Abstract:
An indirect artillery fire control system is shown, in which a plurality of indirect artillery systems are linked with a fire direction system such that a call for fire order is communicated as a fire command to a selected indirect artillery system, with that system being selected by reason of a characteristic of that indirect artillery system.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This Application claims priority of U.S. Patent Application Ser. No. 60/525,109, filed Nov. 25, 2003, entitled Software Architecture Mortar Fire Control System, the entire disclosure of which is hereby incorporated by reference as if being set forth in its entirety herein. 

   FEDERAL STATEMENT INTEREST 
   The inventions described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes. 
   BACKGROUND OF INVENTION 
   1. Field of Invention 
   The present invention relates generally to indirect fire systems and methods. 
   2. Background of the Invention 
   Indirect artillery fire systems, such as mortar systems, are known to be effective. For example, mortars may provide indirect fires that are organizationally responsive to ground maneuvers. In general, indirect fire systems are exceptionally well suited for attacking entrenched enemy troops and targets, which are not vulnerable to attack by direct fires. Indirect fire forces, such as mortar sections and platoons, play an important part of the total fire support system. Accordingly, it is desirable to improve these forces&#39; efficiency and effectiveness. 
   SUMMARY OF THE INVENTION 
   An artillery fire control system including: a plurality of artillery systems, each artillery system including code for receiving a fire command, code for computing a ballistic solution corresponding to the received fire command, code for comparing the computed ballistic solution with the fire command, and code for readying the artillery system to fire only if the comparing indicates a substantial match; and, a fire direction system including: code for receiving a call for fire order from a command, code for selecting at least one of the plurality of artillery systems dependently upon at least one characteristic of the plurality of artillery systems, and code for issuing a fire command corresponding to the call for fire order to the selected at least one of the plurality of artillery systems. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
     Understanding of the present invention will be facilitated by consideration of the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, wherein like numerals refer to like parts and; 
       FIG. 1  illustrates a block diagrammatic representation of a fire control system according to an aspect of the present invention; 
       FIG. 2  illustrates a block diagrammatic representation of the components of a mortar fire control system (MFCS) according to an aspect of the present invention; 
       FIG. 3  illustrates a block diagrammatic representation of a fire direction center/gun interface system according to an aspect of the present invention; 
       FIG. 4  illustrates a block diagrammatic representation of a computer software configuration item (CSCI) according to an aspect of the present invention; and, 
       FIGS. 5-13  illustrate processes according to aspects of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, many other elements found in typical indirect fire systems and methods. Those of ordinary skill in the art will recognize that other elements are desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. 
   According to an aspect of the present invention, an indirect fire control system and method is provided. The present invention will be described as it relates to a Mortar Fire Control System (MFCS) for purposes of clarity. It should be understood that the present invention also has applicability to other indirect fire systems as well. 
   According to an aspect of the present invention, a Mortar Fire Control System (MFCS) integrates with mortars and their transportation systems to provide a combined digital warfare system. A system according to an aspect of the present invention may provide primary indirect fire support for armored and mechanized infantry battalions with digital and automated fire direction and control capabilities, for example. 
   According to an aspect of the present invention, an MFCS may include at least one Fire Direction Center (FDC) node, at least one gun system node, and/or at least one FDC/gun node. These nodes may be operated by corresponding mortar and FDC crews, such as crews including one or more operators, gunners and drivers. According to an aspect of the present invention, an MFCS may provide for self-surveying mortars, digital call for fire exchange and automated ballistic solutions. Training and logistics improvements may also be supported. As will be recognized by those possessing an ordinary skill in the pertinent arts, this provides greatly increased capability over current non-digitized mortar fire control. 
   Referring now to  FIG. 1 , there is shown a diagrammatic representation of an indirect fire control system  10  according to an aspect of the present invention. System  10  generally includes one or more commands  20 , one or more agents  30  and one or more indirect fire systems  40 . Each of the command, agent and fire systems may be in communication with one another, such as by using wireless communications, like Radio Frequency (RF) signals. 
   Command  20  may take the form of a conventional military command in a hierarchical command structure. The present invention will be discussed as it relates to a command in the form of an U.S. Army Battalion Tactical Operations Center (TOC). In this case, TOC  20  may typically include a Force XXI Battle Command Battalion/Brigade and Below (FBCB2) system, a Main Control System (MCS) and an Advanced Field Artillery Tactical Data System (AFATDS). 
