Abstract:
Systems and methods usable to provide synthetic environments for computer generated forces include supplemental surface material identifying information applicable to the respective surface. Polygons used to represent the surface can be overlayed with supplemental surface material information to provide a higher fidelity environment in which to mobilize the computer generated forces.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention pertains to systems and methods for the generation of synthetic environments for training or mission rehearsal. More particularly, the invention pertains to systems and methods to increase speed of creation and accuracy of landscapes for virtual battlefields which might be traversed by computer generated forces.  
       BACKGROUND OF THE INVENTION  
       [0002]     There is a continuing and ongoing need to be able to generate authentic synthetic environments in connection with training or exercise rehearsal. For example, aircraft or vehicular simulators provide more realistic simulations and enhance the training and/or rehearsal experiences of the participants by using dynamically changing, real time, out the window displays or scenes. Particularly in connection with aircraft, these displays can represent large areas of terrain which can be viewed, preferably in real time, by the participant. Such displays require large databases derived from, for example, satellite images, high altitude photography or the like.  
         [0003]     The databases and display equipment must be able to take into account widely changing scenes relative to a common area which could include take offs or landings, as well as high or low altitude engagements with simulated adversaries. One such approach has been disclosed and claimed in published U.S. patent application 2004/0075667 A1, assigned to the Assignee hereof and entitled System and Related Methods for Synthesizing Color Imagery, incorporated by reference herein.  
         [0004]     Realistic simulation experiences will likely include computer generated forces (CGF) which move across the displayed terrain and exhibit behavior consistent with terrain features such as water, trees, buildings and the like. Typical forces could include tanks, self-propelled artillery, boats, as well as mechanized or dismounted infantry.  
         [0005]     Terrain databases for modeling and simulation are known and commercially available. Commercially available software can be used to process such databases and, for example, extract features or the like. In addition commercially available software can be used to create and automate both friendly and enemy forces.  
         [0006]     Another prior art system  10  is disclosed in  FIG. 1 . In the system of  FIG. 1 , the desired real world surface representation is initially provided by database  12 , the corrected imagery/raster map of the region of interest. This imagery could, for example, be an overhead view of the geographical area of interest.  
         [0007]     The database  12  is processed to produce a full feature set  14 . It is recognized that production of the full feature set  14  is both time consuming and is a source of errors, miscorrelations and loss of fidelity.  
         [0008]     As is known, the corrected imagery/raster map  12  could be processed to produce out the window image tiling  16  to at least in part produce visual displays for the simulation participants.  
         [0009]     The full feature set  14  can in turn be combined with a terrain grid  18 , and a model library  20 , to produce terrain triangulation and feature placement information  22 . The out the window image tiling  16  and the terrain triangulation and feature placement  22  are stored in visual/infrared database  26 . Additional databases such as radar database  28  and semi-automated forces (SAF) or CGF database  30  can also be loaded with the terrain triangulation and feature placement information  22 .  
         [0010]     The full feature set  14  typically would incorporate a plurality of polygons to represent the respective geometric surfaces. Each polygon would be assigned a single surface type of material. At times, such polygons may cover a large area which could include a plurality of materials. As a result, the limit of a single material per polygon reduces the fidelity of the surface material presentation during the simulation or training exercise. The limitation is particularly evident in systems which include other presentations of a plurality of materials in the area. This would be evident if the area is visualized using overhead image resources.  
         [0011]     As noted above, the process of extracting the full feature set  14  from the corrected imagery/raster map database  12  requires extensive time and effort. A significant portion of this time and effort is devoted to obtaining the surface material definition for the various polygons. For example, manual digitalization of material outlines from maps or from overhead imagery is often required to provide polygon material definition or assignments.  
         [0012]     There continues to be an ongoing need to produce synthetic or simulated environments and databases for CGF more rapidly than has heretofore been possible. Additionally, it would be desirable to be able to minimize the errors and loss of fidelity that is often associated with the process of developing full feature sets, such as set  14 . 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a diagram of a prior art system and process of developing databases for a simulation or training environment;  
         [0014]      FIG. 2  is a diagram of a system and method in accordance with the invention;  
         [0015]      FIGS. 3A, 3B ,  3 C taken together, illustrate various processes of establishing material coded imagery from various sources;  
         [0016]      FIG. 4  illustrates the results of combining material coded imagery with vector features and producing various synthetic environment databases, including a CGF database;  
         [0017]      FIG. 5  is an overall flow diagram of a process in accordance with the present invention;  
         [0018]      FIG. 6  is a flow diagram of a process for associating material coded image information with various pixels; and  
         [0019]      FIG. 7  illustrates an exemplary process of overlaying respective polygons with information associated with respective pixels. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0020]     While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, and as a disclosure of the best mode of practicing the invention. It is not intended to limit the invention to the specific embodiment illustrated.  
