CA2359599A1 - Positioning system for ground penetrating radar instruments - Google Patents
Positioning system for ground penetrating radar instruments Download PDFInfo
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- CA2359599A1 CA2359599A1 CA002359599A CA2359599A CA2359599A1 CA 2359599 A1 CA2359599 A1 CA 2359599A1 CA 002359599 A CA002359599 A CA 002359599A CA 2359599 A CA2359599 A CA 2359599A CA 2359599 A1 CA2359599 A1 CA 2359599A1
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- gpr
- radar
- ground penetrating
- positioning system
- penetrating radar
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/15—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation specially adapted for use during transport, e.g. by a person, vehicle or boat
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/885—Radar or analogous systems specially adapted for specific applications for ground probing
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- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Electromagnetism (AREA)
- Environmental & Geological Engineering (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geophysics (AREA)
- Geophysics And Detection Of Objects (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
A system and method of providing precise positioning necessary for three dimensional imaging of internals of structures using Ground Penetrating Radar and Electromagnetic instruments.
Description
Background of the Invention It is well known that radar energy that reflects off objects embedded in a medium, or off of sudden changes in the properties of the medium, can be used to understand the gross internal structure found inside the medium. This use of radar is commonly called Ground Penetrating Radar ("GPR"). GPR can be used to detect detail inside a structure such as column or wall or floor. Voids, rebar, conduit, cables, changes in material and material thickness can be detected.
Doerksen and Mc:Naughton Positioning System for Ground Penetrating Radar Instruments Pa ~e 2 of 6 Often the GPR unit is moved along a supposedly straight line on the surface.
This transect commonly has radar returns recorded at a fixed interval, such as every two centimeters, along the line. The start and end points of this line or the whole line are often manually marked on the surface being investigated. The data from a single transect can be processed to provide some useful information about the internal structure.
While a single transect can provide some useful information of the subsurface object distribution, further information and greater detail about the inside of the structure can be learned by gathering enough transects in close proximity to each other that a three dimensional reconstruction of the inside of structure can be generated. One challenge of using multiple transects is accurately knowing the location of each transect.
The common solution when attempting this is to manually mark out a series of parallel lines on the structure. The operator of the GPR unit there manually moves the GPR
instrument along each marked line. Considerable position error is introduced based on the inability of the human operator to follow these pre-drawn lines exactly.
This may be as a result of surface irregularities that the radar must be moved around, or as a lack of hand eye coordination of the user, or a combination of those and of other external stimuli, difficulties maintaining even tracking speed, attitude and location of the GPR
source and sensor unit. This positioning error reduces the accuracy of the three dimensional image that can be generated from the data.
There are three common methods to obtain position information corresponding to the radar data:
(1) the GPR unit is moved at an approximately fixed velocity by hand by the operator with radar readings being taken at set time intervals that will yield approximately the desired point spacing;
Doerksen and Mc:Naughton Positioning System for Ground Penetrating Radar Instruments Pa ~e 2 of 6 Often the GPR unit is moved along a supposedly straight line on the surface.
This transect commonly has radar returns recorded at a fixed interval, such as every two centimeters, along the line. The start and end points of this line or the whole line are often manually marked on the surface being investigated. The data from a single transect can be processed to provide some useful information about the internal structure.
While a single transect can provide some useful information of the subsurface object distribution, further information and greater detail about the inside of the structure can be learned by gathering enough transects in close proximity to each other that a three dimensional reconstruction of the inside of structure can be generated. One challenge of using multiple transects is accurately knowing the location of each transect.
The common solution when attempting this is to manually mark out a series of parallel lines on the structure. The operator of the GPR unit there manually moves the GPR
instrument along each marked line. Considerable position error is introduced based on the inability of the human operator to follow these pre-drawn lines exactly.