   These elements are well understood by those possessing an ordinary skill in the pertinent arts. For example, the FBCB2 system provides for general situational awareness. The MCS provides for maneuver control system. AFATDS provides for general battalion level fire support. As will be recognized by those possessing such a skill, other systems that comply with different protocols and standards than the systems identified here may of course be used, in addition to, or in lieu of, the systems described herein without adversely affecting performance of an MFCS according to the present invention. 
   Agent  30  may take the form of a forward observer. Agent  30  generally makes calls for fire. Agent  30  may take the form of individuals, or groups of individuals, being supported by fire system  40  and directly or indirectly under the command of command  20 . 
   Referring now also to  FIG. 2 , there is shown a non-limiting example of a fire system  40  suitable for use with system  10 . System  40  generally includes one or more fire direction control (FDC) systems  42  and one or more gun systems  44 . System  40  may also include other systems, such as an FBCB2 system, for example. Each of the FDC and gun systems may be in communication with one another, such as by using wireless communications, like Radio Frequency (RF) signals. In the exemplary case of  FIG. 2 , a single FDC  42  and four gun systems  44   a - 44   d  are shown. FDC  42  and guns  44  may be physically independent of one another. 
   Referring now also to  FIG. 3 , there is shown a block diagrammatic representation of a system  300  suitable for use as a FDC  42  ( FIG. 2 ), a gun system  44  ( FIG. 2 ), or both. System  300  may operate using a power supply  305 . Supply  305  may take the form of a battery, generator or existing power system conditioner for example. System  300  generally includes a processor  310 . Processor  310  may take the form of a Pentium processor available from Intel, for example. System  300  generally includes an operator display  315 , driver display  320  and gunner display  325 . Each display may take the form of a conventional text and/or graphical user interface (GUI) display. System  300  may include memory  330 , such as conventional volatile or non-volatile RAM and ROM memory devices. System  300  may include a data store  335  that may take the form of a conventional disk drive or flash memory card, by way of non-limiting example. System  300  may include a transmit/receive interface  340  for a radio  345 , where system  10  ( FIG. 1 ) uses RF transmissions. T/R interface  340  may take the form of a modulator/demodulator (MODEM), for example. System  300  may include a peripheral interface  350 , such as a serial interface, like a universal serial bus (USB), RS-232 or RS-422 interface. Interface  350  may provide interconnection with a conventional Inertial Navigation System (INS)  355 , such as a Talin INS, and a position locator, such as a conventional Global Positioning System (GPS) receiver  360 . Processor  310  and other elements of system  300  may be interconnected using conventional measures, such as bus architectures and the like. 
   Where system  300  is used only as an FDC  42  ( FIG. 2 ), gun and driver displays  320 ,  325  may not be incorporated, though they may be included. 
   Referring now to  FIG. 4 , there is shown a block diagrammatic representation of a MFCS Computer Software Configuration Item (CSCI)  400  according to an aspect of the present invention and suitable for use with system  300  of  FIG. 3 . CSCI  400  includes six Computer Software Components (CSCs). Each CSC may take the form of an executable or dynamic link library, for example. Communications between CSCs may be accomplished through sharing information in a database and/or broadcasting event messages, for example. The six CSCs include a Soldier Machine Interface (SMI)  405 , communications networker (COMNET)  410 , Peripheral Interface (PI)  415 , mission manager  420 , ballistics kernel  425  and Database (DB)  430 . 
   Briefly, SMI  405  is configured to provide a Graphical User Interface (GUI) between the MFCS and an operator using operator display  315  ( FIG. 3 ). COMNET  410  is configured to handle digital communications with other fire support devices, over battalion and mortars communication networks (using modem  340  and radio  345  of  FIG. 3  for example). PI  415  is configured to interface with the gunner display  325  ( FIG. 3 ), driver display  320  ( FIG. 3 ), PI  350  ( FIG. 3 ), and INS  355  ( FIG. 3 ). Optionally, if the system is configured on a vehicle that does not have an INS, then PI  350  may interface with a Precision Lightweight GPS Receiver (PLGR) directly, for example. Mission manager  420  is configured to process fire mission related digital messages. BK  425  includes information indicative of and is configured to compute, or assist in the computation of ballistic solutions, such as for 60 mm, 81 mm, and 120 mm mortars. And, database  430  is configured to provide non-volatile storage and synchronization of system data. Database  430  may take the form of a collection of Microsoft Access Database tables stored in data store  335  ( FIG. 3 ), for example. Offline capabilities of Microsoft Access may be utilized, for example. 
