Patent Publication Number: US-2005126794-A1

Title: Fire prevention system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application claims benefit of U.S. Provisional Application No. 60/529,056 filed Dec. 12, 2003, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      Homes and other structures erected in wooded areas face a significant danger of being lost or severely damaged due to wildfires, especially when the surrounding woodlands are suffering from drought conditions. Such structures are frequently evacuated in the face of an approaching forest fire and thus are least protected by the opportunity for human intervention when the danger is greatest. In addition, vacation homes (which often represent a sizable proportion of the structures found in a given heavily forested area) are typically vacant during the week and thus are most likely to be unoccupied should a forest fire break out in the area, regardless of whether an evacuation is happening or not.  
      It is well known to apply water or some other type of retardant to a structure to prevent it from catching fire. For example, U.S. Pat. No. 5,165,482 to Smagac et al. discloses a fire deterrent system for structures in a wildfire hazard area. In Smagac&#39;s system, spray-type sprinklers and seeper hoses can apply fire retardant fluid such as water to a structure and surrounding vegetation in advance of a determined arrival of a fire. However, the terrestrial fire sensors employed can only determine wildfire danger within a limited distance from the structure.  
      U.S. Pat. No. 4,330,040 to Ence et al. discloses a fire prevention and cooling system that employs a dispensing tube adjacent to a wall and under an eave of a structure. The dispensing tube includes spaced openings, e.g., of 0.069 inch size, formed longitudinally along the tube in multiple parallel paths. As illustrated in Ence&#39;s FIG. 9, the dispensing tube is positioned such that its water spray covers the wall and the eave immediately adjacent to the wall, and also a portion of an extended eave that may lie at a distance from the wall. The dispersal of water by that method is relatively inefficient, however, because sprayed water evaporates quickly (especially in the low-humidity conditions in which wildfire danger is the worst) and a considerable portion of the spray is likely to miss the wall and eave entirely.  
      Thus, despite the the disclosure of the Smagac and Ence patents and other references, the need remains for improvements in water-use efficiency and for a way of preventively applying fire retardant based on the detection of distant fires.  
     SUMMARY OF THE INVENTION  
      A fire retardant application structure according to various aspects of the present invention includes an elongated tube comprised of material that is water-porous throughout on one side of the tube and material that is water-impermeable on the remainder of the tube. Advantageously, fire retardant pressurized inside the tube can cover a wall to which the tube is attached without spraying through the air and without being dispersed away from the wall.  
      A wildfire monitoring and service system according to various aspects of the present invention includes a satellite-image monitoring computer that is programmed to display a composite map image defining locations of wildfires observed by satellite and multiple separate structures. The system also includes a wireless transmission subsystem that is capable of transmitting a signal from the central location to each of the structures selectively and, at each of the structures, a fire-retardant application subsystem. Each of the application systems is directed at exterior surfaces of its respective structure and is responsive to a select signal that is transmitted through the transmission system.  
      By observing fires from a satellite and taking preventive action based on those observations, the system can protect structures from fire danger even when that danger is not apparent by human or automatic observation at the structure itself. By transmitting signals selectively, the system can active its fire-retardant application subsystems only at selected structures, avoiding unnecessary retardant applications at other structures.  
      The above summary does not include an exhaustive list of all aspects of the present invention. Indeed, the inventors contemplate that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the detailed description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic view of a fire prevention system according to various aspects of the present invention in operation to protect a structure.  
       FIG. 2  is a schematic block diagram of a fire retardant distribution station of the system of  FIG. 1 .  
       FIG. 3  is a cutaway perspective view of a porous pipe of the system of  FIG. 1  in operation mounted on a wall of the structure being protected.  
       FIG. 4  is a cutaway end view of the porous pipe of  FIG. 3 .  
       FIG. 5  is a cutaway side view of a pressure reducer employed in the fire retardant distribution station of  FIG. 2 .  
       FIG. 6  illustrates top and side views of the pressure reducer of  FIG. 5 .  
