Abstract:
Operation of a bird deterrent system includes i. measurement of bird habituation to activation of deterrent devices; ii. reduction of habituation through increased selectivity in activating deterrents only for birds posing a threat to or threatened by a protected area, and in particular, those within threat altitudes; iii. provision of analytical data in support of safety management systems, risk management, etc.; iv. integrated, wide-area radar coverage with multiple virtual intrusion zones providing multiple lines of defense around and over very large protected areas.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to deterrent systems and methods to keep birds away from protected areas that are either threatened by birds or pose a threat to birds. The invention is particularly useful for protecting birds from harmful effects of ponds generated during oil and mining processes, for protecting birds from power generation and transmission structures such as wind farms, for prevention of bird-aircraft strikes at airports to enhance aviation safety, and for protecting crops from birds to enhance yield. 
       BACKGROUND OF THE INVENTION 
       [0002]    Several applications require keeping birds away from protected areas, which we define herein as geographical areas that either threaten birds and/or are threatened by birds. Consider for example, mining and oil operations with associated tailings ponds that may be harmful to birds. Operators and regulators desire economical devices and methods designed to help keep birds from landing on these protected areas, i.e. the tailings ponds. 
         [0003]    Electrical power generation structures such as wind turbines pose hazards to birds because birds flying through wind farms, especially during low visibility, can come in contact with turbine blades, which rotate within a confined altitude band up to a couple of hundred meters above the ground. In this example, the wind farm can be treated as a protected area. To protect birds flying at low altitudes, operators and regulators desire economical devices and methods that will cause birds to alter their flight paths when approaching protected areas so as to avoid collision with wind turbines. 
         [0004]    Birds are a significant hazard to aviation safety. Billions of dollars in damage to aircraft and significant loss of life have been recorded as the result of birds colliding with aircraft (referred to as bird-aircraft strikes, or simply bird strikes), particularly while aircraft are on approach or departure in the vicinity of airports. Birds do not survive bird strikes. Several protected areas can be defined around an airport where bird-aircraft strike hazards (BASH) are known to be significant. Airport operators and their regulators desire economical devices and methods designed to cause birds to safely alter their flight path when approaching these protected areas so as to avoid collisions with aircraft. The airport environment requires particular care since we do not want to deter birds from entering one protected area only to steer them into another area of potentially greater hazard. 
         [0005]    Farmers know all too well the damage that birds can do to their crops. They have employed all sorts of bird deterrent devices such as cannons and effigies to harass birds in an attempt to keep them away. If one treats precious crop areas as protected areas, farmers desire economical devices and methods to keep birds away from these protected areas in order to increase the quantity and quality of their crop yields. 
         [0006]    In the above applications, several types of bird deterrents and bird harassment methods have been employed, some of which are automated and run unattended, and some of which are used by trained personnel. Automated deterrents such as propane cannons, effigies, acoustic devices that broadcast aversive auditory emissions such as alarm, distress, and predator vocalizations, and lasers operated in low-light have been used with some success but suffer from habituation—i.e., the birds get used to them and the deterrents eventually lose their effectiveness in harassing and deterring birds. Modern deterrents usually activate randomly in an attempt to increase the time duration before birds become habituated to them. Human-operated deterrents such as hand-held pyrotechnics and hand-held lasers are more effective because they are selectively used only against birds approaching or found within protected areas. As a result, habituation occurs slowly or not at all. These human-operated deterrents, however, are impractical to use in a continuous fashion over large protected areas or at night. 
         [0007]    While radar-activated deterrent systems have been reported in use in rare cases, their effectiveness has not been quantified and reported. The systems were deployed to protect a tailings pond with an attempt to reduce habituation by activating deterrents only when birds were detected by the radar. In these limited cases, 2D radars were employed that did not provide bird altitude selectivity over the protected area. Also, the protected area was small, concentrated over water, and monitored from a single radar location. 
       OBJECTS OF THE INVENTION 
       [0008]    A primary object of the current invention is to provide improved bird-deterrent systems for keeping birds away from protected areas. 
         [0009]    It is a more particular object of the present invention to provide improved bird-deterrent systems that have enhanced intelligence and more automated capabilities relative to conventional systems. 
         [0010]    A further object of the present invention is to provide such bird-deterrent systems with enhanced flexibility and reliability. 
         [0011]    With respect to flexibility, it is an object of the present invention to support all kinds of deterrent devices, including portable devices on platforms floating on water, and fixed and portable devices deployed on land. 
         [0012]    Also with respect to flexibility, it is an object of the present invention to enable integration or use of all kinds of surveillance sensors, including 3D and 2D avian radars, infrared and camera sensors, weather radars, and national radar networks such as NEXRAD. 
         [0013]    Another particular object of the present invention is to provide improved bird-deterrent systems that reduce the impact of avian habituation on system effectiveness over time. 
         [0014]    A related object of the present invention is to provide such bird-deterrent systems that reduce the impact of environmental change on the system effectiveness over time. 
         [0015]    These and other objects of the invention will be apparent from the drawings and descriptions included herein. It is to be noted that each object of the invention is achieved by at least one embodiment of the invention. However, it is not necessarily the case that every embodiment of the invention meets every object of the invention as discussed herein. 
       SUMMARY OF THE INVENTION 
       [0016]    The present invention concerns practical improvements over state-of-the-art 2D radar-activated bird deterrent systems to make them smart, far more effective, flexible, and affordable. 