   Referring now also to  FIG. 5 , there is shown a process  500  corresponding to a call for fire suitable for being processed by CSCI  400  of a gun system  44  ( FIG. 2 ) according to an aspect of the present invention. In a first step  510 , T/R module  340  receives a data indication message from a network, such as via radio  345  ( FIG. 2 ). T/R module  340  forwards  515  this message to COMNET  410 . COMNET  410  processes  520  the forwarded message to identify, extract and validate a fire command message. The fire command message may include firing parameters and orders, for example. 
   COMNET  410  may then add  525  a machine acknowledgement message (MACK) to a transmit queue in database  430 . The MACK may be along the lines of a return receipt corresponding to the fire command message, for example. Database  430  may serve to queue up messages to be transmitted, and then send them to COMNET  410  for transmission via T/R module  430  according to conventional communications prioritization algorithms. 
   COMNET  410  may then call mission manager  420  to process the fire command message, and using the ballistics kernel  425 , calculate a firing solution, using its known position (as may be acquired via GPS  360  ( FIG. 3 ) for example). According to an aspect of the present invention, the received fire command message may include a firing solution as one of the parameters. In such a case, mission manager  420  may still calculate the firing solution and compare it against the received solution to confirm that the solution is accurate. If the calculated solution does not adequately match the received solution, a solution mismatch message may be queued up for transmission by T/R module  340 . Possible reasons for solution mismatches include the gun being relocated without a corresponding FDC for the gun being updated about the new gun location. In this case, the received firing solution, calculated by the corresponding FDC using stale positional information or a characteristics associated with the gun will not match the firing solution calculated by the gun using its updated positional information. As will be recognized by those possessing an ordinary skill in the pertinent arts, this represents a significant improvement over conventional firing solution computation methods, as it allows for a gun choosing decision maker (an FDC, for example) to automatically confirm a firing solution for an assigned gun. If the solution does not match, it allows the decision maker to re-evaluate the gun choosing decision with the updated information rather than allowing a command decision to be based upon stale information. 
   Referring still to  FIGS. 4 and 5 , if the mission manager  420  calculated firing solution adequately matches the received solution, and/or the calculated firing solution is otherwise acceptable as meeting pre-defined criteria, i.e., not being within a no-fire zone, COMNET may add  530  a new fire mission to database  430 . COMNET  410  may then send  535  a new mission notification message, such as a new fire command message, to SMI  405 . 
   Responsively thereto, SMI  405  may retrieve  540  the firing data, which may include the calculated and/or received firing solution(s), from database  430 . SMI  405  may also alert  545  the operator thereof of a new fire mission, such as by activating operator display  315  to illustrate images and/or text indicative of the new mission. SMI  405  may also send fire order data that may include the firing solution, to peripheral interface  415 . PI  415  records  550  an azimuth, elevation, master ordnance configuration (MOC), shell type and fuse type, e.g., the firing solution in memory  330  ( FIG. 3 ). PI  415  may also alert the driver and gunner about the new mission, e.g., via gunner and driver displays  325 ,  320 . 
   PI  415  computes  555  the difference in, or delta, azimuth and elevation based upon the received order and the current direction the gun is pointed (i.e., using PI  350 , INS  355  and/or GPS  360 ). PI  415  then alerts  560  the gunner of the computed deltas and fire orders, such as by causing them to be displayed to the gunner using the gunner&#39;s display  325  ( FIG. 3 ). PI  415  may also alert  565  the driver of the delta azimuth, or difference between direction the gun needs to be pointed and direction it is currently pointed in azimuth, such as by causing the driver&#39;s display  320  to display the information, in case the vehicle supporting the gun needs to be moved to rectify the azimuth delta. The driver may be alerted for every fire order, selectively based upon an automated decision of whether the vehicle needs to be moved to rectify the delta or at a gunner&#39;s or operator&#39;s request, for example. 
   Periodically, such as at a rate of about 4 cycles per second for example, PI  415  may reacquire  570  current positional data regarding the gun. This may be accomplished via PI  350 , INS  355  and/or GPS  360 , for example. This information may be pulled or pushed, for example. P±315 may then repeat steps  555 - 575  until the delta is determined  575  to be within acceptable thresholds (i.e., has been rectified), for example. Once the delta has been rectified, the gunner, driver and/or operator may be notified  580  that the gun is pointed properly. 