       FIG. 7  is an exploded side view of a retardant injector employed in the fire retardant distribution station of  FIG. 2 .  
       FIG. 8  is a flow diagram of a fire prevention method of the invention employing the system of  FIG. 1 .  
       FIG. 9  is a perspective view of the structure that  FIG. 1  illustrates schematically.  
       FIG. 10  is a perspective view of a particularly advantageous type of sprayer for use in the fire retardant distribution station of  FIG. 2 .  
       FIG. 11  is a perspective view of a water vein of the sprayer of  FIG. 10  having an inverted spillway according to various aspects of the invention.  
    
    
     DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS  
      A portion of this specification resides within the appendices of provisional application Ser. No. 60/529,056, which is referred to herein as the &#39;056 application. The appendices, as with the rest of the &#39;056 application, are incorporated herein by reference.  
      A fire prevention system according to various aspects of the invention provides numerous benefits, including efficient use of fire retardant when and where needed for effective protection of a structure. As may be better understood with reference to the simplified diagram of  FIG. 1 , exemplary fire prevention system  100  includes: a fire retardant distribution station  110 ; sprinklers  140 ; a porous pipe  130  attached to a building  120  being protected from fire; and a monitoring station  150  in communication with distribution station  110  via a wide-area connection  51 . ( FIG. 9  is a perspective view of structure  120  illustrating a cabinet  930  that houses various other components of distribution station  110  as discussed below.)  
      Monitoring station  150  obtains image data from a satellite  160  through a wireless connection and one or more intermediate data processing stations, all of which are represented by connection  65 . Station  150  interacts with a human operator  152  via conventional user interface hardware and software (e.g., mouse, keyboard, display, GUI code) represented by arrow  154 .  
      Monitoring station  150  determines, autonomously or with judgment of operator  152 , if image data from satellite  160  (suitably processed as discussed below) indicates an alert condition that would make it prudent to take action intended to improve protection of structure  120  against an approaching fire. Upon detection of the alert condition, specifically, station  150  generates a signal that transmits via connection  51  to distribution station  110 . In response to receipt of the signal, distribution station  110  activates distribution of a fire retardant mixture onto or near structure  120 .  
      As may be better understood with reference to  FIG. 9 , exemplary fire retardant distribution station  110  includes a cabinet  930 , which houses various components. These components, illustrated schematically by  FIG. 2 , include an electrical subsystem having a number of components: an uninterruptible power supply (UPS)  220  capable of operating off of an external source  212  of electrical power or batteries (not shown) in the absence of regular electrical power; a signal transceiver  232  establishing link  51  ( FIG. 1 ) via received and transmitted RF signals  214 ; and a controller  234 . UPS  220  supplies electrical power to signal transceiver  232  and controller  234 , which suitably supplies operating power to temperature sensors  236 . Responsive to activation instructions received via transceiver  232 , controller  234  supplies activating power to valves  272 - 276 . In a variation, controller  234  supplies signals that activate fluid flow, causing hydraulic triggering of valves  272 - 276 .  
      Distribution station  110  further includes a number of plumbing components that also reside in cabinet  930 , including a reduced-pressure backflow device (RPBD)  240  having access to a water supply  216  via tubing  241 ; an injector  250 , coupled to RPBD  240  at its reduced-pressure output port via tubing  245  and to a reservoir  260  of retardant via tubing  251 , to supply a water-retardant mixture to a tubing network  253  (extending to the right in  FIG. 2 ); a sprinkler valve  272  (or several such valves) selectively coupling the mixture from network  253  to sprinklers  140  ( FIGS. 1, 9 ) via tubing  934 ; a porous pipe valve  274  (or several such valves) selectably coupling the mixture from network  253  to porous pipes  130  (FIGS.  1 ,  3 - 4 ) via tubing  933 ; and a micro sprayer valve  276  (or several such valves) selectably coupling the mixture from network  253  to micro sprayers  280  ( FIG. 9 ) via tubing  932 .  
