| 摘要: |
| 针对多星座下RTK（Real Time Kinematic）定位观测数据易被污染、模糊度搜索难度增大、固定率下降的问题，提出了基于抗差的改进部分模糊度固定方法。该方法首先通过引入IGGIII抗差算法调整观测权阵，将粗差的影响最小化，从而提高参数浮点解及其方差的精度。其次，依据高度角、信噪比和模糊度浮点解方差3个指标对可见卫星进行排序。随后采用LAMBDA(Least-square Ambiguity Decorrelation Adjustment)法进行模糊度固定，若固定失败，则依次剔除指标最差的卫星，再次进行模糊度固定，直至固定成功或卫星数不满足条件为止，从而确定模糊度固定最优子集。静态与动态测试下所提方法均能有效改善模糊度固定率和整体定位精度。相比于全模糊度固定方法，该方法模糊度固定率最大提升28.8%，定位精度在东、北、天3个方向上分别最大提升72%、62%和70%。 |
| 关键词: 部分模糊度固定 数据质量控制；抗差法；RTK |
| DOI：10.20079/j.issn.1001-893x.240524001 |
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| 基金项目:国家自然科学基金资助项目（11972079） |
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| An Improved Partial Ambiguity Resolution Method Based on the Robust Algorithm |
| ZHONG Xianfa,XU Chengdong,HUANG Guoxian,WU Ming |
| (School of Aerospace Engineering ,Beijing Institute of Technology ,Beijing 100081 ,China) |
| Abstract: |
| In multi-satellite navigation system positioning of real time kinematic(RTK),the observation data is easy to be contaminated,the ambiguity search difficulty increases and the fixed rate decreases.In order to solve these problems,an improved partial ambiguity resolution method based on the robust algorithm is proposed.Firstly,the IGGIII robust algorithm is introduced to adjust the observation weight matrix to minimize the influence of outliers,so as to improve the accuracy of the parameter floating point solution and its variance.Secondly,the visible satellites are sorted according to three indicators：elevation,signal-to-noise ratio(SNR) and variance of ambiguity floating solution.Then,the least-square ambiguity decorrelation adjustment(LAMBDA) method is used to fix the ambiguity.If the fixation fails,the satellite with the worst index is removed in turn,and the ambiguity is fixed again until the resolution is successful or the number of satellites does not meet the condition,so as to determine the optimal subset of ambiguity resolution.The proposed method can effectively improve the ambiguity fixed rate and the overall positioning accuracy both static and dynamic tests.Compared with that of the full ambiguity resolution method,the ambiguity resolution rate of the proposed method is increased by 28.8% at most.The positioning accuracy is improved by 72%,62% and 70% at most in East,North and Up directions,respectively. |
| Key words: partial ambiguity resolution data quality control robust method RTK |