         [0017]    The present invention provides smart and affordable, automated bird-deterrent systems that keep birds away from protected areas, that are capable of measuring effectiveness and habituation and are capable of altering system configuration in order to maintain high performance. 
         [0018]    The present invention provides software-configured control to alter system configuration in response to measured reductions in performance resulting either from habituation by the birds or from changes in the environment. More specifically, the present invention provides in part means such as an expert system or cognition to automatically alter system configuration in response to measured reductions in performance resulting from either avian habituation or changes in the environment. 
         [0019]    The present invention provides the means to measure the 3D trajectories (latitude, longitude, altitude, speed and heading versus time) of birds to enable or inform the selective activation of deterrents, for instance, against only those birds that are a threat to or are threatened by a particular protected area, thereby reducing or eliminating habituation. 
         [0020]    A feature of the present invention is an information subsystem that permanently and continuously stores and organizes system data, including 3D bird trajectories, threat alerts, and deterrent activation information, and analyzes system effectiveness in a manner suitable for investigations into bird mortalities, litigation, due diligence concerning risk management, safety management systems, detection of habituation, scientific analyses, and training. 
         [0021]    The present invention provides for automatically and flexibly integrating a number of non co-located or mutually spaced surveillance sensors to collectively form a large coverage volume within which multiple virtual sub-volumes (also referred to as lines of defense or intrusion zones) can be established, which, when penetrated by birds that are a threat to or threatened by a protected area, will trigger a threat alert that causes particular sets of deterrent devices to activate in response. 
         [0022]    The present invention contemplates the automatic locating of deterrent devices and the maintenance thereof independently of the surveillance sensors. The deterrent devices can be moved and programmed in virtual sets that activate in response to particular threat alerts. The present invention supports all kinds of deterrent devices, including portable devices on platforms floating on water, and fixed and portable devices deployed on land. 
         [0023]    The present invention integrates all kinds of surveillance sensors, including 3D and 2D avian radars, infrared and camera sensors, weather radars, and national radar networks such as NEXRAD, in order to provide surveillance coverage volume. 
         [0024]    In summary form, the improvements of the present invention include the following features:
       Quantification of avian habituation to activation of deterrent devices   Feedback by altering system configuration to reduce habituation   Reduction of habituation through increased selectivity in activating deterrents only for birds posing a threat to or threatened by a protected area, and in particular, those within threat altitudes   Provision of analytical data in support of safety management systems, risk management, due diligence, investigations, litigation, scientific analyses, training, and public policy   Flexible and affordable, integrated, wide-area coverage with multiple virtual intrusion zones providing multiple lines of defense around and over very large protected areas   Flexible, virtual interface between surveillance subsystem and deterrent subsystem, allowing one to be relocated relatively independently of the other, which is essential when protected areas change frequently   Support for any type of surveillance sensor that can detect birds posing a threat to or threatened by a protected area       
 
         [0032]    In accordance with the present invention, the following general automated bird deterrent system elements work together to provide (to varying degrees) the desired features listed above:
       1. A protected area from which the system is intended to keep birds away.   2. A deterrent subsystem consisting, in the general case, of several deterrent apparatuses (or simply deterrents) arranged within the protected area as well as around and away from the protected area.   3. A surveillance subsystem with a coverage volume that typically includes the protected area as well as volumes around and away from the protected area. The surveillance subsystem tracks birds in the coverage volume, and detects when they pose a threat to or are threatened by a protected area, causing a threat alert to be issued for each instance of a detected threat.   4. A deterrent activation processor that receives threat alerts from the surveillance subsystem and, based on the information contained therein, selects and activates appropriate deterrents to harass the birds in question in an attempt to cause them to change their course and depart away from the protected area.   5. An information subsystem that collects sufficient information on bird trajectories (or tracks), threat alerts, and deterrent activations to enable: (i) measurement of system effectiveness and avian habituation; (ii) alteration of system configuration to reduce habituation; (iii) interface with system operators; and (iv) support of a variety of data analytics.   6. One or more operator situational awareness displays via a mobile computing device or a computer in an operations centre running common operating picture (COP) software that presents in real-time bird tracks within the coverage volume, indications of threat alerts, and indications reflecting the status of deterrents. Operators are able to follow birds&#39; responses to the surveillance-activated deterrents.       
 
         [0039]    A real-time, automated, bird deterrent system comprises, in accordance with the present invention:
       a surveillance subsystem consisting of one or more surveillance sensor apparatuses adapted for detecting birds posing a threat to or threatened by a protected area;   a deterrent subsystem consisting of one or more deterrent apparatuses adapted for harassing detected birds in response to associated threats;   a deterrent activation processor that receives a threat alert from the surveillance subsystem when intruding birds are detected that pose a threat to or are threatened by the protected area, the deterrent activation processor determining and activating a subset of the deterrent apparatuses in response to each threat alert; and   an information subsystem comprising a data storage device that stores the identification, date and time associated with each threat alert, the identification of the respective deterrent apparatuses that were activated in response to a given threat alert, and the respective trajectories of the detected birds provided by the surveillance subsystem to enable determination of whether the detected birds left the protected area in response to the activation of the respective deterrent apparatuses.       
