Abstract:
Methods and systems for electronically tracking the progress of teams as they cover an assigned geographic area are described herein. A server computer establishes a coverage area, divides the coverage area into a plurality of regions, and assigns each region to a team. Each team carries a tracking device capable of autonomously determining its present location without user assistance, thus allowing the team to focus on the assigned task, such as searching for a missing person, plowing a field, paving a road, etc. The server monitors the location of each tracking device as each team covers its assigned region, and updates on a visually displayed geographic map a historical path associated with each tracking device based on the monitored location of each tracking device. In this manner, users can quickly view the visual depiction of the historical to determine as yet uncovered areas.

Description:
FIELD OF THE INVENTION 
   The invention relates generally to electronic tracking of paths traversed by a person or vehicle. More specifically, the invention provides a method and system for electronically tracking paths traversed and visually displaying the path history to illustrate areas which have and have not been traversed. 
   BACKGROUND OF THE INVENTION 
   Search and rescue operations commence whenever a person is reported as missing. The search and rescue operations typically entail identifying or approximating a last known location of the missing person, and initiating a physical search based on the identified position. However, there often is a lack of accurate recordkeeping of those areas that have been searched, resulting in the same area being searched twice, and not searching altogether in other areas (i.e., there are gaps in the search area). 
   Similarly, farmers often have difficulty ensuring that an entire field has been prepared for planting, or even that seed has been thrown over an entire field during the planting process. Road crews often manually keep track of sections of road that have been treated or prepared for some work to be done, and thus often miss sections of road entirely, and treat or prepare other sections twice. 
   Thus, it would be an advancement in the art to provide a location-based tracking system that can detect and monitor a person or vehicle&#39;s historical path and visually display the path history to illustrate area that have been traversed by the person or vehicle versus those areas that have not been traversed by the person or vehicle. 
   BRIEF SUMMARY OF THE INVENTION 
   The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to the more detailed description provided below. 
   To overcome limitations in the prior art described above, and to overcome other limitations that will be apparent upon reading and understanding the present specification, an aspect of the present invention is directed to method for tracking a history of search patterns of a search and rescue operation. The method may include establishing a search area based on a last known location or point of disappearance of a missing person, dividing the search area among search teams each equipped with an appropriate tracking device as described herein, monitoring the location of each search team&#39;s tracking device as each search team searches its assigned region, and updating on a visually displayed geographic map a search trail associated with each search team&#39;s tracking device based on the monitored location of each search tracking device. 
   According to another aspect of the invention, a tracking device may include a processor, a transceiver for communicating with a search and rescue control center, a display screen for outputting a visually displayed geographic map, and memory storing computer executable instructions which, when executed by the processor, cause the tracking device to perform a method for tracking a history of search patterns of a search and rescue operation. The method may include determining a search region of the tracking device and displaying the search region on the visually displayed geographic map; monitoring, at regular intervals, a location of the tracking device as it is carried by a search team searching the search region; and updating the visually displayed geographic map with a search trail corresponding to the monitored location of the tracking device. 
   According to another aspect of the invention, a search and rescue command center may use a computer system having a processor controlling overall operation of the system, a display device that outputs a visual depiction of a geographic map of a search area, and memory storing computer executable instructions for performing a method for tracking a history of search patterns of a search and rescue operation. The method may include establishing the search area; dividing the search area into a plurality of regions; assigning each region to one of a plurality of search teams, wherein each search team is associated with a tracking device; monitoring a location of each tracking device as each search team searches its assigned region; and updating on the visual depiction of the geographic map of the search area a search trail associated with each search tracking device based on the monitored location of each tracking device in the monitoring step. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description in consideration of the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
       FIG. 1  illustrates a network architecture that may be used for one or more aspects of the invention according to an illustrative embodiment of the invention. 
       FIG. 2  illustrates a block diagram of a tracking device according to an illustrative embodiment of the invention. 
       FIG. 3  illustrates a flow chart for tracking search patterns according to an illustrative embodiment of the invention. 
       FIG. 4  illustrates a search area according to an illustrative embodiment of the invention. 
       FIG. 5  illustrates a divided search area according to an illustrative embodiment of the invention. 
       FIG. 6  illustrates another divided search area according to an illustrative embodiment of the invention. 
       FIG. 7  illustrates a composite search map according to an illustrative embodiment of the invention. 
       FIG. 8  illustrates a tracking device screen display according to an illustrative embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the following description of the various embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. 
   One or more aspects of the invention may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. As will be appreciated by one of skill in the art, the functionality of the program modules may be combined or distributed as desired in various embodiments. In addition, the functionality may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. 
