Abstract:
The subject invention provides an improved system and method for combining data obtained from the NEXRAD™ system of the National Weather Service (“NWS”) with geographical and topological database information to achieve an improved and informative graphical storm-tracking display able to project the movement of a storm with a single user-operation. The method of projecting storm movement includes the following steps: collecting NEXRAD data attributes from a weather data source; calculating storm position using the collected NEXRAD attributes; calculating projected storm movement using the storm position and the collected NEXRAD attributes; displaying a graphic representation of the projected storm movement.

Description:
Cross Reference to Related Application 
     This application is a continuation of U.S. application Ser. No. 09/021,448, filed Feb. 10, 1998, now U.S. Pat. No. 6,125,328 which claims the benefit of Provisional Application Ser. No. 60/036,952, filed Feb. 10, 1997, both of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved system and method for combining data obtained from the NEXRAD™ system of the National Weather Service (“NWS”) with geographical and topological data base information to achieve an improved and informative graphical storm-tracking display able to predict and project the direction of a storm with a single user-operation. 
     2. Technical Background 
     NEXRAD is a system of weather services provided by the NWS. NEXRAD employs a system of radars scattered throughout the country which provides weather data to subscribers. Subscribers, such as television stations desiring to transmit weather broadcasts, use data from the NEXRAD system in its basic form. Current systems of subscribers typically extract simple storm information from the NEXRAD data to provide viewers with basic storm location information. 
     One NEXRAD service is the “NEXRAD Attributes.” This service provides the subscribers with detailed information concerning storms detected at each NEXRAD radar site. The NEXRAD Attributes data includes the following information for each storm: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 ID 
                 a unique 3-digit identifier 
               
               
                 AZ 
                 the direction of the storm in degrees from the 
               
               
                   
                 radar source 
               
               
                 RANGE 
                 the distance of the storm in nautical miles from 
               
               
                   
                 the radar source 
               
               
                 TVS 
                 the likelihood of a tornado vortex signature 
               
               
                   
                 (Yes or No) 
               
               
                 MESO 
                 the likelihood of mesocyclonic activity (Yes or No) 
               
               
                 HAIL 
                 the likelihood of hail (% change of hail, % chance of 
               
               
                   
                 severe hail, approximate hail size in inches) 
               
               
                 DBZM 
                 the maximum DBZ level (a measurement of 
               
               
                   
                 precipitation intensity) 
               
               
                 FCST_ANGLE 
                 forecasted movement angle (storm path) in degrees 
               
               
                 FCST_MVMT 
                 forecasted movement speed in nautical miles per hour 
               
               
                   
               
             
          
         
       
     
     The typical current NEXRAD system used by a NEXRAD subscriber receives NEXRAD data via a satellite downlink or over a wired network connection into a computer, such as the computer illustrated in the attached FIG.  1 . Then, the current subscriber&#39;s system extracts the azimuth and range information of the subject storm. From this information, the current systems can plot a two dimensional representation of the storm. Most of the other information in the NEXRAD Attributes goes unused by current systems, although the user, typically a meteorologist, can review this data manually. 
     One problem with a subscriber&#39;s current system is that in order to predict the movement of a storm, the user must manually create projections from the NEXRAD Attributes data. Current systems do not have the capability to create a graphical representation of the storm movement from the NEXRAD Attributes data without substantial human involvement. 
     Moreover, the current graphical storm display is typically limited to simple two dimensional representations of the storm&#39;s location and little else. Typically the viewers of weather displays based on the current systems have only a vague concept of the proximity of the storm to their location. Current systems are incapable of displaying NEXRAD projection information concerning those storms in any appreciable graphical way. 
     SUMMARY OF THE INVENTION 
     A method for projecting storms using NEXRAD attributes comprising the steps of: (a) collecting NEXRAD data attributes from a weather data source; (b) calculating storm position using the collected NEXRAD attributes; (c) calculating projected storm movement using the storm position and the collected NEXRAD data attributes; (d) displaying a graphic representation of the projected storm movement; (e) determining the communities in the path of the projected storm movement. 
     In addition, the present invention, in a preferred embodiment further comprises the following steps: (f) displaying the communities indicating the estimated time of arrival for the projected storm; (g) sorting multiple storms; (h) displaying the sorted storms in order of priority; and (i) displaying single storm details. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram of the preferred embodiment of the internal devices of a computer for use in the present invention. 
     FIG. 2 is a diagram of the computer of FIG.  1  and its use of the NEXRAD radar&#39;s latitude/longitude and the storm&#39;s distance and direction from the NEXRAD radar to determine the storm&#39;s exact latitude and longitude. 
     FIG. 3 is a diagram of the computer of FIG.  1  and its use of the information from the NEXRAD attributes and database information to create storm projections of the present invention. 
     FIG. 4 is a diagram generally describing the storm tracking algorithm of the present invention. 
     FIG. 5 is representative of a graphical output of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention improves over the prior art by utilizing the NEXRAD Attributes storm projection information, represented by the variables FCST_ANGLE and FCST_MVMT above and shown in FIG. 3, to provide the users of the present invention the ability to graphically display storm projection information with a single operation. The present invention extracts the NEXRAD Attributes storm projection information and adapts that information for graphical display. The use of the projection data in the present invention allows the user to have the storm location information graphically displayed, such as on a computer monitor screen or television set, overlaid with a graphical representation of the projected movement of the storm. 
     The steps which the present invention utilizes to achieve a storm projection system that will provide the user with storm prediction information in one operation can be briefly summarized as follows: 
     The first step is collecting NEXRAD Attributes for use by the storm projection system by receiving NEXRAD Attributes information via a satellite downlink, wired network, or other information transfer medium, and storing this information in a database. 
     In a preferred embodiment, the database contains the following attributes for each storm: 
     