This may be as a result of surface irregularities that the radar must be moved around, or as a lack of hand eye coordination of the user, or a combination of those and of other external stimuli, difficulties maintaining even tracking speed, attitude and location of the GPR
source and sensor unit. This positioning error reduces the accuracy of the three dimensional image that can be generated from the data.
There are three common methods to obtain position information corresponding to the radar data:
(1) the GPR unit is moved at an approximately fixed velocity by hand by the operator with radar readings being taken at set time intervals that will yield approximately the desired point spacing;
(2) a measuring wheel (odometer) is incorporated into the GPR unit that triggers the data collection at set intervals of linear travel; and
(3) the operator manually triggers the reading at set intervals based on grid markings previously made on the structure or based upon a tape measure or marked string.
All three of the largely manual positioning techniques described above are poorly suited for three dimensional GPR imaging of structures due to the relatively large and inconsistent or unpredictable positioning error introduced.
More recently, two additional methods have been employed to gather the position information:
(1) a Differential Global Positioning System ("DGPS") where one Global Positioning System ("GPS") antenna is mounted to the GPR instrument and as the radar data is collected, the GPS co-ordinates are collected at the same time; and (2) a self-tracking laser theodohte is pointed at a reflector located on the GPR and the laser constantly tracks the location of the GPR instrument, calculating the GPR
instrument position based upon the angle of the laser and the laser pulse return time.
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 3 of 6 While the use of differential GPS is well suited to outdoor use when surveying large areas while looking for large objects, it is poorly suited for positioning on a structure for several reasons. First, the position error is large relative to the depth of investigation and the object resolution desired for most structural investigation. When looking at rebar within a concrete structure you maybe looking at objects with a 20 mm diameter at depths from just below the surface to 300 mm deep. An X,Y position error of 20 mm and a Z (vertical) position error of 60 mm would be the typical position error of a DGPS
system. This limits the usefulness of DGPS for this type oi= fine structural investigation.
The other major limit of DGPS is that often the location where the work is being done is where GPS will not work. It is either indoors or, when ouiaide, close to walls and other obstructions that obscure the necessary line-of-site to multiple GPS
satellites.
It is further known that laser positioning provides much better position accuracy than the other methods and is indeed suitable for GPR investigation of structures, including indoors use. It does however have a high cost and requires that line-of-site be maintained between the GPR instrument and the laser positioning system that is at a known location.
Summary of the Invention It is an object of the Invention to overcome limitations in the prior art as there exists a need for a low cost highly accurate positioning system Eor use with GPR and other instruments used to investigate what is inside structures. It is desirable that the position information be automatically collected and recorded along with the GPR data via a system and method of providing precise positioning necessary for three dimensional imaging of internals of structures using GPR and electromagnetic instruments.
These and other objects and advantages of the Invention are apparent in the following description of embodiments of the Invention, which is not intended to limit in any way the scope or the claims of the Invention.
Description of the Invention The following described embodiments of the Invention display preferred compositions but are not intended to limit the scope of the Invention. It will be obvious to those skilled in the art that variations and modifications may be made without departing from the scope and essential elements of the Invention.
A GPR instrument, or other like subsurface detection instruments, can be coupled with optical navigation technology to create a system for internal structure data collection that has highly accurate positioning. The positioning is sufficiently accurate so that it is suitable for three dimensional imaging of features within the desired size and position ranges, and the incremental system cost above the cost of the bare GPR
instrument is small. The system has the added advantage that the operator does not need to move the instrument in a highly ordered fashion over the surface. Also, an arbitrary data collection pattern can be used and does not need to be predetermined. In fact, the data Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 4 of 6 collection does not need to follow any preconceived or repeatable pattern at all and the movements of the instrument over the surface can be totally arbitrary or done to the operator's convenience or judgement, as long as sufficient data is collected in all the regions of interest.
Optical navigation is now highly developed in computer mice. The method involves capturing an image and then analyzing and tracking the motion of microscopic texture or other features on a surface along which the mouse is moved. Optical mice depend on tracking the surface detail and it is now understood that most surfaces are microscopically textured. When a light source such as a light emitting diode is used to illuminate these surface textures, a pattern of highlights and shadows is revealed.
