System for and method of determining the location of an object in a medium
First Claim
1. A system for determining the depth of an object having a first permittivity in a medium having a second permittivity substantially different to the permittivity of said object;
- the system comprising first transmitter means for transmitting electromagnetic radiation into said medium for reflection from said object; and
first receiver means for receiving radiation reflected from said object;
said first transmitter means being arranged in use to transmit electromagnetic radiation from either one or a plurality of first transmission locations along an axis over a surface of said medium adjacent said object; and
said first receiver means being arranged in use to receive electromagnetic radiation either at one first receiver location along said axis from said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object, the said first transmission location or each said first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically about a mid point of said axis;
the system including measurement means to measure the time taken for electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reception location by reflection from said object; and
calculation means to calculate the depth of said object in said medium using the measured propagation times and the predetermined distances separating the first transmission location or each first transmission location and the first reception location or each first reception location, the system further including second transmitter means like said first transmitter means and second receiver means like said first receiver means, said second transmitter means and said second receiver means being arranged in use to transmit or receive electromagnetic radiation respectively at one or a plurality of second transmission locations and second reception locations respectively along said axis in a like manner to said first transmitter means and said first receiver means;
the first transmission location or each first transmission location, the second transmission location or each second transmission location, the first reception location or each first reception location and the second reception location or each second reception location forming a symmetrical arrangement about said mid point of said axis;
said measurement means being adapted to measure the time taken for the electromagnetic radiation to propagate from the second transmission location or each second transmission location to the second reception location or each second reception location by reflection from said object;
said calculation means being adapted to calculate a first depth using the measured propagation times for electromagnetic radiation traveling from the first transmission location or each first transmission location to the first reception location or each first reception location and a second depth using the measured propagation times for electromagnet radiation travelling from the second transmission location or each second transmission location to the second reception location or each second reception location, the system including comparison means to compare said first depth with said second depth to determine which direction the first transmission location or each first transmission location, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point.
3 Assignments
0 Petitions
Accused Products
Abstract
The depth of a metal object (for example) beneath the ground (for example) is measured by measuring propagation times of electromagnetic radiation travelling in two different paths within the ground, each from a transmission location via reflection from the object to a receiver location. There should be either multiple transmitter locations, multiple receiver locations or both and the spacing in the ground plane between the transmitter and receiver locations is known. By mathematically manipulating the propagation times for reflected signals travelling in different paths, dependence on the permittivity of the ground itself can be eliminated from the calculation of depth.
68 Citations
31 Claims
-
1. A system for determining the depth of an object having a first permittivity in a medium having a second permittivity substantially different to the permittivity of said object;
- the system comprising first transmitter means for transmitting electromagnetic radiation into said medium for reflection from said object; and
first receiver means for receiving radiation reflected from said object;
said first transmitter means being arranged in use to transmit electromagnetic radiation from either one or a plurality of first transmission locations along an axis over a surface of said medium adjacent said object; and
said first receiver means being arranged in use to receive electromagnetic radiation either at one first receiver location along said axis from said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object, the said first transmission location or each said first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically about a mid point of said axis;
the system including measurement means to measure the time taken for electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reception location by reflection from said object; and
calculation means to calculate the depth of said object in said medium using the measured propagation times and the predetermined distances separating the first transmission location or each first transmission location and the first reception location or each first reception location, the system further including second transmitter means like said first transmitter means and second receiver means like said first receiver means, said second transmitter means and said second receiver means being arranged in use to transmit or receive electromagnetic radiation respectively at one or a plurality of second transmission locations and second reception locations respectively along said axis in a like manner to said first transmitter means and said first receiver means;
the first transmission location or each first transmission location, the second transmission location or each second transmission location, the first reception location or each first reception location and the second reception location or each second reception location forming a symmetrical arrangement about said mid point of said axis;
said measurement means being adapted to measure the time taken for the electromagnetic radiation to propagate from the second transmission location or each second transmission location to the second reception location or each second reception location by reflection from said object;
said calculation means being adapted to calculate a first depth using the measured propagation times for electromagnetic radiation traveling from the first transmission location or each first transmission location to the first reception location or each first reception location and a second depth using the measured propagation times for electromagnet radiation travelling from the second transmission location or each second transmission location to the second reception location or each second reception location, the system including comparison means to compare said first depth with said second depth to determine which direction the first transmission location or each first transmission location, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
- the system comprising first transmitter means for transmitting electromagnetic radiation into said medium for reflection from said object; and
-
19. A system for determining a position on the surface of a medium closest to an object at a depth in said medium, said medium having permittivity substantially different to the permittivity of said object, the system comprising first transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