      Valves  272 ,  274 ,  276  can selectably couple retardant mixture to their various downstream structures in any suitable manner, for example by employing a solenoid and valve combination that provides a fluid passage when electrically switched into an “open” mode and obstructs passage of fluid when electrically switched to a “closed” mode. Suitable electrically activated, data-latching solenoid valves and actuators are available from Evolutionary Concepts, Inc. (www.ecivalves.com) of San Dimas, Calif.  
      Micro sprayers  280 , a preferred embodiment of which is illustrated in  FIG. 10 , advantageously direct their spray upward so that the sprayed retardant has more opportunity to contact the wall near which it is installed, e.g., wall  940  of  FIG. 9 . Micro sprayer  280  has a spray head  1005  suspended upside down from an overhead water main  1020 , to which it fluidly couples via a connecting pipe  1030 . The spillway  1042  of the water vein  1040  ( FIG. 11 ) in head  1005  is inverted from the normal spray head configuration (which would direct spray downward) to direct the spray upward.  FIG. 10  illustrates the upward spray with schematically depicted water droplets  1040 .  
      Exemplary reservoir  260  of  FIG. 2  has a tank with a capacity in the 30-45 gallon range that can be housed inside cabinet  930  or, as illustrated in  FIG. 9 , sit next to cabinet  930 . Advantageously, reservoir  260  provides a base level of retardant that can still be applied under battery power if the main supply of electricity (which drives any well pump employed in the water supply) is cut off. Cabinet  930  can have any suitable dimensions, e.g., 70 by 30 by 18 inches, and can be mounted in any suitable manner, e.g., by being bolted or otherwise attached to building  120 .  
      A signal transceiver according to various aspects of the invention, e.g., transceiver  232  of distribution station  110  ( FIG. 2 ), can be of any type suitable for communicating with a monitoring station (e.g., monitoring station  150  of  FIG. 1 ) to receive a signal directing the application of retardant to a structure. Preferably, the transceiver also transmits information about fire conditions back to the monitoring station. An example of a suitable transceiver is the “Uplink DigiCell 1500 Universal Alarm Transceiver” sold by Uplink Security (www.nmrx.com) of Atlanta, Ga.  
      Tubing according to various aspects of the invention includes any structure suitable for channeling fluid from one place to another. For example, tubing  241 ,  245 ,  251 ,  253 ,  832 ,  934  can be conventional plastic tubing commonly employed for irrigation, flexible vinyl hose, rigid PVC pipe, etc.  
       FIG. 3  illustrates a section of exemplary pipe  130  mounted on a wall  310  of structure  120  ( FIG. 1 ). Pipe  130  includes a tubing portion  324  and a mounting lip  320 , preferably fabricated as an integral structure from a suitable fluid-porous material. Tubing portion  324  has a generally elliptical cross-section that is indented on one side  330  to maintain structural integrity under pressure and for aesthetic appearance.  
      Mounting lip  320  has a suitable width (e.g., 1 cm) and thickness (e.g., 3 mm) to support the weight of pipe  130  and contained fluid on wall  310  with conventional nails  322  (e.g., from a nail gun) or staples (not shown). By including lip  320 , pipe  130  thus can be mounted without having its shape deformed by fasteners around its tubing portion  324 . The front face of lip  320  and front wall  330  can be painted to match the color of wall  310  or to provide aesthetic accent. The pipe  130  can be mounted upside-down from the way shown in  FIG. 3 , if desired.  
      A particularly advantageous composition of pipe  130  includes an approximately even blend of granulated tire rubber and linear low density polyethylene (e.g., 65% rubber), with carbon black added as an ultraviolet light inhibitor. The mixture can be extruded at an elevated temperature and allowed to harden into lengths of semi-flexible porous pipe.  
      The pipe is partially porous. In a preferred embodiment, the polyethylene regulates the porosity of the pipe in addition to serving as a binder for the granules of tire rubber. Because hardened polyethylene itself is fluid-impermeable, increasing the amount of polyethylene in the rubber-polyethylene blend reduces the permeability of the resulting pipe. Thus, the specific ratio of polyethylene versus rubber in the blend can be adjusted for a desired amount of porosity, given the water pressure and seepage requirements of a particular implementation.  