       
         
               
               
             
           
               
                   
               
               
                 Attribute 
                 Range of Values 
               
               
                   
               
             
             
               
                 The presence of a Tornadic Vortex Signature 
                 YES or NO 
               
               
                 (TVS) 
               
               
                 The presence of Mesocyclonic activity (MESO) 
                 YES or NO 
               
               
                 Chance of Hail 
                 0% to 100% 
               
               
                 Chance of Severe Hail 
                 0% to 100% 
               
               
                 Hail Size in inches 
                 0.00″ to 4.00+″ 
               
               
                 Maximum Storm DBZ (measurement of rainfall 
                 30 to 75+ DBZ 
               
               
                 intensity) 
               
               
                 Height of max DBZ reading in the Storm 
                 1-75 thousand of feet 
               
               
                 Storm Height 
                 1-75 thousand of feet 
               
               
                 Storm position (latitude and longitude) 
                 N/A 
               
               
                 Storm forecasted angle 
                 0 to 359 degrees 
               
               
                 Storm forecasted movement 
                 0 to 60+ mph 
               
               
                 Storm Vertically Integrated Liquid (VIL) 
                 0 to 75+ kg/m 3   
               
               
                 Range in nautical miles from radar 
               
               
                 Azimuth (direction) in degrees from radar 
               
               
                   
               
             
          
         
       
     
