 中国科学院研究生院（测量与地球物理研究所） ， 大地测量与测量工程， 2004， 硕士

【摘要】 低轨卫星星载GPS低轨精密定轨是近年来迅速发展起来的一项新的精密定轨技术。利用星载GPS接收机低轨卫星提供的相对经济、精确、连续观测值进行低轨卫星的自主定轨成为精密定轨的有效的途径，具有广泛的应用前景。非差GPS定位与差分方法相比具有不需要地面站、能直接得到测站坐标、工作量小、效率高等优点，因此精密单点定位在低轨卫星的定轨方面具有良好的应用前景。本文系统研究了非差星载GPS低轨卫星定轨中的理论和方法，对以下一些关键问题作了一些有益的探索： (1)系统的研究了非差GPS定轨的观测模型及其误差分析 非差GPS定位观测模型是描述非差观测值与被估计参数之间的函数关系，是非差精密单点定位的基础。本文讨论了GPS非差定轨模型，比较了非差和差分定位模型的优缺点。本文还讨论了一些特殊的非差线形组合观测值的性质及用途，并仔细研究了影响非差定轨的误差因素及其改正方法。 (2)制定了有效的数据预处理方案 星载GPS数据质量控制是星载GPS定轨的关键，数据质量的好坏对最终解的结果有着直接的、十分明显的影响。而本文采用了非差几何法定轨，根据星载GPS观测数据的特点，采用双频观测值之间的组合，制定了适合星载GPS数据预处理方法，详细讨论了数据预处理计算机程序设计思路和一些细节问题。算例结果表明，计算结果表明本文所采取的预处理过程是有效和可靠的，较好的提高了数据质量。 (3)系统地研究了非差几何法定轨方法 本文讨论了精密单点定位的数学模型、其未知参数的估计方法以及随机模型，并详细的讨论了定轨误差的处理方案。本文描述的精密单点定位方法，仅利用低轨卫星的GPS观测资料和IGS精密卫星星历与钟差就可实现低轨卫星的精密定轨。 (4)较系统的研究了消电离层组合的模糊度解算问题 在非差星载GPS定轨中，要想获得高精度的定轨结果，必须使用相位观测CHAMPJ之星非差几何法定轨的4沙}究值。而不采用差分时，需要求解相位模糊度。对于利用多余观测来求模糊度由于存在复杂病态问题，本文加入了伪距观测值进行约束，并取得了优于平滑伪距的定轨结果。更多还原

【Abstract】 Methods and theories of precise orbit determination of LEOS with GPS have been developed very quickly in recent years ,Using economy , consecutive, precise data from GPS receiver of LEO satellite , precise orbit determination of LEOS is efficiently achieved .Precise orbit determination with GPS has the good and applied foreground. Compared with differencing model, the method of precise orbit determination of low earth orbiters with GPS point positioning have a few advantages, such as no using of terrain receivers, small amount of work. It has a good foreground in precise orbit determination. So the theory, methods and some key issues of kinematic orbit determination are discussed in this dissertation:1. Observation equations and correction models have been presented in details in thispaper.The observation equations are related to user position, clock, and ambiguity parameters, it is the base of Precise Point Positioning .The correction model is quite important in PPP. This paper has presented the observation equations and correction model in details.2. The preprocessor is build up successfully through several combinations of observation.It was found that the geometric CHAMP orbit solutions are very sensitive to data editing performed in the preprocessor. Data editing consists of applying a signal-to-noise filter and a rate-of-change of widelane-phase minus narrowlane-pseudorange linear combination filter. The former removes low strength signals at the measurement input stage, while the latter eliminates measurements that deviate from the norm before the initial estimation process. This preprocessor strategy therefore cleans the data in the measurement domain, without need for post-estimation residual analysis or need for a reference CHAMP orbit to constrain the definition of typical measurement behaviour.3. The theories, principles, specific methods and selection of suitable design of GPS-based absolute OD are discussed at full length.Firstly, the principles, specific method and precision evaluation of GPS-basedOD using carrier-phase smoothed ionosphere-free combination of dual-frequeny P codes is discussed. Then the method of combination of both codes and carrier phase is discussed .The last results show that the precision of GPS-based absolute OD using carrier-phase smoothed ionosphere-free combination of dual-frequency P codes can attain 1 meter level, and the combination of both codes and carrier phase, can reach to less than 1 meter. 4. Ambiguity of ionosphere-free combination was well studied.For high speed LEOS, the ill-conditioned problem exists in absolute OD using GPS carrier phase data. To get rid of ill-conditioned problem, the P codes are used to constrain ambiguity solution. And the method using Melourne-Wubbena (M_W) linear combination of phase and code observations to first resolve the wide-lane ambiguities and the narrow-lane ambiguities resolved through ionosphere-free linear combination of the L] and L2 phase observations is not ok for POD, because of high speed change of ionosphere.更多还原