      Front wall  330  of porous pipe  130  is advantageously made fluid-impermeable with a coating of the same type of linear low-density polyethylene employed in the polyethylene-rubber blend of pipe  130 . Back wall  410  ( FIG. 4 ) is left uncoated and fluid-porous, permitting retardant mixture  420  to escape through interstices between rubber granules of back wall  410 , as  FIG. 4  represents with arrows leading from retardant  420  inside pipe  130  to the exterior behind wall  410 . It is particularly desirable to have about 54% of the circumference of tubing portion  324  coated with polyethylene. Having one half of the circumference coated is suboptimal because tubing portion  324  assumes a rounded shape when pressurized, and a significant amount of the non-coated half is not in direct contact with the wall.  
      Further information pertinent to making and using porous pipe according to various aspects of the invention is found in the detailed description portions of U.S. Pat. No. 5,876,387 (“Method of Forming Stabilized Porous Pipe”); U.S. Pat. No. 5,474,398 (“Stabilized Porous Pipe”); U.S. Pat. No. 5,445,875 (“Method of Forming U.V. Stabilized Porous Pipe”); and U.S. Pat. No. 5,299,985 (“Stabilized Porous Pipe”), which are incorporated herein by reference.  
      A reduced-pressure backflow device according to various aspects of the invention includes a particularly advantageous combination of backflow preventer and pressure reducer in series. As may be better understood with reference to  FIG. 5 , exemplary reduced-pressure backflow device (RPBD)  240  includes: a manual inlet valve  510  with a body  512  and handle  514 ; a backflow prevention portion  520  containing a pair of sequential backflow valves  522 ,  532  separated by a reservoir  540 ; a manual outlet valve  550  with a body  552  and handle  554 ; and a pressure reducer  560 .  
      Backflow valves  522 ,  532  include respective stoppers  524 ,  534  mounted on compression springs  526 ,  536 . Spring  526  keeps stopper  524  pushed against a wall  523  separating reservoir  540  from body  512  of inlet valve  510  unless the pressure differential between fluid in those two bodies is sufficient to overcome compression resistance of spring  526 . Similarly, spring  536  keeps stopper  534  pushed against a wall  533  separating reservoir  540  from body  552  of outlet valve  550  unless the pressure differential there is sufficient to overcome compression resistance of spring  536 . In one embodiment, the pressure differential for each spring is about 22 PSI.  
      When valves  510 ,  550  are open and fluid is present in body  512  of inlet valve  510  at pressure greater than the combined compression resistance of springs  526 ,  536 , some of the fluid will emerge at outlet valve  550 . As fluid emerges, some back pressure will develop in body  552  of outlet valve  550  from fluid resistance arising from fluid flow in the structure downstream of outlet valve  550 . That structure includes drainage tap  560  and items illustrated schematically in  FIG. 2 , namely injector  250 , valves  272 - 276 , and retardant distribution structures like sprinklers  140 . Failure of the water supply at inlet valve  510  or a blockage in the tubing downstream of outlet valve  560  can cause the difference between that back pressure and the inlet pressure in body  512  to approach or equal the combined compression resistance of springs  526 ,  536 . In such an event, springs  526 ,  536  close and fluid communication breaks between inlet valve  510  and outlet valve  550 .  
      Advantageously, RPBD  240  includes petcocks  610 ,  620 ,  630 ,  640  ( FIG. 6 ) along one side. RPBD  240  can be mounted in a housing (e.g., cabinet  930  of  FIG. 9 ) and still be tested, as required annually by some municipalities, without the need for removal from the housing.  
