Methods and apparatus for a tunnel detection system

Systems and methods are discussed to image lithological data within the strata beneath the earth surface, including a subterranean object detection system. The system may further comprise a pipeline operable to conduct a working fluid and an instrumented pig operable to travel within the pipeline and operable to image lithological strata and voids within the strata beneath and around the pipeline. The instrumented pig may comprise an outer case, a battery coupled to the outer case, a ground imaging unit operable to send a signal to image the lithological strata and voids within the strata beneath and around the pipeline and may be operable to receive a reflected signal indicating lithology data, wherein the ground imaging unit may be operably coupled to the battery.

BACKGROUND

Methods and apparatus are disclosed herein for a tunnel detection system. National borders and tactical perimeters must be defended against the threat of persons gaining illegal entry or those trying to transport drugs or contraband. Detecting hidden tunnels under the border perimeter has been largely unsuccessful. At many international borders, including the southern border of the United States with Mexico, fences and walls rising high above ground or electronic surveillance systems assisting border security agents in preventing illegal crossers will never stop 100 percent of the illegal entries into the United States. Between five and ten percent can still enter through an unknown number of tunnels under the border. The security of most all international borders throughout the world suffers from the same vulnerability.

SUMMARY

Embodiments of the invention include a subterranean object detection system. The system may comprise a pipeline operable to conduct a working fluid and an instrumented pig operable to travel within the pipeline and operable to image lithological strata and voids within the strata beneath and around the pipeline. The instrumented pig may comprise an outer case, a battery coupled to the outer case, a ground imaging unit operable to send a signal to image the lithological strata and voids within the strata beneath and around the pipeline and is operable to receive a reflected signal indicating lithology data, wherein the ground imaging unit is operably coupled to the battery.

Embodiments further include an instrumented pig, that may comprise an outer case, a rechargeable battery coupled to the outer case, an acoustic sub-bottom profiling unit operable to image lithology beneath and around the pig. The acoustic sub-bottom profiling unit may be operably coupled to the rechargeable battery. The acoustic sub-bottom profiling unit may comprise a transducer operable to produce an acoustic pulse directed to ground strata. The lithological features and voids within the strata may create a reflected acoustic pulse upon interacting with the acoustic pulse. The transducer of the acoustic sub-bottom profiling unit may be operable to receive the reflected acoustic pulse. The instrumented pig may further comprise waypoint detector operable to read and receive global positioning system data from an external waypoint.

Embodiments further include a method of detecting a subterranean object. The method may comprise broadcasting an acoustic signal from an acoustic sub-bottom profiler contained within an instrumented pig, the instrumented pig traveling within a pipeline. The method may further comprise receiving, at a receiver within the acoustic sub-bottom profiler, a reflected acoustic signal. The method may further comprise processing, at a signal processor, the reflected acoustic signal. The method may further comprise receiving from a magnetically coded waypoint, at a waypoint detector, a global positioning system location. The method may further comprise geocoding a processed lithology data with the GPS location.

The various embodiments described in the summary and this document are provided not to limit or define the disclosure or the scope of the claims.

DETAILED DESCRIPTION

Some embodiments include the subterranean object detection system100as shown inFIG. 1The subterranean object detection system100may be operable to detect subterranean features, such as tunnels, which may be located near a border or a protected perimeter and may be used to subterraneously cross the border or perimeter. The subterranean object detection system100may gather and transmit data regarding any subterranean feature, including anomalous subterranean features, that have been detected by an external receiver operably coupled to a centrally located processing station, as will be discussed herein below.

In some embodiments the subterranean object detection system100may comprise a pipeline110, a cutout view of which is shown inFIG. 1. The pipeline110may be operable to contain a working fluid120. The working fluid120may be supplied by a fluid supply130, as shown inFIG. 3. The fluid supply130may be coupled to the pipeline110. The working fluid120may be propelled through the pipeline110by a first pump140, as shown inFIG. 3. The first pump140may be coupled to the fluid supply130at an inlet. The first pump140may further be connected to the pipeline110at a pump outlet, the pump outlet being operably connected to the pipeline110.

Referring still toFIG. 1, in some embodiments, the pipeline110may be operable to accommodate an instrumented pig200. In some embodiments, the instrumented pig200may project a ground imaging signal, such as a pulse of acoustic energy230, as will be discussed in further detail below. The pulse of acoustic energy230may be operable to detect the presence of lithological features and voids, such as a tunnel190. In further embodiments, a ground imaging signal may be created using a different technique or technology.

In some embodiments, the pipeline110may be adjacent to an above-ground barrier structure300. In some embodiments, the above-ground barrier300may comprise a wall or a fence. The above-ground barrier structure300may be operable to support a transceiver310.

In some embodiments, the pipeline110may comprise a high-density polyethylene (HDPE) material. As shown inFIG. 2a, in some embodiments, the pipeline110may be laid on the surface of ground102. As shown inFIG. 2b, in further embodiments, the pipeline110may be at least partially buried in the ground102. As shown inFIG. 2c, in some embodiments, half of the pipeline110may be buried into the ground102. As shown inFIG. 2d, the pipeline110may be completely buried in the ground102.