 
         [0044]    A related method in accordance with the present invention comprises:
       operating a surveillance subsystem with one or more surveillance sensor apparatuses to substantially continuously monitor a surveillance volume to detect birds posing a threat to or threatened by a protected area and generating and sending a threat alert to a deterrent activation processor when such birds are detected, the operating of the surveillance subsystem further including tracking and generating trajectories for each bird;   operating a deterrent activation processor by receiving the threat alerts and selecting and activating one or more deterrent apparatuses included in the deterrent subsystem in response to the threat alerts;   operating a deterrent subsystem with one or more deterrent apparatuses by activating those deterrent apparatuses selected by the deterrent activation processor in response to threat alerts received from the surveillance subsystem; and   operating an information subsystem by storing sufficient bird deterrent system information to enable determination of whether the detected birds left or avoided the protected area in response to activation of the respective deterrent apparatuses.       
 
         [0049]    Preferably, the information subsystem continuously organizes and stores indefinitely all narrowband target data, threat alert data, and deterrent subsystem activation data. These data allow system effectiveness and avian habituation to be measured so that system configuration can be altered and performance maintained by reducing or obviating the habituation that would otherwise occur. The data also provide support for a rich situational awareness picture to operators, allowing them to react with deployment of response personnel and other resources to reduce threats. In addition, these data support a variety of data analytics suitable for safety management systems, risk management, due diligence, investigations, litigation, scientific analyses, training, and public policy. 
         [0050]    One embodiment of deriving measures of effectiveness and habituation includes computing one or more metrics from the following set: i. total number of bird intrusions successfully deterred per hour, day, week, month, season, or year;—and ii. percentage of bird intrusions successfully deterred per hour, day, week, month, season, or year and comparing the result to previously recorded values. 
         [0051]    A significant increase in measured habituation will prompt an alteration of system configuration based on a set of system configuration parameter sets designed for this purpose. The smart deterrent system is preferably software configurable, allowing the simple loading of a new configuration parameter set to alter the system configuration. Surveillance subsystem configuration alterations include changes in beam scanning geometry, transmitted waveform, digital radar processor (DRP) tuning, virtual intrusion zone design, and threat logic. Deterrent activation processor alterations include adjustments to mappings between intrusion zones and selection of responding deterrent apparatuses. Deterrent subsystem alterations include adjustments to the nature of the responses of the deterrent devices associated with each deterrent apparatus. For example, predator and distress calls could be varied, or cannon firing sequences could be altered. 
         [0052]    Selection of a suitable alternate configuration parameter set is either done by an operator following analysis, or made automatically by an optional automated expert system such as a cognitive processor, inference engine, neural network, or rule-based processor. 
         [0053]    It should be noted that in accordance with the present invention, the surveillance subsystem may include surveillance sensors that are airborne or space-based as well as land-based. As used herein, land-based includes being deployed or mounted on the earth (including dry ground and water surfaces), on vehicles or vessels, and on structures that may rise into the air but are tethered to or mounted on or in contact with the earth. The land-based surveillance sensors are preferably mounted on pole-tops, towers, or on one or more re-locatable trailers. A trailer could also house the indoor equipment and electronics associated with the surveillance subsystem, the deterrent activation processor, the deterrent subsystem, and the information subsystem. 
         [0054]    In accordance with the present invention, sensor apparatuses are preferably avian radars and networks. Avian radars and networks are known to those skilled in the art, and are described in the following:  Could Avian Radar have Prevented US Airways Flight  1549&#39; s Bird Strike? , Nohara, T J, 2009 Bird Strike North American Conference, Sep. 14-17, 2009, Victoria, B. C.,  Reducing Bird Strikes—New Radar Networks can help make Skies Safer , Nohara, T J, Journal of Air Traffic Control, Vol 51, No. 3, Summer 2009, pages 25 to 32 , Affordable Avian Radar Surveillance Systems for Natural Resource Management and BASH Applications , Nohara, T J et al, 2005 IEEE International Radar Conference, May 9-12, 2005, Arlington, Va., and US, U.S. Pat. No. 7,940,206 entitled “Low-cost, high-performance radar networks”, and U.S. Pat. No. 7,864,103 entitled “Device and method for 3D height finding radar”, all of which are incorporated herein by reference. 
         [0055]    The present invention preferably uses a pencil beam antenna such as a dish antenna with each avian radar sensor apparatus so that it can be inclined vertically to survey a particular band of altitudes while providing 360° coverage. Preferable dish antennas include ones that not only scan horizontally, but also scan in the vertical dimension under electronic or software control, providing preferably cylindrical coverage (e.g., 0 to 5 km range, 0 to 1000′ altitude above ground level, 0 to 360°). Antennas that also scan in the vertical dimension allow improved target altitude estimates to be made and consequently improved radar cross section estimates as described in U.S. Pat. No. 7,864,103. The pencil beam antenna is preferably coupled to an X-band radar transceiver and a digital radar processor (DRP) that implements adaptive clutter-map processing, automated low-threshold detection and MHT/IMM tracking (multiple hypothesis testing/interacting multiple models) for small maneuvering bird targets, all as described in detail in the aforementioned references incorporated herein. The key advantage that results from this preferred embodiment over conventional systems using array antennas is that 3D bird trajectories containing latitude, longitude, altitude, heading, speed, and radar cross-section (RCS)} updated every couple of seconds are available from the surveillance subsystem, completely characterizing bird movements and behavior in response to activation of deterrents, which is essential to measure habituation. Multipath suppression and sidelobe suppression are preferably included in accordance with the present invention to reduce false targets and hence habituation. In airport and mining operations, both of these artifacts are commonly experienced as the result of the presence of large buildings, vehicles, aircraft, and machines. Multipath suppression cancels false targets that appear at multiple ranges, whereas sidelobe suppression cancels false targets that appear at multiple azimuths. Multipath and sidelobe false targets, if not suppressed, can cause false threat alerts. 
