Short note: DHEM and spurious responses

A common area of application for DHEM is in defining extensions or additional lenses on the edges of current economic mineralisation. This may demand surveys in close proximity to infrastructure being conducted during mining operations. Numerous spurious responses may occur which do not necessarily fall into the three categories of noise as defined by McCracken et al (1986): namely, electromagnetic, geologic and observational. The response from an unnatural feature can have two general forms. The first is passive, as a spurious conductor, processed metal is generally far more conductive than our target commodities, albeit with a significantly reduced volume. The second is active, as a primary source of electromagnetic radiation.