Optical mice "watch" these surface details move by imaging them onto navigation integrated circuits (IC). Typically the optical-navigation IC captures images at the rate of over 1,000 pictures per second, using a small 16-by-16-pixel image sensor. As each image is captured, it is transferred to the processing and computation section of the navigation circuit, where the movement of the mouse is computed by comparing successive images.
Such a system can detect movement of the mouse relative to the surface in any direction.
This yields relative position which, when measured relative to markers or targets at known surface locations, can be transformed into real world coordinates.
Rotation (or relative attitude or "pitch and yaw' of the GPR unit's scanning function's focus of attention) can be detected by further processing of the returned image stream.
Alternately, two optical positioning sensors with some distance separating them can be used to measure their relative movement and thus resolve orientation information.
When the system is first placed on the surface to be investigated, the X,Y
starting point is set to some coordinates entered by the user in order to give an absolute positioning reference to the system. The system then records all relative movements from the starting point so that at all times the system knows its X,'~' location with respect to the starting point. Once the scan of an area is started, the system must at all times remain in contact with the surface in order to "know" or sense or calculate or infer its location. If it loses contact with the surface, it would need to be returned to a reference marker, and then the scan could continue. Positioning system drift can also be corrected by returning to a reference marker. Multiple reference markers at knovvn locations on the surface of the subject of interest can be used (that is, tracked over and noted or referenced during the scanning process) to further increase accuracy over a single marker. As the system begins recording data, in the case of GPR the amplitude of the return radar signal with respect to time, the system also records the surface position at the same time.
The optical navigation device ("OND") can not readily be positioned co-incident with the surface penetrating instrument. For example with GPR it would be desirable to locate the center of the OND at the center point between the radar transmitter and the radar receiver. Since this is not practical for reasons of physical room and interference with the radar signals, the OND must be located elsewhere on the system. An offset between the center of the OND and the center of the surface penetrating instrument must be known and used in calculating or inferring the position of the GPR's measuring location.
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 5 of 6 When the system is moved over the surface of a structure it is useful to have a method of indicating which areas of the surface have been covered. This may be done by displaying the movement of the system on a display that traces out lines showing where the investigative center of the system has been. (Alternatively, the GPR/OND
system may also have installed a physical marking device.) The display can assist the user with moving over an area by showing a guiding pattern on the display that the user attempts to follow. For example, the display may show a serpentine pattern to be followed to cover a rectangular area. The serpentine pattern would be displayed in one color or as a dashed line. The actual path traversed by the operator would be displayed in another color or as a solid line. The fact that the user does not exactly follow the offered tracing pattern does not reduce the quality of the image that can be generated from the radar data since the actual location that each data point was collected at is recorded with high accuracy by the system. This actual location, not the intended location, is used in the processing algorithms. The serpentine pattern can be designed to guide the user toward an optimal scanning pattern for the item of interest being scanned, and can be tailored or pre-configured. An alternate display can show which areas have had sufficient data sampled over them to provide high confidence estimates of buried object distributions.
False color could be used to indicate which regions are sufficiently sampled and which require more data to be collected. If a physical marking device is used, protocols for adequacy of coverage would be developed for the operator's reference.
When the radar or EM data collected with the system is processed into a three dimensional image or a plan view, it is necessary to be able to orient or spatially register the processed data with the object that was scanned. 'The conventional method of marking the surface with paint or chalk at the time it was scanned can still be practiced with this new system. Alternatively, a new method can now be practiced that uses targets placed on the surface being scanned. These target) in one embodiment take the form of a small adhesive label stuck to the surface. The target is recognizable by either the OND or the radar or both, or the user may input that the system is over a given marker, and if desired, at a particular time. The OND or radar can be passed over the target to set the starting point of the scan. The center of the target becomes a known coordinate of the scan. If the surface of the area being surveyed is not flat or geometrically simple, then geometry correction algorithms can be applied if registration marks are located in known positions and the surface geometry is known or can be modelled. For example the position on a round pillar could be correctly determined if the diameter of the pillar is provided to the system. Irregular surfaces can also be modeled if they can be mathematically described.
