Research On MANAR Based On GMI Sensor

Magnetic sensor for detecting weak signal is the basis of many military applications, such as military target monitoring, exploration of the Earth's resources and geomagnetism-aided navigation. However, there is no evidence of micro magnetic sensor with wide-range and high resolution in our country, and we always import the magnetic sensor with 0.01 nT resolution from abroad. Accordingly, it is still one of the challenging problems in detection field to develop the high performance micro magnetic sensor.A detecting system for weak magnetic signal consists of a magnetic sensor, signal modulate circuit and data acquisition circuit. The work of this paper is to study the implementation technology of the high performance magnetic sensor, magnetic signal acquisition system and the detection algorithm.In order to produce the high performance micro magnetic sensor, we had studied the theoretical basis of GMI effect on amorphous wire. Then through the experiment constrasts, the key parameter of sensitive device based on the amorphous wire is confirmed. At last, we use the sensitive device to design and produce ‘MANAR', which is a new triaxial magnetic sensor for detecting magnetic anomaly signal and distance measurement.In the study of the magnetic signal acquisition system, we treat microprocessor SIM3U167 as the core of the system to design the hardware and software.In the detection of magnetic signal, a new detection algorithm based on OBF decomposition was proposed using an adaptive AR whitening filter combined with an adaptive noise canceller. Firstly, an adaptive noise canceller was designed to improve the input SNR of the magnetic anomaly signal. Secondly, the de-noised signal was whitened by the adaptive AR whitening filter. Finally,the whitened signal was passed through matched filters based on OBFs of the detected magnetic anomaly signal. The new algorithm was verified by the simulation data and actual measured data. And the results show that the improved algorithm will increase the output SNR significantly and the detection ability of weak magnetic anomaly signal in pink noise. Especially when ? equals to 0.8, the output SNR of the improved algorithm is increased by 7 dB.