         [0056]    In addition, threat alerts can be inhibited if detected birds are not at altitudes that pose a threat; altitude selectivity will significantly reduce habituation. For example, by setting a maximum altitude threshold of say 500′ AGL (above ground level), deterrents will not activate when birds are flying high through an area with tailings ponds or above a wind farm. 
         [0057]    Finally, the use of adaptive clutter-map processing means that the surveillance subsystem will be able to see (track) birds over land and issue threat alerts as they approach a tailings pond while still a distance away. Early threat alerts support multiple lines of defense by staggering and activating outward-facing long-range deterrents such as high-pressure acoustic devices (e.g., HPADs or Hyperspike emitters), followed by short-range deterrents (such as cannons, effigies, lasers, etc.) if the birds make it through the outer defense layer and penetrate the protected area. This multi-layered approach is in contrast to conventional radar-activated deterrents which are not able to reliably see birds over land, and have been limited to a few inward facing deterrents directed over a tailings pond and hard-wired to the radar sensor near the ponds edge. 
         [0058]    In accordance with the present invention, the surveillance sensor apparatuses can use any sensor capable of localizing birds in at least the horizontal ground plane. Therefore, 2D avian radars and/or camera (visible or infrared) or acoustic sensors with suitable processing can be used to provide surveillance coverage volume. 
         [0059]    The flexible separation between the surveillance subsystem and the deterrent subsystem is an important and novel feature of the present invention. The interface between the two is provided by the deterrent activation processor, which is programmable and maps threat alerts to particular deterrent apparatus activations. With network interfaces between the deterrent activation processor and the surveillance, deterrent and information subsystems, these components can be located anywhere (in the world) where network connectivity is available. As a result, third-party sensors can also be used to supplement or provide surveillance coverage volume and generate threat alerts including national radar networks such as NOMAD, airport surveillance radars, and weather radars. In addition, deterrents can be located anywhere; they need not be located close to the surveillance sensor apparatuses. This flexibility facilitates organizing lines of defense with deterrent apparatuses placed where they are most efficacious. In a preferred embodiment in accordance with the present invention, the deterrent subsystem communicates with its multitude of deterrent apparatuses using a radio mesh network, optionally in the 900 MHz band, so deterrent apparatuses can be located in virtually any arrangement, even where line of sight is not available. A GPS device is also preferably located on each deterrent apparatus with its location reported on a regular basis to the deterrent subsystem and from there to the information subsystem so that the system always knows where the deterrent apparatuses are located. This is particularly important for floating deterrents on tailings ponds that can drift or move due to ice build-up or melting. 
         [0060]    In accordance with the present invention, the deterrent subsystem can include land-based and airborne deterrent apparatuses. Land-based includes direct ground deployments, trailer mountings, floating platform or barge mountings, vehicle or boat-mounted, and pole or tower mounting. Airborne deterrent apparatuses include deterrent devices mounted on manned as well as small un-manned aircraft such as remotely controlled (RC) aircraft. RC aircraft carrying lightweight deterrent payloads could be directed to intersect and harass birds, as could RC boats. 
         [0061]    The deterrent subsystem is preferably powered by on-board power including generator, and solar or wind power to maintain re-locatability, which is required typically in tailings pond applications. Otherwise, shore-power can be used. The surveillance subsystem is preferably powered by on-board generator when re-locatability is needed, or shore-power otherwise. 
         [0062]    A desirable surveillance subsystem option and related method option in accordance with the current invention combines the antenna coverage volumes of each respective surveillance sensor apparatus to form a composite coverage volume of the surveillance subsystem within which multiple virtual sub-volumes or intrusion zones are defined and within which the detected birds threatened or posing threats are localized. These virtual intrusion zones are very flexible in that they support multiple lines of defense for the protected area; i.e., each intrusion zone can be associated with or mapped to particular subsets of deterrents by the deterrent activation processor. For example, long range deterrent devices such as high-power acoustic devices (HPADs) can be located around a protected area such as a tailings pond, directed outwards and focused at birds located 1 km or more away from the pond, and activated by an intrusion zone located 1 to 2 km away only when birds are detected therein, approaching the pond, and at an altitude where landing on the pond is feasible. 
         [0063]    The aforementioned, integrated, composite coverage volume with virtual intrusion zones is an especially important feature of the present invention for applications such as tailings ponds that require several, non co-located or mutually spaced surveillance sensors spanning a large geographic area to provide the required coverage for a single large protected area, or a very large protected area made up of multiple disjoint protected areas. In such cases, hundreds of deterrent apparatuses may be deployed, making it very difficult for operators to understand what is going on without integrated coverage and virtual, earth-coordinates-based intrusion zones. Preferably, the present invention employs avian radar networks (which are further described in the aforementioned references incorporated herein) to implement the composite coverage volume. The avian radar network is formed by each sensor&#39;s DRP integrating its tracks with a radar data server (RDS) that collates and serves the integrated data. A radar fusion engine (RFE) is optionally employed to fuse tracks from overlapping coverage areas (as further described in the aforementioned references incorporated herein). Each DRP converts all tracks to earth-coordinates before writing them to the RDS. This means that virtual intrusion zones can be easily defined directly in earth coordinates from the composite track data contained in the RDS. Each intrusion zone can be penetrated by birds seen (tracked) by any of the contributing avian radars. 