Another method of collecting data is to attach a paper or thin plastic template or web of lines to the surface of the structure being investigated. This template may be printed with a starting point and a pattern to follow, or it may simply act as a smooth surface over which to move the scanner. Again the users adherence to the pattern is not critical for accuracy since the precise location actually achieved is recorded. The purpose of the template is simply to provide a method of guiding the user to collect sufficient data over the area of the template and to provide for lining up registration marks of the template with registration marks from the results. The template can be left on the surface and Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 6 of 6 then its registration marks can be used when overlaying a print out of the processed results. The results or a section of the results along with annotations can be printed on a full scale. Overlaying the full scale results on the surface of the scanned object can assist with visualization by persons or equipment in later cutting or coring or further investigation of the structure. In some cases, the detected subsurface features could be directly projected onto the surface using a digital projector, or overlayed on a user s field of vision by retinal projector or head's up display (for example).
All components used in the Invention may be comprised of any suitable system or systems, including but not limited to GPR and electromagnetic instruments In the foregoing descriptions, the Invention has been described in known embodiments.
However, it will be evident that various modifications and changes may be made without departing from the broader scope and spirit of the Invention.
Accordingly, the present specifications and embodiments are to be regarded as illustrative rather than restrictive.
The descriptions here are meant to be exemplary and not limiting. It is to be understood that a reader skilled in the art will derive from this descriptive material the concepts of this Invention, and that there are a variety of other possible implementations;
substitution of different specific components for those mentioned here will not be sufficient to differ from the Invention described where the substituted components are functionally equivalent.
Dated at Calgary, Alberta, this ~~G' day of ~~ 1~ , 2001 '~ . _.
ALAN . M l AUGHTON
(Witness) '~rNA~.4r~S .
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments a f6 To: Canadian Intellectual Property Office, The From: Kyle J. Doerksen and Alan G. McNaughto 0'_ Inventors: Doerksen, Kyle J., and McNaughton, Alan G.. _. __ ''~ _ _ _ Assignee: Kymatix Research Inc, 3553-31 Street NW, Calgary, Alberta, Canada, T2L OZ7 Title: Positioning System for Ground Penetrating Radar Instruments Declaration, Formalities We, Kyle J. Doerksen and Alan G. McNaughton, are the inventors and the applicants herein, and we hereby seek the grant of a Canadian Patent to protect the described invention (the "Invention"). We are residents of Canada with the mailing addresses set forth below. We fall within the definition of "small entity' set forth in the Patent Rules.
This document and its attachments set forth a description of the Invention in accordance with Rule 93 of the Patent Rules to the Patent Act, which together with the payment of the requisite fees, is sufficient to permit the filing of this material, and the obtaining of a filing date (and receipt indicating the same) for our application under section 28(1) of the Patent Act of Canada.
I, Alan G. McNaughton, have executed this application on behalf of both of the inventors and with the full authority and right to do so.
We hereby appoint Michael Rayburn Whitt (Registered Agent #11061) as our agent in this application, whose address is Michael R. Whitt, Whitt & Company, 555, 407-8~t Avenue SW, Calgary, Alberta, T2P 1E5.
Abstract A system and method of providing precise positioning necessary for three dimensional imaging of internals of structures using Ground Penetrating Radar and Electromagnetic instruments.
Background of the Invention It is well known that radar energy that reflects off objects embedded in a medium, or off of sudden changes in the properties of the medium, can be used to understand the gross internal structure found inside the medium. This use of radar is commonly called Ground Penetrating Radar ("GPR"). GPR can be used to detect detail inside a structure such as column or wall or floor. Voids, rebar, conduit, cables, changes in material and material thickness can be detected.