      Reservoir  540  ( FIG. 5 ) has adequate depth and a suitably designed cross-sectional shape to minimize the possibility of any fluid splashing or otherwise migrating from outlet valve  550  to inlet valve  510 . If pressure remains at outlet valve  550  for some unforeseen reason, petcock  620  at the bottom area  542  of reservoir  540  can open and allow the potentially contaminated fluid to bleed out of all the tubing structure that resides downstream of outlet valve  550 . With those safeguards, the water supply upstream of inlet valve  510  is strongly protected from contamination by retardant in reservoir  260  ( FIG. 2 ).  
      Pressure reducer  560  is a device that regulates the fluid pressure at its outlet at a substantially fixed value despite fluctuations within an acceptable range of input fluid pressures. For example, pressure reducer  560  is preferably set to maintain a substantially fixed pressure of 30 PSI.  
      A type of reduced-pressure backflow device with a design that can be modified (with side-mounted petcocks) to conform with the design of backflow prevention portion  520  is presently available from Conbraco Industries, Inc. of Matthews, N.C., in the one-inch 40-200 series. That company also supplies, separately, a one-inch 36C-Series pressure reducing valve that can be employed for pressure reducer  560 . When the Conbraco device is employed for pressure reducer  560 , the pressure at inlet valve  510  should be kept no greater than 175 PSI and the temperature no greater than 180° F.  
      In exemplary system  100 , injector  250  produces a water-retardant mixture with about a 3% concentration of retardant. The mixture can be combined with class A foam (e.g., at 12% concentration) and a corrosion inhibitor (e.g., at 3% concentration). The retardant is formulated to be visually clear, to avoid defacing the structure and surrounding landscape. It is also formulated to have a “sticky” or viscous type of dispersal rather then a rapid flow like water, to help it adhere somewhat to surfaces to be protected rather than quickly drain into or onto the ground. The retardant material itself is preferably a fertilizer with high phosphate content, e.g., a 10-35-0 type fertilizer.  
      As may be better understood with reference to  FIG. 7 , exemplary injector  250  includes a rigid section of tubing  710  having opposite threaded ends  712 ,  716  and a “T” junction  714  approximately midway between them. A threaded ball valve receptacle  724  screws into a short stub  720  of tubing leading from junction  714 , sealed with an “O” ring  722 . Receptacle  724  receives a compression spring  726  and a ball  728 , held in place by a gasket  730  and an end cap  732 . End cap  732  terminates in a coupling  734  for flexible tubing  251  ( FIG. 2 ), which leads from the source of retardant, reservoir  260  ( FIG. 2 ).  
      When water flows through tubing  710  at pressure limited by RPBD  240  to approximately 30 PSI, the Bernoulli effect creates suction at stub  720 , pulling ball  728  away from end cap  732  and opening a path for retardant to flow from reservoir  260  ( FIG. 2 ) through coupling  734  and into the water stream passing out of end  716 . When the flow of water is cut off, by activation of valves  272 - 276  or exhaustion of water supply  216  ( FIG. 2 ), the suction at stub  720  disappears, and compression spring  726  pushes ball  728  into a receptacle (not shown) in end cap  732 , cutting off fluid communication to retardant reservoir  260 .  
      A suitable type of injector to serve as injector  250  is the Model 1078 marketed by Mazzei Injector Corp. (www.mazzei.net) of Bakersfield, Calif., preferably with a suction orifice that is configured to accommodate the specific density of retardant being used. Further information about the Mazzei injector can be found in U.S. Pat. No. 5,863,128, incorporated herein by reference.  
      An exemplary method  800  of the invention for combating fire, e.g., with system  100  of  FIG. 1 , may be better understood with reference to the flow diagram of  FIG. 8 . At process  810 , workers deploy retardant distribution station  110  of  FIG. 1 , install cabinet  930  ( FIG. 9 ) alongside structure  120 , and install sprinklers  140 , porous pipe  130 , and micro sprayers  280  ( FIGS. 1-4 ,  9 ) on structure  120 . With station  110  deployed, a process group  820  can commence monitoring activities at monitoring station  150  ( FIG. 1 ), and another process group  850  is ready for activities at distribution station  110 .  
