CPC E21B 47/13 (2020.05) [E21B 7/046 (2013.01); E21B 47/024 (2013.01); E21B 47/0228 (2020.05); E21B 47/107 (2020.05)] | 20 Claims |
1. A system, comprising:
a transmitter that is configured to move through the ground in a region during an operational procedure while transmitting a depth signal at a depth frequency that is selectable in a rebar frequency range below a threshold frequency to provide at least some immunity to passive interference and which is also subject to electromagnetic noise that can vary within said region; and
a portable device configured to (i) measure the electromagnetic noise at a plurality of incrementally spaced apart frequencies in the rebar frequency range and (ii) compare the measured noise to a low noise threshold to identify a lowest one of the frequencies having a measured noise that satisfies the low noise threshold as a potential depth frequency.
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