Abstract:
A system for detection of underground intrusions and reporting those intrusions, including a plurality of sensor packages planted underground, the plurality of sensor packages providing a corresponding plurality of detection outputs to a controller, the controller operative to receive at least one of the plurality of detection outputs and to provide a high speed output indication of intrusion presence.

Description:
FIELD 
       [0001]    The present invention relates generally to disturbance detection and warning systems. More particularly, the present invention relates to a network-based underground warning and reporting system and method. 
       BACKGROUND 
       [0002]    Border patrol has become an increasingly important issue for governments seeking to control persons entering and leaving their respective countries. Border control can be especially difficult when the border concerned spans a vast, largely unpopulated terrain, such as the 6,000 miles of border between the United States and Mexico. To help reduce illegal crossings, more officers are being hired, walls are being installed, and more technology is being applied to border enforcement. 
         [0003]    There is a need for a sensor system that can provide unmanned coverage of underground areas for long periods of time. It is highly desirable to provide a new and improved network for providing remote supervision of underground intrusions. It is thus highly desirable to provide a new and improved communication network between a plurality of underground sensors at different locations and a controller, where the network utilizes a plurality of sensory displays, signals and prompts to supervise and report intrusions and intrusion information at spaced remote locations. 
       SUMMARY 
       [0004]    The present invention overcomes many of the disadvantages of the prior art by providing a tunnel activity detection system designed to detect intrusions within an area, to inform users monitoring the area when an intrusion has occurred, and to inform the users of the location of the intrusion. 
         [0005]    The tunnel activity detection system includes one or more sensor packages and a local controller. Each of the one or more sensor packages are planted underground in a target area in which intrusion detection is desired. A user will then associate each sensor package with the local controller to form a wireless network. The sensors within the sensor packages are connected as routing nodes via a radio network. 
         [0006]    The sensor network is configured for flexible use. The sensors are spaced to allow for messaging around a disabled sensor node. Additionally, low duty cycle sensors may be placed among sensors with longer duty cycles to prolong battery life. 
         [0007]    When a sensor detects an intrusion, an appropriate signal is transmitted to the controller via the radio network. A display associated with the controller allows the user to view details concerning the intrusion. These details may include information regarding the time and location of the intrusion. 
         [0008]    The display on the local controller may be interactive display, wherein the user can select screen options from an initial screen. The screen options may be, for example, an alert screen, an add sensor screen, a command screen, or a network status screen. The alert screen may show information regarding the last alert and allow the user to further select an image screen to view images of an intrusion. The add sensor screen allows the user to add more sensors to the network. The command screen allows the user to change the status of a sensor; a sensor could be set to a number of different modes. For example, the sensor could be either active or inactive, depending on whether the particular area within which the sensor is placed requires surveillance. A network status screen may provide the user with information regarding the mode set for each sensor and the amount of battery remaining in each sensor. In addition, the local controller may inform the user of an intrusion with any one of numerous types of annunciators, such as a vibration annunciator. 
         [0009]    The local controller may be housed within a computer, such as a laptop or desktop computer. The controller may also be housed within a personal digital assistant. 
         [0010]    Natural disturbances, such as earthquakes, do not exhibit a prolonged uniform pulse pattern as do other disturbances, such as pedestrian disturbances. Thus natural disturbances can be readily identified and rejected by a system designed to detect pedestrian disturbances. 
         [0011]    The intrusion detection and reporting network may have many practical applications. For example, the intrusion detection and reporting network can be applied to military, home, industrial, corporate, neighborhood, or penitentiary use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Various embodiments are described herein with reference to the following drawings. Certain aspects of the drawings are depicted in a simplified way for reason of clarity. Not all alternatives and options are shown in the drawings and, therefore, the invention is not limited in scope to the content of the drawings. In the drawings: 
           [0013]      FIG. 1  depicts a tunnel activity sensor system according to one embodiment of the present invention; 
           [0014]      FIG. 2  depicts a tunnel activity sensor system according to one embodiment of the present invention; 
           [0015]      FIGS. 3   a - c  depict various exemplary embodiments of sensor packages; and 
           [0016]      FIG. 4  is a simplified block diagram of an exemplary display screen. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  depicts a tunnel activity sensor system  100 . Tunnel activity sensor system  100  includes a plurality of sensor packages  102  arranged across a target area  104 , as shown in  FIG. 1 . The plurality of sensor packages  102  may communicate wirelessly with one another and/or with other devices in system  100 . For example, the plurality of sensor packages  102  may communicate with a local controller  106 . 