      The various operations performed by processes of group  820  include interfacing with operator  152  at process  828 , updating fire data in a data store  824  at process  822 , and updating subscriber data in data store  824  at process  826 . In an exemplary implementation of method  800  discussed below, fire data and subscriber data reside on separate computer servers. However,  FIG. 8  depicts the data as residing in a common data store  824  for clarity of illustration.  
      An operator interface process according to various aspects of the invention can be implemented with any combination of hardware and software suitable for presenting information relating to possible fire alerts to an operator and obtaining direction from the operator to establish that a fire alert condition is present or to take other appropriate action. For example, process  828  is implemented by a suitable client and server combination that renders a conventional image display and solicits form input (e.g., radio buttons, check boxes, text fields).  
      One server (not shown) includes a conventional computer hardware and software combination implementing a middleware application known as “Fusion LT,” which is described in Appendix C of the &#39;056 application. The Fusion LT server receives terrain data  818  from a remotely located terrain visualization server known as a “Keyhole” server (see www.keyhole.com) and overlays it with (1) fire data, e.g., from the U.S. Government-operated Hazard Mapping System (HMS), and (2) subscriber data from a local database server, e.g., running the mySQL software, that is suitably accessible, e.g., via a UNIX domain socket, a dedicated TCP port, and/or a web server (e.g., running the Apache and PHP software). The database server can run on the same computer as the Fusion LT server or on a locally-networked computer of its own.  
      Process  826  updates the subscriber data with GPS-derived latitude and longitude, owner or responsible party name, phone number, and address information when a retardant distribution station is employed, e.g., at process  810 . Some of this information can be omitted when not needed, and additional information can be included such as height (typically available from the same GPS device that provides latitude and longitude) and neighbor&#39;s contact information.  
      The client (not shown) employed at process  828  includes a conventional computer hardware and software combination implementing a Keyhole client, display screen with graphics subsystem, and a human-interface device subsystem with associated peripheral hardware, all of which are conventional and represented in  FIGS. 1, 8  by arrow  154 . Operator  152  interacts with the Fusion LT server via the client over a local, regular network or encrypted network (e.g., with SSH tunneling) connection via the Keyhole client, display screen with graphics subsystem, and human-interface device subsystem.  
      When an alert condition is identified at process  830 , e.g., by a decision ultimately made by operator  152  as discussed above, or by computer, process  832  activates the distribution of retardant by sending a suitable transmission to fire retardant distribution station  110  at a particular structure over communications link  51  ( FIG. 1 ). In response, station  110  distributes the retardant, implementing process  854  of group  850 .  
      Process  850  can include several acts that are carried out sequentially in any desired manner that enhances fire protection for a given amount of available retardant. In one example, there is sufficient retardant for three treatments. Each treatment involves separate dispersal structures (all illustrated in  FIG. 9 ) with separate activation times. In one embodiment, the treatments can be custom activated on-site by a local operator. Sprinklers, which treat the structure&#39;s roof and surrounding landscape, including perhaps decks or lumber piles, or even nearby trees, can also be automatically activated for a first period, e.g., 10 minutes, when fire is determined to be 3-5 miles from the structure and moving toward it. That treatment protects against flying embers, a hazard discussed in Appendix E of the &#39;056 application.  
      Then the porous pipe(s) soak the walls of the structure. That period can also be 10 minutes, for example, either simultaneously, sequentially, or overlapped. The next treatment is with micro sprayers  280 , which can protect decks and other horizontal structures in addition to vertical structures, also optionally for 10 minutes, particularly the undersides of such components, such as the eaves shown in  FIG. 9 .  
      Especially in large structures, it can be advantageous to plumb the system to allow for several stations, with treatments within the three periods described above having sub-steps during which one station addressing only part of the structure is activated in turn. In that manner, it is possible to create a rotating sequence of station activations. For the protection of large structures, it can be advantageous to use separate, independently operating systems using duplicates of the components illustrated in  FIG. 2 .  
