Abstract:
The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter&#39;s coverage relative to the position of the EA aircraft and to the position of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour and a Jam Assessment Strobe (JAS) for display via designated aircraft cockpit processors and devices. The JAR and JAS will aid the EA aircrew in assessing the effectiveness of a given jamming approach.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter&#39;s coverage relative to the position of the EA aircraft and to the position of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour and a Jam Assessment Strobe (JAS) for display via designated aircraft cockpit processors and devices. The JAR and JAS will aid the EA aircrew in assessing the effectiveness of a given jamming approach and assists in determining the optimum flight path for both the PE and EA. The optimized flight paths will minimize exposure to threat emitters allowing accomplishment of the mission. 
   2. Description of the Prior Art 
   Electronic Warfare (EW) tactics employed by EA aircraft strive to direct electromagnetic energy into a threat radar receiver with sufficient power to prevent the threat radar receiver from accurately detecting or tracking the PE. EW includes the basic concepts of Noise Jamming and Deception Jamming. Key to the successful jamming effort is generating a signal that exceeds the expected target return signal seen by the threat receiver and concentrating the radar jamming signal in the direction of the threat receiver antenna. Barrage noise jamming floods the threat radar receiver with massive amounts of electronic emissions and significantly degrades low technology threat receiver performance. With the evolution of advanced radar concepts the noise jamming approach is less effective against high technology threat emitters. Advanced technology threat radar emitters have led to tuning the EA jamming frequency to match the frequency of the threat emitter and to follow any frequency hopping or other frequency agile characteristics the threat emitter may employ. Deception jamming requires the EA platform to generate a signal that is similar to the target return signal the threat receiving system expects while modifying target characteristics such as return signal strength, range, heading, velocity or acceleration. Overcoming multiple threat emitters employing advanced radar techniques, while transitioning a hostile area and providing protection jamming is a high workload environment for an aircrew. Cockpit display information and aircrew decision aids are required to improve situational awareness for the EA aircrew. It is an objective of this invention to reduce aircrew workload by providing decision aids. 
   Systems to aid the EA flight crew decision making process in positioning the jamming source carried by the EA are in need of improvement. Current aids available to EA flight crew provide text and rudimentary visual cues depicting gross EA position relative to threat receiver position. Current EA systems force the flight crew to manually incorporate current PE position relative to the position of the EA and threat receiver, then forces the aircrew to manually determine the optimum EW countermeasure to employ driving up aircrew workload. Current systems are incapable of fusing EA jamming capability with projected threat emitter performance information in order to obtain optimal geometrical positioning of the EA relative to threat emitters. The novel method of combining threat emitter system characteristics with EA aircraft capabilities while simultaneously incorporating PE position in a single display format greatly reduces EA aircrew workload and makes the EA more effective. 
   SUMMARY OF THE INVENTION 
   The preferred embodiment is a software program to generate the information to display a Jam Acceptability Region (JAR) and a Jam Assessment Strobe (JAS) for a multitude of ground based threat emitters updated in real-time. The JAR and JAS are composed of a threat emitter system susceptibility area based on the position of the Protected Entities (PE) and the Electronic Attack (EA) position. The JAR and JAS provides the EA aircrew visual information depicting the current position of the EA aircraft in relationship to ground based threat emitters and in relationship to the accompanied PE. The PE is the aircraft in need of protection jamming. Electronic Warfare (EW) employs tactics to direct electromagnetic energy into the enemy radar receiver to prevent the receiver from accurately detecting the PE. Key to successful radar jamming is obtaining the proper Signal to Noise (S-N) ratio threshold. One of the most critical factors in achieving this S-N ratio is placing the EA jamming signal in the correct geometric position to blind the threat receiver while the threat antenna is slewed in the direction of the PE. The Jam Assessment software program that is the preferred embodiment of this invention is a real-time software application that will be employed by the EA aircrew during prosecution of their tactical mission. The Jam Assessment software program provides the aircrew with visual cues that enable the flight crew to ascertain current jamming effectiveness. The Jam Assessment software program receives as input EA and PE positional information. The performance characteristics of the threat emitter and EA jamming capabilities are also received as input to the Jam Assessment software program. The information received as input is processed by designated computers on board the EA aircraft and used to generate the visual cues that allow an assessment of jam effectiveness. 