         [0064]    Optionally, in accordance with the present invention, the system includes common operating picture (COP) software that runs on a computer in an operations centre as well as on mobile devices connected by data network to the information subsystem to give one or more operators complete situational awareness of real-time bird movements within the composite coverage volume provided by the surveillance subsystem, intrusion zone penetrations, protected area penetrations, deterrent apparatus activations, and bird responses to deterrents. 
         [0065]    The various data networks connecting the surveillance, deterrent, and information subsystems, the deterrent activation processor, and the operation center computers and mobile devices running the COP software support various network protocols including TCP/IP and can be wired (e.g., CAT5/6, Ethernet, fibre) or wireless (e.g. WiFi, cellular, radio), in a local area network (LAN) configuration, wide-area network (WAN) configuration, public network such as the Internet, or hybrid network. The system design affords complete flexibility between locations and connections of system components. 
         [0066]    The smart, automatic bird deterrent system network architecture in accordance with the present invention is also very useful for allowing independent operators from adjacent or nearby properties to share and integrate information. As transient or migrating birds fly from one property to another, operators can gain early warning of significant bird movements (as during migration) simply by allowing their respective COPs to receive selected information from their neighbor&#39;s information subsystem. If further integration is desired, they can even expand their composite coverage of their own surveillance subsystem by allowing a neighbor&#39;s DRP to write to their own RDS. 
         [0067]    Accordingly, the present invention seeks to overcome the above-mentioned limitations associated with conventional automatic bird deterrent systems by providing and integrating new capabilities to reduce habituation, to provide wide-area protection over large and complex protected areas, and to provide protection at night. In particular, 3D surveillance sensor means are disclosed herein that can selectively respond, much like wildlife control personnel using hand-held deterrents, only to birds at altitudes and trajectories likely to penetrate and threaten or be threatened by protected areas, thereby reducing habituation. The radar apparatus and methods described in U.S. Pat. No. 7,864,103 entitled “Device and method for 3D height finding radar” incorporated herein by reference are applicable 3D sensor means, as well as other devices described herein. Furthermore, practical and economic means are disclosed herein that provide automatic, wide-area protection of large protected areas by integrating a multitude of non co-located radar sensors collectively used to define numerous virtual lines of defense associated with protected areas and deterrent devices. The radar networks apparatus and methods described in U.S. Pat. No. 7,940,206 entitled “Low-cost, high-performance radar networks” incorporated herein by reference are applicable wide-area, non co-located radar sensors means, in addition to those described herein. Finally, novel means are disclosed herein for measuring system effectiveness and avian habituation, thus allowing for system configuration to be adjusted and high performance to be maintained over time. We refer to these automated bird deterrent systems in accordance with the present invention as being smart in that they are selective, flexible, and adaptive, and can measure and respond to their environment in order to maintain effectiveness. 
         [0068]    It will be obvious to those skilled in the art that the same improvements described herein are applicable to other non-bird targets, such as wildlife and humans, in order to protect areas in other applications including homeland security. Furthermore, the improvements can be achieved through the use of other sensors and devices. The focus on deterring birds in this disclosure is in no way intended to limit the scope and application for the invention disclosed herein to birds. Nor is the focus on radar intended to limit the scope and application to only using radar sensors. 
         [0069]    These and other novel features of the present invention will become apparent in the sequel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0070]      FIG. 1  is a deployment diagram of an automated bird deterrent system in accordance with the present invention. 
           [0071]      FIG. 2  is a system block diagram of a smart bird deterrent system in accordance with the present invention. 
           [0072]      FIG. 3  is a block diagram of the information subsystem in accordance with the present invention. 
           [0073]      FIG. 4  is a diagram of the composite coverage volume with multiple intrusion zones in accordance with the present invention. 
           [0074]      FIG. 5  is a block diagram of a preferred embodiment of the automatic bird deterrent system in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0075]    A deployment diagram  1  of a typical, automated bird deterrent system  20  (see  FIG. 2 ) in accordance with the present invention is shown in  FIG. 1 . A protected area  2  represents a region that threatens birds or is threatened by birds. For the example of  FIG. 1 , the protected area  2  is a large tailings pond. A surveillance subsystem  21  (see  FIG. 2 ) monitors birds that may come into the protected area and consists of two sensor apparatuses  3   a  and  3   b  located in this example on either side of the protected area  2 . The sensor apparatuses  3   a  and  3   b  are preferably avian radars as described previously herein which together provide coverage of birds in the vicinity of the protected area. Two virtual lines of defense are implemented in this example, an outer line of defense and an inner line of defense. The surveillance subsystem  21  defines in this case four outer intrusion zones  4  that surround the tailings pond that make up the outer line of defense. A number of deterrent apparatuses  5  are arranged in each intrusion zone along the water&#39;s edge facing outward towards incoming birds. The surveillance subsystem  21  continuously detects and tracks birds in the airspace using methods known to those skilled in the art and preferably those described herein. When birds  8  penetrate a particular outer intrusion zone  4 , the surveillance subsystem  21  determines if they pose a threat and issues a threat alert to the deterrent subsystem  23  (see  FIG. 2 ), which causes respective deterrent apparatuses  5  to activate. Outward facing deterrent apparatuses  5  are preferably high-pressure acoustic devices that can harass approaching birds while they are still a kilometer or more away from the pond. Eight inner intrusion zones  6  make up an inner line of defense in this example. The inner line of defense has deterrent apparatuses  7  organized on floating platforms on the surface of the pond to harass birds that make it through the outer line of defense and attempt to land on the tailings pond. Several inner deterrent apparatuses  7  are arranged in each inner intrusion zone  6  and activate when birds are detected there. A specially designed information subsystem  24  is the heart of the smart bird deterrent system  20  in accordance with the present invention. The information subsystem  24  stores the following: bird target trajectories as they approach an intrusion zone, intrusion zone penetrations and threat alerts, deterrent activations, and bird trajectory responses thereafter. This information provides real-time situational awareness to operators, and supports the calculation of measures of effectiveness and habituation so that system performance can be maintained. Operators monitor the bird deterrent system displays from within an operations centre  9  or on a remote mobile device or computer  10 . Operators need not monitor system displays continuously and are alerted to bird intrusions. Alerts can include an audible alarm and display indication to an operator, or a transmitted message to a remote user. At the operations centre  9 , operators can watch and interact with an integrated common operating picture (COP) display that presents in real-time the tracked birds in the area, and provides visual indications when intrusion zones are penetrated and when deterrents are activated. Operators can also monitor the effectiveness of the system, review measures of effectiveness and habituation computed by the system, and alter system configuration in response to degradation in performance and increases in habituation, as described herein. 