      After activation of retardant distribution by monitoring station  150 , or even without any such activation, detection of a temperature above a predetermined threshold, e.g., 137° F., can automatically initiate a second treatment or cycle of treatments. Temperature sensors  236  are mounted on sides of the structure to perform such detection. The system can be customized to allow activation of a particular station controlling a particular side of the structure only if one of the several temperature sensors exceed the threshold at a particular time. A third activation (or more, if the supply of retardant is sufficient) can occur at a predetermined time after conclusion of the second activation, or alternatively based on some predetermined pattern of temperature changes. An example of such a pattern is a drop in temperature followed by a rise in temperature. That pattern might occur if two low-brush types of fire occurred in sequence, or if a fire front passed nearby and was followed by a low-brush type of fire.  
      Performance is best when plenty of water is available for mixing with retardant, for example between 250-500 gallons per treatment sequence. The dispersal of a large amount of water provides a “humidity envelope” that surrounds and thus protects the structure. When well flow capacity is limited, a water reservoir (often required by local ordinance) can be included for the desired water supply.  
      Station  110  can also implement process  852  of group  850 , sensing fire conditions and reporting back to fire data updating process  822  of monitoring station  150 . For example, a number of subscribers can report on local temperatures to a single monitoring station, which can use differentials between local temperatures to further refine its estimate about fire location and direction of movement.  
      Various particular features of exemplary system  100  may be better understood with reference to the labeled paragraphs below. In variations where the benefits of these particular features are not required, they may be suitably omitted or modified while retaining the benefits of the various aspects of the invention discussed above. With possible exceptions, structural elements not introduced with a reference numeral are not illustrated in the drawings.  
      IMAGE ANALYSIS AND MAPPING—System  100  ( FIG. 1 ) employs satellite data to monitor for fire alert conditions. A fire alert according to various aspects of the invention is a condition that makes it prudent to protect a structure against fire by distributing retardant onto the structure. The prudence of distributing a potentially limited supply of retardant is evaluated based on the danger presented by a nearby fire. Additional factors can be considered, such as the supply of retardant, the direction of movement of the fire (e.g., using the FARSITE fire area simulator), and the size and rate of growth of the fire.  
      System  100  can employ satellite data captured by the Satellite Services Division (SSD) of the National Oceanic and Atmospheric Administration (NOAA), both of which are government agencies. The captured satellite data is collected from four satellite sources and is manually integrated into a single mapping layer known as the Hazard Mapping System (referred to herein as “HMS”). The manual integration process helps remove false detects from the raw data of the various satellite sources.  
      The four data sources used by the satellite analysis are: (1) WF-ABBA—Wildfire Automated Biomass Burning Algorithm; (2) FIMMA—Fire Identification Mapping and Monitoring Algorithm; (3) MODIS—Moderate Resolution Imaging Spectroradiometer Fire Algorithm; and (4) DMSP/OLS—Defense Meteorological Satellite Program Operational Linescan System Nighttime Lights Algorithm.  
      The HMS web page warns as follows regarding the usage of published fire data: “The information on fire position should be used as a general guidance and for strategic planning. Tactical decisions, such as the activation of a response to fight these fires, should not be made without other information to corroborate the fire&#39;s existence and location.” Additional quoted material that may be instructive about HMS are found in Appendix A of the &#39;056 application.  
      DATA ACQUISITION—Appendix A of the &#39;056 application contains information about an exemplary software architecture for receiving HMS Geographic Information System (GIS) shape file data when it is available from NOAA. The Fusion LT system converts the GIS shape file data into its own database format used by the local Keyhole server. This local Keyhole server database is then used as an overlay to an existing Keyhole bitmap geographical image server database, e.g., at the vendor&#39;s location in California. To avoid adversely affecting system performance, the Fusion LT database can be set to only update when the HMS data has changed.  
      The same Fusion LT middleware application can be employed to process latitude and longitude coordinates of customer locations directly from data store  824  ( FIG. 8 ). Updates can occur at midnight each day to avoid affecting local server performance. The process can be made transparent so that customer data only needs to be entered once in data store  824 .  