As shown in theseFIG. 2D, in some embodiments, the pipeline110may be completely buried in the ground102. In some embodiments, the pipeline110may be buried by approximately three feet of overburden. The pipeline110may be buried three or more feet beneath the ground102over the length of the pipeline110. Burying or partially burying the pipeline110may be of value in protecting the pipeline110from damage due to various causes, such as, for example: (1) malicious acts/intent of individuals to destroy, damage, or inhibit the pipeline110from performing its function, (2) exposure to accidental damage from surface vehicles and other equipment operated or controlled by people in the proximity of the pipeline110, or (3) exposure to natural sunlight, especially ultraviolet light) temperature extremes, especially freezing temperatures. Any of these could reduce the working life cycle of the HDPE pipeline110to less than its optimal life, which may be approximately 30 years or more.

As shown in these figures, in some embodiments, between zero percent and fifty percent of the pipeline110may be buried in the ground102. In further embodiments, between fifty percent and one hundred percent of the pipeline may be buried under the ground102. In further embodiments, the entire pipeline110may be buried under the ground by as much overburden as three feet or more. In some embodiments, as shown inFIG. 2e, the pipeline110may be elevated off of the ground102and may be supported by a frame103. The frame103may be anchored to the ground102. The pipeline110may be coupled to the frame103using clamps, fasteners, or may rest in a U-shaped carrier as part of frame103. In some embodiments,

Referring again toFIG. 1, the pipeline110may, in some embodiments, comprise multiple sections, such as first section112, second section114, third section116to an nth section. The multiple sections may be coupled together, with a first section112of pipeline110being coupled to a second section114of the pipeline110, with the second section114of the pipeline110being coupled to a third section116and so on with fourth, fifth, sixth and nth sections of the pipeline110. In some embodiments, when the sections are joined together, the pipeline110may have a length ranging from 30-150 miles. Further, the pipeline110may have curves and corners as necessary to go around obstacles, such as physical obstacles, private property, or to surround a protected area, such as a military installation, building, or airport.

The pipeline110may be operable to accommodate the working fluid120. The working fluid120may comprise any suitable fluid, such as, for example water, gasoline of any grade, oil of various viscosities, or other fluids that may comprise a low electrical conductivity and compressibility. The working fluid120may comprise any fluid of low viscosity that is not corrosive to the material of pipeline110, such as HDPE.

Referring now toFIG. 3, which illustrates an overhead view of the ends of the pipeline110, in some embodiments, the system100may comprise the working fluid supply130. The working fluid supply130may comprise a supply line connected to a main supply, such as, for example, an existing supply system or a naturally occurring supply. In further embodiments, the supply130may comprise a first storage tank132located proximate to the pipeline110. The first storage tank132may be positioned above the pipeline110such that the working fluid120is gravity fed to the pipeline110. The first storage tank132may be filled by an existing pipeline system, or, alternatively, by a natural source. The first storage tank132may, in some embodiments, be manually filled using a truck with a tank or other means.

As discussed herein above, the system100may further comprise the first pump140, operable to receive the working fluid120through the pipeline110. The first pump140may further be operable to pump water into the pipeline110. The pump140may be connected to a first control unit138, the first control unit138being programmed to control how much fluid is pumped and for how long. The first control unit138may be a variable speed controller of the first pump140and may be able to control the speed and amount of fluid being pumped. The first control unit138may be programmed and operable to activate the first pump140. In some embodiments, the first control unit138may be enabled to receive wired communications or wireless communications, such as a communications via a cellular network using 5G technology, from an external source to provide instruction to the first control unit138and the first pump140. In further embodiments, the first pump140may be activated and deactivated by a float switch in the first storage tank132, wherein the float switch may be operably connected to the first pump140. Such a float switch may indicate a sufficient quantity of working fluid120present within the first storage tank132or an insufficient quantity of working fluid120, which would deactivate the pump.

Referring still toFIG. 3, in further embodiments, the pipeline110may comprise a second storage tank134located at the end of pipeline110. The second storage tank134may be operable to receive the working fluid120when it arrives at the end of the pipeline110via a fluid connection146, which may comprise HDPE piping, metal piping, or rubber tubing, as is known in the art. The system100may further comprise a second pump142. The second pump142may be coupled to the second storage tank134and to the pipeline110via tank connection145, with fluid flowing in the direction indicated by the arrows ofFIG. 3. The second pump142may be coupled to a second control unit144. The second control unit144may be programmed and operable to activate the second pump142. In some embodiments, the second control unit144may be enabled to receive wired communications or wireless communications from an external location to provide instruction to the second control unit144and the second pump142. In further embodiments the second pump142may be activated or deactivated by a float switch in the second storage tank134, the float switch being operably coupled to second pump142. In some embodiments, the second storage tank134may comprise a door135operable to allow working fluid120to be replenished or removed, as necessary. The door135may be operable to accommodate working fluid120being replenished via truck, a local supply, treated water, or purification units for nearby rivers, lakes, etc. All electrical components may be powered by either a wired connection to a power station or by solar energy obtained via solar panels.

In some embodiments where the length of the pipeline110exceeds 40 miles and may approach an overall length of 80 miles or more, an intermediate third pump143may be required to compensate for pressure losses from friction between the working fluid120and the inner wall of the pipeline110. The first control unit138and/or the second control unit144may have telemetered controls for the operation of the intermediate third pump143. Whenever the instrumented pig160approaches the intermediate third pump143, valves152may be opened to divert the instrumented pig200to connected line154and to redirect the instrumented pig to pipeline110. The valves152may be automatically opened and closed to bypass the intermediate third pump143. The valves152may be operably coupled to the first control unit138or to the second control unit144and may have a wired power connection to solar panels or to another power source.

In some embodiments, once the instrumented pig200has arrived at the end of pipeline110and a sufficient amount of working fluid120has been deposited in the second storage tank134, the working fluid120may be pumped back to the first storage tank132, as will be described herein below.