- second transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
first receiver means for receiving radiation transmitted by said first transmitter means and reflected by said object;
second receiver means for receiving radiation transmitted by said second transmitter means and reflected by said object;
each of said first and second transmitter means being arranged in use to transmit electromagnetic radiation from either one or a plurality of first or second transmission locations respectively along an axis over said surface of said medium in the vicinity of said object, and each of said first and second receiver means being arranged in use to receive electromagnetic radiation either at one first or second receiver location respectively along said axis from said plurality of first or second transmission locations respectively after reflection from said object, or at a plurality of first or second reception locations respectively along said axis from either said one or said plurality of first or second transmission locations respectively after reflection from said object, the first transmission location or each first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically along said axis, the second transmission location or each second transmission location and the second reception location or each second reception location being separated by predetermined distances and arranged asymmetrically along said axis, the first transmission location or each first transmission location and the first reception location or each first reception location being arranged in symmetrically opposed positions about a mid point of said axis to the second transmission location or each second transmission location and the second reception location or each second reception location;
the system including measurement means to measure the time taken for the electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reception location and from the second transmission location or each second transmission location to the second reception location or each second reception location by reflection from said object; and
determination means to determine from the measured times which direction the first transmission location or each first transmission location, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point. - View Dependent Claims (20, 21, 22)
- second transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
-
23. A method of determining the depth of an object in a medium having a permittivity substantially different to the permittivity of the object, the method comprising the steps of transmitting electromagnetic radiation into said medium from either one or a plurality of first transmission locations along an axis over a surface of said medium adjacent said object;
- receiving electromagnetic radiation either at one first reception location along said axis from either said one or said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object;
the first transmission location or each said first transmission location and the first reception location or each first reception location being arranged asymmetrically along said axis and separated by predetermined distances;
measuring the time taken for electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reflection location by reflection from said object; and
calculating the depth of said object in said medium using the measured propagation times and the predetermined distances separating the first transmission location or each first transmission location and the first reception location or each first reception location, the method further including the steps of transmitting electromagnetic radiation into said medium from either one or a plurality of second transmission locations along said axis;
receiving electromagnetic radiation either at one second reception location along said axis from said plurality of second transmission locations after reflection from said object, or at a plurality of second reception locations along said axis from either said one or said plurality of second transmission locations after reflection from said object;
the first transmission or each first transmission location and the first reception location or each first reception location being arranged in symmetrically opposed positions about a mid point of said axis to the second transmission location or each second transmission location and the second reception location or each second reception location;
the step of measuring including the step of measuring the time taken for electromagnetic radiation to propagate from the second transmission location or each second transmission location to the second reception location or each second reception location;
the step of calculating including the step of calculating a second depth using the measured propagation times for electromagnetic radiation propagating from the second transmission location or each second transmission location to the second reception location or each second reception location;
comparing the calculated depths to determine which direction the first transmission location or each first transmission location, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicular to said axis from said mid point. - View Dependent Claims (24, 25, 26, 27, 28)
- receiving electromagnetic radiation either at one first reception location along said axis from either said one or said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object;
-
29. A method of determining a position on the surface of a medium closest to an object at a depth in said medium, said medium having a permittivity substantially different to the permittivity of said object, the method comprising the steps of:
- transmitting electromagnetic radiation into said medium from either one or a plurality of first transmission locations and from either one of a plurality of second transmission locations arranged along an axis over the surface of said medium i the vicinity of said object;
receiving electromagnetic radiation either at one first reception location along said axis from said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object;
receiving electromagnetic radiation either at one second reception location along said axis from said plurality of second transmission locations after reflection from said object, or at a plurality of second reception locations along said axis from either said one or said plurality of second transmission locations after reflection from said object;
the first transmission location or each first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically along said axis;
the second transmission location or each second transmission location and the second reception means or each second reception location being separated by predetermined distances and arranged asymmetrically along said axis;
the first transmission location or each first transmission location and the first reception location or each first reception location being arranged in symmetrically opposed positions about a mid point of said axis to the second transmission location or each second transmission location and the second reception location or each second reception location;
measuring the time taken for the electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each second reception location;
measuring the time taken for the electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reception location and from the second transmission means or each second transmission location to the second reception location or each second reception location by reflection from said object; and
determining from the measured time which direction the first transmission location or each first transmission location, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point.
