多星座多频组合高精度基线解算算法研究及软件开发

发布时间：2018-03-28 22:04

本文选题：多星座多频融合　切入点：病态性　出处：《东南大学》2017年硕士论文

【摘要】：随着GPS、BDS、GLONASS、Galileo全球四大卫星导航系统的不断发展和完善,全球卫星导航系统进入多星座多频融合定位时代。多星座融合将有助于提高定位精度、可靠性,以及高遮挡、复杂环境下的可用性,而如何有效进行数据融合,是实现多星座融合基线定位解算关键技术之一;多频观测值组合具有快速固定模糊度的特性,目前BDS是唯一全星座播发三频信号的卫星系统,因此如何充分利用BDS三频观测值,建立附有BDS三频约束的GNSS基线解算模型,实现GPS/GLONASS/Galileo组合模糊度快速固定,对于推广我国BDS应用具有重要意义。鉴于此,本文针对以上问题进行了研究,主要内容与成果如下:1、详细阐述了多星座多频GNSS融合定位基础理论。对GPS、BDS、GLONASS、Galileo坐标系统、时间系统进行了对比分析并且实现了四系统时空统一;以BDS为例介绍了多频观测值线性组合以及GNSS定位中常见的双频观测值组合模型及其观测值噪声。2、GNSS多星座融合基线解算关键技术研究。在对模型病态性介绍的基础上,基于条件数法分析了基线解算模型病态性以及对模糊度解算的影响,基线解算中引入伪距观测方程,显著降低模型病态性加快模糊度收敛速度;针对短基线、中长基线、长基线不同特点以及CDMA信号卫星系统与FDMA信号卫星系统的差异,建立了适合于不同基线长度的GPS/BDS/GLONASS/Galileo四系统融合基线解算模型;实验结果表明:双系统、多系统融合定位精度优于单系统;短基线、中长基线四系统定位相对于单GPS,在N、E、U 三个方向定位精度分别提高了 53.3%、60.0%、42.8%和 47.2%、38.2%、42.8%,在GPS/BDS/GLONASS三系统组合中,42km、61km两组中长基线的平面和高程定位精度均优于2cm,119km、174km两组长基线平面定位精度优于2cm,高程优于4cm。3、附有BDS三频约束基线解算模型研究。针对BDS超宽巷模糊度固定,提出超宽巷模糊度搜索方法,通过该方法提高超宽巷模糊度固定成功率;利用已经固定的BDS模糊度,建立附有BDS三频约束的GPS/GLONASS/Galileo基线解算模型;实验结果表明:对于短基线,采用约束模型Ratio值大于50为87.6%,而传统基线解算模型不足10%,采用约束模型法方程条件数比传统方法小2～4个数量级,显著减弱模型病态性,提高模糊度固定可靠性。4、GNSS多星座多频融合基线解算软件(GBSS)研发及测试。利用前述的理论算法成果,开发了一套GPS/BDS/GLONASS/Galileo四系统融合基线解算软件;利用多组数据进行实验验证,结果表明,不同长度基线GBSS与GAMIT解算基线向量互差均小于1cm,单独采用GBSS软件对14901条基线进行处理,N、E两个方向定位精度优于1cm分别占99.7%、96.9%,从而验证了软件的可靠性与稳定性。
[Abstract]:With the continuous development and perfection of GPS BDS GLONASS Galileo global four satellite navigation systems, the global satellite navigation system has entered the era of multi-constellation multi-frequency fusion positioning. Multi-constellation fusion will help to improve positioning accuracy, reliability, and high occlusion. Availability in complex environment, and how to effectively perform data fusion, is one of the key techniques to solve base-line positioning of multi-constellation fusion, and multi-frequency observation value combination has the characteristics of fast fixed ambiguity. At present, BDS is the only satellite system in which the three-frequency signal is broadcast in the whole constellation. Therefore, how to make full use of the BDS three-frequency observation value to establish the GNSS baseline solution model with BDS tri-frequency constraint, so as to realize the fast fixing of GPS/GLONASS/Galileo combination ambiguity. It is of great significance to popularize the application of BDS in China. In view of this, this paper studies the above problems, the main contents and results are as follows: 1, the basic theory of multi-constellation multi-frequency GNSS fusion positioning is elaborated in detail. The time system is compared and analyzed and the four systems are unified in time and space. Taking BDS as an example, this paper introduces the linear combination of multi-frequency observations and the common dual-frequency observation combination model in GNSS location, and the key technology of the baseline solution of the multi-constellation fusion baselines. Based on the introduction of the ill-condition of the model, the key technology of the base-line solution of the multi-constellation fusion is studied. Based on the conditional number method, the ill-condition of the baseline solution model and its influence on the ambiguity resolution are analyzed. The pseudo-range observation equation is introduced into the baseline solution, which can significantly reduce the ill-condition of the model and accelerate the convergence speed of ambiguity. Different characteristics of long baseline and the difference between CDMA signal satellite system and FDMA signal satellite system are used to establish a GPS/BDS/GLONASS/Galileo four-system fusion baseline solution model suitable for different baseline lengths. The accuracy of multi-system fusion positioning is better than that of single system. Relative to single GPS, the positioning accuracy of the middle and long baseline four system in three directions has been improved by 42.8% and 47.2% in the three directions, respectively, and 47.2% and 38.2%, respectively. The accuracy of plane and elevation positioning of the long baseline in the two groups of GPS/BDS/GLONASS system combination of 42 km / 61 km is better than that of 2cm 119km / 174km and 174km / s respectively. The positioning accuracy is better than 2 cm, the height is better than 4 cm. 3. The model of baseline solution with BDS tri-frequency constraint is studied. The ambiguity of BDS super-wide roadway is fixed. In this paper, a fuzzy searching method for ultra-wide roadway is proposed, by which the success rate of fixed ambiguity in ultra-wide roadway is improved, the GPS/GLONASS/Galileo baseline solution model with BDS tri-frequency constraint is established by using fixed BDS ambiguity, and the experimental results show that: for short baselines, The Ratio value of the constraint model is 87.6, while the traditional baseline solution model is less than 10. The conditional number of the constrained model equation is 2 ~ 4 orders of magnitude less than that of the traditional method, which significantly weakens the morbid property of the model. To improve the fixed reliability of ambiguity. 4% GNSS multi-constellation multi-frequency fusion baseline solution software (GBSS) is developed and tested. A GPS/BDS/GLONASS/Galileo four-system fusion baseline solution software is developed based on the theoretical and algorithmic results mentioned above, and the experimental results are verified by using multiple sets of data. The results show that the difference between GBSS and GAMIT solutions is less than 1 cm, and the accuracy of orientation of 14901 baselines is better than that of 1cm in two directions by using GBSS software. The reliability and stability of the software are verified.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P228.4

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