基于经验累积分布归一化最优的GNSS综合随机模型

GNSS Comprehensive Stochastic Model Based on Empirical Cumulative Distribution Normalization Optimization

  • 摘要: 在复杂滑坡监测环境下,全球导航卫星系统(global navigation satellite system,GNSS)信号受大气延迟、多路径效应、局部遮挡等因素的影响,基于单一指标的高度角或信噪比随机模型无法满足复杂场景下的高精度定位需求。多模多频GNSS数据在复杂环境下站间数据质量差异也对建立精准可靠的随机模型提出了更高的要求。针对此,提出了一种基于经验累积分布归一化最优的GNSS综合随机模型,该模型基于高度角和信噪比信息进行构建,利用权重系数细化了单一模型间、多频多系统间以及测站间的差异对随机模型的影响程度。高遮挡环境下实验结果显示,模型连续10天的平均历元固定率为97.8%,相比高度角随机模型、信噪比随机模型和引入主成分分析的综合随机模型分别提高24.4%、25.6%和15.3%。固定解在东西向、北向和高程方向的均方根值分别为0.007 m、0.007 m和0.012 m。模型在提高历元固定率的同时,固定解精度能够满足复杂滑坡监测环境下GNSS厘米级定位需求。

     

    Abstract:
    Objectives In the complex landslide monitoring environment, the global navigation satellite system (GNSS) signals are affected by factors such as atmospheric delay, multipath effect, and local occlusion, resulting in the elevation or signal-to-noise ratio stochastic model based on a single index can not meet the high-precision positioning in complex scenes. Meanwhile, variations in data quality among stations using multi-mode and multi-frequency GNSS observations further increase the demand for accurate and reliable stochastic modeling.
    Methods In order to solve this problem, a GNSS comprehensive stochastic model based on empirical cumulative distribution normalization optimization is proposed. The model is constructed based on elevation and signal-to-noise ratio information, and the weight coefficient is used to refine the influence of differences between single model, multi-frequency and multi-system and stations on the stochastic model.
    Results The experimental results under high occlusion environment show that the average fixed rate of the new model for ten consecutive days is 97.8%, which is 24.4%, 25.6% and 15.3% higher than that of the elevation stochastic model, the signal-to-noise ratio stochastic model and the comprehensive stochastic model with principal components analysis, respectively. The root mean square error of the fixed solutions is 0.007 m in the east/west and north directions and 0.012 m in the up direction.
    Conclusions The new model improves the epoch fixed rate while the accuracy of fixed solution can meet the requirement of GNSS centimeter positioning in complex landslide monitoring environment.

     

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