         [0076]    The automatic bird deterrent system exemplified in  FIG. 1  illustrates the various features of the present invention using a specific arrangement of sensor apparatuses, deterrent apparatuses, protected area, virtual lines of defense with specific intrusion zones, groupings of deterrent apparatuses, etc., without loss of generality. These arrangements are examples only, and in no way limit the variety of configurations and combinations that are in the spirit of the present invention. Any type of sensor apparatus and deterrent apparatus known to those skilled in the art apply herein. While most applications have the automatic bird deterrent system largely installed on land, that system could also be deployed in whole or in part on offshore platforms, or even on moving airports such as that provided by an aircraft carrier. 
         [0077]    Preferably, embodiments of the automatic bird deterrent system  20  disclosed herein aim to take advantage of standardized COTS (commercial off-the-shelf) technologies to the maximum extent possible in order to keep the system cost low and to provide for low life cycle costs associated with maintainability, upgrade ability and training. Preferably, COTS marine radars are used as the radar sensor apparatus ( 3   a  and  3   b ) in order to minimize sensor costs. COTS personal computers (PC) are used preferably to carry out the various data processing tasks required by the bird deterrent system. The system preferably exploits COTS data communication technology to provide remote control of the sensor and deterrent apparatus, and to inexpensively distribute remote alerts and displays which contain rich system information to operators. 
         [0078]    For bird deterrent applications involving large protected areas, one avian radar system, or even several independently operating avian radar systems are often not enough to provide a high-performance, composite picture covering the area of interest. For any single radar, there are gaps in coverage caused by obstructions, and the area covered may not be a large enough. One or more radar sensor apparatuses are preferably connected to a radar network to distribute their composite information to remote users as described earlier herein. Since the target data contain all of the important target information (date, time, latitude, longitude, altitude, speed heading, intensity, radar cross section (RCS), etc.), remote situational awareness is easily realized. Radar systems as disclosed herein may be networked to a central monitoring station (CMS) or operations centre  9 . In addition to real-time display on a COP in the operations centre  9 , various tools for target analytics are provided, as is the capability to replay past recorded target data, and preferably, to also replay intrusion zone and deterrent apparatuses responses. 
         [0079]    A block diagram of the automatic bird deterrent system  20  in accordance with the present invention is provided in  FIG. 2 . The surveillance subsystem  21  detects birds threatened by or posing a threat to a protected area (such birds are referred to simply in the sequel as the “threatened birds”) and issues corresponding threat alerts  25  to a deterrent activation processor (DAP)  22 , which controls a deterrent subsystem  23 . Depending on where the threatened birds have been detected, the DAP selects appropriate deterrent apparatuses (or simply deterrents)  5 ,  7  and issues an activation command  26  to the deterrent subsystem  23  along with, preferably, the deterrents&#39; respective IDs (identification numbers)  26 , which the deterrent subsystem  23  uses to activate the selected deterrents  5 , 7 . The selected deterrent identifications (IDs) and activation commands and times are stored in the information subsystem  24  over interface  29 . Time formats known to those skilled in the art that uniquely capture date and time are used preferably in support of both wide-area integration described herein and long-term analysis over annual cycles. The deterrent subsystem  23  preferably acknowledges a deterrent response or activation by storing this feedback in the information subsystem  24  over interface  27 . The surveillance subsystem  21 , when detecting threatened birds, also stores the related bird tracks or associated trajectories in information subsystem  24  using interface  28 . Each bird track or trajectory preferably contains latitude, longitude, altitude, speed, heading, RCS, and time data, updated preferably every couple of seconds to fully represent the 3D path or trajectory taken by the target. At a minimum, respective trajectories associated with a particular alert begin in time immediately prior to each issuance of the corresponding threat alert and continue well after the firing of respective selected deterrents, in order to allow either an operator, automated software, or target analytic tools to measure system effectiveness by examining the response of the threatened birds to the activated deterrents. Preferably, tracks for all birds are stored continuously and indefinitely in an information subsystem  24 , including those tracks associated with particular threat alerts. Operators located in operations center  9  or using mobile or computing device  10  monitor and control the smart bird deterrent system  20  using common-operating-picture software or other software user-interfaces that connect to information subsystem  24  over network  30 . The COP preferably interacts directly with information subsystem  24  and not only displays target tracks, threat alerts, and deterrent activations, but also provides a user-interface to control the various subsystems through interfaces  31 ,  32  and  33 . Interface  31  provides configuration parameters to the surveillance subsystem  21  to alter its state so as to reduce habituation and maintain system performance. Similarly, configuration parameters associated with DAP  22  and deterrent subsystem  23  can be altered to reduce habituation and maintain performance. Operators can also check on the status of deterrents, including testing them, activating them or resetting them (for example when refueled or restarted due to a fault) using interface  27 . Operators preferably can also access directly the surveillance subsystem  21 , DAP  22  and deterrent subsystem  23  over standard network links  28 ,  29 , and  27  respectively, for setup, initialization, and routine maintenance using standard tools and protocols such as virtual network computing (VNC) remote desktops. 