All three of the largely manual positioning techniques described above are poorly suited for three dimensional GPR imaging of structures due to the relatively large and inconsistent or unpredictable positioning error introduced.
More recently, two additional methods have been employed to gather the position information:
(1) a Differential Global Positioning System ("DGPS") where one Global Positioning System ("GPS") antenna is mounted to the GPR instrument and as the radar data is collected, the GPS co-ordinates are collected at the same time; and (2) a self-tracking laser theodohte is pointed at a reflector located on the GPR and the laser constantly tracks the location of the GPR instrument, calculating the GPR
instrument position based upon the angle of the laser and the laser pulse return time.
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 3 of 6 While the use of differential GPS is well suited to outdoor use when surveying large areas while looking for large objects, it is poorly suited for positioning on a structure for several reasons. First, the position error is large relative to the depth of investigation and the object resolution desired for most structural investigation. When looking at rebar within a concrete structure you maybe looking at objects with a 20 mm diameter at depths from just below the surface to 300 mm deep. An X,Y position error of 20 mm and a Z (vertical) position error of 60 mm would be the typical position error of a DGPS
system. This limits the usefulness of DGPS for this type oi= fine structural investigation.
The other major limit of DGPS is that often the location where the work is being done is where GPS will not work. It is either indoors or, when ouiaide, close to walls and other obstructions that obscure the necessary line-of-site to multiple GPS
satellites.
It is further known that laser positioning provides much better position accuracy than the other methods and is indeed suitable for GPR investigation of structures, including indoors use. It does however have a high cost and requires that line-of-site be maintained between the GPR instrument and the laser positioning system that is at a known location.
Summary of the Invention It is an object of the Invention to overcome limitations in the prior art as there exists a need for a low cost highly accurate positioning system Eor use with GPR and other instruments used to investigate what is inside structures. It is desirable that the position information be automatically collected and recorded along with the GPR data via a system and method of providing precise positioning necessary for three dimensional imaging of internals of structures using GPR and electromagnetic instruments.
These and other objects and advantages of the Invention are apparent in the following description of embodiments of the Invention, which is not intended to limit in any way the scope or the claims of the Invention.
Description of the Invention The following described embodiments of the Invention display preferred compositions but are not intended to limit the scope of the Invention. It will be obvious to those skilled in the art that variations and modifications may be made without departing from the scope and essential elements of the Invention.
A GPR instrument, or other like subsurface detection instruments, can be coupled with optical navigation technology to create a system for internal structure data collection that has highly accurate positioning. The positioning is sufficiently accurate so that it is suitable for three dimensional imaging of features within the desired size and position ranges, and the incremental system cost above the cost of the bare GPR
instrument is small. The system has the added advantage that the operator does not need to move the instrument in a highly ordered fashion over the surface. Also, an arbitrary data collection pattern can be used and does not need to be predetermined. In fact, the data Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 4 of 6 collection does not need to follow any preconceived or repeatable pattern at all and the movements of the instrument over the surface can be totally arbitrary or done to the operator's convenience or judgement, as long as sufficient data is collected in all the regions of interest.
Optical navigation is now highly developed in computer mice. The method involves capturing an image and then analyzing and tracking the motion of microscopic texture or other features on a surface along which the mouse is moved. Optical mice depend on tracking the surface detail and it is now understood that most surfaces are microscopically textured. When a light source such as a light emitting diode is used to illuminate these surface textures, a pattern of highlights and shadows is revealed.
Optical mice "watch" these surface details move by imaging them onto navigation integrated circuits (IC). Typically the optical-navigation IC captures images at the rate of over 1,000 pictures per second, using a small 16-by-16-pixel image sensor. As each image is captured, it is transferred to the processing and computation section of the navigation circuit, where the movement of the mouse is computed by comparing successive images.
Such a system can detect movement of the mouse relative to the surface in any direction.
