We propose a novel method that combines gray system theory and robust M-estimation method to suppress the interference in controlled-source electromagnetic data. We estimate the standard deviation of the data using a ...We propose a novel method that combines gray system theory and robust M-estimation method to suppress the interference in controlled-source electromagnetic data. We estimate the standard deviation of the data using a gray model because of the weak dependence of the gray system on data distribution and size. We combine the proposed and threshold method to identify and eliminate outliers. Robust M-estimation is applied to suppress the effect of the outliers and improve the accuracy. We treat the M-estimators of the preserved data as the true data. We use our method to reject the outliers in simulated signals containing noise to verify the feasibility of our proposed method. The processed values are observed to be approximate to the expected values with high accuracy. The maximum relative error is 3.6676%, whereas the minimum is 0.0251%. In processing field data, we observe that the proposed method eliminates outliers, minimizes the root-mean-square error, and improves the reliability of controlled-source electromagnetic data in follow-up processing and interpretation.展开更多
Time–frequency electromagnetic data contain frequency and transient electromagnetic information and can be used to determine the apparent resistivity both in the frequency and time domains.The observation data contai...Time–frequency electromagnetic data contain frequency and transient electromagnetic information and can be used to determine the apparent resistivity both in the frequency and time domains.The observation data contains three types of noise:the harmonics interference at 50 Hz,high-frequency random noise,and low-frequency noise.We use frequency-domain bandstop filtering to remove the harmonics interference noise,segmentation and extension median filtering,and fitting of fixed extremes in empirical mode decomposition to remove the high-frequency and low-frequency noise,respectively;furthermore,we base the selection of median filtering window size on the variance and skewness coefficient of the data.We first remove the harmonics interference at 50 Hz,then the high-frequency noise,and finally the low-frequency noise.We test the proposed methodology by using theory and experiments,and we find that the three types of noises are removed,the phase and amplitude information of the signal are maintained,and high-quality waveforms are obtained in the time domain.展开更多
现有广域电磁接收机采集监控设备便携性、人机交互、续航能力不佳给野外数据采集带来一定困难,为此可借助Android智能手机在普及率高、用户基础好、便携性佳、计算能力相对较强、人机交互好、续航能力佳、随时随地的无线通信能力等方面...现有广域电磁接收机采集监控设备便携性、人机交互、续航能力不佳给野外数据采集带来一定困难,为此可借助Android智能手机在普及率高、用户基础好、便携性佳、计算能力相对较强、人机交互好、续航能力佳、随时随地的无线通信能力等方面的优势实现监控设备朝轻量化和移动化发展,而实现该目标的关键在于设计一款针对通用Android平台智能手机的采集监控软件.该文在搭载Android系统的通用智能手机上设计开发了集Wi Fi(Wireless Fidelity)通信、多线程并行、实时监控、数据可视化、SQLite存储、文件存储于一体的应用程序,在其中可设置或接入WLAN(Wireless Local Area Network)无线局域网,设置测点、测线、采集周期、工作次数等采集任务参数,实时监控多台电磁接收机的运行状态,实现处理数据的双对数坐标显示等.经过试验表明该监控软件功能高效、便携性好,能极大方便工作人员的野外数据采集,具有一定的实际应用价值.展开更多
基金supported by the National Natural Science Foundation of China(No.41227803)the State High-Tech Development Plan of China(No.2014AA06A602)the Fundamental Research Funds for the Central Universities of Central South University(No.2017557)
文摘We propose a novel method that combines gray system theory and robust M-estimation method to suppress the interference in controlled-source electromagnetic data. We estimate the standard deviation of the data using a gray model because of the weak dependence of the gray system on data distribution and size. We combine the proposed and threshold method to identify and eliminate outliers. Robust M-estimation is applied to suppress the effect of the outliers and improve the accuracy. We treat the M-estimators of the preserved data as the true data. We use our method to reject the outliers in simulated signals containing noise to verify the feasibility of our proposed method. The processed values are observed to be approximate to the expected values with high accuracy. The maximum relative error is 3.6676%, whereas the minimum is 0.0251%. In processing field data, we observe that the proposed method eliminates outliers, minimizes the root-mean-square error, and improves the reliability of controlled-source electromagnetic data in follow-up processing and interpretation.
基金supported by the National Natural Science Foundation of China(No.41574127 and No.41227803)
文摘Time–frequency electromagnetic data contain frequency and transient electromagnetic information and can be used to determine the apparent resistivity both in the frequency and time domains.The observation data contains three types of noise:the harmonics interference at 50 Hz,high-frequency random noise,and low-frequency noise.We use frequency-domain bandstop filtering to remove the harmonics interference noise,segmentation and extension median filtering,and fitting of fixed extremes in empirical mode decomposition to remove the high-frequency and low-frequency noise,respectively;furthermore,we base the selection of median filtering window size on the variance and skewness coefficient of the data.We first remove the harmonics interference at 50 Hz,then the high-frequency noise,and finally the low-frequency noise.We test the proposed methodology by using theory and experiments,and we find that the three types of noises are removed,the phase and amplitude information of the signal are maintained,and high-quality waveforms are obtained in the time domain.
文摘现有广域电磁接收机采集监控设备便携性、人机交互、续航能力不佳给野外数据采集带来一定困难,为此可借助Android智能手机在普及率高、用户基础好、便携性佳、计算能力相对较强、人机交互好、续航能力佳、随时随地的无线通信能力等方面的优势实现监控设备朝轻量化和移动化发展,而实现该目标的关键在于设计一款针对通用Android平台智能手机的采集监控软件.该文在搭载Android系统的通用智能手机上设计开发了集Wi Fi(Wireless Fidelity)通信、多线程并行、实时监控、数据可视化、SQLite存储、文件存储于一体的应用程序,在其中可设置或接入WLAN(Wireless Local Area Network)无线局域网,设置测点、测线、采集周期、工作次数等采集任务参数,实时监控多台电磁接收机的运行状态,实现处理数据的双对数坐标显示等.经过试验表明该监控软件功能高效、便携性好,能极大方便工作人员的野外数据采集,具有一定的实际应用价值.