   For the EA to determine its instantaneous optimum position it must continually ascertain the position of the PE in relationship to each threat emitter and mathematically generate a JAR along with its own position within the JAR. The Jam Assessment software program must account for the interaction of the JAR and the PE position as the PE transits its intended flight path. The Jam Assessment software program blends the position of the EA aircraft and PE aircraft with the information residing in an electronic library designated as an Electronic Order of Battle (EOB). The positional and EOB information are used to generate the visual cues that allow an assessment of jam effectiveness. 
   The Jam Assessment software program has at its core a JAR processing algorithm executed on designated aircraft computers driving designated display hardware to provide the aircrew with improved situational awareness using visual cues in the form of JAR and JAS symbols. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a drawing showing the various Jam Acceptability Region (JAR) contours. 
       FIG. 2  is a drawing showing the relationships between the JAR, the threat emitter system, the EA and the PE flight path. 
       FIG. 3  is a drawing showing multiple threat emitter systems and the JAR overlap area. 
       FIG. 4  is a high level software flowchart showing the processing steps for generating the Reactive Assignment and the Preemptive Assignment JAR contours and Jam Assessment Strobe (JAS) displays. 
       FIG. 5  is a lower level flowchart focusing on the processing steps to generate the Reactive Assignment JAR and JAS information. 
       FIG. 6  is a lower level flowchart focusing on the processing steps to generate the Preemptive Assignment JAR and JAS information. 
       FIG. 7  is a drawing showing the segments that make a JAS. 
       FIG. 8  is a drawing showing JAS and a PE that is detectable by a threat emitter system. 
       FIG. 9  is a drawing showing a JAS and a PE that is not detectable by a threat emitter system. 
       FIG. 10  is a drawing showing two JAS, an effective EA and a protected PE in a representative display format. 
       FIG. 11  is a drawing of a combined JAR, JAS, EA and protected PE in a representative display format. 
       FIG. 12  is a drawing of undesignated threat emitters. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Broadly stated, the present invention comprises a method and software module that efficiently and simultaneously receives disparate information and transforms the disparate information into usable graphical displays. The graphical displays convey information that is used to position the EA relative to a threat emitter system. A typical threat emitter system is composed of an antenna, a transmitter, a receiver, a mechanism to position the antenna, electronics to process information received and a user interface. Key to the success of any radar jamming technique is exceeding the Signal to Noise ratio threshold that is an inherent characteristic of the threat emitter system. When the noise signal generated by the EA exceeds the signal return of the PE you have defeated the threat emitter system. Likewise, if the EA generates a stronger yet similar signal to the actual return signal of the PE while shifting a PE parameter, such as range or speed, the threat emitter system will be deceived, masking the true position of the PE. Generating a jamming signal to mask the true position, speed or course of the PE degrades acquisition and tracking performance in the threat emitter system. 
   Generally, threat radar coverage is viewed as the instantaneous threat radar volume swept vertically and horizontally over time through azimuth and elevation limits defined by the threat radar antenna mount. Multiple three-dimensional concentric ellipsoids extend from the transmitting antenna and compose the threat radar volume. The threat radar volume is composed of a main-lobe ellipsoid, numerous side-lobe ellipsoids and numerous back-lobe ellipsoids. The main-lobe ellipsoid extends much farther than any side-lobe ellipsoid or back-lobe ellipsoid. The main-lobe ellipsoid is the primary beam that is swept across a target to generate a return signal strong enough to be detected by a threat receiver. One critical factor in successful radar jamming is placing the jamming signal emitted by the EA in a position to enter the threat receiver via the threat antenna while the threat antenna is slewed in the direction of the PE. 
