Magnetic Anomaly Detection And Processing System Based On Dual Vector Magnetometer

In recent years,the measurement technology based on the passive magnetic field has been paid more and more attention because of its ability to measure the real mag-netic field data and not affect the magnetic field.The key technology of weak mag-netic field measurement is to find magnetic anomaly by magnetic field sensor and ex-tract its magnetic field characteristics and analytical data.Based on the principle and characteristics of AMR sensor,this paper designs a set of magnetic anomaly detection and processing system based on the advantage of gradient measurement.The system includes the hardware detection part,the data acquisition part and the Labview magnetic field recording and analysis software part.The front-end hardware detection part is a more important part of the detection system,which is composed of magnetic signal acquisition circuit,reset/reset circuit and power supply circuit.The magnetic signal acquisition circuit realizes the conversion of the magnetic signal to the electric signal through the AMR sensor,and the subsequent processing of ampli-fication and filterin;Set/reset circuit implements a set of strong magnetic pulse gen-eration,will be out of order domain re arrangement,ensure that the sensor is main-tained in a state of high sensitivity;The power circuit provides different and stable power supply according to the working requirements of the two board.The data ac-quisition module adopts USB 6009 data acquisition card of NI company.The acquisi-tion card provides 8 single ended analog input channels,and the maximum sampling rate is 48ks/s,which meets the needs of design.Through the high-speed USB inter-face,data can be uploaded to the Labview magnetic field recording analysis software part.The software part of Labview magnetic field recording and analysis has the func-tion of real-time display,recording and analysis of the data waveform.In the acquisi-tion process,the software can observe the six road magnetic field intensity waveforms of two sensors X,Y and Z in real time,and support the data to be saved to the speci-fied folder.The measured data are analyzed and calculated by means of gradient measurement.This method can effectively overcome the influence of the earth's background magnetic field and the surrounding environment temperature changes on the system.By testing,the system can display the intensity of three-dimensional magnetic field in real time in Labview software,and make use of the gradient measurement method to make the detected magnetic anomalies prominent.