         [0021]     Systems and methods for creating databases with material coded imagery for computer generated forces in accordance with the invention can shorten preparation time thereby incorporating more flexibility into the training process. Missions can be simulated sooner and with greater realism than with prior art systems.  
         [0022]      FIG. 2  illustrates a system and process  50  in accordance with the present invention. Those elements of  FIG. 2  which correspond to previously discussed elements of  FIG. 1  have been assigned the same identification numerals.  
         [0023]     Item image classification software  56  of a known type can process data from the corrected image/raster map  12  to form pixel based material coded imagery data  58 . For example, each pixel could represent geographical area such as 5 meters square of the region of interest. The pixel based material coded imagery data includes type of surface material present at some or all of the respective pixel.  
         [0024]     The corrected image/raster map  12  is processed, using commercially available software, to produce a reduced feature set  52  which can be represented using a plurality of polygons as would be understood by those of skill in the art. The reduced feature set illustrates three dimensional aspects of the terrain of interest along with key lineals; points or other features that are not adequately represented in the material coded imagery. The reduced feature set is generally much smaller than the full feature set, and can even be an empty set, so it can be created more quickly than the full feature set. The reduced feature set  52  is combined with terrain grid  18  and model library  20  to form terrain triangulation and reduced feature placement data  22 ′.  
         [0025]     Each pixel is assigned a data value which represents the material for that particular geographical area. For example, and without limitation, indicia and types of material could include:  
                                       0   corresponds to a null entry       1   corresponds to water       2   corresponds to sand       3   corresponds to trees       4   corresponds to grass       5   corresponds to concrete       6   corresponds to dirt                  
 
         [0026]     Additionally, each pixel material can be assigned a height, as discussed in Donovan U.S. Pat. No. 4,780,084 for a radar simulator and incorporated by reference herein. In such an instance, the material height for a pixel can be used to modify the underlying elevation for the pixel, increasing fidelity. For example, a pixel with “tree” material may be assign an elevation (e.g. 10 meters), indicating that the pixel is higher than the underlaying surface.  
         [0027]     The material coded imagery pixels  58  include a geographical position header to identify the location of the respective pixel in the subject environment. For example, each pixel could be identified with either Cartesian or geodesic coordinates. Different resolutions can be provided for different pixels.  
         [0028]     More than on type of material can be identified per pixel. In such an instance, pixel data can incorporate multiple codes reflecting multiple types of surfaces present in respective portions of the pixel.  
         [0029]     Those of skill will understand that the information from the respective pixels 58 will be layered on terrain surface data  22 ′. Surface data  22 ′, for example polygons, can exhibit lineals, areas and default material attributes. Conflicts need to be addressed. Lineals, roads for example, will usually take precedence over MCI data  58 . If no MCI data is present for respective coordinates, the default terrain material will be used.  
         [0030]     Prioritization can be provided to resolve areas where multiple objects are defined for the same area with different materials. For example, a material coded pixel might be coded for a selected material. On the other hand, three dimensional objects, areals might be present at the corresponding coordinates  22 ′. In such instances, one form of prioritization can correspond to:  
         [0031]     1. Where there is a conflict between material coded imagery  58  and 3D objects, lineals or areals at a respective coordinate or region, lineals, are always assigned a higher priority than the respective material coded imagery  58 . Conflicts can be resolved with areals using the following exemplary priority process:  
         [0032]     1. MCI priority designation of “true” indicates that the MCI data take priority over the current areal material.  
         [0033]     2. MCI priority designation of “false” indicates that the current areal material takes priority over the MCI coded material.  
         [0034]     3. MCI priority designation of “available” indicates that MCI data is available for at least part of the respective polygon.  
         [0035]     It will be understood that databases  26 ′,  28 ′ can be used with various simulation programs to present displays for participants (such as visual, IR or radar). Database  30 ′ can be used by CGF mobilizing software  32  to provide more realistic force behavior. These databases incorporate respectively, at least material coded imagery  58 , and the reduced feature placement data correlated to the triangulated terrain  22 ′ for purposes of presenting an appropriate display as well as providing enhanced terrain information for CGF.  