         [0018]    The plurality of sensor packages  102  and other devices preferably communicate using a self-forming, self-healing mesh ad-hoc network. While many protocols exist for such networks, presently preferred protocols are in accordance with IEEE 802.15 Wireless Personal Area Network (WPAN) standards. For example, the ZigBee suite of communications, based on the IEEE 802.15.4 standard is a desirable protocol suite due to its suitability for low-power, low data-rate applications. However, other communication systems may also be used. 
         [0019]      FIG. 2  is a simplified diagram illustrating the tunnel activity sensor system  100  of  FIG. 1 . As shown in  FIG. 2 , local controller  106  may comprise a display  108 . In addition, the plurality of sensor packages  102  may communicate with an existing security infrastructure  110 . Sensor packages  102  may be in a staggered formation, as in the configuration shown in  FIG. 2 . However, the plurality of sensor packages  102  may also be arranged in a number of other configurations. As an example configuration alternative, the plurality of sensor packages  102  may be arranged in a straight line in series. As another alternative, the sensor packages  102  may be arranged to form a circle or square. 
         [0020]      FIGS. 3   a - c  illustrate possible configurations for the plurality of sensor packages  102 . Each sensor package of the plurality of sensor packages  102  may comprise a seismic sensor and processor  402 , a battery  404 , a radio  406 , a cable  408 , and an antenna  410 . Seismic sensor and processor  402  should be in direct or indirect solid physical contact with the ground so as to improve sensing capabilities. With the possible exception of the antenna  410 , each of these components may be substantially enclosed within an enclosure  412 .  FIG. 3   a  shows enclosure  412  enclosing radio  406  and battery  404 , leaving cable  408  and seismic sensor and processor  402  open to the surrounding terrain.  FIGS. 3   b  and  3   c  show enclosure  412  enclosing cable  408 , radio  406 , battery  404 , and at least a portion of seismic sensor and processor  402 . Enclosure  412  may be a PVC pipe having an inner diameter and length sufficient to accommodate the aforementioned components. Enclosure  412  protects the components from possible damaging forces. In an alternative embodiment, two enclosures  412  may be used. A first enclosure containing sensor package  102  could be permanently buried in a hole and the hole filled with dirt. A second enclosure may contain the radio  406  and battery  404  buried near the surface. A cable attached to antenna  410  and running through the first enclosure could then couple the first enclosure to the second enclosure. In some embodiments, antenna  410  may be a retractable antenna. 
         [0021]    Radio  406 , in combination with the processor and software, allows each sensor package of the plurality of sensor packages  102  to function as a network router, relaying data from adjacent nodes. Thus, the network can be dynamically configured. Radio  406  is preferably a radio offered by Honeywell International Inc. For example, a 100 mW radio may be used for communications between the plurality of sensor packages  102 . Higher-powered radios may be used if greater communication range is desired. However, with higher-powered radios, the life of battery  404  will be shortened. A 100 mW radio is preferably used for communications up to approximately 200 meters. A 250 mW radio may be used for communications up to around 400 meters. A 500 mW radio may be used for communications up to around 500 meters. As the distance between neighboring sensor packages  102  increases, however, the ability to sense very small disturbances at the midpoints between sensor packages  102  may decrease. 