   In addition to the geometric relationship (bearing relationship) of the EA and the PE to the threat emitter system other factors also determine the effectiveness of the threat emitter system. The other factors are the jamming technique and the jamming tactic employed by the EA. Two representative jamming techniques are Preemptive Assignment (PA) and Reactive Assignment (RA). The PA technique is invoked when the threat emitter characteristics and threat emitter location are known before the mission is undertaken. The RA technique is employed when an unexpected threat emitter or threat emitter wave form are encountered during a mission requiring the EA to adapt to the threat. Generally, the PA technique results in Jam Acceptability Region (JAR) contours that are smaller in area and shorter in range relative to the JAR contours associated with the RA technique. A JAR is defined as the family of positions an EA may occupy and still provide effective jamming to protect the PE. The difference in area and range, PA relative to RA, is attributed to the relationship of bandwidth to power. When an EA jams the entire known PA bandwidth for a planned threat emitter lower EA jam power is applied to any specific threat emitter frequency. When the EA detects a threat emitter the RA jamming power may be narrowed into a band focused on the frequency of interest resulting in a JAR that has a larger area and a longer range, relative to the PA JAR. 
   Three representative jamming tactics are associated with three JAR contours, irrespective of activating either a PA or an RA technique. Referring to  FIG. 1 , two dimensional depictions of the three dimensional JAR contours are Out of Alignment (O)  110 , In Side-Lobe Alignment (S)  115  and In Main-Lobe Alignment (I)  120 . The Out of Alignment tactic  110  means the jamming asset can be geographically located anywhere within a hemispherical region centered at the threat emitter and will remain effective in protecting the PE. This is by-far the simplest tactic. The center of JAR  110  represents the location of threat emitter system  160 . A disadvantage of the Out of Alignment tactic is that the EA must be close in range  125  to the threat antenna in order to impart adequate energy to exceed the threat receiver signal to noise ratio, regardless of the direction of arrival of the EA jamming signal. To overcome this range vulnerability the S or I tactic is used. Using either the S or I tactic necessitates maintaining a stringent geometric relationship between the EA and the PE to the threat emitter system. 
   The S tactic results in a conically shaped JAR directly related to the side lobe radiation pattern of the threat emitter antenna. The EA is effective anywhere within JAR  115  provided the EA does not exceed the AS range  135 . 
   Successful jamming of the threat emitter system using the S tactic requires the EA to be within the side-lobe volume of the threat emitter while the main lobe of the threat emitter volume encompasses the PE. While the S tactic increases the standoff range for the EA, relative to the O tactic, the EA is effective only while maintaining the geometric relationship to the PE and to the threat emitter. 
   The I tactic results in a conically shaped JAR directly related to the main lobe radiation pattern of the threat emitter antenna. A two dimensional depiction of the conically shaped JAR contour is depicted in  FIG. 1  item  120 . The EA is effective anywhere within JAR  120  provided the EA does not exceed I range  145 . 
   The I tactic provides an improved EA stand off range from the threat antenna but requires that a stringent geometric relationship be maintained between the EA and PE to the threat antenna. The I tactic requires that the EA and PE are in alignment while the threat antenna main-lobe volume encompasses the PE, hence the narrowness of JAR  120 . 
   Each of the techniques and tactics are combined in all permutations to produce a set of jamming approaches to degrade the performance of the threat emitter system. The jamming approaches are: Preemptive Assignment—Out of Alignment (PAO), Preemptive Assignment—In Side-Lobe Alignment (PAS), Preemptive Assignment—In Main-Lobe Alignment (PAI), Reactive Assignment—Out of Alignment (RAO), Reactive Assignment—In Side-Lobe Alignment (RAS), and Reactive Assignment—In Main-Lobe Alignment (RAI). 
