Wavelet transform in denoising magnetic archaeological prospecting data

Magnetic measurements in archaeological prospecting are often affected by cultural noise having the same high-frequency content as anomalies arising from buried antiquities. Also, in many cases the microrelief of the ground surface causes a noise that is coherent, pseudorandom and periodic. The main cause of this kind of noise is the ploughing of the earth. In this paper the efficiency of a wavelet denoising scheme is tested with respect to these types of unwanted disturbances. The proposed scheme combines the cyclospinning algorithm with a variable threshold calculated in each cycle of the algorithm. Tests on synthetic and real data show a satisfactory performance of the technique in suppressing both the white noise and the coherent noise caused by the systematic undulations of the ground surface. Copyright © 2007 John Wiley & Sons, Ltd.