   Referring now to  FIGS. 1 ,  2  and  6 , there is shown a process  600  corresponding to a gun occupying a firing position and initially providing and receiving information according to an aspect of the present invention. For purposes of completeness, it may be assumed that communications between a command  20  ( FIG. 1 ) and fire system  40  ( FIG. 1 ), and FDC  42  ( FIG. 2 ) and Gun  44  ( FIG. 2 ) have been properly established. Messages may be in the form User Datagram Protocol (UDP) messages, for example. Communications to and from control  20  may be via AFATDS, for example. 
   Command  20  may send  605  a message to an FDC  42  instructing that a firing position be occupied. This message may be in the form of a free-text message. FDC  42  may request  610  tactical reports, such as operational status and current ammunition supply, from guns  44 , such as guns  44   a - 44   d . This message may be a free text message. Ammunition inventory messages may then be sent  615  from each gun system  44  to FDC  42 . An ammunition summary message, indicative of each of the ammunition inventory messages, may then be sent  620  from FDC  42  to command  20 . 
   A gun status message may be sent  625  from each gun system  44  to FDC  42 . This message may indicate the operational status of each gun. A status summary message, indicative of each of the gun status messages, may then be sent  630  from FDC  42  to command  20 . 
   Tactical reports may be requested  635  by FDC  42  from command  20 . The tactical reports may include information useful to FDC  42  and/or guns  44 , such as atmospheric data, fire restrictions (i.e., no fire zones) and agent  30  locations. This request may take the form of a free text message. A meteorological tactical report  640  may be sent by command  20  to FDC  42 . This report may be compiled from known meteorological conditions by command  20  in response to the request  635 , for example. FDC  42  may forward  645  received meteorological reports to gun systems  44 . 
   Command  20  forwards  650  fire support coordination information to FDC  42 . This information may include such items as coordinated fire lines and no fire areas. Command  20  also forwards  655  the location of agents to FDC  42 , also to facilitate fire support. This information may or may not be provided  660 ,  665  to gun systems  44 . 
   Referring now also to  FIG. 7 , there is shown a process  700  corresponding to a call for immediate smoke. This represents one type of shell that may be fired by a gun  44 . Illustrated process  700  begins with a call for fire  705  (designating immediate smoke) from agent  30  to command  20 . A corresponding fire order with immediate smoke message is sent  710  from command  20  to FDC  42 . The fire order may include the call for fire message, or information indicative thereof. The fire order may indicate a number of ordered volleys, taking the expected number of rounds expected to be fired per volley into account. A corresponding fire command is sent  715  from FDC  42  to gun systems  44 . The fire command may again include the call for fire message, or information indicative thereof. FDC  42  may send  720  a mission acknowledge message that may include a message to agent or observer component, to command  20 . The mission acknowledgement message may again include the call for fire message, or information indicative thereof. The mission acknowledgement message may be sent  725  by command  20  to agent  30 , to indicate the mission has been approved. 
   A mission update message may be sent  730  from each gun system  44  to FDC  42  each time a shot has been fired. A message may also be sent  735  each time a splash is observed. A message may also be sent  740  after a shot has been fired and a splash has been observed indicating the number of rounds expended. One or more of these messages may again include the call for fire message, or information indicative thereof. One or more mission update messages  745  may be sent from FDC  42  to command  20 . These mission update messages may indicate a first shot has been fired, a first splash has been observed and a last round has been expended. A mission update message may then be sent  750  from command  20  to agent  30 , to indicate shots have been fired, splashes have been observed and the number of rounds that have been completed. 
   Agent  30  may send  755  command  20  a mission complete message to indicate an end of mission. A corresponding end of mission message may be sent  760  from command  20  to FDC  42 . Optionally, a corresponding end of mission message may be sent  765  from FDC  42  to gun systems  44 . 
   Referring now also to  FIG. 8 , there is shown a process  800  for an adjust fire call. This call may be suitable to adjust the ranging of and aim of gun systems  44 . Illustrated process  800  begins with a call for fire  805  with an adjust fire request from agent  30  to command  20 . A corresponding fire order with an adjust fire message is sent  810  from command  20  to FDC  42 . The fire order may include the call for fire message, or information indicative thereof. The fire order may indicate a number of ordered volleys, taking the expected number of rounds expected to be fired per volley into account. A corresponding fire command is sent  815  from FDC  42  to gun systems  44 . The fire command may again include the call for fire message, or information indicative thereof. FDC  42  may send  820  a mission acknowledge message that may include a message to agent or observer component, to command  20 . A mission acknowledgement message may again include the call for fire message, or information indicative thereof. The mission acknowledgement message may be sent  825  by command  20  to agent  30 , to indicate the mission has been approved. 