   A given EA jamming approach has a determinable impact upon the threat emitter radar coverage. The JAR represents a volume of space in which the EA may position itself to provide effective jamming to mask the PE or deceive the threat emitter system regarding the true course and speed of the PE. Generating the JAR, assessing jamming effectiveness, determining optimum positioning of the EA and conveying this information to the EA aircrew are objectives of this invention. 
   Referring to  FIG. 2 , JAR volumes for PAO-JAR  250 , PAS-JAR  230  and PAI-JAR  215  are represented as two dimensional JAR areas. A JAR defines an area in which an EA may position itself for a given jamming approach and provide protective jamming to the PE. As PE  205  progresses along its flight path  210 , PAI-JAR  215  and PAS-JAR  230  will remain centered on PE  205 . The EA  240  must maintain its position within PAI-JAR  215  and move along with PAI-JAR  215  while jamming threat emitter system  160  using the PAI jamming approach. Positioning EA  240  in the corner of PAI-JAR  215  places EA  240  farthest from threat emitter system  160 , optimum for EA safety while providing protective jamming. As another example, EA  260  is the sole EA and is positioned outside of JAR contours  250 ,  230  and  215 . EA  260  would be ineffective in jamming threat emitter  160  regardless of the jamming approach employed resulting in threat emitter system  160  detecting and tracking PE  205 . PE  205  is now vulnerable to attack. 
   Optionally, placing the EA  240  within PAS-JAR  230  would enable the PAS jamming approach that would provide adequate protection for PE  205 . It should be noted that the PAS jamming approach would place the EA  240  closer to the threat emitter  160 . 
   Optionally, placing the EA  240  within PAO-JAR  250  would enable the PAO jamming approach that would provide adequate protection for PE  205 . It should be noted that the PAO jamming approach would place the EA  240  even closer to the threat emitter  160 . 
     FIG. 4  is a flowchart describing the software processing steps necessary to generate Jam Assessment displays. After program initialization is complete program execution begins, item  405 . Own aircraft navigational parameters for the PE and the EA are read into memory buffers where the information is used to initialize navigational parameters. The navigational parameters are provided by a designated suite of aircraft equipment specialized to provide latitude, longitude, aircraft attitude, speed and course. An Electronic Order of Battle (EOB) is a an electronic library of information functioning as a database of information related to the characteristics and locations for threat emitter systems likely to be encountered on a given mission, the expected flight path of the PE and the jamming capabilities of the EA. The EOB is generated during the planning phase of a mission and is derived from sources of intelligence specific to the theater of operation. The EOB is downloaded into computer memory residing in the existing suite of aircraft equipment and is made available to the Jam Assessment software program via designated aircraft interfaces and computers. Both the navigational information and the EOB information are used in processing step  410  to determine the PE and EA bearing to the threat emitter and to determine whether the PE lies within the range of the threat emitter system. Processing step  410  is performed with the assumption that the threat emitter is functioning according to the EOB data and the EA is not radiating a jamming signal. 
   Relying on the bearing relationships between the EA and PE to the threat emitter and the maximum range of the threat emitter, the software performs a check  415  to determine if the PE is within the maximum range of the threat emitter. If the PE is not within the range of the threat emitter a no jam required flag is set  420 , the displays are cleared of stale information in step  465 , then step  475  determines program end  480  or directs program control to step  410  for a subsequent iteration. 
   If the PE is within range of the threat emitter, step  425  determines the alignment of the EA, PE and threat emitter. If the result of alignment check  425  is that the EA, PE and threat emitter are in alignment then a flag is set  430  to “I”. If alignment check  425  returns an out of alignment result then a side lobe check is made at step  435 . If the side lobe check  435  result is positive for the PE being within the side lobe then the alignment flag is set to “S”  445 . If the side lobe check  435  is negative the assumption is the EA, PE and threat emitter are Out of alignment and the alignment flag is set to “O”  440 . 