     The database information is accessed to report the contents and characteristics of storms and to track the storms in near real-time. 
     Second, in response to a user request for a projection of a storm&#39;s movement, the system retrieves the NEXRAD Attributes information for a subject storm stored in the first step above. The user request may be made using a manual input device such as a mouse or keyboard as shown in FIG.  1 . 
     Third, the system calculates a storm projection arc to create a graphical representation of the storm for display, said calculation comprising the steps of: 
     (a) Using the storm&#39;s offset in meters from the view center of the graphical display (FIG. 2) to find the storm&#39;s position in latitude/longitude; 
     (b) Using the storm information (including fanout in degrees, direction in degrees, projection length in meters, and position as an offset in meters) to find the four corners of an arc describing the storm&#39;s projected path (the “storm projection arc”); 
     (c) Using the storm information (including fanout in degrees, direction in degrees, projection length in meters, and position as an offset in meters) to find the storm&#39;s projected position after moving “length” meters; 
     (d) Using the storm information (including fanout in degrees, direction in degrees, projection length in meters, and position as an offset in meters) to find the center of a bounding circle that helps define the limits of the projection; 
     (e) Using the four corners of the storm projection arc to define the maximum latitude, maximum longitude, minimum latitude, and minimum longitude at which a place in this track may be positioned; 
     (f) Using the four corners of the storm projection arc (see (b) above) to define the bounding lines of the arc that will define the storm projection; 
     Fourth, a general database of geographical information (FIG. 3) is stored on the computer in the form of a database containing latitude and longitude information, as well as other identifying and prioritizing information for all known cities and communities, hereinafter “places”, in the area of interest for a user of the present invention. 
     In a preferred embodiment, the places may be further grouped and related based upon their geographic proximity to each other such as being members of the same county, same state, same region, etc. The selected groups may be identified by minimum and maximum longitude and minimum and maximum latitude. 
     When determining which places are in the path of a storm, the following steps are performed: 
     1. If the places are grouped as described in the preferred embodiment, and the group&#39;s minimum latitude, minimum longitude, maximum latitude and maximum longitude indicate that one of the places in the group are within the arc of the storm projection, then skip that group of places; 
     2. Next, for each place not eliminated in step ( 1 ) above, do the following: 
     (a) If the place&#39;s latitude exceeds the minimum or maximum latitude requirements—skip it; 
     (b) If the place&#39;s longitude exceeds the minimum or maximum longitude requirements—skip it; 
     (c) If the place&#39;s priority level indicates that it should not appear at this track range (based on user-defined parameter for this particular track)—skip it; and 
     (d) If the place&#39;s latitude/longitude is not within the bounding circle (see above)—skip it. 
     (The above elimination steps represent the preferred embodiment, but they may be performed in any order. In addition, the user may identify other bases for eliminating certain places from the eventual display.) 
     Fifth, if a particular place has not been eliminated, it is within the path of the storm. 
     Sixth, by linear extrapolation, the current time, the storm&#39;s position, the storm&#39;s speed/direction, and the position of this place are used to determine the storm&#39;s ETA for this place. 
     Seventh, the system displays the storm projection arc, a topographical map of the affected area, and iconic representations of the places affected (refer to FIGS. 3 and 4 for general diagrams of this step) overlaid on top of a graphical representation of the storm. 
     FIG. 5 illustrates a preferred embodiment of a display of projected storm movements, the communities within the path of a storm, and the ETA for each community. 
     Finally, in the case of multiple storms, a sorting technique is used to prioritize storms. The priorities for sorting are based upon the following criteria: 
     1. The presence of a Tornadic Vortex Signature (a.k.a. TVS). This is either YES or NO. 
     2. The presence of mesocyclonic activity (a.k.a. MESO). This is either YES or NO. 
     3. The presence and estimated size of hail (size is measured in inches and is accurate to ¼ of an inch). 
     4. The highest recorded DBZ (a measurement of the intensity of the rainfall). 
     5. The estimated storm speed in mph. 
     These sorting criteria are in order of importance. The criteria are plugged into the following formula to determine the “weight” of the storm. The storm with the greatest weight has the highest priority. 
     weight=0; 
     if TVS presence 
     weight=weight+1,000,000,000 
     if MESO presence 
     weight=weight+100,000,000 
     if hail size&gt;0.00 
     weight=weight+hail size*10,000,000.0 
     weight=weight+DBZ*100 
     weight=weight+speed (in mph) 
     This formula tracks and assures that each criteria has a larger weight factor than its successor. 
     It should be noted that, in addition to the storm prediction achieved through the novel and non-obvious use of the NEXRAD Attributes, the present invention improves over the prior art by merging the weather, storm, and prediction information described above with geographic and topological information to achieve an enhanced and visually-appealing display. This application allows the user to provide a graphical weather display which overlays storm information on top of actual geographical information. Combining these two forms of information allows the user of the present invention to provide to its viewers or consumers weather forecasting at its most advanced level. 
     The ease with which the user can use the present system to obtain a storm tracking prediction, is evidenced by the fact that the user need only select the storm cell of interest, and the storm position is displayed automatically. Therefore, viewers of weather forecasting displayed through the use of the present invention will have available prediction information specifically tailored to the viewers&#39; own viewing area. For instance, viewers in small towns that previously could only guess at what time a storm would arrive at their location may now be given that information in a highly accurate and graphically appealing way. This improvement will detail exact and highly precise times at which storms or other weather phenomenon will arrive at any of several towns or cities in a geographical database provided with the present invention. 
     It should be understood to those skilled in the art that other modifications and changes can be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the following claims.