Application of Low Pass Filter and Orthonormalized Functions Decomposition Algorithm in Magnetic Target Detection

Magnetic anomaly signal of magnetic target is low frequency signal by the analysis of time and frequency characteristic and SNR is low in magnetic anomaly detection. A new algorithm is proposed using FIR lowpass filter integrated into orthonormalized functions decomposition algorithm. Firstly constrained least square FIR filter is designed to filter the high frequency noise in the raw signal by the analysis of filter characteristic. Then the disposed signal is decomposed by orthonormalized functions decomposition algorithm to increase SNR. The simulation result demonstrates the method can filter the high frequency noise and increase the SNR to improve the detection ability of magnetic objects.