   The software must now determine whether to invoke RA processing or PA processing. The software then checks for activation of RA  450 , a check to determine whether the EA has detected a threat emitter waveform. If the result of RA  450  check is positive, the threat emitter is not in the EOB, then RA processing  455  is called. Refer to  FIG. 5  for a high level flowchart describing RA processing or the detailed description below. If the result of RA  450  check is negative, the threat emitter is in the EOB, then PA processing  460  is called. Refer to  FIG. 6  for a high level flowchart of describing PA processing or the detailed description below. Both RA and PA processing routines return to the same software control point in  FIG. 4 , a call to draw the displays  470 . The displays convey information related to overall EA jamming effectiveness and relative location of the PE and EA to the threat emitter. Step  475  then determines program end  480  or directs program control to step  410  for a subsequent iteration. 
   Referring to  FIG. 4  several flags (steps  440 ,  445  and  430 ) correspond to the alignment of the PE and the threat emitter. These flags are common to RA  455  and to PA  460  processing routines and must be set prior to calling either RA or PA processing routines. 
   Referring to  FIG. 5 , when RA processing is invoked in step  455  ( FIG. 4 ) program flow is routed to step  505  ( FIG. 5 ) and RA processing  505  begins. RA processing determines RAI range  510  by running the Jammer and Tactics Optimization (JATO) power equation 1-1 with the variables and constants set for the RAI jamming approach. RAS range  515  is determined by running JATO power equation 1-1 with the variables and constants set for the RAS jamming approach. RAO range  520  is then determined by running JATO power equation 1-1 with the variables and constants set for the RAO jamming approach. The variable definitions and constants used in equation 1-1 are based on the critical threat attribute parameters residing in the EOB, real time own aircraft navigational information from the PE and EA aircraft and the characteristics of the specific RA jamming approach. 
   The limits of threat emitter coverage, in the presence of jamming, obtained from the JATO power equation yield a JAR contour. The constants and variable definitions for the JATO power equation 1-1 are provided below. 
                   R   max     =       {         P   R     ·     G   RT   2     ·   σ   ·     λ   2     ·     G   m     ·     G   i                   (     4   ⁢   π     )     3     ·       (     S   /   N     )     min     ·     L   RX     ·     L   TX     ·     L   rp     ·                 B   R     ·     [       k   ·   T   ·     N   f       +                         (     λ     4   ⁢   π       )     2     ⁢       ∑     i   =   1     N     ⁢     (           P   J     ·     G   JR     ·     G   RJ           R   J   2     ·     B   J         ·       Δ   ⁢           ⁢   M         L   P     ·     L   J     ·     L   RX           )         ]             }       1   4               JATO   ⁢           ⁢   Equation   ⁢           ⁢   1   ⁢     -     ⁢   1               
where:
 
   R max =Maximum effective range for a threat emitter 
   P R =Receiver Power 
   G RT =Receiver Antenna Gain 
   σ=Radar Cross Section 
   λ=Wavelength 
   G m =Modulation Gain 
   G i =Integration Gain 
   S/N=Signal to Noise Ratio 
   L RX =Receiver Loss 
   L TX =Transmitter Loss 
   Lrp=Receiver Processing Loss 
   B R =Receiver Bandwidth 
   k·T·N f =constant for transmission noise figure 
   P J =Jammer Power 
   G JR =Jammer Receiver Antenna Gain 
   G RJ =Jammer Receiver Gain 
   R J =Range of Jammer 
   B J =Jammer Bandwidth 
   ΔM=Modulation Change 
   L P =Jammer Processing Loss 
   L J =Jammer Loss 
   The accuracy of R max  is dependent upon the accuracy of the critical threat attribute parameters drawn from the EOB, the positional information of the threat emitter system, the positional information of the EA and the EA jamming approach parameters. 
   Equation 1-1 is a variation of the well known radar range equation. Equation 1-1 is invoked for each jamming approach, for each threat emitter, and for changing PE and EA positions. 