- transmitting electromagnetic radiation into said medium from either one or a plurality of first transmission locations and from either one of a plurality of second transmission locations arranged along an axis over the surface of said medium i the vicinity of said object;
-
30. A system for determining a position on the surface of a medium closest to an object at a depth i said medium, said medium having a permittivity substantially different to the permittivity of said object, the system comprising first transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
- second transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
first receiver means for receiving radiation transmitted by said first transmitter means and reflected by said object;
second receiver means for receiving radiation transmitted by said second transmitter means and reflected by said object;
each of said first and second transmitter means being arranged in use to transmit electromagnetic radiation from either one or a plurality of first or second transmission location respectively along an axis over said surface of said medium in the vicinity of said object, and each of said first and second receiver means being arranged in use to receive electromagnetic radiation either at one first or second receiver location respectively along said axis from said plurality of first or second transmission locations respectively after reflection from said object, or at least a plurality of first or second reception locations respectively along said axis from either said one or said plurality of first or second transmission locations respectively after reflection from said object, the first transmission location or each first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically along said axis, the second transmission location or each second transmission location and the second reception location or each second reception location being separated by predetermined distances and arranged asymmetrically along said axis, the first transmission location or each first transmission location and the first reception location or each first reception location being arranged in symmetrically opposed positions about a mid point of said axis to the second transmission location or each second transmission location and the second reception location or each second reception location;
the system including measurement means to measure the time taken for the first electromagnetic radiation to propagate from the first transmission location or each first transmission location top the first reception location or each first reception location and from the second transmission location or each second transmission location to the second reception location or each second reception location by reflection from said object;
ad determination means to determine from the measured times and said predetermined distances;a) which direction the first transmission location or each first transmission location, the second transmission location or each second transmission location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point; and b) the depth of said object.
- second transmitter means for transmitting electromagnetic radiation into said medium for reflection by said object;
-
31. A method of determining a position of the surface of a medium closest to an object at a depth in said medium, said medium having a permittivity substantially different to the permittivity of said object, the method comprising the steps of:
- transmitting electromagnetic radiation into said medium from either one or a plurality of first transmission locations and from either one or a plurality of second transmission locations arranged along an axis over the surface of said medium in the vicinity of said object;
receiving electromagnetic radiation either at one first reception location along said axis from said plurality of first transmission locations after reflection from said object, or at a plurality of first reception locations along said axis from either said one or said plurality of first transmission locations after reflection from said object;
receiving electromagnetic radiation either at one second reception location along said axis from said plurality of second transmission locations after reflection from said object, or at a plurality of second reception locations along said axis from either said one or said plurality of second transmission locations after reflection from said object;
the first transmission location or each first transmission location and the first reception location or each first reception location being separated by predetermined distances and arranged asymmetrically along said axis;
the second transmission location or each second transmission location and the second reception location or each second reception location being separated by predetermined distances and arranged asymmetrically along said axis;
the first transmission location or each first transmission location and the first reception location or each first reception location being arranged in symmetrically opposed positions about a mid point of said axis to the second transmission location or each second transmission location and the second reception location or each second reception location;
measuring the time taken for the electromagnetic radiation to propagate from the first transmission location or each first transmission location to the first reception location or each first reception location and from the second transmission location or each second transmission location to the second reception location or each second reception location by reflection from said object; and
determining from the measured times and said predetermined distances;a) which direction the first transmission locations or each first transmission locations, the first reception location or each first reception location, the second transmission location or each second transmission location and the second reception location or each second reception location should be moved to position said mid point of said axis so that said object lies in a direction extending perpendicularly to said axis from said mid point; and b) the depth of said object.
- transmitting electromagnetic radiation into said medium from either one or a plurality of first transmission locations and from either one or a plurality of second transmission locations arranged along an axis over the surface of said medium in the vicinity of said object;
Specification