         [0036]     The image classification software can process various types of source data to produce the material coded imagery data  58 .  FIGS. 3A and 3B  illustrate two different sources of data from which the image classification software  56  can produce the material coded imagery data  58 . For example, in  FIG. 3A , data from a multi-spectral source  70  can be processed by the image classification software  56  to produce material coded imagery data, on a per pixel basis,  72 . Similarly, as illustrated in  FIG. 3B , color source data  76  can be processed using image classification software  56  to produce pixels, such as pixel  78  of material coded imagery  58 .  
         [0037]      FIG. 3C  illustrates material coded imagery  58  derived from an image  80 - 1 , and correlated with a vector representation, such as representation  80 - 2 . Image  82  illustrates different material classes associated with respective regions of geography  80  in response to processing by image classification software  56 .  
         [0038]      FIG. 4  illustrates exemplary run-time results relative to each of the databases  26 ′,  28 ′ and  30 ′ using the material coded imagery data  58 ′. In exemplary  FIG. 4 , the MCI surface information has been obtain from multi-band imagery  70 ′ to produce pixelized representations with surface indicia  58 ′.  
         [0039]     Correlated run time information associated with respective databases  26 ′,  28 ′ and  30 ′ is illustrated by colorized out the window visual displays and thermal images  26 ′- 1 , - 2 , the respective radar image correlated with vector information from the reduced feature set  52  is illustrated in image  28 ′- 1 . Finally, trafficability information usable by the computer generated, or, semi-automated forces, database  30 ′, is illustrated by display  30 ′- 1 .  
         [0040]     Database  30 ′ thus reflects both material coded imagery data  58  as well as the reduced feature set polygonal-type representation  22 ′. As would be understood by those of skill in the art, the computer generated forces would behave more realistically during a simulation or training exercise than would be the case without the additional material coded data.  
         [0041]      FIG. 5  illustrates additional details of a method  100  in accordance with the invention. In step  102 , a particular geographical database, such as the database  12  is selected. In step  104 , the material coded imagery information is generated from selected inputs. The reduced feature set of at least part of that database is then created, step  106 .  
         [0042]     The reduced feature set, such as reduced feature set  52 , is combined with terrain grid  18  and model library  20 , step  110 . The material coded imagery information, such as information  58  can then be stored along with the combined reduced feature set information, terrain grid and library information in respective databases such as  26 ′,  28 ′ and  30 ′, step  112 . The stored material coded data and terrain data can be used at simulation run-time, step  114  to improve realism of mobility of computer generated forces.  
         [0043]      FIG. 6  is an exemplary flow diagram of a process  130  of pixel coding in accordance with the invention. In step  132  a pixel based representation of a selected region is provided. In step  134 , the next pixel to be processed is selected.  
         [0044]     The material for the current pixel is established, step  136 . In step  138  a surface material code is established for the current pixel. If the last pixel has been processed, the material coded pixel data and associated attribute table can be stored in a respective database, step  140 . Otherwise, the process returns to step  134  to process the next pixel.  
         [0045]      FIG. 7  illustrates yet another exemplary process  160  in accordance with the invention. In the process  160 , the material coded data is associated with respective polygons of the reduced feature placement data  22 ′ which might be stored in a database, such as database  30 ′.  
         [0046]     In a step  162 , the next Cartesian coordinate is specified. The respective polygon corresponding to that pair of coordinates is then selected, step  164 .  
         [0047]     In step  166  a check is made to determine if the material data flag of the respective polygon has been set. If yes, in step  168  an evaluation is carried out to determine if lineals are present. If so, they take priority over any MCI data. If not, the respective coordinates X, Y are mapped to the respective pixel of the material coded imagery  58 , step  170 . Those of skill in the art will understand that processes are known and available for establishing a correlation between Cartesian coordinates of a region X, Y and the geodedic coordinates of various pixels. One such system has been disclosed in Donovan et al. U.S. Pat. No. 5,751,62 entitled “System and Method for Accurate and Efficient Geodetic Database Retrieval” assigned to the Assignee hereof, and incorporated by reference herein.  
         [0048]     In step  172 , the respective pixel data is accessed. In step  174  the respective material coded data is extracted for the respective pixel. In step  176  a determination is made if priority needs to be established between a local areal(s) and the respective MCI data. If not, then in step  178 , that respective MCI surface information is associated with the respective polygon. Otherwise the prioritizing process, discussed above is carried out, step  180 . Then the appropriate material data is associated with the subject polygon, step  178 . If finished, the composite polygon information, including the overlayed coded imagery information can be subsequently retrieved and displayed or used in the operation of computer generated forces, step  182 . It will be understood that variations in the above processes can be implemented and come within the spirit and scope of the invention.  
         [0049]     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.