Patent ID: 7088105
Filing Date: 2006-08-08
Classification: G01V

Abstract:
1. A locator for identifying a passive electromagnetic signal emitted from an underground utility, said locator comprising: a portable housing; an antenna disposed within said housing; a control circuit; and a frequency bandpass circuit disposed operatively between said antenna and said control circuit so that said bandpass circuit receives measurement signals from said antenna corresponding to electromagnetic signals received by said antenna and passes to said control circuit a portion of said received measurement signals within a frequency pass band, wherein said control circuit sequentially sets said bandpass circuit to a plurality of different frequency pass bands within a measurement frequency range expected to include a frequency of said passive electromagnetic signal, receives said measurement signal portion corresponding to each said frequency pass band set by said control circuit and selects at least one of said different frequency pass bands corresponding to said frequency of said passive electromagnetic signal based on a predetermined criteria applied to said corresponding measurement signal portions.