         [0080]    A block diagram of a preferred embodiment of information subsystem  24  in accordance with the present invention is illustrated in  FIG. 3 . Data storage device  40  provides storage and access to the bird deterrent system information described herein, including bird tracks, threat alerts, and activated deterrent information, which is stored in real-time. Preferably, data storage device  40  is a SQL (structured query language) relational database management system, with schema and tables designed to facilitate use of the information by users and by analytical tools  42  that calculate measures of system effectiveness and measures of habituation  43  as shown in  FIG. 3 . These measures are used by configuration selection processor  44  to maintain system performance by determining when habituation has exceeded acceptable operating limits. In such a case, configuration selection processor  44  provides a set of new configuration parameters and control  45  to interfaces  31 ,  32 ,  33  that can be preferably loaded into the bird deterrent system  20  to reconfigure it so as to reduce habituation. 
         [0081]    Data storage device  40  preferably organizes and stores continuously and indefinitely all narrowband target data, threat alert data, and deterrent subsystem activation data for periodic calculation of habituation measures, as well as other analytical calculations and statistics in support of safety management systems, risk management, due diligence, investigations, litigation, scientific analyses, training, and public policy. Such calculations and statistics are carried out using analytical tools  42 , which are preferably implemented as software-configured generic digital processing circuits that can easily execute pertinent calculations exploiting the data contained in data storage device  40 . Habituation and performance measures tabulate the number or percentage of birds deterred by the automatic bird deterrent system  20  over some period of time and/or space and thus allow the tracking of changes in such measures over time. The configuration selection processor  44  is provided preferably with a multitude of configuration parameter sets that reconfigure automatic bird deterrent system  20  by varying one or more parameters in surveillance subsystem  21 , DAP  22 , and/or deterrent subsystem  23 . When a change in habituation is determined by configuration selection processor  44 , it provides one of these new configuration parameter sets and causes, through control, the change in such parameters to those found in the new configuration parameter set. Preferably, configuration parameter sets are stored in files and the control required to reconfigure the automatic bird deterrent system  20  is simply the loading of a new configuration parameter file, causing respective surveillance subsystem  21 , DAP  22 , and deterrent subsystem  23  to change accordingly. A trained operator can use analytical tools  42  to measure habituation and configuration selection processor  44  to change the configuration of automatic bird deterrent system  20 ; or alternatively, analytical tools  42  and/or configuration selection processor  44  could be optionally replaced by an expert system, known to those skilled in the art, such as a cognitive processor, inference engine, neural network, or rule-based processor to automatically reconfigure bird deterrent system  20 . In this case, control interfaces  31 ,  32 , and  33  to surveillance subsystem  21 , DAP  22 , and deterrent subsystem  23 , respectively, are preferably command interfaces controlled in software over a data network by the expert system to automatically change particular parameters on the fly, or to reload parameter sets to alter the state of respective surveillance subsystem  21 , DAP  22 , and deterrent subsystem  23 . 
         [0082]    Other sources of information about the environment, bird activity and deterrence effectiveness can be used in the aforementioned analysis and configuration selection processes such as weather, man-made clutter sources (e.g. vehicle and aircraft patterns), known diurnal and seasonal patterns of bird movement (incl. migration), human-observed presence or absence of birds in and around protected areas, and observed migration in other regions that might be heading toward protected areas. This information can also be used in establishing a general or background a priori threat assessment condition for a facility with a protected area, increasing general awareness of bird condition. 
         [0083]    In accordance with a feature of the present invention, flexible and affordable, integrated, wide-area coverage is provided through the use of multiple surveillance sensors as illustrated in  FIG. 4 . When a large protected area cannot be sufficiently covered by sensor apparatuses at a single location, a multitude of non co-located or mutually spaced sensor apparatuses are used to provide the required composite coverage. For example, consider the two sensor apparatuses  3   a  and  3   b  shown in  FIG. 4 , which are preferably avian radars as described previously. Coverage volume  51   a  and coverage volume  51   b  denote, respectively, the antenna coverage volumes of avian radars  3   a  and  3   b . The combined composite coverage volume  53  is the union of the individual coverage volumes and, hence, in the example shown in  FIG. 4 , almost doubles the surveillance coverage volume of each sensor apparatus. In accordance with the present invention, one or more intrusion zones or sub-volumes  54  are defined within the composite coverage volume to implement virtual lines of defense against birds threatening or threatened by one or more protected areas. Typically, the protected area(s) are contained within the composite coverage volume  53  but need not be so. Arbitrarily shaped and located intrusion zones can be defined within composite coverage volume  53 . For example, intrusion zone  54   a  is contained within antenna coverage volume  51   a  and has no part contained in antenna coverage volume  51   b . On the other hand, intrusion zone  54   b  is contained completely within antenna coverage volume  51   b  and has no part contained in antenna coverage volume  51   a . Intrusion zone  54   c  is completely contained within the overlapping region of antenna coverage volumes  51   a  and  51   b . Finally, intrusion zone  54   d  has a portion of its volume only within  51   a , another portion only within  51   b , and the remainder within the overlapping region. 
