Object locating system
First Claim
1. A method for locating an object that is positioned within a material having a relative permittivity and a conductivity, comprising:
- obtaining an indicia of said relative permittivity of said material in which said object is positioned;
radiating a transmitter signal into said material, said transmitter signal having a transmitter frequency;
passively reradiating said transmitter signal as a reradiated signal;
detecting said reradiated signal with a receiver antenna;
determining an indicia of phase of said reradiated signal; and
determining an indicia of distance from said receiver antenna to said object using said indicia of phase and said indicia of said relative permeability.
1 Assignment
0 Petitions
Accused Products
Abstract
A portable system is provided that is operational for determining, with three dimensional resolution, the position of a buried object or a proximately positioned object that may move in space or air or gas. The system has a plurality of receivers for detecting the signal from a target antenna and measuring the phase thereof with respect to a reference signal. The relative permittivity and conductivity of the medium in which the object is located is used along with the measured phase signal to determine a distance between the object and each of the plurality of receivers. Knowing these distances, an iteration technique is provided for solving equations simultaneously to provide position coordinates. The system may also be used for tracking movement of an object within close range of the system by sampling and recording subsequent positions of the object. A dipole target antenna, when positioned adjacent to a buried object, may be energized using a separate transmitter which couples energy to the target antenna through the medium. The target antenna then preferably resonates at a different frequency, such as a second harmonic of the transmitter frequency.
42 Citations
46 Claims
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1. A method for locating an object that is positioned within a material having a relative permittivity and a conductivity, comprising:
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obtaining an indicia of said relative permittivity of said material in which said object is positioned; radiating a transmitter signal into said material, said transmitter signal having a transmitter frequency; passively reradiating said transmitter signal as a reradiated signal; detecting said reradiated signal with a receiver antenna; determining an indicia of phase of said reradiated signal; and determining an indicia of distance from said receiver antenna to said object using said indicia of phase and said indicia of said relative permeability. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for locating a buried object that is buried in a material having a conductivity and a relative permittivity, comprising:
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producing a transmitter signal having a transmitter frequency; filtering said transmitter signal to remove harmonics of said transmitter frequency; providing said buried object with a dipole target antenna having a non-linear element electrically connected thereto; energizing said dipole target antenna with said transmitter signal, said energized target antenna reradiating a reradiated signal, said reradiated signal having a frequency that is different from said transmitter frequency due to said non-linear element; and receiving said reradiated signal. - View Dependent Claims (10, 11, 12, 13)
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14. A system for locating an object disposed within a medium having a conductivity and a relative permittivity, comprising:
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a transmitter for producing a transmit signal, said transmit signal having at least one transmitter frequency; a target antenna for said object, said target antenna providing a reradiated signal; a first receiver, said first receiver being tuned to said reradiated signal; a calculation unit having a memory element operative for storage of an indicia of said conductivity, said calculation unit and said memory element having circuitry for determining an indicia of distance between said transmitter and said target antenna. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 46)
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26. A system for locating an object proximately positioned with respect to said system, comprising:
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a microwave transmitter circuit for producing a transmit signal in the 10 to 100 MHz frequency range; a target antenna for said object, said target antenna being energized by said transmit signal; a plurality of microwave receivers, each of said plurality of microwave receivers measuring the phase of the transmitted signal and having a known relative position with respect to said microwave transmitter; and a calculation unit, using the phase measurements from each of the receivers, for calculating respective distances between each of said plurality of microwave receivers and said target antenna, said calculation unit determining an X-Y position of said target antenna that may be expressed in terms of measurement units from a selected reference point. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A system for locating a buried object, said object being buried within a substantially solid material, said system comprising:
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at least one transmitter with a dipole transmitter antenna, said at least one transmitter broadcasting a transmitter signal in the range of 10 to 100 Mhz; a dipole antenna positioned for locating said object, said dipole antenna having a non-linear element mounted thereto, said dipole antenna being responsive to said transmitter signal for producing a reradiated signal, said reradiated signal being a harmonic of said transmitter signal; and at least one receiver for detecting said reradiated signal. - View Dependent Claims (40, 41, 42, 43, 44, 45)
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Specification