   A mission update message may be sent  830  from each gun system  44  to FDC  42  each time a shot has been fired. A message may also be sent  835  each time a splash is observed. One or more of these missions may again include the call for fire message, or information indicative thereof. One or more mission update messages  840  may be sent from FDC  42  to command  20 . These mission update messages may indicate a first shot has been fired and a splash has been observed. A mission update message may be sent  845  from command  20  to agent  30 , to indicate shots have been fired and splashes have been observed. 
   Agent  30  may then send  850  command  20  a subsequent adjust fire message, requesting a change to firing coordinates, i.e., a requested shift, and optionally a fire for effect request, for example. A corresponding adjust fire order may be sent  855  from command  20  to FDC  42 . A corresponding adjust fire command may be sent  860  from FDC  42  to guns  44 . 
   A mission update message may be sent  865  from each gun system  44  to FDC  42  each time a shot has been fired. A message may also be sent  870  each time a splash is observed. A message may also be sent  875  after a shot has been fired and a splash has been observed indicating the number of rounds expended. One or more of these messages may again include the call for fire message, or information indicative thereof. One or more mission update messages  880  may be sent from FDC  42  to command  20 . These mission update messages may indicate a first shot has been fired, a first splash has been observed and a last round has been expended. A mission update message may be sent  885  from command  20  to agent  30 , to indicate shots have been fired, splashes have been observed and the number of rounds that have been expended. 
   Agent  30  may send  890  command  20  a mission complete message to indicate an end of mission. A corresponding end of mission message may be sent  895  from command  20  to FDC  42 . A corresponding end of mission message may be sent  900  from FDC  42  to gun systems  44 . 
   Referring now also to  FIG. 9 , there is shown a process  900  suitable for use after receipt of an end of mission message by a gun system  44 . Process  400  may also be executed at predetermined intervals, upon request, or after any firing activity, for example. An inventory update message may be sent  910  from a gun system  44  to FDC  42 . One or more corresponding inventory update messages, either independently or in the form of a summary, may be sent  920  from FDC  42  to command  20 . 
   Referring now also to  FIG. 10 , there is shown a process  1000  for effecting a check fire. As is understood by those possessing an ordinary skill in the pertinent arts, a check fire is an immediate request to hold fire. For purposes of completeness, process  1000  may be well suited after a call for fire is being acted upon, such as after step  725  of  FIG. 7 , or steps  825  or  860  of  FIG. 8 . 
   Illustrated process  1000  begins with a checkfire request  1005  from agent  30  to command  20 . A corresponding check fire order is sent  1010  from command  20  to FDC  42 . The check fire order may include the agent check fire message, or information indicative thereof. A corresponding check fire command is sent  1015  from FDC  42  to gun systems  44 . The check fire command may again include the check fire message, or information indicative thereof. FDC  42  may send  1020  a mission acknowledge message that may include a message to agent or observer component, to command  20 . The mission acknowledgement message may again include the check fire message, or information indicative thereof. The mission acknowledgement message may be sent  1025  by command  20  to agent  30 , to indicate the check fire has been approved. The check fire messages may refer to target numbers or mission related information, to ensure the check fire is acted upon the proper mission. 
   Referring now also to  FIG. 11 , there is shown a process  1100  for canceling a check fire. Illustrated process  1100  begins with a check fire cancel request  1105  from agent  30  to command  20 . A corresponding cancel order with is sent  1110  from command  20  to FDC  42 . The order may include the cancel check fire message, or information indicative thereof. A corresponding cancel command is sent  1115  from FDC  42  to gun systems  44 . The cancel command may again include the cancel check fire message, or information indicative thereof. FDC  42  may send  1120  a mission acknowledge message that may include a message to agent or observer component, to command  20 . The mission acknowledgement message may again include the check fire cancel message, or information indicative thereof. A mission acknowledgement message may be sent  1125  by command  20  to agent  30 , to indicate the checkfire has been cancelled. Alternatively, acknowledgement messages may not be used. 
   Regardless, a mission update message may be sent  1130  from each gun system  44  to FDC  42  each time a shot has been fired. A message  1135  may also be sent indicating the number of rounds expended. A message indicating a splash has been observed may, or may not, be sent. One or more of these messages may again include the call for fire message, or information indicative thereof. One or more mission update messages  1140  may be sent from FDC  42  to command  20 . These mission update messages may indicate a first shot has been fired and a number of rounds that has been expended. A mission update message may also be sent  1155 , in fire missions without check fires as well, from FDC  42  to command  20  to indicate that the first shot and the last of the rounds have been completed. A mission update message may be sent  1150  from command  20  to agent  30 , to indicate shots have been fired and the number of rounds completed, and optionally that the first of the shots have been made and the last of the rounds completed. 
