Patent ID: 7397417
Filing Date: 2008-07-08
Classification: G01V

Abstract:
1. A passive geophysical prospecting apparatus, the apparatus comprising: an antenna, wherein said antenna comprises a magneto-resistive sensor and is configured to (i) detect an oscillating magnetic component of electromagnetic radiation naturally emanating from a section of the Earth's near surface while blocking a DC component of the electromagnetic radiation as the antenna traverses above said section, and (ii) generate an AC electrical antenna signal from said detected magnetic component; an amplifier adapted to amplify the antenna signal; a filter, wherein said filter is configured to filter from said antenna signal frequencies below 65 Hz and above 12,000 Hz to generate a filtered signal; a level detector, wherein said level detector is configured to determine when said filtered signal exceeds a reference voltage and generate a pulse; and a computer, wherein said computer is configured to analyze a plurality of pulses occurring over a unit of time to determine the absence or presence of a subsurface deposit of interest underneath said section.