Signal Processing Technique for a Metal Detector

A method for improving a metal detector, including: processing at least one receive signal due to a receive magnetic field using at least two functions to produce two processed signals, the at least two functions are selected such that the first processed signal is more sensitive to deeply buried targets than the second processed signal; and the second processed signal is more sensitive to shallow-buried conductive objects with characteristic frequency greater than 100 kHz than the first processed signal but not sensitive to saline soil, and that the two processed signals substantially complement each other in terms of sensitivity to targets in terms of target frequency and detection depth; and processing the two processed signals to produce at least one output signal which is sensitive to deeply buried low-frequency targets, shallow-buried low-frequency targets and shallow-buried high-frequency targets while signals due to saline soil are substantially rejected from the output signal.