     FIG. 1  illustrates a sample network architecture that may be used to perform one or more aspects of the invention. In  FIG. 1 , multiple tracking devices  103   a - 103   g  (collectively and generically referred to as tracking device  103 ) have wireless communications capabilities to send and receive data. Each tracking device  103  may be any device that has two-way data communications, for example, a mobile phone, personal digital assistant, smart phone, tablet- or pen-based computer, laptop or palmtop computer, or other suitable device. Tracking devices  103  may communicate through wireless communication towers  105   a ,  105   b ,  105   c  (collectively/generically,  105 ). Each wireless communication tower  105  is operated by a wireless network operator  107   a ,  107   b  (collectively/generically,  107 ) to relay communications to and from a command center server  111 , and/or others, via a data network  109 , such as the Internet. Those of skill in the art will appreciate that various network architectures and topologies may be used to accomplish the same or similar goals as described herein. For example, instead of a terrestrial wireless communications system, one or more tracking devices may communicate via a satellite based wireless communication system, and one or more towers  105  may be replaced with one or more satellites (not shown). 
   According to an illustrative embodiment of the invention, one or more of tracking devices  103  may be a STORM HAWK® brand handheld GPS mobile information system available from WeatherData, Inc. of Wichita, Kans. According to another illustrative embodiment of the invention, one or more of tracking devices  103  may be a device as described in Smith, U.S. Pat. No. 6,845,324, issued Jan. 18, 2005, herein incorporated by reference in its entirety for all purposes. Those of skill in the art will appreciate that any device having the requisite capabilities as described herein may be used. 
     FIG. 2  illustrates a block diagram of a generic tracking device  103  that may be used according to an illustrative embodiment of the invention. Tracking device  103  may have a processor  203  for controlling overall operation of the tracking device and its associated components, including RAM  205 , ROM  207 , input/output module  209 , location module  211 , transceiver  213 , and memory  215 . 
   I/O  209  may include a keypad, touchscreen, and/or stylus through which a user of device  103  may provide input, and may also include one or more of a speaker for providing audio output and a video display device for providing textual, audiovisual and/or graphical output. 
   Location module  211  determines the location (e.g., latitude, longitude, and/or altitude) of the tracking device  103 . Location module  211  may include a global position system (GPS) receiver to autonomously determine the location of the tracking device using the commercially accessible GPS satellite network. Alternatively, when a network operator providing wireless telecommunication services to tracking device  103  is equipped with E911 location detection capabilities (e.g., mobile device location determination by time difference of arrival (TDOA), angle of arrival (AOA), and/or triangulation technologies, etc.) location module  211  may query the network operator for the location of the tracking device  103 . In such a manner, the methods and systems described herein are usable with devices capable of autonomously determining their own location, as well as with devices that work in a network which can determine the location of individual devices with reasonable specificity. 
   Transceiver  213  includes any component that enables tracking device  103  to wirelessly communicate via antenna  214  with a wireless telecommunications network provided by a network provider. Memory  215  may store software used by tracking device  103 , such as an operating system  217 , application programs  219 , and associated data  221 . For example, one application program  221  used by tracking device  103  according to an illustrative embodiment of the invention may be a tracking client application  223 , which communicates directly or indirectly with a tracking manager application resident on a central server, such as server  111  ( FIG. 1 ). As described herein, tracking manager is described synonymously with server  111 . 
   The initial example of an illustrative embodiment described below is with respect to search and rescue operations, and is not intended to limit the application of the invention to search and rescue operations, but rather illustrates one of a variety of uses of the present invention. Subsequent examples will follow. 
   With reference to  FIG. 1  and  FIG. 3 , a tracking manager on server  111  may provide overall management of multiple tracking devices  103  as search and rescue operations commence for a missing person.  FIG. 3  illustrates a flowchart of a search and rescue management method performed by server  111  according to an illustrative embodiment of the invention. Server  111  may be any computing device that can send and receive communications, directly or indirectly, between multiple tracking devices  103 , for example, via the Internet  109  and via one or more network operators  107 . 
   Server  111  initiates the method in step  301  upon receiving information regarding a base point, here a point of disappearance of a missing person, around which a coverage area will be determined. The point of disappearance may be entered manually as determined or approximated by a human user, or may be calculated automatically based on known information regarding a know path of travel of the missing person and an amount of time since last contact with the missing person. With further reference to  FIG. 4 , once the point of disappearance  401  is determined, the server  111  in step  303  establishes a coverage area  403  (a search area in the present example) based on the point of disappearance. 
   For example, the server  111  may establish a circular search area  403  around the point of disappearance  401  with a radius r, where r is based on an estimated amount of time t lapsed since the missing person was estimated to be at the point of disappearance and a rate or speed of travel s with which the missing person is estimated to be moving. Thus, in one example, the radius r may be calculated using the formula r=t×s. Those of skill in the art will appreciate that the search area may be a shape other than circular, and may be established based on other criteria. For example, a rectangular search area may be used, and the size of the search area may be based on a known area in which the missing person is located, rather than based on an amount of lapsed time t and a speed s. 