      Once latitude and longitude coordinates of each customer property location have been acquired, e.g., via a portable Global Positioning System (GPS) unit, operators obtain access to most database fields stored in data store  824 . These fields can be displayed as interactive “hot links” with customer data such as customer name, phone number, and important geographic location information.  
      SPACE IMAGING OPTIONS—Appendix B of the &#39;056 application describes various options for analyzing space images to determine presence of fire alert conditions. Briefly, vendor solutions such as the “Fire Behavior Modeling Application” offered by Space Imaging and the Firemapper® system offered at www.firemapper.com can be employed.  
      MANUAL, ASSISTED, OR AUTOMATED ALERT ANALYSIS—The ultimate decision about whether a fire alert exists or not, and consequently whether or not to activate distribution of retardant, can be made by a human operator after evaluation of raw or partially analyzed data (e.g., seeing fires near “hot link” icons representing structures under protection) or based on a computer-generated recommendation. For example, an operator at monitoring station  150  ( FIG. 1 ) can note when a fire is within a given distance (e.g., 2 miles, 5 miles, 10 miles) of structure  120  and either activate fire retardant distribution station  110  to begin a process of retardant distribution or alert a local operator in a region (e.g., a county) responsible for structure  120 , who can make the ultimate decision about activation based on his or her additional local observations. The local operator can soon find out if the satellite-based preliminary alert proves unfounded, e.g., because the 1 km resolution of the GIS-based data from the HMS product was unable to tell that the fire was only a property owner&#39;s 10 foot by 10 foot slash fire. In systems where the accuracy of an automated alert analysis and detection system is sufficient given the cost of unnecessary retardant distribution, the need for a decision by a human operator can be eliminated.  
      At any place in the detailed description of preferred exemplary embodiments above where the detailed description portions of a patent or publicly accessible document is mentioned, the contents of that document are hereby incorporated herein by reference. The detailed description portions of all U.S. patents and patent applications incorporated by reference into such documents are also specifically incorporated herein by reference.  
     PUBLIC NOTICE REGARDING THE SCOPE OF THE INVENTION AND CLAIMS  
      The description above is largely directed to preferred exemplary embodiments of the invention. Specificity of language and statements of advantageous performance do not imply any commensurate limitation on the scope of the invention, nor do they require the stated performance. Portions of the application introducing structural and method elements of the various inventions should be understood as including broadening terminology such as “preferably,” “in a variation,” “in one embodiment,” etc.  
      No one embodiment disclosed herein is essential to the practice of another unless indicated as such. Indeed, the invention, as supported by the disclosure above, includes all systems and methods that can be practiced from all suitable combinations of the various aspects disclosed, and all suitable combinations of the exemplary elements listed. Such combinations have particular advantages, including advantages not specifically recited herein.  
      Alterations and permutations of the preferred embodiments and methods will become apparent to those skilled in the art upon a reading of the specification and a study of the appendices and drawings. In variations where the benefits of satellite-based fire alert detection are not required, for example, a ground-based area observation type of alert detection can be employed.  
      Accordingly, none of the disclosure of the preferred embodiments and methods defines or constrains the invention. Rather, the issued claims variously define the invention. Each variation of the invention is limited only by the recited limitations of its respective claim, and equivalents thereof, without limitation by other terms not present in the claim.  
      In addition, aspects of the invention are particularly pointed out in the claims using terminology that the inventors regard as having its broadest reasonable interpretation; the more specific interpretations of 35 U.S.C. § 112(6) are only intended in those instances where the terms “means” or “steps” are actually recited.  
      The words “comprising,” “including,” and “having” are intended as open-ended terminology, with the same meaning as if the phrase “at least” were appended after each instance thereof. A clause using the term “whereby” merely states the result of the limitations in any claim in which it may appear and does not set forth an additional limitation therein. Both in the claims and in the description above, the conjunction “or” between alternative elements means “and/or,” and thus does not imply that the elements are mutually exclusive unless context or a specific statement indicates otherwise.