         [0022]    Seismic sensor and processor  402  preferably comprises a MEMS accelerometer capable of sensing micro-g disturbances. Such sensors are offered by Honeywell International Inc., for example, the assignee of the present invention. Other sensors capable of detecting micro-g disturbances may also be used. The seismic sensors may use any of a number of technologies including geophones, accelerometers, seismometers, or other technologies capable of detecting digging activities. Additional sensors capable of detecting tunnels or tunneling may be included in the sensor package to augment the seismic sensor. These may include acoustic sensors, magnetic anomaly sensors, density anomaly sensors, or other sensors. Optimal sensors will exhibit the requisite sensitivity with minimal power consumption. The sensors are preferably low duty cycle sensors that “listen” for digging during only a fraction of each hour. For example, each sensor may actively sense for only one minute out of each hour, in order to prolong battery life. Suspicious signals could trigger longer duty cycles for the detecting sensor package, as well as adjacent sensor packages  102 . Processing may include executing situational understanding and control software to assist in characterizing and/or identifying detected disturbances. In an alternative embodiment, the primary characterizing and identifying functions are carried out by the local controller  106 . Processing may also include accelerometer calibration, RF processing, and other processing. 
         [0023]    Each sensor package of the plurality of sensor packages  102  may be installed so that substantially the entire assembly is below ground, with the exception of antenna  410 . Alternatively, each of the plurality of sensor packages  102  may be only partly below ground and partly above ground, to improve the coverage area of antenna  410 . For security applications, however, installation is preferably substantially below ground to prevent detection by possible intruders. The plurality of sensor packages  102  may be installed by boring a hole, extending the retractable antenna  410 , and placing the sensor package in the hole. Alternatively, if the enclosure is of sufficient strength and rigidity, each of the plurality of sensor packages  102  may be pushed, driven, or screwed into soft soil or sand, without boring an installation hole beforehand. 
         [0024]    The plurality of sensor packages  102  are preferably arranged around target area  104  in such a way that at least two sensor packages  102  will detect any particular underground disturbance occurring below the target area, to the depth at which the sensor packages are able to sense such a disturbance. For most applications, a sensing depth of up to about 30 meters may be sufficient. Increasing the density of sensor packages  102  placed in the target area  104  may lead to improved depth consistency, as well as deeper sensing capabilities. The underlying geology of any particular area will affect sensing depths and characteristics. Suitable distances between neighboring sensor packages  102  may be on the order of hundreds of meters (e.g. 200 meters between neighboring sensor packages  102 ). In a basic implementation, a single sensor package and a single local controller  106  make up the entire system. 
         [0025]    To assist in locating detected disturbances, the location of installed sensor packages  102  should be recorded. Triangulation may be used to identify approximate locations for possible tunneling activity. As an alternative, each sensor package of the plurality of sensor packages  102  could include a GPS module to communicate its location as appropriate. 
         [0026]    For a border security application, the plurality of sensor packages  102  may be placed at various points along a border to be secured. The plurality of sensor packages  102  may be emplaced in any configuration desired for a given geology, desired detection range, and expected tunnel depth as long as communication is established with the radio network. 
         [0027]    The local controller  106  functions, in part, as the primary situational awareness display and preferably comprises a short-haul radio, situational understanding software (e.g. disturbance characterization/identification modules), a display  108  and input and output components. Local controller  106  communicates with the networked sensor packages  102  to receive alerts and to assist in controlling and monitoring the system  100 . Alerts may indicate the possible detection of an underground disturbance, a faulty sensor package (as detected by neighboring sensor packages, for example), or a low-battery condition. In addition, local controller  106  may interface with other devices and systems, such as intrusion and/or imaging sensors, as well as other user controller devices or a central facility. 
