传感技术学报
傳感技術學報
전감기술학보
Journal of Transduction Technology
2014年
7期
916-921
,共6页
磁异信号%相关检测%自适应AR白化滤波器%自适应噪声抵消器
磁異信號%相關檢測%自適應AR白化濾波器%自適應譟聲牴消器
자이신호%상관검측%자괄응AR백화려파기%자괄응조성저소기
magnetic anomaly detection%correlation detection%adaptive AR whitening filter%adaptive noise canceller
针对在分形噪声1/fα(0≤α<2)中检测磁异信号存在的问题,提出了一种自适应噪声抵消器与自适应AR白化滤波器相结合的磁异信号正交基函数( OBF)检测算法---改进的OBF检测算法。由于固定AR白化滤波器对分形噪声1/fα的白化效果不佳,影响了OBF检测算法的性能,因此采用自适应噪声抵消器对被检测信号进行预处理以提高其信噪比,再利用自适应AR白化滤波器对预处理信号进行白化滤波,以实现OBF检测算法的最优化。理论仿真结果表明:当α值接近于0时,改进的OBF检测算法的处理增益略高于未经白化的OBF检测算法;当α值接近于2时,改进的OBF检测算法的处理增益略高于基于AR白化滤波器的OBF检测算法;当α值约等于0.8时,改进的OBF检测算法的处理增益高于其他两种算法7 dB,实验结果表明改进的OBF检测算法可以检测更微弱的磁异信号。
針對在分形譟聲1/fα(0≤α<2)中檢測磁異信號存在的問題,提齣瞭一種自適應譟聲牴消器與自適應AR白化濾波器相結閤的磁異信號正交基函數( OBF)檢測算法---改進的OBF檢測算法。由于固定AR白化濾波器對分形譟聲1/fα的白化效果不佳,影響瞭OBF檢測算法的性能,因此採用自適應譟聲牴消器對被檢測信號進行預處理以提高其信譟比,再利用自適應AR白化濾波器對預處理信號進行白化濾波,以實現OBF檢測算法的最優化。理論倣真結果錶明:噹α值接近于0時,改進的OBF檢測算法的處理增益略高于未經白化的OBF檢測算法;噹α值接近于2時,改進的OBF檢測算法的處理增益略高于基于AR白化濾波器的OBF檢測算法;噹α值約等于0.8時,改進的OBF檢測算法的處理增益高于其他兩種算法7 dB,實驗結果錶明改進的OBF檢測算法可以檢測更微弱的磁異信號。
침대재분형조성1/fα(0≤α<2)중검측자이신호존재적문제,제출료일충자괄응조성저소기여자괄응AR백화려파기상결합적자이신호정교기함수( OBF)검측산법---개진적OBF검측산법。유우고정AR백화려파기대분형조성1/fα적백화효과불가,영향료OBF검측산법적성능,인차채용자괄응조성저소기대피검측신호진행예처리이제고기신조비,재이용자괄응AR백화려파기대예처리신호진행백화려파,이실현OBF검측산법적최우화。이론방진결과표명:당α치접근우0시,개진적OBF검측산법적처리증익략고우미경백화적OBF검측산법;당α치접근우2시,개진적OBF검측산법적처리증익략고우기우AR백화려파기적OBF검측산법;당α치약등우0.8시,개진적OBF검측산법적처리증익고우기타량충산법7 dB,실험결과표명개진적OBF검측산법가이검측경미약적자이신호。
As for the poor effect of correlation detection algorithm based on orthonormal basis functions( OBF) with AR whitening filter in pink noise 1/fα(0 ≤α<2),a new OBF detection algorithm was proposed,which is 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 improved algorithm was verified by the simulation data and actual measured data. The simulation results show that when αis close to zero,the improved algorithm has advantage over OBF detection algorithm without whitening filter. And the improved algorithm is better than OBF detection algorithm based on AR whitening filter,whenαapproaches to 2. Especially,whenαis approximately equal to 0. 8,the output SNR of the improved algorithm is 7 dB higher than the other two algorithms mentioned above. The experiment results show that the improved algorithm increases the detection ability of weak magnetic anomaly signal in pink noise.