The positioning receiver system of pipeline inner detector based on extremely low frequency electromagnetic signal

The location technology of oil and gas pipeline inner detector can improve the performance and application value of detector. In view of the shielding characteristics of electromagnetic signals in underground pipelines, the magnetic dipole model of extremely low frequency (ELF) electromagnetic signal transmitting antenna is studied and the principle of positioning technology based on ELF electromagnetic wave is deduced in this paper. Then, the working principle of the positioning system is introduced and the receiving and processing method of weak electromagnetic signal is expounded. According to the demand of engineering applications, the positioning receiver system of pipeline inner detector is designed and the engineering prototype is manufactured. The experimental results show that the positioning receiver system can realize the localization of the pipeline inner detector, and the location accuracy of the pipeline defect could be corrected by using the time reference of global positioning system (GPS). Its effective detecting depth and positioning accuracy meet the demand of engineering.