     FIG. 5  further describes the steps necessary to assemble a JAS representing the RA-JAR information. The In alignment flag (I) is checked at step  525  ( FIG. 5 ). If the I flag is set then a check  530  is made to determine whether the PE is within the RAI range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to RAI alarm  545 , the JAS color is set to red  550  and the RA routine is exited  598 . If the PE is not within the range of the threat emitter then the Jam flag is set to RAI  540  and the JAS color is set to green  555  and the RA routine is exited  598 . If the I flag was not set then the Side lobe (S) alignment flag is checked  535 . 
   If the S flag is set then a check  565  is made to determine whether the PE is within the RAS range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to RAS alarm  585 , the JAS color is set to red  590  and the RA routine is exited  598 . If the PE is not within the range of the threat emitter then the Jam flag is set to RAS  580  and the JAS color is set to green  595  and the RA routine is exited  598 . 
   If the S flag was not set then the alignment must be Out of alignment (O). A check  560  is made to determine whether the PE is within the RAO range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to RAO alarm  575 , the JAS color is set to red  576  and the RA routine is exited  598 . If the PE is not within the range of the threat emitter then the Jam flag is set to RAO  570  and the JAS color is set to green  571  and the RA routine is exited  598 . 
     FIG. 6  describes the steps necessary to assemble a JAS representing the PA-JAR information. After calculating the PAI range  610 , the PAS range  615  and the PAO range  620  the in alignment flag (I) is checked at step  625 . If the I flag is set then a check  630  is made to determine whether the PE is within the PAI range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to PAI alarm  645 , the JAS color is set to red  650  and the PA routine is exited  698 . If the PE is not within the range of the threat emitter then the Jam flag is set to PAI  640 , the JAS color is set to green  655  and the RA routine is exited  698 . If the I flag was not set then the Side lobe (S) alignment flag is checked  635 . 
   If the S flag is set then a check  665  is made to determine whether the PE is within the PAS range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to PAS alarm  685 , the JAS color is set to red  690  and the PA routine is exited  698 . If the PE is not within the range of the threat emitter then the Jam flag is set to PAS  680  and the JAS color is set to green  695  and the PA routine is exited  698 . 
   If the S flag was not set then the alignment must be Out of alignment (O). A check  660  is made to determine whether the PE is within the PAO range of the threat emitter. If the PE is within range of the threat emitter the Jam flag is set to PAO alarm  675 , the JAS color is set to red  676  and the PA routine is exited  698 . If the PE is not within the range of the threat emitter then the Jam flag is set to PAO  670  and the JAS color is set to green  671  and the PA routine is exited  698 . 
   Referring to  FIG. 4 , RA  455  and PA  460  processing routines return control to the draw display routine  470  providing the information necessary to draw the JAR and the JAS. The information to draw the JAR and JAS is in a format suitable for further processing by the designated aircraft display processor. Once the boundaries of the JAR contours and jamming effectiveness are determined any number of user defined displays may be used to present the information to the EA aircrew. 
   Typical displays are JARs with PE and EA positions plotted with respect to their last known or extrapolated position and a color coded Jam Assessment Strobe (JAS) indicating jamming effectiveness. The length of the JAS represents the maximum effective range for a threat emitter experiencing EA jamming. Each jamming approach (RAO, RAI, RAS, PAO, PAS, PAI) affects the maximum detection range of the emitter adversely. Color coding the JAR contours and JAS is a user preference and is limited by the display processor and the properties of the display hardware residing in the EA aircraft. 
   In the event multiple threat emitters have overlapping coverage the overlap volume can be determined. Refer to  FIG. 3  for a two dimensional representation of the JAR overlap volume for two threat emitters. Threat emitter  160  is associated with JAR  315  while threat emitter  340  is associated with JAR  320 . Each point within every JAR has a three dimensional coordinate corresponding to latitude, longitude and altitude. Using EOB data for azimuth and elevation scan limits, the maximum effective range of emitter coverage, positional information describing the latitude, longitude and altitude for a given threat emitter, allows points in common between multiple JARs to be compared. The comparison of JAR points results in common points between the JARs to be identified and used to define an overlap in threat emitter coverage areas. Plotting EA flight path  210  through the threat emitter coverage allows assessment of the EA position with respect to jamming effectiveness. This method of determining the JAR overlap area can be expanded to include any number of threat emitters having overlapping coverage and is only limited by the processing throughput of the interfaces and computers in the EA aircraft. 