   Once the search area  403  has been established, the server  111  in step  305  divides the search area into a plurality of sub-regions (search regions in the present example), and assigns each region to a team (search teams in the present example). Each search team includes one or more people or devices that physically cover an assigned region, and that have a tracking device  103  among them.  FIG. 5  illustrates a circular search area  403  split into pie-shaped search regions in such as manner that search teams fan out from the point of disappearance  401 .  FIG. 6  illustrates an alternative split of search area  403  into a grid of search regions. 
   In step  307 , while search teams are searching their respectively assigned search regions, each team&#39;s tracking device monitors the tracking device&#39;s current location and reports the location to the tracking manager at regular intervals. With further reference to  FIG. 7 , based on the location information received in step  307 , the server in step  309  updates a visually depicted geographic map  701  of the coverage area displayed on a display device connected to server  111 . The term ‘connected,’ as used herein, includes both direct connections as well as indirect connections that pass data through one or more intermediate nodes, devices, hops, etc., before reaching the intended destination. 
   Map  701  may include a visual representation of the coverage area  403 , as well as visual cues on the map  701  regarding the search status of each search region, here grid cells A 1 , A 2 , A 3 , A 4 , B 1 , B 2 , B 3 , B 4 , C 1 , C 2 , C 3 , C 4 , D 1 , D 2 , D 3 , and D 4 . The visual cues displayed on map  701  may include an indication that a region has been fully covered (in the present example, searched), such as is illustrated in  FIG. 7  for cells A 1 , A 4 , B 3 , and C 1 , an indication that a region has not yet been covered at all, such as is illustrated for cells D 1 , D 2 , and D 3 , or an indication that progress in a region is underway, such as is illustrated for cells A 2 , A 3 , B 1 , B 2 , B 4 , C 2 , C 3 , C 4 , and D 4 . 
   According to an illustrative embodiment of the invention, the visual cue indicating that a search of a region is underway may include a historical trail of a search path undertaken by the search team associated with that region. For example, each of cells A 2 , A 3 , B 1 , B 2 , B 4 , C 2 , C 3 , C 4 , and D 4  are illustrated with such a historical trail. Each historical trail may be color coded (not illustrated) to correspond to a specific search party. In addition, the width of the historical trail drawn may vary depending on the size of the search party, to account for the width searched by the search party based on its number of people. For example, the trail in cell B 2  may represent a search party consisting of a single individual, the trail in cell C 3  may represent a search party consisting of two individuals, and the trail in cell C 2  may represent a search party consisting of three individuals. 
   The width of the historical trail may also be adjusted based on other factors, such as the visibility or elevation of the searcher. For example, the width might be narrowest for a searcher on foot in a forest, wider for a searcher on horseback in a cornfield, and wider still for a helicopter based search. The width of the search trail might be narrowed proportionately if a search is conducted in low visibility conditions, such as in fog or blowing dust or sand. In one embodiment each tracking device has a GPS attachment with an accuracy within 8 feet, and thus the minimum width is representative of 8 feet. In other embodiments where location can be determined with greater specificity, e.g., as location technology improves, the trail width may be even narrower. The maximum trail width is limited only by visibility of the search team to which a tracking device is assigned. 
   Upon the occurrence of certain predefined conditions, the server  111  may change a visual representation of a search region to indicate the entire region has been covered. According to an illustrative embodiment of the invention, for example, the server may automatically change a region to indicate it has been completely covered when the historical trail represents or indicates that the team assigned to that region has been within a predefined distance of every point within that region. If the trail is drawn to indicate those points of which the search team has been within the predefined distance, the server  111  may detect when a region is completely filled in by the historical trail and then indicate that the region has been completely covered. Other criteria may alternatively be used, for example, when a percentage of the region is filled up and/or there are no gaps in the region larger than a predefined size and/or width. For example, assuming the team assigned to cell A 2  continues its current search pattern, server  111  may indicate that the region has been completely covered in approximately four additional back-and-forth cycles. In some embodiments the server  111  might leave the historical trail displayed, or provide a query button to allow a user of the server  111  to view a search trail after the server has marked a region as having been completely covered. 
   In step  311  each team&#39;s tracking device may be updated to display the historical trail of its own path, such as is illustrated in  FIG. 8 . Thus, between steps  309  and  311 , maps are updated both on a display associated with the coordinating central server  111 , as well as on displays associated with each tracking device  103 .  FIG. 8  illustrates a sample screen  801  of a tracking client application on a tracking device  103  associated with the team assigned to cell A 3  of  FIG. 7 . Those of skill in the art will appreciate that not all devices capable of providing information to tracking manager  111  may be capable of displaying information such as is illustrated in  FIG. 8 , depending on the features of the tracking device  103  (e.g., screen size, graphics capabilities, etc.). Screen  801  may include a visual representation of the team&#39;s historical path  803 , and may include an icon or graphic  805  indicating the team&#39;s assigned region in relation to the entire search area. Screen  801  may also include an indication  807  of the current region, and one or more buttons  809 ,  811  for other application functionality, e.g., menu, reporting options, features, etc. 
