GNSS实时高精度单差测姿方法与关键技术

In GNSS-based attitude determination applications with double-differenced model, the strong vertical geometry inhomogeneity of the satellite sky distribution will lead to strong mathematical correlations among the estimates of relative receiver clock and vertical component of baseline coordinates, which further result in much lower accuracy of pitch and roll, which is closely related to the vertical component of baseline coordinates. It has become a bottleneck problem that restricts GNSS high-precision attitude determination applications. An effective way to solve this problem is using GNSS receivers with a common clock to eliminate the influence of the relative receiver clock error directly from the hardware level, and meanwhile using the single-differenced model to achieve high precision solutions for vertical component of baseline coordinates. Consequently, the achievable accuracy and reliability of pitch and roll is significantly improved. For this purpose, this project intends to carry out research on approach of GNSS real-time and high-precision attitude determination with single-differenced model. We then solve the key techniques such as real-time fast and accurate estimation, modeling and prediction of the Line Bias, and the theoretical proof of the contributions that the single-differenced model give rise to ambiguity resolution, etc. Finally, we realize the real-time high-precision data processing for GNSS attitude determination based on single-differenced model. This will improve the capability of GNSS high-precision attitude determination in military and civil field. This research is of great academic value and wide range of application prospect to develop and improve the theory and method of GNSS attitude determination with single-differenced model, and promote the development of GNSS real-time high-precision positioning and attitude determination technology.

在当前普遍采用的基于双差模型的GNSS姿态测量中，垂直方向上非对称的几何观测条件使得接收机相对钟差与高程方向基线分量间具有显著的数学相关性，进而导致与垂直分量紧密相关的俯仰角和横滚角的测量精度偏低，其已成为限制GNSS测姿高精度应用的瓶颈问题。解决此问题的有效途径是采用共时钟接收机从硬件层面直接消除接收机相对钟差的影响，同时结合单差处理方法实现高程方向基线分量的高精度解算，最终显著提升俯仰角与横滚角的精度与可靠性。为此，本项目拟开展GNSS实时高精度单差测姿方法研究，解决LBias的实时快速准确估计与建模预报、单差模型对模糊度解算贡献的理论证明等关键问题，实现多频GNSS单差测姿实时高精度数据处理，提升GNSS测姿技术在军事与民用领域的高精度应用能力。项目研究对发展完善GNSS单差测姿的理论与方法，推动GNSS实时高精度定位测姿技术的进步，具有重要的学术价值和广阔的应用前景

在当前普遍采用的基于双差模型的GNSS姿态测量中，垂直方向上非对称的几何观测条件使得接收机相对钟差与高程方向基线分量间具有显著的数学相关性，进而导致与垂直分量紧密相关的俯仰角与横滚角的测量精度偏低，其已成为限制GNSS测姿高精度应用的瓶颈问题。解决此问题的有效途径是采用共时钟接收机从硬件层面直接消除接收机相对钟差的影响，同时结合单差处理方法实现高程方向基线分量的高精度解算，最终显著提升俯仰角与横滚角的精度与可靠性。为此，本项目研究了GNSS实时高精度单差测姿方法与关键技术。构建了基于共时钟接收机的GNSS多频单差测姿模型；建立了LB的事后精确估计方法，并从短期稳定性与长期稳定性以及接收机重启、GNSS天线类型、线缆长度等影响因素方面，全面细致地分析了LB的产生机制、时变特征以及影响因素；提出并实现了基于单维粒子滤波以及改进的多维粒子滤波的相位LB实时估计方法，可在无相位LB先验信息、不增加额外相位LB参数的情形下，实现相位LB的实时快速准确估计；从理论上揭示了单差模型提升模糊度解算效果的机制；研制了一套基于共时钟接收机的GNSS多频多系统单差测姿精密数据处理软件，并采用实测数据评估了GNSS单差模型的相对定位与测姿精度。项目研究对发展完善GNSS单差测姿的理论与方法，推动GNSS实时高精度定位测姿技术的进步，提升GNSS测姿技术在军事与民用领域的高精度应用能力，具有重要的学术价值和广阔的应用前景。