Patent ID: 9568635
Date: 2017-02-14
CPC Classifications: G01V

Claim:
1. A system for mapping the soil using electromagnetic transmitters and receivers inserted within boreholes extending to any practical depth, wherein, the distance between said electromagnetic transmitters and receivers are maximized by operating at the local resonant frequency (f) of the soil f=(1/2π)[L(μ)C(∈)] −12 where the resistance is minimal and wherein, activating the transmitter for a short wavelet time “Δt=(3λ/V)” wherein (λ) is the wavelength and (V) the speed of the radiation in said soil, such that at least one wavelet of radiation reaches the receiver in least-time, hereinafter referred to as the straight-line distance “SLD”, and wherein, the receiver stays shut for a time period equal to the propagation-time “T0” between the transmitter and the receiver, and after said “T0” time, it opens for the short time “Δt” and wherein, all events arriving at the receiver are checked for the phase shift “Δφ” between their original phase “φ 0 ” when transmitted, and the current one “φc”, and if there is a phase difference “Δφ=φc−φ0” larger than φmin, they are not given access to the receiver, and wherein, the polarization of all the events arriving at the receiver are passed through a mechanical polarization filter tuned to the same linear polarization, when emitted by the transmitter, so that events with a different polarization are eliminated, and wherein, both the receiver and the transmitter wait for several “T0” periods, hereinafter referred to as an “nT0” period, where (n)>(nmin), until all events detected by the receiver subside, and wherein, the sequence comprising, the transmitter transmitting for Δt period, followed by the receiver waiting for “T0” period and opening for a “Δt” period and shutting back, and then waiting for “nT0” period, is repeated “m” times, until the cumulative “Straight-Line” events overcome the random noise of the receiver and consequently reach the minimal sensitivity level of the receiver and trigger it, and wherein, the maximal distance between the transmitter and the receiver at which the receiver is triggered according to the above procedure, is referred to as the maximal “SLD”.