摘要
磁悬浮陀螺全站仪定向系统中转子电流数据的噪声是影响仪器定向精度的重要因素之一。文章经统计分析知转子电流信号为非平稳信号,对其进行对比分析,确定选取特定的阈值和小波基函数对转子电流信号进行小波阈值去噪。借助信噪比、均方根误差和平滑度多类评价指标的变化特征随小波分解层数增加而收敛的特性,来确定最佳分解层数。实验结果表明:此种方法实现了转子电流有效信号和环境噪声信号的有效分离,剔除了不同观测环境条件下转子电流观测数据的噪声,提高仪器的定向精度。
The noise of rotor current data in the directional system for the maglev gyro total station is one of the important factors affecting the accuracy of the instrument orientation. In the paper, through the statistical analysis, it was known that the rotor current signal is non-stationary. After the comparative analysis, the rotor current signal was de-noised with wavelet threshold by determination of the specific threshold and wavelet function. The optimal decomposition level was determined by the characteristic that the multiclass evaluation index variation including of SNR, the root mean square error and smoothness converge with the increase of wavelet decomposition levels. The experimental results showed that the method could realize the effective separation between rotor current signal and noise signal, eliminate the noise of the rotor current observation data under different observation conditions, and improve the direc tional accuracy of the instrument.
出处
《测绘科学》
CSCD
北大核心
2014年第11期29-32,24,共5页
Science of Surveying and Mapping
基金
安徽省卓越人才培养计划质量工程项目资助项目(2012zjjh003)
中央高校基本科研业务费专项资金资助项目(J2014HGBZ0130)
关键词
磁悬浮陀螺全站仪
小波分析
阈值去噪
最佳分解层数
测量数据处理
maglev gyro total station
wavelet analysis
threshold denoising
optimal decompositionlevel
surveying processing