         [0084]    Especially in the overlapped regions of a composite coverage volume, the same bird will likely be tracked by more than one sensor apparatus. As a result, the present invention preferably resolves duplicate bird tracks so as to avoid multiple threat alerts being issued in response to the same bird entering an intrusion zone. This can be achieved using a number of different approaches. For example, bird tracks for the same bird generated by multiple sensors can be fused into a single track before testing intrusion zones for birds threatening or threatened by a protected area. Alternatively, two threat alerts could be generated, one for each contributing track, but the second threat alert could be inhibited if it is associated with the same intrusion zone, occurs near-simultaneously, and if the trajectory would result in the same deterrent apparatuses being activated. 
         [0085]    A preferred embodiment of the present invention that is well suited for very large protected areas is shown in  FIG. 5 . A surveillance subsystem  21  consists of a multitude of avian radars at different locations that are preferably used to form an avian radar network as described in U.S. Pat. No. 7,940,206. Preferably, dish antennas with pencil beams are used so that latitude, longitude, and altitude localization of bird targets is provided. Other antennas such as those described in U.S. Pat. No. 7,864,103 can also be used. These include dual-axis scanning dish antennas that rotate horizontally 360° on one axis and can scan vertically as well on a second axis. A multitude of radar platforms (typically towers, pole tops, or trailers)  83 , each including an avian radar antenna  82 , are preferably used as sensor apparatuses placed strategically throughout the combined coverage volume  53 . Each antenna  82  couples with radar transceiver  84 . Preferably, radar transceiver  84  is an X-band (or S-band) transceiver. Each transceiver  84  is connected to a digital radar processor  85  (DRP) that digitizes the received radar signals and carries out detection and track processing, as described earlier herein. Target data (which includes tracks and preferably includes detections as well) is stored locally in DRP  85  but is also sent continuously in real-time over network  70  to an optional but preferable radar data server  80  through network connection  73  for permanent storage and distribution (access) to other system elements. An optional and preferable threat processor  81  accesses real-time target tracks from radar data server  80  over a network connection, determines whether intrusion zones are penetrated by corresponding birds and whether such birds are threatened by or are a threat to a protected area, and issues threat alerts  25  accordingly to deterrent activation processor  22 . Target data and threat alerts are also sent to information subsystem  24  in real-time as previously described herein, over network interface  71 . The surveillance subsystem  21  also preferably includes optional radar controllers  86  (typically one for each radar transceiver) that provide operator control or automatic control  31  of radar transceiver  84  and antenna  82 . In addition, software control  31  of radar processor  85  is preferably provided to change the radar processor configuration. The aforementioned controls  31  facilitate configuration parameter changes in response to configuration selection processor  44  of information subsystem  24 . Information subsystem  24  also facilitates configuration parameter changes for deterrent activation processor  22  over interface  32  and for deterrent subsystem  23  over interface  33 , all of which are connected to network  70 . 
         [0086]    Deterrent activation processor  22  receives threat alerts from surveillance subsystem  21  (directly from threat processor  81  if it is provided) from which it determines and selects the specific deterrents to be activated, communicating this information to deterrent subsystem  23  over network interface  26 , while providing the same data to information subsystem  24  over network interface  71 . Deterrent subsystem  23  preferably uses radio  74  to communicate with deterrent apparatuses  5  and  7  causing the selected deterrent(s) to activate in response to each threat alert. Preferably, radio  74  supports a mesh network with deterrent apparatuses  5  and  7 . Note: there can be hundreds of these in practice to protect large protected areas; the two shown here are simply illustrative, indicating that multiple deterrent devices are typically deployed and of different varieties and serving different lines of defense as described earlier. Alternative forms of technology to radio (e.g. wired, including coax, cat6, twisted pair) can provide the communication between  23  and  5 ,  7 . Preferably, deterrent subsystem  23  confirms when the selected deterrent(s) have activated, providing feedback over network interface  26  to information subsystem  24  connected to network  70  through network interface  71 . Furthermore, deterrent subsystem  23  preferably polls the status of deterrent apparatuses  5 ,  7  and provides such data to information subsystem  24  so that it can maintain system operational-status information. 
         [0087]    One or more operations centers  9  as well as mobile or remote user displays  10  can connect to network  70  from virtually anywhere to receive real-time bird deterrent information via common operating picture software as described earlier. Users have complete control of the automatic bird deterrent system through user interfaces implemented in software that control the various system elements over the various control interfaces described herein, and referenced to  FIG. 5 . Each system element (e.g., radar processor  85 , radar controller  86 , threat processor  81 , radar data server  80 , deterrent activation processor  22 , deterrent subsystem  23 , information subsystem  24 , operations center  9 , and mobile/remote user display  10 ) can be connected to network  70  via any standard network connection including wired or wireless, LAN, WAN, Internet, Intranet, Wi-Fi, 3g, 4g, point-to-point, SATCOM, etc. This means that in accordance with the present invention, system elements can be located virtually anywhere, providing the flexibility needed for complex deployments and information sharing arrangements and integration. 
         [0088]    Particular features of our invention have been described herein. However, simple variations and extensions known to those skilled in the art are certainly within the scope and spirit of the present invention. This includes variations on integration of the functional blocks described herein.