   Agent  30  may send  1160  command  20  a mission complete message to indicate an end of mission. A corresponding end of mission message may be sent  1165  from command  20  to FDC  42 . Optionally, a corresponding end of mission message may be sent  1170  from FDC  42  to gun systems  44 . An ammunition update process, such as that illustrated in  FIG. 9 , may also be effected. 
   Referring now to  FIGS. 1 ,  2  and  12 , there is shown a process  1200  for simultaneous fire missions according to an aspect of the present invention. Illustrated process  1200  begins with a first call for fire  1205  from agent  30  to command  20 . A corresponding first fire order message is sent  1210  from command  20  to FDC  42 . A corresponding fire command is sent  1215  from FDC  42  to gun systems  44   a - 44   d . FDC  42  may send  1220  a mission acknowledge message to command  20 . A mission acknowledgement message may be sent  1225  by command  20  to agent  30 , to indicate the mission has been approved. 
   While in the course of conducting the first mission, agent  20  requests  1230  a second call for fire. A corresponding second fire order message is sent  1235  from command  20  to FDC  42 . 
   In response thereto, FDC  42  may issue  1240  an end of mission to gun systems  44   c ,  44   d —to in effect free up these resources for the second call for fire order. Gun systems  44   c ,  44   d  may conduct an inventory messaging, as shown in  FIG. 9 , for example. 
   FDC  42  may issue  1245  a fire command to gun systems  44   c ,  44   d  corresponding to the second fire order message. FDC  42  may send  1250  a mission acknowledge message to command  20 . A mission acknowledgement message may be sent  1255  by command  20  to agent  30 , to indicate the second mission has been approved. 
   A mission update message may be sent  1260  from each gun system  44  to FDC  42  each time a shot has been fired. For the first mission in the case of gun systems  44   a ,  44   b , and for the second mission in the case of gun systems  44   c ,  44   d . Another message may be sent  1265  from each gun system  44  to FDC  42  indicating a splash has been observed. And, a message  1270  may also be sent indicating the number of rounds expended. One or more of these messages may again include the corresponding call for fire message, or information indicative thereof. One or more mission update messages  1275  may be sent from FDC  42  to command  20 . These mission update messages may indicate a first shot has been fired, a first splash has been observed and a last round has been expended. A mission update message may be sent  1280  from command  20  to agent  30 , to indicate shots have been fired and the number of rounds completed, and optionally that the first of the shots have been made and the last of the rounds completed. 
   Agent  30  may send  1285  command  20  a mission complete message to indicate an end of mission corresponding to the first or second mission. A corresponding end of mission message may be sent  1290  from command  20  to FDC  42 . Optionally, a corresponding end of mission message may be sent  1295  from FDC  42  to gun systems  44 . An ammunition update process, such as that illustrated in  FIG. 9 , may also be effected. 
   Referring now also to  FIG. 13 , there is shown a process  1300  for selecting guns to issue fire commands to. Process  1300  may be used by FDC  42  when a fire command is received from command  20 . Upon receipt of a fire command  1310 , available gun systems (e.g.,  44   a - 44   d  of  FIG. 2 ) may be identified  1315 . Guns not having the appropriate type of ammunition for the received fire order may be eliminated from consideration  1320 . Guns that are not in range to fulfill the received fire order may be eliminated from consideration  1330 . Guns not reporting an operationally ready state may be eliminated from consideration  1340 . Finally, FDC  42  may issue a fire command  1350  to the remaining guns (e.g., gun systems  44   c ,  44   d  in the example of  FIG. 12 ). 
   FDC  42  may optionally issue fire commands to suitable gun systems  44  that represent a total number of shots that correspond to the total number of expected shots expected by command  20 . For example, if command  20  ordered two volleys from FDC  42 , assuming that each of four gun systems would fire for each volley, FDC may order four volleys to two guns if only two guns are determined to be suitable for carrying out the ordered mission, thereby commanding a number of shots consistent with the number of shots expected by command  20 . 
   It will be apparent to those skilled in the art that various modifications and variations may be made in the apparatus and process of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modification and variations of this invention provided they come within the scope of the appended claims and their equivalents.