   Referring to  FIG. 7 , segment  710  represents the current effective (Jammed) range, and segment  720  represents the un-jammed range of the threat emitter. The JAS orientation represents the geometric relationship between the PE and the threat emitter. 
   Referring to  FIG. 8 , JAS  810  has a length that passes through PE  205  indicating that PE  205  is within the detection range of the threat emitter. JAS  810  would be color coded to indicate that PE  205  is not vulnerable to attack because jamming is effective.  FIG. 8  represents the scenario in which the EA is effective despite the PE position within the PAI range of the threat emitter. In the event that PE  205  drifts into line segment  820  which results in jamming not being effective, the EA aircrew is prompted to either: maneuver to address the threat, use other tactical options such as change jam techniques, deploy a kinetic weapon, or advise the PE to maneuver further away from the threat. 
   Referring to  FIG. 9 , JAS segment  910  has a length that is short of PE  205  indicating that PE  205  is not within the detection range of the threat emitter. JAS  910  would be color coded to indicate that PE  205  is not vulnerable to attack. 
   Another embodiment of this invention generates a display format as depicted in  FIG. 10 . JAS  1010  and JAS  1020  represents jamming employed by EA  1030  which is positioned in the JAR overlap area of the two threat emitters. In this configuration JAS  1010  and JAS  1020  would be color coded green indicating that PE  205  is not vulnerable to detection by either threat emitter. 
     FIG. 11  depicts another display embodiment combining the JAR and JAS information with the relative positions of EA  1130  and PE  1140 . The explanation for  FIG. 11  is applicable to either the PA or RA jamming technique. Assume EA  1030  is positioned within the In alignment JAR  1120  employing the PAI jamming approach. JAS  1125  calculated for the PAI jamming approach falls short of PE  1140  and would be colored green indicating that PE  1140  is not vulnerable to attack. At a glance the aircrew can determine that PE  1140  is safe from detection by threat emitter  1150  and that EA  1130  could maneuver anywhere within JAR  1120  while employing PAI jamming and remain effective in protecting PE  1140 . Equally important, is the situational awareness that shifting to the PAS jamming approach and maneuvering EA  1130  into JAR  1115  would provide adequate protection for PE  1140 . Equally important is the situational awareness that shifting to PAO jamming and maneuvering into JAR  1110  would also provide protection for PE  1140 .  FIG. 11  provides critical information to the EA aircrew in a format that is easy to understand, is used to ascertain jamming effectiveness and improves the ability to adapt to changing conditions. The capability to assess jam effectiveness as described in the preferred embodiment fills a need unmet by the current aircraft displays. 
   Providing information to the EA aircrew related to detected threat emitters not currently assigned a jamming approach is critical to overall situational awareness.  FIG. 12  represents the scenario in which threat emitter  1250  has been defined by the EA  1230  and an assessment of PE  1220  vulnerability has been made along flight path  1240 . At this point threat emitter  1250  has not been assigned a jamming approach, as indicated by the dashed segment  1260 . At a glance, EA  1230  is able to determine that threat emitter  1250  is a threat that requires EA  1230  jamming or that flight path  1240  needs to be altered to avoid detection. 
   The aircrew controls the display format posted by the aircraft display processor via designated aircraft interfaces. Depending on the need, the aircrew display options include the JAR contours, the JAS or a combined JAR JAS display format. The software algorithm and method described above is suitable for implementation upon any number of electronic warfare systems and architectures. It is not necessary to limit the implementation of the preferred embodiment to currently existing aircraft computers, aircraft interfaces or electronic warfare capabilities.