This yields relative position which, when measured relative to markers or targets at known surface locations, can be transformed into real world coordinates.
Rotation (or relative attitude or "pitch and yaw' of the GPR unit's scanning function's focus of attention) can be detected by further processing of the returned image stream.
Alternately, two optical positioning sensors with some distance separating them can be used to measure their relative movement and thus resolve orientation information.
When the system is first placed on the surface to be investigated, the X,Y
starting point is set to some coordinates entered by the user in order to give an absolute positioning reference to the system. The system then records all relative movements from the starting point so that at all times the system knows its X,'~' location with respect to the starting point. Once the scan of an area is started, the system must at all times remain in contact with the surface in order to "know" or sense or calculate or infer its location. If it loses contact with the surface, it would need to be returned to a reference marker, and then the scan could continue. Positioning system drift can also be corrected by returning to a reference marker. Multiple reference markers at knovvn locations on the surface of the subject of interest can be used (that is, tracked over and noted or referenced during the scanning process) to further increase accuracy over a single marker. As the system begins recording data, in the case of GPR the amplitude of the return radar signal with respect to time, the system also records the surface position at the same time.
The optical navigation device ("OND") can not readily be positioned co-incident with the surface penetrating instrument. For example with GPR it would be desirable to locate the center of the OND at the center point between the radar transmitter and the radar receiver. Since this is not practical for reasons of physical room and interference with the radar signals, the OND must be located elsewhere on the system. An offset between the center of the OND and the center of the surface penetrating instrument must be known and used in calculating or inferring the position of the GPR's measuring location.
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 5 of 6 When the system is moved over the surface of a structure it is useful to have a method of indicating which areas of the surface have been covered. This may be done by displaying the movement of the system on a display that traces out lines showing where the investigative center of the system has been. (Alternatively, the GPR/OND
system may also have installed a physical marking device.) The display can assist the user with moving over an area by showing a guiding pattern on the display that the user attempts to follow. For example, the display may show a serpentine pattern to be followed to cover a rectangular area. The serpentine pattern would be displayed in one color or as a dashed line. The actual path traversed by the operator would be displayed in another color or as a solid line. The fact that the user does not exactly follow the offered tracing pattern does not reduce the quality of the image that can be generated from the radar data since the actual location that each data point was collected at is recorded with high accuracy by the system. This actual location, not the intended location, is used in the processing algorithms. The serpentine pattern can be designed to guide the user toward an optimal scanning pattern for the item of interest being scanned, and can be tailored or pre-configured. An alternate display can show which areas have had sufficient data sampled over them to provide high confidence estimates of buried object distributions.
False color could be used to indicate which regions are sufficiently sampled and which require more data to be collected. If a physical marking device is used, protocols for adequacy of coverage would be developed for the operator's reference.
When the radar or EM data collected with the system is processed into a three dimensional image or a plan view, it is necessary to be able to orient or spatially register the processed data with the object that was scanned. 'The conventional method of marking the surface with paint or chalk at the time it was scanned can still be practiced with this new system. Alternatively, a new method can now be practiced that uses targets placed on the surface being scanned. These target) in one embodiment take the form of a small adhesive label stuck to the surface. The target is recognizable by either the OND or the radar or both, or the user may input that the system is over a given marker, and if desired, at a particular time. The OND or radar can be passed over the target to set the starting point of the scan. The center of the target becomes a known coordinate of the scan. If the surface of the area being surveyed is not flat or geometrically simple, then geometry correction algorithms can be applied if registration marks are located in known positions and the surface geometry is known or can be modelled. For example the position on a round pillar could be correctly determined if the diameter of the pillar is provided to the system. Irregular surfaces can also be modeled if they can be mathematically described.
