基于经验小波变换的GNSS多路径误差改正

多路径误差是影响GNSS测量精度的主要因素及误差改正难点。将经验小波变换(EWT)算法在分解复杂信号上的优势与GNSS多路径误差的周日重复特性相结合，提出基于EWT的多路径误差提取及改正新方法。将能量熵与相关系数相结合来定义筛选系数，并将其变化显著的点作为含噪分量及信息分量的分界点；通过对含噪分量进行去噪并与信息分量重构的方式建立基于EWT的去噪新方法。模拟和实测数据实验表明，EWT能较好地提取及改正GNSS多路径误差，并且其效果显著优于EMD及小波分析方法。

GNSS Multipath Error Correction Based on Empirical Wavelet Transform

Multipath error is the main factor affecting the measurement accuracy of GNSS and the difficulty of error correction. Combining the advantages of empirical wavelet transform(EWT) algorithm in the decomposition of complex signals with the daily repetition characteristics of GNSS multipath error, we propose a new method of multipath error extraction and correction based on EWT. The screening coefficient is defined by combining the energy entropy with the correlation coefficient, and the points with significant changes are taken as the dividing points of the noisy components and the information components. A new denoising method based on EWT is established by denoising the noisy components and reconstructing the information components. Through the analysis of simulation and experiment data, it is shown that EWT can extract and correct the GNSS multipath error better than EMD and wavelet method.