Referring still toFIG. 3, the pipeline110may comprise a first access panel182. In some embodiments, the first access panel182may be operable to be opened and closed and may be sealed shut so as to prevent the leakage of any fluid or the entry of any foreign objects into the pipeline110. When the first access panel182is open, the instrumented pig200may be inserted into the pipeline110through the opening created when access panel182is in an open position.

Referring still toFIG. 3, in some embodiments, the pipeline110may further comprise a second access panel184located distally from first access panel182and located at the “end” of the pipeline110. In some embodiments, the second access panel184may be operable to be opened and closed and may be sealed shut so as to prevent the leakage of any fluid or the entry of any foreign objects into the pipeline110. In some embodiments, when the instrumented pig200has reached the end of pipeline110at or near the second access panel184, the instrumented pig200may be removed from the pipeline110via the second access panel184, either manually or via automated robotic means, and placed back into the pipeline110via the opening created when the second access panel184is in an open position.

The second access panel184may comprise a pig catcher coupled to the inside of second access panel184. The pig catcher may be operable to catch a moving pig. The pig catcher may comprise a rigid meshed net, or may comprise a flexible meshed net, allowing the water to pass through the mesh. The pig catcher may be raised out of the pipeline when the second access panel184is opened, thereby removing the instrumented pig as well. The first access panel184may comprise a similar pig catcher.

As discussed herein above, the second pump142may be activated by either the second control unit144or the float valve, or may be activated by the second control unit and interlocked by the float valve, when sufficient working fluid120has been deposited into the second storage tank134. When the second pump142is activated, the second pump142may pump the working fluid120toward the beginning of the pipeline110and thereby propel the instrumented pig200in the opposite direction to the beginning of the pipeline110at or near the first access panel182of the pipeline110. As the working fluid120flows back to this area, the first storage tank132may fill with working fluid120via fluid connection136. The instrumented pig200may be removed from the pipeline110via the first access panel182, either manually or via automated robotic means, and placed back into the pipeline110via the opening created when the first access panel182is in an open position. The first pump140may be activated by either the first control unit138or the float valve when sufficient working fluid120has been deposited into the first storage tank132. When the first pump140is activated, the first pump140may pump the working fluid120toward the end of the pipeline110and thereby propel the instrumented pig200to the end of the pipeline110at or near the second access panel184of the pipeline110. This process may be repeated each time the instrumented pig200reaches the first access panel182or adjacent thereto or the second access panel184or adjacent thereto. The instrumented pig200may travel at a rate of approximately 10 feet per second.

In some embodiments, the system100may be duplicated to provide detection coverage over large distances, such as, for example, national borders, In such embodiments, a second detection system, similar to system100, may be located end-to-end with system100. In such embodiments, the second storage tank132may be used as a supply for the working fluid to the second system.

Referring again toFIG. 3, in some embodiments, the working fluid120may comprise water and the pipeline110may comprise a watering station186. The watering station186may comprise a water treatment apparatus188, such as, for example, a water filter, a chemical treatment, an ultra-violet light treatment, or combination of these. The watering station186may comprise a faucet or drinking fountain or other means to extract that may be used for human consumption. The watering station186may comprise multiple faucets or drinking fountains.

The watering station186may be located 70 to 100 feet or more from the pipeline110, from which a small pipeline187of only ½ inch to ¾ inch diameter may be tapped into the pipeline110and carry the water to the watering station186. In many border areas, which may be far removed from populations centers, watering stations186may act as natural gathering areas and may enable identification of people in the area by capturing facial features and vocal features via related artificial intelligence system and identification software.

As mentioned herein above, in some embodiments, a working fluid120may comprise water. In certain applications, the system100may be used to detect lithological strata such as tunnel190, as illustrated inFIG. 1. The system100may be used in connection with new or existing tunnels across borders or perimeters intended to protect national borders from illegal entry or departure of unauthorized individuals or contraband. The system100may further be used in connection with new or existing tunnels across borders or perimeters intended to protect or across perimeters of protected assets, such as, for example, military bases, airports, nuclear power plants, banks, courts, schools, universities, or any valued asset or across perimeters guarding against potential threats, such as criminal elements in penal institutions. In applications involving national borders, it may be of benefit for the pipeline110to make available treated potable water. This may be available in regions where there is little potable water available and where government agents or others may be visiting and may be in need of potable water.

Referring again toFIG. 3, in some embodiments, the system100may comprise first storage tank132. In some embodiments, the first storage tank132may be operably coupled to the fluid supply130. In some embodiments, the tank132may be filled manually via door133. Such manually filling may be done via a supply truck or other means known in the art.

Referring still toFIG. 3, in some embodiments, the pipeline110may be fitted with permanently encoded magnetic waypoints128that may pass the exact position to the instrumented pig200, as will be discussed herein below. The magnetic waypoints128may comprise a member of magnetically encoded material. The magnetically encoded material may contain global position data as determined by a global positioning system surveyed prior to installation on the pipeline110and pre-encoded with the global position data or other waypoint identification data, such as a waypoint number. When the instrumented pig200passes the magnetic waypoint128, the position data may be passed to the instrumented pig200, as will be explained herein below. The waypoints128may be passively activated, only responding when pinged by external sources, such as instrumented pig200. In such instances the responding magnetic signal may communicate the data encoded on the waypoints128.

In some embodiments, the pipeline110may be operable to accommodate an instrumented pig200. The instrumented pig200may be operable to travel within the pipeline110. A cutout view of the instrumented pig200is shown in further detail inFIG. 4. The instrumented pig200may comprise an outer case210. The outer case210may comprise any suitable material, such as, for example, stainless steel, aluminum, fiberglass, carbon composite, lexan, hard rubber, or a combination of these. Further, the outer case210may comprise multiple members, for example an upper member and a lower member, which are joined together and sealed shut, such that fluid cannot enter the interior of the instrumented pig200. For example, if the working fluid120were water, the instrumented pig200would be sealed such that the instrumented pig200is waterproof. The instrumented pig200may be propelled, pushed, or driven through the pipeline110by the working fluid120being pumped through the pipeline110and effectively pushing the instrumented pig200through the pipeline110. The pressure of the working fluid around the outside of the instrumented pig200may exceed 300 psi and the outer case210may withstand such pressures without fracture, leak, or any permanent deformation.

In some embodiments, instrumented pig200may comprise a control unit224. The control unit224may be an automated, self-contained, and pre-programmed unit to provide instruction to other components of the acoustic sub-bottom profiler220, as described herein below. The control unit may comprise a signal processor250and a memory260and may be operable to provide instruction and direction for the operation of an acoustic sub-bottom profiler220, as described herein below.

In some embodiments, the instrumented pig200may comprise an acoustic sub-bottom profiler220. The acoustic sub-bottom profiler220may comprise a transducer226. The transducer226may operate in approximately the range of 25 kilohertz (KHz) to 45 KHz. The transducer226may be operable to act as a sound source. The transducer may release the pulse of acoustic energy230. The transducer226may be coupled to the battery280and in some embodiments, a power amplifier, to produce the vibrational acoustic energy at the frequency of 25 KHz to 45 KHz to produce the pulse of acoustic energy230.

The acoustic sub-bottom profiler220may be operably coupled to the control unit224. The control unit224may be operable to provide instruction to the acoustic sub-bottom profiler220, such as for example, the frequency at which to operate, the number of pulses sent, and how and when to transfer received and gathered data to the signal processor250and the memory260.

The pulse of acoustic energy230may propagate in the direction the ground, such as ground102as illustrated inFIG. 1. The transducer226may produce multiple pulses of acoustic energy230per second. The pulse of energy230may be elongate in the fore-aft direction and is narrow across the path of travel. When new lithological features begin to be detected, such a pulse of acoustic energy and the corresponding reflections may provide an enhanced or better signal-to-noise ratio, making the lithological features, such as new tunnels easier to detected and identify.

The pulse of acoustic energy230may be reflected from the features underground and may create many pulses of reflected energy240. The transducer226may be operable to receive the multiple pulses of reflected energy230per second. The intensity of the reflected energy may depend on the different densities of the ground and the features within the ground. Based on the time required for the pulses of reflected energy240to return to the transducer226and the intensity of the pulses of reflected energy240, the processor250may image the lithology. For example, if the pulse of acoustic energy230encounters a solid formation, such as a rock, most of the acoustic energy will be reflected in the pulses of energy240. If the pulse of acoustic energy230encounters a void, very little energy will be returned. Based on this information, the sub-bottom profiler220may be operable to image lithology from zero meters to 35 meters deep.

In some embodiments, the reflected energy240may travel back to the instrumented pig200. The instrumented pig may capture the signal from the reflected energy240at a hydrophone array, wherein the hydrophone elements and the spacing between the elements are matched to the acoustic characteristics of the sound source. The hydrophone array may trail the acoustic pig and may be operably coupled to the acoustic sub-bottom profiler220, the control unit224, and the processor250. The transducer226may be operably coupled to a signal processor250. The signal processor250may amplify the signals from the reflected energy240. The signal processor250may further process the signals such that they can be displayed in a readable format. This may include a visual representation of the lithological features of the strata, which may comprise earth, dirt, rock formations, and voids, such as tunnels, within the strata.

In some embodiments, the instrumented pig200may further comprise a memory260operably coupled to the processor250and to the sub-bottom profiler220. The memory260may comprise a solid-state memory, flash memory, or other suitable memory. The memory260may be operable to store the raw data received by the ground imaging unit220and may be operable to store the image data produced by the processor250.

In some embodiments, the instrumented pig200may further comprise a waypoint detector254. The waypoint detector254may comprise a magnetically sensitive device that may read magnetically encoded data from magnetically encoded mediums, such as for example, waypoints128. The waypoint detector254may be operable to detect the location of the magnetic waypoints128located on the pipeline110. Upon passing a magnetic waypoint128, the waypoint detector254may read the position data encoded on the magnetic waypoints128. The waypoint detector254may be operably coupled to the processor250. The waypoint detector254may convey the waypoint information to the processor250. The processor250may be programmed with the pattern recognition necessary to decipher the pattern of information from the magnetic waypoints128that store the position data. The processor250may be operable to geocode lithological data with the data received from the waypoint detector254.

In further embodiments, magnetic waypoints128may be encoded with alternative identifying information, such as a counter number or an identifying number, providing information such that the processor250could identify the location of the waypoint based on preloaded information.

In some embodiments, the instrumented pig200may alternatively comprise a global positioning system (GPS) receiver. The GPS receiver may be operable to receive information related to the position of instrumented pig200and may be operably coupled to the processor250. The processor250may be operable to geocode lithological data with the data received from the GPS receiver.

In some embodiments, the instrumented pig200may further comprise a transceiver270. The transceiver270may be operable to transmit and receive data signals. The transceiver270may be operably coupled to the processor250. The transceiver270may be operable to transmit data, including geocoded data prepared by the processor250to an external receiver.

Signals may be transmitted from the transceiver270to an external transceiver172, as illustrated inFIG. 1. The external transceiver172may be mounted on an exterior surface of the pipeline110at a point that is above the ground102or under the ground102. In some embodiments, the external transceiver172may comprise multiple external transceivers, each operable to receive information from the transceiver270in the instrumented pig200when the instrumented pig200passes by the external transceiver172. For example, the external transceiver172may be located at fixed intervals along the pipeline route consisting of every mile every 5 miles, every 10 miles, or any distance therebetween. The intervals between downloads may be roughly 9 or 10 minutes so that processing at a centralized facility may be completed in 10 or 15 minutes after the instrumented pig200completes the survey of a pipeline segment. The transceiver172may be operably connected to solar power generators, such as solar panels, which may be used to provide power to the transceiver172

In some embodiments, the instrumented pig200may comprise a battery280. The battery280may be supported by the outer case210. In some embodiments, the battery280may be operably coupled to each of sub-bottom profiler220, the processor250, the waypoint detector254, the data transceiver270, and the memory260. The battery280may comprise a rechargeable lithium-ion battery.

In some embodiments, the instrumented pig200may comprise at least one external guide290coupled to the outer side of the outer case210. The at least one external guide290may comprise a wheel that may roll on an inner surface of a pipeline, such as pipeline110ofFIG. 1. A wheel may be mounted on a bearing coupled to a strut292, the strut292being coupled to the outer case210. In further embodiments, the at least one external guide290mmay comprise a fin that may prevent the outer case210from contacting an inner surface of a pipeline, such as pipeline110ofFIG. 1. In some embodiments, the at least one external guide290may comprise multiple external guides radially positioned about the outer case210. In some embodiments, the at least one external guide290may further comprise multiple external guides longitudinally opposite from the at least one external guide, such that the instrumented pig200is supported near the front of the instrumented pig200and near the back of the instrumented pig200.

Referring again toFIG. 1, in some embodiments, as discussed above, the system100may comprise the above-ground barrier300. The above-ground barrier300may be adjacent to the pipeline110. The above-ground barrier300may extend substantially parallel to the pipeline110. In some embodiments the above-ground barrier300may be made from concrete, steel, wood, other common fence materials, or a combination thereof. The above-ground barrier300may extend beyond the pipeline110.

In some embodiments, the above-ground barrier300may be operable to support the wall transceiver310. The wall transceiver310may comprise a receiver and transmitter and may be operable to receive information from the external transceiver172. In some embodiments, the external transceiver172may be connected to the wall transceiver310via a wired connection320. In further embodiments, the data may be transmitted via a network, such as, for example, a 5G network. Similar to external transceiver172, there may be multiple corresponding wall transceivers310to receive information from the external transceivers172. The information may include geocoded data containing the location of subterranean lithological features, objects, and/or voids. Such voids may comprise tunnel190. The tunnel190may comprise a man-made or naturally occurring tunnel. In some embodiments the tunnel190may be used to facilitate the transport of people and/or objects from one side of above-ground barrier300to an opposite side of barrier300.

The transceiver310may further be operable to communicate with a central server, located distally from the fence300. The transceiver310may communicate with the central server via a wired connection, such as a fiber optic connection, or via a cellular connection, such as a 5G connection. The central server may be accessed by border enforcement personnel. Any data transferred may be further processed after receipt at the central server.

Further embodiments of the invention may include an instrumented pig as shown inFIG. 5.FIG. 5illustrates a cutout view of an instrumented pig400. The instrumented pig400may be operable to travel within a pipeline, such as pipelines described herein. The instrumented pig400may further be operable to send data to external receivers and receive data from external sources, similar to external receivers and sources described herein above. The instrumented pig400may comprise an outer case410. The outer case410may comprise any suitable material, such as, for example, fiberglass, rubber, carbon composite, lexan, or a combination of these. Further, the outer case410may comprise multiple members, for example an upper member and a lower member, which are joined together and sealed shut, such that fluid cannot enter the interior of the instrumented pig400. For example, if the working fluid in a pipeline were water, the instrumented pig400would be sealed such that the instrumented pig400is waterproof to water pressures exceeding 300 psi.

In some embodiments, the instrumented pig400may comprise a ground penetrating radar (GPR)420. The GPR420may comprise a control unit424. The control unit424may be an automated, self-contained, and pre-programmed unit to provide instruction to other components of the GPR420, as described herein below.

The GPR420may further comprise a transmission antenna426. The transmission antenna426may operate in approximately the range of 100 Megahertz (MHz). In some embodiments, the transmission antenna may operate anywhere in the range of 10 MHz to 200 MHz. The transmission antenna426may be operable to produce an electromagnetic signal430, the electromagnetic signal430being operable to image lithological strata and voids within the strata beneath and around the instrumented pig400. The transmission antenna426may operate at 100 to 200 MHz and may be fully contained within the outer case410.

The electromagnetic signal430may be projected into the ground. The electromagnetic signal430may be broad across the direction of travel, that is, perpendicular to the pipeline and very narrow in the direction of travel. Upon the electromagnetic signal430striking an object, the electrical conductivity and magnetic resonance of the object reflects, refracts, and scatters the electromagnetic signal430. The antenna426may further comprise a receiver, or receiver antenna. The antenna426may be operable to receive the reflected, refracted, and scattered electromagnetic signals, referred to herein as reflected electromagnetic signals440. The reflected electromagnetic signals440may comprise the same beam pattern as the electromagnetic signal430. The GPR420may be useful in lithology that is dry and contains a minimal amount of salt. The GPR420may be effective at depths ranging from zero meters to 30 meters under those favorable conditions. The antenna426may be operably coupled to the control unit424. The control unit424may provide instruction to the antenna regarding the frequency at which to generate electromagnetic signals and when and how to transfer data to the signal processor450and the memory460.

The control unit424may operably coupled to a signal processor450. The signal processor450may amplify the signals from the reflected signals440. The signal processor450may further process the signals such that they can be displayed in a readable format. This may include a visual representation of the lithological features of the strata, which may comprise earth, dirt, rock formations, and voids within the strata.

In some embodiments, the control unit424may further comprise a memory460operably coupled to the signal processor450and to the GPR420. The memory460may comprise a solid-state memory, flash memory, or other suitable memory. The memory460may be operable to store the raw data received by the GPR420and may be operable to store the image data produced by the processor450.

In some embodiments, the instrumented pig400may further comprise a waypoint detector454. The waypoint detector454may be operable to detect the location of the magnetic waypoints located on a corresponding pipeline. Upon passing a magnetic waypoint on the corresponding pipeline, the waypoint detector454may read the position data encoded on the magnetic waypoints. The waypoint detector454may be operably coupled to the processor450. The waypoint detector454may convey the waypoint information to the processor450. The processor450may be programmed with the pattern recognition necessary to decipher the pattern of information from the magnetic waypoints that store the position data. The processor450may be operable to geocode lithological data with the data received from the waypoint detector454.

In some embodiments, the instrumented pig400may further comprise a global positioning system (GPS) receiver. The GPS receiver may be operable to receive information related to the position of the instrumented pig400and may be operably coupled to the processor450. The processor450may be operable to geocode lithological data with the positioning data received from the GPS receiver454.

In some embodiments, the instrumented pig400may further comprise a GPR data transceiver470. The GPR data transceiver470may be operable to transmit and receive signals. Signals may be transmitted to an external receiver. The GPR data transceiver470may be operably coupled to the processor450. The transceiver470may be operable to transmit data prepared by the processor450to an external receiver.

In some embodiments, the instrumented pig400may comprise a battery480. The battery480may be supported by the outer case410. In some embodiments, the battery480may be operably coupled to each of sub-bottom profiler420, the processor450, the GPS receiver454, the transceiver470, and the memory460. The battery480may be a rechargeable battery. The battery480may be a lithium-ion battery.

In some embodiments, the instrumented pig400may comprise at least one external guide490coupled to the outer side of the outer case410. The at least one external guide490may comprise a wheel that may roll on an inner surface of a pipeline. A wheel may be mounted on a bearing coupled to a strut492, the strut492being coupled to the outer case410. In further embodiments, the at least one external guide may comprise a fin that may prevent the instrumented pig400from contacting an inner surface of a pipeline. In some embodiments, the at least one external guide490may comprise multiple external guides radially positioned about the outer case410. In some embodiments, the at least one external guide490may further comprise multiple external guides longitudinally opposite from the at least one external guide, such that the instrumented pig400is supported near the front of the instrumented pig400and near the back of the instrumented pig400.

In some embodiments of a subterraneous object detection system, in cases where a second tank is not possible, a pipeline may further comprise a fluid outlet located at either end of the pipeline. In some embodiments, the fluid outlet may act to return a working fluid to the fluid supply. The fluid outlet may comprise a second pipeline with fluid flowing in the direction opposite the direction of flow within pipeline. In some embodiments, the fluid outlet may be coupled to the fluid supply, with means to prevent the working fluid from flowing back into the second pipeline, such as, for example, a check valve. In some embodiments, the pipeline may comprise a second pump located on the second pipeline operable to pump the working fluid back to the fluid supply. In further embodiments, the fluid outlet may allow the working fluid to exit from an opening in the second pipeline162and be deposited in the ground.

Referring now toFIG. 6, a method500of detecting a subterranean object is disclosed. The method may include step510, locating or placing an instrumented pig within a pipeline. The pipeline may comprise various elements, similar to those already described herein. The instrumented pig may be placed inside the pipeline via an opening created when a first access panel is opened. A first control unit may communicate with a first pump. The first control unit may provide an instruction to the first pump to begin pumping a working fluid. The first control unit may be pre-programmed with instruction or may receive instruction from a remote location via wired communication, or, in some embodiments, via wireless communication. The wireless communication may occur via a wireless network, such as a cellular network. In some embodiments, the first pump may also be coupled to a float switch and may be activated or deactivated as the float switch is activated or deactivated.

The working fluid may comprise water or other fluids already described herein. Upon receiving instruction from the first control unit or the float switch, the pump may begin pumping the working fluid through the pipeline. The working fluid may be operable to push or propel the instrumented pig through the pipeline.

In some embodiments, the method may comprise520, the instrumented pig producing and broadcasting an acoustic signal. The instrumented pig may comprise an acoustic sub-bottom profiler. The acoustic sub-bottom profiler may comprise a transducer. The transducer may comprise a boom plate operable to convert electric energy to acoustic energy and may broadcast the acoustic energy from the instrumented pig through the pipeline and into the ground. The transducer may be coupled to a rechargeable lithium-ion battery within the instrumented pig.

The method may comprise the acoustic signal being reflected by lithological features located within the strata beneath the pipeline. The lithological features may include features such as solid objects and voids, both naturally occurring and man-made. Such objects may include mad-made or natural tunnels being used to bring items and people across a border subterraneously. The acoustic signal may reflect off of such lithological features and may created reflected and refracted acoustic signals.

In some embodiments, the method may further comprise530receiving at a receiver a reflected acoustic signal. The transducer may comprise a receiver and may receive and capture the reflected acoustic signals.

In some embodiments the method may comprise540processing at a signal processor the reflected acoustic signal. The instrumented pig may comprise a signal processor coupled to the transducer and to the battery. The signal processor may be operable to process the received acoustic signals into a form that is readable. In some embodiments the processor may be coupled to a memory, such as a flash memory or solid-state memory, and may store the received and/or processed data in the memory.

In some embodiments, the method may comprise550receiving global positioning system (GPS) data. The instrumented pig may comprise a waypoint detector. The method may comprise the waypoint detector reading the magnetically encoded information found on waypoints which have been preprogrammed and magnetically encoded and fixed to the pipeline. The method may include programming and encoding the GPS data, specifically the GPS location of the waypoint, on each waypoint. The method may include the instrumented pig passing by the waypoints and reading the encoded GPS location data. The waypoint detector may be operably coupled to the processor. The method may include the waypoint detector sending the information to the signal processor.

In other embodiments the method may further comprise receiving GPS location data at a GPS receiver within the instrumented pig. The GPS receiver may be operably coupled to the battery and to the processor. A method may comprise the GPS receiver receiving GPS location data of the instrumented pig and communicating the GPS location data to the processor.

In some embodiments, the method may further include560, the processor geocoding the processed lithology data with the GPS data. The method may include the processor interpolating the position of any lithological feature based on the position of one or more way points and the estimated speed of the instrumented pig.

In some embodiments, the method may further include570, sending geocoded data to an external receiver. The method may further comprise the signal processor being in communication with a transceiver within the instrumented pig. The method may comprise the transceiver sending the geocoded information to an external transceiver coupled to the outside of the pipeline. The method may the instrumented pig passing the external transceiver and wirelessly transmitting the geocoded information to the external transceiver.

The method may further include580, sending the geocoded data from the external transceiver to a wall transceiver. The wall transceiver may be mounted on an above the ground barrier adjacent to the pipeline. The wall transceiver may be wired to the external transceiver and the method may include sending the geocoded data at regular intervals.

The method may further comprise590, sending the geocoded data to a central server. The method may include the wall transceiver being operably coupled to a central server and may comprise the wall transceiver to be connected via a wired connection, such as a fiber optic connection, or via a wireless connection, such as a 5G connection.

The method may comprise further steps. For example, the method may comprise providing, near the first tank, a watering station. The method may comprise treating the working fluid via a filter, chemical treatment, and/or treatment via ultraviolet light, to provide potable water. The method may further comprise providing a means to persons to receive water from the system, such as a drinking fountain or faucet.

The method may further comprise extracting the instrumented pig from the pipeline via a second access panel at the end of the pipeline. The method may further comprise rotating the instrumented pig 180 degrees and placing the instrumented pig into the pipeline.

The method may further comprise extracting the instrumented pig from the pipeline via a first access panel at the beginning of the pipeline. The method may further comprise rotating the instrumented pig 180 degrees and placing the instrumented pig into the pipeline.

The method may further comprise providing a second storage tank at the end of the pipeline. The method may comprise directing the working fluid at the end of the pipeline to the second storage tank. The method may further comprise pumping the fluid from the second storage tank into the pipeline flowing in the direction of the beginning of the pipeline, where the first storage tank is located, using a second pump controlled be a second control unit. The method may include the instrumented pig collecting and transmitting geocoded lithological data as the instrumented pig travels toward the beginning of the pipeline.

The method may further include providing an intermediate pump at a midpoint of the pipeline to compensate for the friction losses between the pipeline and the working fluid. The method may further comprise a first valve receiving a signal from the first control unit or the second control unit to open and redirect the instrumented pig, such that the instrumented pig bypasses the intermediate pump. The method may comprise a second valve receiving a signal from the first control unit or the second control unit to open and redirect the instrumented pig such that the instrumented pig returns to the main flow of the pipeline. The method may comprise the first valve and the second valve receiving signals from the first control unit and/or the second control unit to open and/or close.

The method may further comprise the instrumented pig receiving lithological imaging data via a ground penetrating radar unit. The method may comprise the ground penetrating radar unit producing an electromagnetic signal at an antenna operating at approximately 100 MHz-200 MHz and operable to transmit an electromagnetic signal. The method may further comprise receiving a reflected electromagnetic signal at the antenna.

EMBODIMENTS

A first embodiment may include a subterranean object detection system, comprising a pipeline operable to conduct a working fluid, and an instrumented pig operable to travel within the pipeline and operable to image lithological strata and voids within the strata beneath and around the pipeline. The instrumented pig may comprise an outer case, a battery coupled to the outer case, a ground imaging unit operable to send a signal to image the lithological strata and voids within the strata beneath and around the pipeline and is operable to receive a reflected signal indicating lithology data, wherein the ground imaging unit is operably coupled to the battery.

A second embodiment may include the system of embodiment 1, wherein the pipeline further comprises at least one preprogrammed magnetically coded waypoint and wherein the instrumented pig may comprise a waypoint detector operable to read data from the magnetically coded waypoint.

A third embodiment may include the system of embodiment 1, wherein the instrumented pig may comprise a global positioning system (GPS) locator and telemetry transmitter operably coupled to the battery and to the ground imaging unit.

A fourth embodiment may include the system of embodiment 2 or of embodiment 3, wherein the instrumented pig may further comprise a signal processor operably coupled to ground imaging unit and to one of the waypoint detectors and the GPS receiver. The signal processor may be operable to geocode data gathered from the ground imaging unit with data received from one of the waypoint detectors and the GPS locator.

A fifth embodiment may include the system of embodiment 4, and may further comprise a data transceiver operable to receive data from each of the signal processor, ground imaging unit, and from the one of the waypoint detector and GPS locator, and may be further operable to send data to an external receiver.

A sixth embodiment may include the system of embodiment 5, wherein the instrumented pig may further comprise at least one external guide coupled to an outside of the outer case.

A seventh embodiment may include the system of embodiment 6, wherein the ground imaging unit may comprise an acoustic sub-bottom profiler. The acoustic sub-bottom profiler may comprise a transducer operable to project an acoustic signal into the ground. The acoustic signal may be operable to create a reflected signal upon encountering objects within strata. The transducer may further be operable to receive the reflected signal, wherein the signal processor may be operable to process the reflected signal.

An eighth embodiment may include the system of embodiment 7. The ground imaging unit may comprise a ground penetrating radar. The ground penetrating radar may comprise a transmission antenna operable to produce an electromagnetic signal propagating into the ground, a receiving antenna operable to receive a reflected electromagnetic signal, wherein the signal processor is operable to process the reflected electromagnetic signal.

A ninth embodiment may include the system of embodiment 7 or 8, which may further comprise at least one pump coupled to the pipeline operable to pump the working fluid through the pipeline.

A tenth embodiment may include the system of embodiment 9, wherein the pipeline comprises a high-density polyethylene pipe.

An eleventh embodiment may include the system of embodiment 10, wherein the pipeline is at least partially buried in the ground.

A twelfth embodiment may include system of embodiment 11, wherein the pipeline may further comprise multiple sections coupled together, at least one access panel operable to open and close and operable to allow the instrumented pig to be removed, and at least one watering station.

A thirteenth embodiment may include the system of embodiment 12, wherein the subterranean object may comprise a tunnel.

An fourteenth embodiment may include the system of embodiment 9, further comprising: a fence adjacent to the pipeline, wherein the fence is operable to support a transceiver, wherein the transceiver is operable to communicate with a central server, and wherein the data transceiver is operable to transmit data to the transceiver on the wall and operable to receive data from the data acquisition system on the wall.

A fifteenth embodiment may include an instrumented pig, comprising an outer case, a rechargeable battery coupled to the outer case, an acoustic sub-bottom profiling unit operable to image lithology beneath and around the pig. The acoustic sub-bottom profiling unit is operably coupled to the rechargeable battery. The acoustic sub-bottom profiling unit may comprise a transducer operable to produce an acoustic pulse directed to ground strata and wherein lithological features and voids within the strata create a reflected acoustic pulse. The transducer of the acoustic sub-bottom profiling unit may be operable to receive the reflected acoustic pulse. The instrumented pig may further comprise a waypoint detector operable to read from a preprogrammed magnetic waypoint external to the instrumented pig a global positioning system location of the magnetic waypoint.

A sixteenth embodiment may include the system of embodiment 15, further comprising a signal processor operably coupled to the acoustic sub-bottom profiling unit.

A seventeenth embodiment may include the instrumented pig of embodiment 16, wherein the signal processor is operable to geocode data gathered from the acoustic sub-bottom profiling unit with data received from the GPS receiver.

An eighteenth embodiment may include the instrumented pig of embodiment 17, further comprising a data transceiver operably coupled to the signal processor and the rechargeable battery and operable to send data to an external transceiver and further operable to receive data from an external transceiver.

A nineteenth embodiment may include the instrumented pig of embodiment 18, wherein the instrumented pig further comprises at least one external guide coupled to an outside of the outer case.

A twentieth embodiment may include method of detecting a subterranean object. The method may comprise broadcasting an acoustic signal from an acoustic sub-bottom profiler contained within an instrumented pig, the instrumented pig traveling within a pipeline. The method may include, receiving, at a receiver within the acoustic sub-bottom profiler, a reflected acoustic signal, receiving, at a signal processor the acoustic signal, processing, at the signal processor, the reflected acoustic signal, receiving, at a waypoint detector from a preprogrammed magnetic waypoint, a location data, such global positioning system (GPS) data, receiving, at the signal processor, the location data, and geocoding a processed lithology data with the location location.

A twenty-first embodiment may include the method of embodiment 20, further comprising sending, by a transmitter, a geocoded processed lithology data to a receiver external to the instrumented pig, receiving, by a receiver on a wall adjacent to the pipeline, the geocoded processed lithology signal, and sending the geocoded processed lithology data to a central server.

Unless otherwise specified, the term “substantially” means within 5% or 10% of the value referred to or within manufacturing tolerances. Unless otherwise specified, the term “about” means within 5% or 10% of the value referred to or within manufacturing tolerances.

The conjunction “or” is inclusive.

The terms “first”, “second”, “third”, etc. are used to distinguish respective elements and are not used to denote a particular order of those elements unless otherwise specified or order is explicitly described or required.

The system or systems discussed are not limited to any particular hardware architecture or configuration. A computing device can include any suitable arrangement of components that provides a result conditioned on one or more inputs. Suitable computing devices include multipurpose microprocessor-based computer systems accessing stored software that programs or configures the computing system from a general-purpose computing apparatus to a specialized computing apparatus implementing one or more embodiments of the present subject matter. Any suitable programming, scripting, or other type of language or combinations of languages may be used to implement the teachings contained in software to be used in programming or configuring a computing device.