Another method of collecting data is to attach a paper or thin plastic template or web of lines to the surface of the structure being investigated. This template may be printed with a starting point and a pattern to follow, or it may simply act as a smooth surface over which to move the scanner. Again the users adherence to the pattern is not critical for accuracy since the precise location actually achieved is recorded. The purpose of the template is simply to provide a method of guiding the user to collect sufficient data over the area of the template and to provide for lining up registration marks of the template with registration marks from the results. The template can be left on the surface and Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments Page 6 of 6 then its registration marks can be used when overlaying a print out of the processed results. The results or a section of the results along with annotations can be printed on a full scale. Overlaying the full scale results on the surface of the scanned object can assist with visualization by persons or equipment in later cutting or coring or further investigation of the structure. In some cases, the detected subsurface features could be directly projected onto the surface using a digital projector, or overlayed on a user s field of vision by retinal projector or head's up display (for example).
All components used in the Invention may be comprised of any suitable system or systems, including but not limited to GPR and electromagnetic instruments In the foregoing descriptions, the Invention has been described in known embodiments.
However, it will be evident that various modifications and changes may be made without departing from the broader scope and spirit of the Invention.
Accordingly, the present specifications and embodiments are to be regarded as illustrative rather than restrictive.
The descriptions here are meant to be exemplary and not limiting. It is to be understood that a reader skilled in the art will derive from this descriptive material the concepts of this Invention, and that there are a variety of other possible implementations;
substitution of different specific components for those mentioned here will not be sufficient to differ from the Invention described where the substituted components are functionally equivalent.
Dated at Calgary, Alberta, this ~~G' day of ~~ 1~ , 2001 '~ . _.
ALAN . M l AUGHTON
(Witness) '~rNA~.4r~S .
Doerksen and McNaughton Positioning System for Ground Penetrating Radar Instruments a f6 To: Canadian Intellectual Property Office, The From: Kyle J. Doerksen and Alan G. McNaughto 0'_ Inventors: Doerksen, Kyle J., and McNaughton, Alan G.. _. __ ''~ _ _ _ Assignee: Kymatix Research Inc, 3553-31 Street NW, Calgary, Alberta, Canada, T2L OZ7 Title: Positioning System for Ground Penetrating Radar Instruments Declaration, Formalities We, Kyle J. Doerksen and Alan G. McNaughton, are the inventors and the applicants herein, and we hereby seek the grant of a Canadian Patent to protect the described invention (the "Invention"). We are residents of Canada with the mailing addresses set forth below. We fall within the definition of "small entity' set forth in the Patent Rules.
This document and its attachments set forth a description of the Invention in accordance with Rule 93 of the Patent Rules to the Patent Act, which together with the payment of the requisite fees, is sufficient to permit the filing of this material, and the obtaining of a filing date (and receipt indicating the same) for our application under section 28(1) of the Patent Act of Canada.
I, Alan G. McNaughton, have executed this application on behalf of both of the inventors and with the full authority and right to do so.
We hereby appoint Michael Rayburn Whitt (Registered Agent #11061) as our agent in this application, whose address is Michael R. Whitt, Whitt & Company, 555, 407-8~t Avenue SW, Calgary, Alberta, T2P 1E5.
Abstract A system and method of providing precise positioning necessary for three dimensional imaging of internals of structures using Ground Penetrating Radar and Electromagnetic instruments.
Background of the Invention It is well known that radar energy that reflects off objects embedded in a medium, or off of sudden changes in the properties of the medium, can be used to understand the gross internal structure found inside the medium. This use of radar is commonly called Ground Penetrating Radar ("GPR"). GPR can be used to detect detail inside a structure such as column or wall or floor. Voids, rebar, conduit, cables, changes in material and material thickness can be detected.