         [0028]    In one embodiment, local controller  106  is housed within a computer. In another embodiment, local controller  106  is housed within a handheld device, for example, a personal digital assistant (“PDA”) having integrated short-haul communications capabilities. Local controller  106  may also be a housed within a ruggedized PDA, (“RPDA”) which comprises a hardened case for rugged and dangerous environments. The user may then view information regarding an intrusion via display  108 . Display  108  may be a graphical user interface (“GUI”), and may provide screens for network status, command and control, adding a sensor (i.e., missing loading), alerts, and disturbance characterization, identification and location information. Display  108  may show details about the intrusion including information regarding the time of the intrusion. Display  108  may show information regarding the location of the intrusion. For example, details regarding the location of the intrusion may include geographic coordinates. Some exemplary display  108  screens are shown in  FIG. 4 .  FIG. 4  depicts various functions that may be implemented by local controller  106  that are used to implement the system of  FIG. 1 . Display  108  may show a plurality of screen options. Although four screen options are depicted in  FIG. 4 , display  108  is not limited to four screen options, and a number of other screen options may be present. A user may select one of the plurality of screen options from display  108 . The plurality of screen options shown in  FIG. 4  are an alerts screen  510   a , an add sensor screen  510   b , a command screen  510   c , and a network status screen  510   d . Although only these particular screen options are shown, the display is not limited to these specific options and other options may be included or substituted. 
         [0029]    Alerts screen  510   a  may show information regarding the last intrusion alert. Alerts screen  510   a  may also show or provide access to any of the location information of an intrusion previously discussed. 
         [0030]    Add sensor screen  510   b  allows a user to add more sensors to the network. 
         [0031]    A sensor may be set to a number of different modes; command screen  510   c  allows a user to change the sensor mode. As an example, a sensor could be set to be either active or inactive, depending on whether that particular area within which the sensor is placed requires surveillance. 
         [0032]    Network status screen  510   d  may provide a user with information regarding the mode set for each sensor, the amount of battery remaining in each sensor, as well as the type of sensor. 
         [0033]    In addition to providing location information, local controller  106  may vibrate to alert a user of an intrusion. In this embodiment, a vibration annunciator may be included and the controller may turn on the vibration annunciator to provide an additional alert to a user that an intrusion has occurred. 
         [0034]    In a second embodiment, local controller  106  may not be part of the mesh LAN comprising sensor packages  102 . Instead, sensor packages  102  communicate with a centralized control and monitoring station over the mesh LAN (i.e. short haul LAN). The centralized control and monitoring station then communicates with one or more remote user controllers via a long haul RF network. The centralized control and monitoring station may include, for example, a gateway (and possibly a backup gateway) to one or more other networks. In yet another embodiment, the plurality of sensor packages  102  communicate both with one or more local user controllers  106  and with a centralized control and monitoring station that, in turn, communicates with one or more remote controllers. The remote controllers may be carried, for example, by border patrol agents, enabling them to respond to potential border breaches. 
         [0035]    In operation, when a sensor package of the plurality of sensor packages  102  detects a disturbance, it alerts the local controller  106  and other nearby sensor packages. The sensor packages  102  then begin processing the data in an attempt to characterize and/or identify the disturbance. Disturbance information, such as empirical data and/or suspect waveforms, may be maintained at the local controller  106 , for example, for use in comparing the detected disturbance data with the stored disturbance information. In addition or as an alternative, the sensor packages  102  could communicate the detected disturbance data over a long-haul communication link with one or more remote users or a central facility. As yet another alternative, the sensor packages  102  could obtain detailed stored disturbance information from a remote site, such as the central facility. 
         [0036]    Alerts are preferably sent in a plurality of directions (e.g. both directions along a border) to existing towers, networks, and mobile terminals. The sensor spacing preferably allows for messaging around a disabled node (i.e. each sensor package should be able to communicate with more than one other sensor package in any general direction). 
         [0037]    The system  100  described above provides unmanned coverage of target areas for long periods of time, due to relatively low power consumption. The sensor packages  102  may be small, lightweight, and expendable, making placement easy and inexpensive. The flexible architecture allows additional sensor packages  102  to be added to expand or alter a particular target area  104 . By arranging the placement of the sensor packages  102  appropriately, underground disturbances can be detected to prevent intruders from breaching borders, boundaries, buildings, and other assets to be secured. 
         [0038]    Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above, are hereby incorporated by reference.