   In an illustrative embodiment, button  809  may be used, e.g., to toggle between the maps illustrated in  FIG. 7  and  FIG. 8  where server  111  sends information to the tracking device  103  regarding other tracking devices. Button  811  may be used to obtain an options menu, e.g., to report that an objective is complete (e.g., that the missing person has been found), to send a custom message other than indicating that the objective is complete, to request an update of other tracking device&#39;s progress (if not automatically received), to quit the application, etc. For example, where a tracking device is equipped with a camera (not shown), an option might include sending a time-stamped, location-stamped digital photograph depicting someone or something found by the search team. Another option might include reporting hazardous or medical conditions via one or more data messages as taught in U.S. Pat. No. 6,845,324. 
   In step  313  server  111  determines whether the objective is complete (i.e., whether the missing person has been found, in this example), e.g., by determining whether server  111  has received a message from any tracking device indicating that the missing person has been found. If the objective is complete, the method ends. If the objective is not complete, then in step  315  the server  111  determines whether there is any coverage area remaining to be covered. If so, then server  111  cycles through steps  307 - 317  again, as applicable. If not, then in step  317  the server  111  expands the coverage area (preferably incrementally each time step  317  is encountered) and cycles through steps  305 - 317  again, as applicable. 
   Those of skill in the art will appreciate that not all steps need be performed in the recited order, and one or more steps may be optional. For example, the order of steps  309  and  311  is immaterial, and step  317  may be optional. In other embodiments, step  303  may be delayed or skipped altogether, and search teams may begin searching prior to the establishment of an official search area. In such an embodiment, a search team may provide input into a tracking device to begin tracking based on the search team&#39;s present location. Thus, a search team can begin searching upon reaching an anticipated search area without waiting for the server to establish search regions for each search team. Once the server establishes search regions, tracking devices associated with teams that have already begun searching may upload their data regarding areas already searched. These are merely examples of step reordering and optional steps, and are not intended to limit the steps which can be reordered or omitted. 
   Various modifications and permutations are foreseen and considered within the spirit and scope of the invention. For example, each tracking device may (alternatively or in addition to the server  111 ) determine when the tracking device has completely searched its assigned region, and output an alert to the user or team member holding the device, and/or send a message to the tracking manager informing that the region has been searched. The message may also optionally request another search region, if any are left, or such a request may be sent in a separate message. 
   In addition, when any tracking device sends a message to the tracking manager that a missing person has been found, the tracking manager may relay the message to all tracking devices, and inform each team whether any missing persons remain to be located, or whether the search has thus ended because all missing persons have been found. The system may thus be easily modified for use with multiple missing persons at a time. 
   The methods and systems described herein may also be used for other operations where ensuring that a person or vehicle traverses an entire predefined area can be useful to the success of the operation. For example, a farmer may carry a tracking device  103  in each tractor working a field to ensure that the entire field gets worked. Alternatively, the farmer may use a single tracking device not in communication with a server, but rather one that manages its own progress and historical path information as described herein (i.e., has a standalone mode), or the farmer may even use multiple tracking devices in a peer-to-peer mode or configuration without the use of a central server, where each tracking device communicates with the other tracking devices. Use by a farmer to ensure coverage of a field is also an example of scenario in which steps  301  and/or  303  ( FIG. 3 ) are unnecessary, because the coverage area may already be known (i.e., the field). The objective in such a scenario may simply be to cover the entire field, and thus either of method steps  313  and  315  may be used for this determination, rendering the other method step unnecessary in this example, as well as method step  317 . 
   In another similar example, road crews may carry a tracking device on each paver, bulldozer, steamroller, or other piece of maintenance equipment to ensure that every part of a road is properly maintained. Again, a single road crew might carry a single tracking device in standalone mode, may use multiple tracking devices in peer-to-peer mode, or may use multiple tracking devices managed by a server, thus allowing a management center (e.g., a state&#39;s Department of Transportation) to ensure that the work is completed properly over an entire portion of road. 
   Other illustrative uses include finding stray livestock, locating a weapon of mass destruction (e.g., based on known partial information such as the geographically-assigned prefix of a telephone number assigned to a landline telephone used to make a suspicious telephone call), and locating a missing train in “dark territory” (i.e., territory where there is no signaling system that keeps track of the train&#39;s location). 
   The present invention includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.