Claims
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002359599A CA2359599A1 (en) | 2001-10-22 | 2001-10-22 | Positioning system for ground penetrating radar instruments |
| US10/278,483 US20030112170A1 (en) | 2001-10-22 | 2002-10-22 | Positioning system for ground penetrating radar instruments |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002359599A CA2359599A1 (en) | 2001-10-22 | 2001-10-22 | Positioning system for ground penetrating radar instruments |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2359599A1 true CA2359599A1 (en) | 2003-04-22 |
Family
ID=4170320
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002359599A Abandoned CA2359599A1 (en) | 2001-10-22 | 2001-10-22 | Positioning system for ground penetrating radar instruments |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US20030112170A1 (en) |
| CA (1) | CA2359599A1 (en) |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL1024427C2 (en) * | 2003-10-01 | 2005-04-05 | Arcadis Geo En Vastgoedinforma | Device is for contactless measurement of underground structure and uses ground radar, whereby an active ground radar unit is moved along a number of parallel running measurement lines |
| US7057548B1 (en) * | 2003-10-03 | 2006-06-06 | Geophysical Survey Systems, Inc. | Automatic data capture technology to enhance data collection |
| WO2006099059A2 (en) * | 2005-03-10 | 2006-09-21 | Witten Technologies, Inc. | Method for correcting a 3d location measured by a tracking system assuming a vertical offset |
| US20080143581A1 (en) * | 2006-12-19 | 2008-06-19 | Bellsouth Intellectual Property Corporation | Scanning and projection systems and methods |
| IL184972A0 (en) * | 2007-08-01 | 2008-11-03 | Camero Tech Ltd | System and method for volume visualization in through-the-obstacle imaging system |
| US7548192B1 (en) * | 2008-02-07 | 2009-06-16 | Fdh Engineering, Inc. | Method of mapping steel reinforcements in concrete foundations |
| CA2739891C (en) * | 2008-10-16 | 2017-03-28 | Zircon Corporation | Dynamic information projection for a wall sensor |
| TR201205754T1 (en) | 2009-11-03 | 2012-09-21 | Vawd Applied Science & Technology Corporation | Safety distance, despite the obstacle detection radar system. |
| US9377528B2 (en) * | 2010-03-19 | 2016-06-28 | Northeastern University | Roaming mobile sensor platform for collecting geo-referenced data and creating thematic maps |
| WO2011120141A1 (en) * | 2010-03-31 | 2011-10-06 | Ambercore Software Inc. | Dynamic network adjustment for rigorous integration of passive and active imaging observations into trajectory determination |
| US9341740B1 (en) * | 2012-02-13 | 2016-05-17 | See Scan, Inc. | Optical ground tracking apparatus, systems, and methods |
| US9073347B2 (en) * | 2012-10-11 | 2015-07-07 | Geophysical Survey Systems, Inc. | Hand-held radar device with direct printing based on radar input |
| JP6294588B2 (en) * | 2013-01-28 | 2018-03-14 | 東北電力株式会社 | Subsurface radar system capable of 3D display |
| CN105116457A (en) * | 2015-08-10 | 2015-12-02 | 安徽理工大学 | Exploration device of roadway surrounding rock three-dimensional geological change in detection area |
| GB2541658B (en) * | 2015-08-24 | 2020-01-01 | Thales Holdings Uk Plc | Video-assisted inverse synthetic aperture radar (VAISAR) |
| US10585203B2 (en) * | 2016-04-28 | 2020-03-10 | Fluke Corporation | RF in-wall image visualization |
| IT201700047233A1 (en) * | 2017-05-02 | 2018-11-02 | Ids Georadar S R L | Method perfected for the execution of georadar surveys and related equipment |
| JP7061529B2 (en) * | 2018-07-20 | 2022-04-28 | 日本信号株式会社 | Exploration device |
| IT201800009761A1 (en) * | 2018-10-24 | 2020-04-24 | Ids Georadar Srl | Photogrammetric system to assist in positioning the georadar data on the measurement scenario |
-
2001
- 2001-10-22 CA CA002359599A patent/CA2359599A1/en not_active Abandoned
-
2002
- 2002-10-22 US US10/278,483 patent/US20030112170A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US20030112170A1 (en) | 2003-06-19 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued |