Patent Publication Number: US-11024181-B2

Title: Systems and methods for generating avionic displays including forecast overpressure event symbology

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/235,923, filed with the United Stated Patent and Trademark Office (USPTO) on Dec. 28, 2018, now U.S. Pat. No. 10,720,064, which is a continuation of U.S. application Ser. No. 15/798,692, filed with the United Stated Patent and Trademark Office (USPTO) on Oct. 31, 2017, now U.S. Pat. No. 10,209,122. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with Government support under Contract No. 7016372654 awarded by NASA. The Government has certain rights in the invention. 
    
    
     TECHNICAL FIELD 
     The following disclosure relates generally to avionic display systems and, more particularly, to systems and methods for generating avionic displays including symbology and other graphics pertaining to overpressure events forecast to occur during supersonic aircraft flight. 
     ABBREVIATIONS 
     Abbreviations appearing relatively infrequently in this document are defined upon initial usage, while abbreviations appearing more frequently in this document are defined below. 
     A/C—Aircraft; 
     AGL—Above Ground Level; 
     ATC—Air Traffic Controller; 
     FMS—Flight Management System; 
     HDD—Head Down Display; 
     HNAV—Horizontal Navigation; 
     HUD—Head Up Display; 
     PFD—Primary Flight Display; 
     UAV—Unmanned Aerial Vehicle; and 
     VNAV—Vertical Navigation. 
     BACKGROUND 
     Regulatory authorities currently restrict over-land supersonic flight of civilian A/C throughout much of the populated world. In the United States, for example, current Federal Aviation Administration (FAA) regulations prohibit supersonic flight of civilian A/C over land. Such restrictions are generally motived by noise abatement rationale and a desire to protect ground structures, such as building windows, from damage due to the pressure waves generated during supersonic air travel. These concerns notwithstanding, regulatory authorities have indicated that existing supersonic over-land flight restrictions might soon be eased, within certain limits. Industry attention has thus turned to the development and production of so-called “low boom” A/C suitable for service as commercial airliners or passenger jets operable at lower Mach speeds. As industry efforts increasingly focus on the development of low boom A/C, a corresponding demand arises for the development of tools and systems supporting civilian A/C engaged in supersonic flight, while ensuring adequate control of the pressure waves and noise levels produced by such supersonic air travel. 
     BRIEF SUMMARY 
     Avionic display systems are provided for generating avionic displays, which include symbology and other graphics pertaining to forecast overpressure events. In embodiments, the avionic display system includes a display device on which an avionic display, such as an HNAV or VNAV display, is produced. A controller architecture is operably coupled to the display device. Storage media contains computer-readable code or instructions that, when executed by the controller architecture, cause the avionic display system to determine whether an overpressure event is forecast due to the anticipated future occurrence of a sonic boom, which is predicted to have a magnitude exceeding a boom tolerance threshold. When the controller architecture determines that an overpressure event is forecast to occur, the avionic display system further generates symbology on the avionic display indicative of the forecast overpressure event. Such symbology may visually denote various characteristics relating to the forecasting overpressure event, such as the projected origin and/or a projected ground strike location of the sonic boom predicted to trigger the forecast overpressure event. 
     In further embodiments, the avionic display system includes a display device, a controller architecture operably coupled to the display device, and storage media containing computer-readable instructions or code. When executed by the controller architecture, the computer-readable instructions cause the avionic display system to repeatedly determine flight parameter margins enabling an A/C to travel at supersonic speeds, while avoiding the generation of a sonic boom having a magnitude exceeding a boom tolerance threshold. The avionic display system further generates graphics on the avionic display, which visually express or convey the flight parameter margins. The flight parameter margins can include, for example, minimum altitudes and/or maximum speeds at which the A/C can travel without triggering a sonic boom having a magnitude exceeding the boom tolerance threshold. The avionic display system may determine the flight parameter margins through independent calculations, by retrieval of the flight parameter margins from a remote source (e.g., a cloud-based forecasting service) in wireless communication with the display system, or utilizing a combination of these approaches. 
     Computer-implemented methods are further provided for generating avionic displays including symbology indicative of forecast overpressure events. Embodiments of the method may be carried-out by an avionic display system including a controller architecture and an avionic display. In implementations, the method includes the step or process of generating at least one avionic display, such as an HNAV or VNAV display, on the avionic display device. Utilizing the controller architecture, it is determined whether an overpressure event is forecast to occur during impending supersonic A/C flight due to the generation of a sonic boom having a magnitude exceeding a boom tolerance threshold. When determining that an overpressure event is forecast to occur, symbology is generated on the avionic display indicative of the forecast overpressure event. As stated above, such symbology may visually denote the projected origin and/or a projected ground strike location of the sonic boom predicted to trigger a particular overpressure event. Various other graphics, such as suggested preemptive actions suitably performed by an A/C to avert the occurrence of a forecast overpressure event, can also be presented on the avionic display in at least some instances. 
     The methods set-forth above and described elsewhere in this document can be implemented utilizing program products, such as software applications executed on suitably-equipped avionic display systems and disseminated in any suitable manner. Various additional examples, aspects, and other useful features of embodiments of the present disclosure will also become apparent to one of ordinary skill in the relevant industry given the additional description provided below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       At least one example of the present invention will hereinafter be described in conjunction with the following figures, wherein like numerals denote like elements, and: 
         FIG. 1  is a block diagram of an avionic display system, which generates one or more avionic displays to selectively include forecast overpressure event symbology, as illustrated in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 2  is a flowchart of a process usefully carried-out by the avionic display system shown in  FIG. 1  in generating one or more avionic displays to include forecast overpressure event symbology, as further illustrated in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 3  is a screenshot of an exemplary HNAV display including forecast overpressure event symbology, which may be generated by the avionic display system of  FIG. 1  when implementing the process set-forth in  FIG. 2 ; 
         FIG. 4  is a screenshot of an exemplary VNAV display, which likewise includes forecast overpressure event symbology and which may be generated by the avionic display system in addition to or in lieu of the HNAV display shown in  FIG. 3 ; and 
         FIG. 5  illustrates an exemplary hierarchy of advisory messages, which can be selectively presented on one or more of the avionic displays generated by the avionic display system shown in  FIG. 1  to provide suggested actions to avert the occurrence of forecast overpressure events. 
     
    
    
     For simplicity and clarity of illustration, descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the exemplary and non-limiting embodiments of the invention described in the subsequent Detailed Description. It should further be understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise stated. 
     DETAILED DESCRIPTION 
     The following Detailed Description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. The term “exemplary,” as appearing throughout this document, is synonymous with the term “example” and is utilized repeatedly below to emphasize that the description appearing in the following section merely provides multiple non-limiting examples of the invention and should not be construed to restrict the scope of the invention, as set-out in the Claims, in any respect. 
     As appearing herein, the term “avionic display” refers to a computer-generated display or imagery, which depicts the flight environment of at least one A/C. Similarly, the term “avionic display system” refers to a system that generates at least one avionic display (as previously defined) during system operation. Generally, then, the term “avionic” may be regarded as synonymous with the term “aircraft-related” in the present context. The usage of the term “avionic” thus does not require that the avionic display system is deployed onboard an A/C in all instances. Indeed, in many implementations, some or all of the components contained in the avionic display system will not be located onboard an A/C. This may be the case when, for example, the avionic display system is utilized to pilot a UAV and certain components of the display system are located within the facility from which the UAV is controlled. This may also be the case when the avionic display system is utilized in directing or managing supersonic air traffic, in which case the display system may be situated within a control tower, an ATC facility, or another non-A/C location. 
     Overview 
     The following provides avionic display systems and methods for producing avionic displays including symbology pertaining to forecast overpressure events; that is, events or instances during which impending supersonic A/C flight is predicted to cause a sonic boom having a magnitude exceeding a boom tolerance threshold. When an overpressure event is forecast to occur, the avionic display system generates symbology on one or more avionic displays indicative of the forecast overpressure event. The symbology may visually identify the origin of a sonic boom, which is predicted to occur and ultimately trigger a forecast overpressure event. Additionally or alternatively, the forecast overpressure event symbology may identify a ground strike location of the forecast overpressure event; that is, a geographical location at which the sonic boom driving the overpressure event is projected to impact the earth (ground or water) generally located beneath the A/C engaged in supersonic flight. If desired, such symbology can be visually coded to indicate a projected severity of a forecast overpressure event as based upon, for example, an estimated disparity between the boom tolerance threshold and a magnitude of the sonic boom predicted to cause the overpressure event. Other graphics can also be generated on the avionic display(s) in conjunction with such forecast overpressure event symbology. For example, in embodiments, the avionic display system may also identify and present suggested preemptive actions, which can be implemented to avert the occurrence of forecast overpressure events. 
     In certain embodiments, the boom tolerance threshold may have a single value, which is universally applied in determining whether a predicted sonic boom will trigger an overpressure event regardless of the particular characteristics of the sonic boom under consideration. In other embodiments, the boom tolerance threshold may have a variable value, which is varied by the avionic display system based upon one or more characteristics of a predicted sonic boom. For example, in such embodiments, the avionic display system may assign a particular value to the boom tolerance threshold based upon a geographical location at which a sonic boom is predicted to originate or at which the sonic boom is projected to impact the earth (ground or water). By actively varying the value of the sonic boom threshold in this manner, sonic booms having greater intensities (e.g., higher peak pressure and decibel levels) may be permitted within certain (e.g., relatively unpopulated) geographical regions; while only low intensity sonic booms are tolerated in other (e.g., densely populated) geographical regions, if sonic booms are permitted in such regions at all. If desired, various other criteria can further be considered by the avionic display system in assigning values to the boom tolerance threshold including, for example, the time-of-day at which a particular sonic boom is predicted to occur. 
     In further implementations, the avionic display system may establish flight parameter margins at which an A/C can travel at supersonic speeds without triggering or inducing an overpressure event. The flight parameters can include, for example, minimum altitudes and/or maximum speeds at which the A/C can fly without causing an overpressure event. The avionic display system may establish such flight parameters by independent calculation or instead by retrieving the flight parameters from a remote source, such as a cloud-based forecasting service, dedicated to performing relatively complex sonic boom forecasting algorithms. The avionic display system may then visually convey the flight parameter margins on one or more avionic displays. As one possibility, the maximum speeds suitably flown by an A/C without triggering an overpressure event can be indicated at selected junctures or intervals along the projected flight path of the A/C by numerical readouts generated on an HNAV display, a VNAV display, or other avionic display. Comparatively, the minimum AGL altitudes suitably flown by the A/C without triggering an overpressure event may be expressed as visual markers (e.g., connected line segments) generated on a VNAV display. 
     By selectively generating one or more avionic displays to include forecast overpressure event symbology and/or other related graphics in the above-described manner, embodiments of the avionic display system can enhance the situational awareness of decision makers, such as pilots and ATC personnel members, responsible for piloting and managing A/C engaged in supersonic flight. Imparted with this awareness, the decision makers can then perform those actions appropriate to avert forecast overpressure events that may otherwise occur during supersonic A/C flight; or, in certain instances, to lessen the severity of overpressure events that cannot otherwise be averted. A reduction in the rate at which overpressure events occur can therefore be realized, even as regulatory restrictions governing the supersonic flight of civilization A/C over land are potentially relaxed or eased. This is highly desirable. An exemplary embodiment of an avionic display system suitable for generating forecast overpressure event symbology will now be described in conjunction with  FIG. 1 . 
     Example of Avionic Display System Suitable for Generating Avionic Display(s) Including Forecast Overpressure Event Symbology 
       FIG. 1  is a block diagram of an avionic display system  10 , as illustrated in accordance with an exemplary and non-limiting embodiment of the present disclosure. As schematically shown, avionic display system  10  includes the following components or subsystems, each of which may assume the form of a single device or multiple interconnected devices: (i) a controller architecture  12 , (ii) at least one avionic display device  14 , (iii) computer-readable storage media or memory  16 , and (iv) a user input interface  18 . In embodiments in which avionic display system  10  is utilized to pilot an A/C, avionic display system  10  may further contain a number of ownship data sources  22  including, for example, an array of flight parameter sensors  24 . Finally, avionic display system  10  can contain a datalink subsystem  26  including an antenna  28 , which may wirelessly transmit data to and/or receive data from various sources external to display system  10 . Such external sources can include, for example, ATC stations, nearby A/C, weather forecasting services, and remotely-located sonic boom forecasting services, to list but a few examples. In other embodiments, such as when display system  10  is utilized in directing or managing supersonic air traffic, avionic display system  10  may not contain ownship data sources  22 , as indicated in  FIG. 1  by the usage of phantom line. 
     When avionic display system  10  is utilized to pilot a manned A/C or “ownship A/C,” the various components contained within display system  10  may be deployed onboard the ownship A/C. Comparatively, in embodiments in which avionic display system  10  is utilized to pilot a remotely-controlled UAV, certain components of avionic display system  10  may be carried by the UAV, while other components may be situated at the ground-based station or other facility from which the UAV is remotely piloted. For example, in such implementations, avionic display device(s)  14 , user input interface  18 , and some or all of the storage media contained in memory  16  may be located offboard the UAV. Finally, when utilized to direct or to manage supersonic air traffic (rather than in directly piloting an A/C), avionic display system  10  may not be deployed onboard an A/C, but rather situated in a control tower, in a ground-based ATC station, or in another location. 
     Generally, controller architecture  12  includes at least first, second, third, and fourth inputs, which are operatively coupled to user input interface  18 , to memory  16 , to ownship data sources  22  (when present), and to datalink subsystem  26 , respectively. Controller architecture  12  also includes at least first, second, and third outputs, which are operatively coupled to avionic display device(s)  14 , to memory  16 , and to datalink subsystem  26 , respectively. In further embodiments, avionic display system  10  may include a greater or lesser number of components, which may be interconnected in other manners utilizing any combination of wireless or hardline (e.g., avionic bus) connections. Although avionic display system  10  is schematically illustrated in  FIG. 1  as a single unit, the individual elements and components of avionic display system  10  can be implemented in a distributed manner using any number of physically-distinct and operatively-interconnected pieces of hardware or equipment. Similarly, user input interface  18  can include various different types of hardware or software components, such as touchscreen devices, cursor devices, keyboards, voice recognition modules, and the like, suitable for recognizing input received from a pilot, an ATC personnel member, or other user of avionic display system  10 . 
     Avionic display device(s)  14  can include any number and type of image generating devices. When avionic display system  10  is utilized to pilot a manned A/C, avionic display device(s)  14  may be affixed to the static structure of the A/C cockpit as, for example, one or more HDD or HUD units. Alternatively, in such embodiments, avionic display device(s)  14  may be a movable display device (e.g., a pilot-worn display device) or a portable display device, such as an Electronic Flight Bag (EFB), a laptop, or a tablet computer, which is carried into the cockpit of the manned A/C by a pilot or other aircrew member. Similarly, when avionic display system  10  is utilized to pilot a UAV, display device(s)  14  may be realized as one or more HDD or HUD units affixed to the static structure of a control facility, portable electronic device(s) carried into such a control facility, or movable display devices worn by a pilot when remotely operating the UAV. Finally, when avionic display system  10  is utilized to direct or manage supersonic air traffic, display device(s)  14  can be realized as one or more HDD display units, HUD display units, portable electronic devices, or head-worn display devices. 
     Controller architecture  12  can encompass or be associated with one or more processors, flight control computers, navigational equipment pieces, computer-readable memories (including or in addition to memory  16 ), power supplies, storage devices, interface cards, and other standardized components. Controller architecture  12  may also include or cooperate with any number of firmware and software programs or computer-readable instructions designed to carry-out the various process tasks, calculations, and control/display functions described herein. Although illustrated as a separate block in  FIG. 1 , memory  16  may be integrated into controller architecture  12  in embodiments as, for example, a system-in-package, a system-on-a-chip, or another type of microelectronic package or module. Controller architecture  12  may also exchange data with one or more external sources, such as a cloud-based forecasting service of the type described below, in various embodiments of avionic display system  10 . In this case, bidirectional wireless data exchange may occur over a communications network, such as a public or private network implemented in accordance with Transmission Control Protocol/Internet Protocol architectures or other conventional protocols. Encryption and mutual authentication techniques may be applied, as appropriate, to ensure data security. 
     Memory  16  can encompass any number and type of storage media suitable for storing computer-readable code or instructions, as well as other data utilized to support the operation of avionic display system  10 . In embodiments, memory  16  may store one or more local databases  30 , such as geographical (terrain), runway, navigational, and historical weather databases. Such local databases  30  are beneficially updated on a periodic basis to maintain data timeliness; and, in embodiments in which display system  10  is utilized to pilot a manned A/C, the databases maintained in memory  16  may be shared by other systems onboard the A/C, such as an Enhanced Ground Proximity Warning System (EGPWS) or a Runway Awareness and Advisory System (RAAS). In other cases, one or more of databases  30  may be maintained by an external entity, such as a cloud-based forecasting service, which can be accessed by controller architecture  12  on an as-needed basis. As generically represented in  FIG. 1  by box  32 , memory  16  may further store one or more values associated with the below-described boom tolerance threshold. Finally, one or more A/C-specific sonic boom profiles may be stored within memory  16 ; e.g., in embodiments in which display system  10  is utilized to pilot a UAV or a manned A/C, memory  16  may store a sonic boom profile specific to an A/C on which display system  10  is deployed. 
     As previously mentioned, ownship data sources  22  may include a constellation of flight parameter sensors  24  in implementations in which display system  10  is utilized for piloting purposes. When present, flight parameter sensors  22  supply various types of data or measurements to controller architecture  12  recorded or captured during A/C flight. Such data can include without limitation: initial reference system measurements, Flight Path Angle (FPA) measurements, airspeed data, groundspeed data, altitude data, attitude data including pitch data and roll measurements, yaw data, data related to A/C weight, time/date information, heading information, data related to atmospheric conditions, flight path data, flight track data, radar altitude data, geometric altitude data, wind speed and direction data, and fuel consumption data. Further, in such embodiments, controller architecture  12  and the other components of avionic display system  10  may be included within or cooperate with any number and type of systems commonly deployed onboard A/C including, for example, an FMS, an Attitude Heading Reference System (AHRS), an Instrument Landing System (ILS), and an Inertial Reference System (IRS), to list but a few examples. 
     During operation, avionic display system  10  generates one or more avionic displays on avionic display device(s)  14 . For example, as schematically indicated in  FIG. 1 , avionic display system  10  may generate a horizontal navigation display  34  on avionic display device(s)  14 . As appearing herein, the term “horizontal navigation display” or, more succinctly, “HNAV display” refers to an avionic display presented from a top-down or planform viewpoint. In addition to or in lieu of HNAV display  34 , at least one vertical navigation display  36  may be generated on avionic display device(s)  14  in at least some embodiments; the term “vertical navigation display” or “VNAV display” referring to an avionic display presented from a side or lateral viewpoint (also commonly referred to as a “vertical situation display”). In many implementations, avionic display system  10  may generate displays  34 ,  36  concurrently. For example, in this case, displays  34 ,  36  may be presented on separate screens of multiple avionic display devices  14  or, instead, on a single screen of one display device  14  in a picture-in-picture or side-by-side format. In other implementations, avionic display system  10  may only generate one of HNAV display  34  and VNAV display  36  at a given time and/or display system  10  may generate a different type of avionic display, as discussed below. 
     The foregoing paragraph and the following description focus primarily on the generation of forecast overpressure event symbology (and other related graphics) in the context of certain two dimensional (2D) avionic displays, such as HNAV display  34  and VNAV display  36  schematically shown in  FIG. 1  and further discussed below in conjunction with  FIGS. 3-4 . This notwithstanding, it will be appreciated that the forecast overpressure event symbology (and the other related graphics described herein) can be generated on any type of avionic display or displays, which depict the flight environment of at least one A/C. For example, in alternative embodiments, the forecast overpressure event symbology may be generated on one or more 3D avionic displays, such as a PFD or an exocentric 3D avionic display, in addition or in lieu of one or more 2D avionic displays. To help emphasize this possibility, avionic display system  10  is further illustrated to include an “other” avionic display block  37  contained within avionic display device(s) block  14  in  FIG. 1 . An exemplary method, which can be performed by avionic display system  10  in generating one or more of avionic displays  34 ,  36 ,  37  to selectively include forecast overpressure event symbology, will now be described in conjunction with  FIG. 2 . 
     Exemplary Method for Generating Avionic Display(s) Including Forecast Overpressure Event Symbology 
       FIG. 2  is a flowchart setting-forth an exemplary computer-implemented method  40 , which can be performed by avionic display system  10  ( FIG. 1 ) to selectively generate forecast overpressure event symbology on one or more of avionic displays  34 ,  36 ,  37  ( FIG. 1 ). In the illustrated example, method  40  includes a number of computer-implemented functions or process steps identified as STEPS  42 ,  44 ,  46 ,  48 ,  50 ,  52 ,  54 . Depending upon the particular manner in which method  40  is implemented, each process step generally illustrated in  FIG. 2  may entail a single process or multiple sub-processes. The illustrated process steps are provided by way of non-limiting example only. In alternative embodiments, additional process steps may be performed, certain steps may be omitted, and/or the illustrated steps may be performed in alternative sequences. 
     Referring jointly to  FIGS. 1-2 , computer-implemented method  40  commences at STEP  42  ( FIG. 2 ). In some embodiments, method  40  commences upon system startup and is then performed on a repeated or iterative basis until system shutdown. In other embodiments, method  40  may commence in response to input, such as pilot or ATC personnel input, entered via user input interface  18 . In still other embodiments, method  40  can commence in response to the occurrence of a predetermined trigger event. For example, when avionic display system  10  is utilized for piloting an A/C, method  40  may automatically commence (that is, initiate without requiring additional user input) when the A/C surpasses a predetermined speed threshold. The predetermined speed threshold can be, for example, slightly below or above Mach 1 or a predetermined airspeed threshold; here, noting that any such airspeed threshold may be varied as a function of meteorological conditions affecting the speed at which sound or pressure waves propagate through the ambient environment. Following commencement, method  40  may then be performed iteratively on a relatively rapid (e.g., real-time) basis until termination. 
     At STEP  44  of method  40 , data utilized in generation the avionic display(s) is gathered. When avionic display system  10  is utilized for piloting purposes, sensor data from ownship data sources  22  may be collected; e.g., data may be received from flight parameter sensors  24  and/or extracted from other systems carried by the A/C, such as an FMS. Stored data may also be recalled from one or more local databases  30  during STEP  44 . Such data can include, for example, historical meteorological conditions, relevant terrain information, and/or appropriate values to assign to the boom tolerance threshold. Embodiments of avionic display system  10  can also gather data from any number of external sources during STEP  44  of method  40 . The particular external sources from which such data is gathered will vary amongst embodiments depending upon, for example, whether display system  10  is utilized to pilot an A/C or to direct supersonic air traffic. Generally, however, avionic display system  10  may gather data from weather forecasting services, from other A/C traveling through or scheduled to travel through a particular airspace, and/or from a remote sonic boom forecasting service of the type described below. After collecting the pertinent data, avionic display system  10  then updates the avionic display(s) accordingly. 
     Next, at STEP  46  of method  40 , avionic display system  10  determines whether a sonic boom is forecast to occur during the supersonic flight of one or more A/C, as projected into a future timeframe. Avionic display system  10  renders this determination utilizing sonic boom forecast data. Such sonic boom forecast data usefully indicates, expressly or implicitly, whether the impending supersonic flight of one or more A/C is likely to generate sonic pressure waves or “sonic booms” within certain confidence thresholds; and, if so, further indicates the projected locations and intensities of such sonic boom predictions. As a more specific example, the sonic boom forecast data may contain time-phased data specifying the anticipated locations, spread, and intensities of pressure waves resulting from sonic boom predictions, as mapped across three dimensional airspace. As a point of emphasis, the sonic boom forecast data can be generated utilizing any suitable algorithms or processes, which are carried-out by avionic display system  10  itself, by another entity in communication with display system  10 , or a combination thereof. For example, in certain implementations, avionic display system  10  outsources the generation of sonic boom forecast data to a remote entity dedicated to performing such algorithms, such as a cloud-based forecasting service or server farm. In this manner, relatively complex, computationally-intensive forecasting algorithms are thus advantageously performed by the remote external entity to increase the speed and accuracy with which the sonic boom forecast data is generated, while processing demands placed on controller architecture  12  are reduced. In other embodiments, avionic display system  10  may independently generate the sonic boom forecast data, in whole or in part, when carrying-out method  40 . 
     The sonic boom forecasting algorithms can consider a relatively comprehensive range of static and dynamic inputs in generating the sonic boom forecasting data. Meteorological conditions impacting the propagation of sonic pressure waves through the ambient environment are usefully considered, including current wind speeds and directions, air temperatures, humidity levels, and information regarding the presence of rain, sleet, snow, or other precipitation. Data regarding current meteorological conditions may be extracted from XM weather broadcasts or similar reports transmitted by dedicated weather forecast services. Additionally or alternatively, measurements of current meteorological conditions can be obtained from flight parameter sensors  24  when included within display system  10 . 
     The sonic boom forecasting algorithms further consider the predicted future flight parameters of one or more A/C. A non-exhaustive list of such flight parameters include the FPA, speed, and location (longitude, latitude, and altitude) of at least one A/C, which is presently engaged in or which is anticipated to engage in supersonic flight. Such future A/C flight parameters may be extrapolated from current A/C flight parameters or, perhaps, derived from flight plan information extracted from an FMS or other onboard system. In one approach, the supersonic flight of a given A/C is predicted based upon the current flight vector data and flight trends of the A/C; e.g., the time-correlated position and supersonic speed of the A/C may be extrapolated into a future timeframe based upon the current speed, attitude, direction, and FPA of the A/C. Further, when avionic display system  10  is located offboard an A/C, in whole or in part, such data may be transmitted to display system  10  from an A/C. For example, when avionic display system  10  is utilized for air traffic management, flight plan information and/or other relevant data pertaining to one or more A/C may be provided to display system  10  as Automatic Dependent Surveillance-Broadcast (ADS-B) transmissions or other data transmissions. 
     In certain embodiments, A/C-specific sonic boom profiles are further taken into account when generating or interpreting the sonic boom forecast data. Generally, an A/C-specific sonic boom profile provides an approximation of the three dimensional pressure wave shape created by a particular A/C when engaged in supersonic flight. The sonic boom profile for a particular A/C may be determined upon the physical characteristics of the A/C, such as shape, weight class, and engine type. In embodiments, avionic display system  10  may store one or more A/C-specific sonic boom profiles in memory  16  and recall such profiles during the course of method  40 , when needed. In one implementation, avionic display system  10  may store a sonic boom profile specific to the ownship A/C in memory  16  and then recall this sonic boom profile when independently performing onboard forecasting algorithms. Alternatively, controller architecture  12  may recall and transmit the A/C-specific sonic boom profile, along with other pertinent data (e.g., current flight vector data and/or flight plan information) to a remote entity for consideration when carry-out the sonic boom forecasting algorithms utilized to generate the sonic boom forecast data. 
     Advancing to STEP  46  of method  40 , avionic display system  10  next analyzes the recently obtained sonic boom forecast data to determine whether a sonic boom is forecast to occur during impending A/C flight. If the sonic boom forecast data does not portend the occurrence of a sonic boom, avionic display system  10  returns to STEP  44  of method  40  and the above-described process steps repeat. Conversely, if a sonic boom is forecast to occur, avionic display system  10  progresses to STEP  48  of method  40 . At STEP  48 , avionic display system  10  determines whether a reference magnitude (e.g., a pressure or decibel level) of the predicted sonic boom exceeds the corresponding boom tolerance threshold and, therefore, whether an overpressure event is forecast to occur. The reference magnitude of the forecast sonic boom may be the maximum or peak magnitude of the sonic boom, considered in its entirety. Alternatively, the reference magnitude of the forecast sonic boom may be an estimated pressure or decibel level taken at a particular location encompassed by a sonic boom prediction, such as the pressure or decibel level taken at the projected origin of the sonic boom or at a location at which the sonic boom is projected to strike the earth. This latter approach may be particularly beneficial as it will typically better estimate the impact of the sonic boom on human populations, manmade structures, and other ground-based items in proximity of the overpressure event. 
     In determining whether an overpressure event is forecast to occur due to the future anticipated occurrence of a sonic boom, avionic display system  10  assigns a value to the boom tolerance threshold for comparison purposes. In certain implementations, a single or universal boom tolerance threshold value may be assigned to the boom tolerance threshold, stored in memory  16 , and recalled by controller architecture  12  during STEP  48  of method  40 . In such implementations, avionic display system  10  may utilize the same boom tolerance threshold in evaluating all predicted sonic booms, regardless of the particular characteristics of a given sonic boom prediction. While a single value is assigned to the sonic boom threshold in such embodiments, avionic display system  10  may allow the value of the boom tolerance threshold to be modified through software updates, pilot input, by ATC communications, or in another manner. In other implementations, the boom tolerance threshold may have a dynamic or variable value, which is actively modified or varied by avionic display system  10  as a function of one or more parameters relating to a particular forecast overpressure event. In this latter case, memory  16  may store a range of boom tolerance threshold values differentiated by or corresponding to varying geographical zones, to varying times of day, or to other differentiating factors. 
     In embodiments in which memory  16  stores multiple values for the boom tolerance threshold, the boom tolerance threshold values are usefully georeferenced; that is, differentiated by geographical location or region. By actively varying the value of the sonic boom threshold in relation to geographical region, more intensive sonic booms (that is, sonic booms having greater pressures or decibel levels) may be permitted within certain geographical regions, such as those that are relatively unpopulated; while only sonic booms of relatively low intensities may be permitted in other geographical regions, such as those that are densely populated, or sonic booms may be strictly banned in such regions. Furthermore, such georeferenced values can be varied as a function of local or regional noise abatement regulations, political boundaries, the type and vulnerability of manmade structures within a region to pressure wave damage, proximity to land if a sonic boom is forecast to occur over water, and various other parameters. Other characteristics pertaining to predicted sonic booms and, specifically, overpressure events can further be utilized in differentiating amongst boom tolerance threshold values in embodiments. For example, the values assigned to boom tolerance threshold are usefully varied based upon the time-of-day at which a particular sonic boom is predicted to occur; e.g., in this latter regard, higher (more permissive) values may be assigned to the boom tolerance threshold during waking hours, while lower (more stringent) threshold values may apply at times during which local populations are largely asleep and, therefore, prone to disturbance by excessively loud sonic booms. 
     In the above-described manner, avionic display system  10  determines whether the reference magnitude of any sonic boom prediction(s) remain below a corresponding boom tolerance threshold and, therefore, whether an overpressure event is forecast to occur. If determining that a sonic boom is forecast to occur, but is not predicted to drive or induce an overpressure event, avionic display system  10  advances to STEP  50  of method  40 . At this step, avionic display system  10  may or may not generate symbology representative of the predicted sonic boom on one or more avionic display(s). In certain instances, relatively inconspicuous or non-obtrusive symbology may be generated on at least one of avionic displays  34 ,  36 ,  37  to inform a pilot, ATC personnel member, or other viewer of the impending sonic booms, while concurrently indicating that the sonic boom predictions are in compliance with their corresponding boom tolerance thresholds. Such symbology can be relatively small in size or color coded to a pre-established informational color (e.g., white or green) to provide the desired advisory function, without distracting from higher level information presented on displays  34 ,  36 ,  37 . Alternatively, in other embodiments, symbology representative of such conforming sonic booms may not be expressed on avionic displays  34 ,  36 ,  37  to declutter the avionic display(s). Afterwards, avionic display system  10  returns to STEP  44  of method  40 , and the above-described process steps repeat. 
     If, during STEP  48  of method  40 , avionic display system  10  instead determines that a sonic boom is predicted both to occur and to trigger an overpressure event, avionic display system  10  generates symbology on one or more avionic displays indicative of the forecast overpressure event (STEP  52 ). Avionic display system  10  may generate the overpressure event symbology on any combination of avionic displays  34 ,  36 ,  37  in a manner visually signifying the forecast overpressure event. Such symbology usefully provides a visual indication of the ground strike location(s) of the impending sonic boom predicted to cause an overpressure event, the origin of the sonic boom or overpressure event, and/or other relevant parameters related to the forecast overpressure event. Examples of such symbology are discussed more fully below in conjunction with  FIGS. 3-4 . Furthermore, as indicated at STEP  54  of method  40 , avionic display system  10  may also determine whether any preemptive actions or navigational solutions are available to the pertinent A/C to avert the forecast overpressure event. If found, any such preemptive actions or navigational solutions may also be presented on one or more of avionic displays  34 ,  36 ,  37 . Examples of such preemptive actions are further discussed below in conjunction with  FIGS. 3-5 . Afterwards, avionic display system  10  returns to STEP  44 , and method  40  loops. 
     Examples of Avionic Displays Including Forecast Overpressure Event Symbology 
       FIG. 3  is a screenshot of a HNAV display  34 , which may be generated on avionic display device  14  by avionic display system  10  ( FIG. 1 ) in an exemplary embodiment of the present disclosure. As can be seen, HNAV display  34  has a field-of-view (FOV) encompassing a geographical region represented by synthetic terrain  56 . An A/C icon  58  appears on HNAV display  34  and indicates the current horizontal position (latitude and longitude) of the A/C under consideration, which may be the ownship A/C when avionic display system  10  is utilized for piloting purposes. The rotational orientation or clocking of A/C icon  58  denotes the current heading of the A/C, as visually emphasized by compass graphic  70  located adjacent icon  58 . A horizontal multi-leg flight route graphic  60 ,  62  is also generated HNAV display  34  and indicates the planned flight route of the A/C. In this particular example, flight route graphic  60 ,  62  includes two legs as represented by connected line segments  60 ,  62 . Line segment  60  extends from a first waypoint marker  64  (DIRECT) to a second waypoint marker  66  (TRM), while line segment  62  extends from waypoint marker  66  (TRM) to a third waypoint marker  68  (TOD). Avionic display system  10  may generated HNAV display  34  to further contain various other symbols or graphics conveying pertinent information, as desired; e.g., as further shown in  FIG. 3 , HNAV display  34  may also include a range ring  72  to provide a sense of scale. 
     Further presented on HNAV display  34  are three symbols  74 ,  76 ,  78 , which visually signify overpressure events. Specifically, symbols  74 ,  76  are representative of an overpressure event that is forecast to occur in the immediate future or, perhaps, an overpressure event that is presently occurring. Symbol  74  may represent the beginning of the overpressure event (that is, the occurrence of the initial sonic boom underlying the overpressure event), while symbol  76  may represent the predicted conclusion of the overpressure event. Comparatively, symbol  78 , which appears in the lower right corner of HNAV display  34 , represents an overpressure event projected to occur in the more distant future, absent the performance of preemptive actions on behalf of the A/C represented by icon  58 . Symbols  74 ,  78  may be positioned at locations representative of the origin of the sonic booms, as taken along the flight path of the A/C. In other embodiments, symbols  74 ,  78  may be positioned at ground strike locations associated with the sonic booms; and/or other graphics may be produced on HNAV display  34  indicative of the geographical locations at which the sonic booms or overpressure events are projected to impinge the earth. For example, in this latter regard, shading or a similar visual effect can be applied to selected regions of synthetic terrain  56  to identify the swath or region of land anticipated to be affected by an overpressure event. 
     The appearance of symbols  74 ,  76 ,  78  will vary amongst embodiments. As can be seen, in the example of  FIG. 3 , symbols  74 ,  76 ,  78  are generated as parabolic shapes or markers having geometries suggestive of pressure waves, as seen in two dimensions. If desired, symbols  74 ,  76 ,  78  can be visually coded to provide additional information useful in evaluating any forecast overpressure events. For example, as indicated in  FIG. 3  by cross-hatching, one or more of symbols  74 ,  76 ,  78  may be color-coded based, at least in part, upon an estimated severity of a forecast overpressure event; e.g., as determined based upon the disparity between the sonic boom inducing the overpressure event and the corresponding boom tolerance threshold. If there exists a relatively minor discrepancy between the magnitude of a forecast sonic boom and the boom tolerance threshold, the predicted overpressure event may be categorized as relatively non-severe or mild and the symbol or symbols indicative of the overpressure event may be color coded to a pre-established warning color, such as amber. Conversely, if a relatively large discrepancy exists between the magnitude of the forecast sonic boom and the boom tolerance threshold, the corresponding symbol may be color coded to a pre-established alert color, such as red. The size, shape, or other visual characteristics of the symbology may also be varied in accordance with such a visual coding scheme. Animation or other visual effects can be applied in the case of high level alerts to further draw the attention of the viewer thereto, as appropriate. 
     Turning now to  FIG. 4 , a screenshot of an exemplary VNAV display  36  is further presented. VNAV display  36  ( FIG. 4 ) can be generated concurrently with HNAV display  34  in embodiments, in which case the symbology generated on VNAV display  36  may generally correspond to that generated on HNAV display  34 . As does HNAV display  34 , VNAV display  36  includes an ownship A/C icon  80  and a vertical multi-leg flight route graphic  82 . In keeping with the exemplary flight scenario introduced above, flight route graphic  82  includes at least two legs represented by connected line segments extending from opposing sides of waypoint marker  84  (corresponding to waypoint marker  66  shown in  FIG. 3 ). The geographical regions containing waypoint markers  64 ,  68  shown in  FIG. 3  are offscreen in this example. VNAV display  36  further includes terrain graphics  86 , which generally depict the topology profile of the terrain underlying the A/C; a flight trajectory indicator  88 , which is generated as a line segment extending from the nose of A/C icon  80 ; an AGL altitude tape or scale  90  shown on the right of  FIG. 4 ; and a Flight Level (FL) indicator  89 , which extends from a readout window of scale  90  to indicate the current FL occupied by the A/C. 
     As does HNAV display  34  shown in  FIG. 3 , VNAV display  36  ( FIG. 4 ) is generated to contain symbology indicative of forecast overpressure events in the present example. This symbology includes a number of symbols or “boom strike” graphics  94 ,  96 ,  100 . As can be seen, boom strike graphics  94 ,  96 ,  100  are generated on HNAV display  34  to generally extend from the origin of the anticipated sonic booms to the ground strike locations of such sonic booms. Boom strike graphics  94 ,  96  thus specifically indicate the origins and projected ground strike locations of the sonic booms driving the overpressure events corresponding to symbols  74 ,  76  ( FIG. 3 ). Comparatively, boom strike graphic  100  visually indicates the origin and projected ground strike location of the sonic boom driving the overpressure event corresponding to symbols  87  shown in  FIG. 3 . Visual coding may be applied to graphics  94 ,  96 ,  100  to, for example indicate the severity of the overpressure event at the point of ground strike or another characteristic pertaining to a predicted overpressure event, as previously described. In further embodiments, multiple graphics similar to graphics  94 ,  96 ,  100  may be generated and vary in color, thickness, or the like to convey the severity of any overpressure event and/or to indicate whether the A/C represented by icon  80  should perform certain actions (e.g., climb and/or reduce speed) prior to the identified point along the flight path of the A/C. 
     With continued reference to  FIG. 4 , VNAV display  36  can be generated to further include a plurality of graphical elements or markers, which identify minimum AGL altitudes at which an A/C can travel without triggering an overpressure event. In this particular example, these graphical elements are presented as a series of connected line segments collectively forming a boom floor graphic  102 . The connected line segments forming boom floor graphic  102  vary in vertical positioning and, therefore, AGL altitude as taken along the length of graphic  102 . The variance in vertical positioning of different segments of boom floor graphic  102  may be due to any number of factors, such as disparities in terrain topology, variations in the value of the boom tolerance threshold in different geographical regions encompassed by the present FOV of VNAV display  36 , and/or changes in forecast weather conditions. Boom floor graphic  102  thus visually conveys minimum altitudes above which the A/C should remain as the A/C progresses along its flight path to avoid triggering an overpressure event. If desired, and as indicated in  FIG. 4  by dot stippling, an appropriately-colored gradient fill or a similar graphical effect may be applied above boom floor graphic  102  to further indicate that A/C flight at altitudes above graphic  102  is acceptable. 
     When rising above or extending vertically beyond flight trajectory indicator  88  or flight level indicator  89 , boom floor graphic  102  provides an intuitive visual cue that an overpressure event is forecast occur absent additional actions performed by the A/C corresponding to icon  80 . Such overpressure event symbology is further emphasized by the provision of filled or shaded regions  92 ,  98 , which may be generated in orange or another visually-striking color. Shaded regions  92 ,  98  may thus be regarded as secondary indicators of overpressure events, which further mark any point or points along the flight path of the A/C at which an overpressure event is forecast to occur. Specifically, as shown on the right side of  FIG. 4 , region  98  between boom floor graphic  102  and flight trajectory indicator  88  may be shaded in a predetermined color to further emphasize the projected occurrence of an overpressure event corresponding to boom strike graphic  100 . Similarly, shaded region  92  may indicating the projected occurrence of an overpressure event corresponding to symbols  94 ,  96 . In the exemplary flight scenario shown in  FIG. 4 , shaded region  92  extends to the top or to the upper edge of VNAV display  36  as the portion of boom floor graphic  102  corresponding to shaded region  92  is presently offscreen. 
     In the above described manner, the respective spatial relationship between boom floor graphic  102  and the other graphics presented on display  36  (e.g., A/C icon  80 , flight trajectory indicator  88 , and a flight level indicator  89 ) provide an intuitive visual cue as to permissible changes in altitude suitably implemented by the A/C represented by icon  80  without inducing an overpressure event. Consider, for example, the initial segment of boom floor graphic  102  appearing on the left side of VNAV display  36 . Here, a relatively large vertical disparity exists between this portion of boom floor graphic  102  and flight trajectory indicator  88 . Consequently, by glancing at this portion of VNAV display  36 , a pilot (or other viewer of display  36 ) can quickly ascertain that the A/C represented by icon  80  can accelerate or descend, within reason, while ensuring with a relatively high confidence level that an overpressure event will not occur. Similarly, the relatively minor vertical disparity between the portion of boom floor graphic  102  and flight level indicator  89  visually indicates that the overpressure event corresponding to symbol  98  can likely be averted by ascending to an altitude equal to or above that identified by peak segment  99  of boom floor graphic  102 . Similarly, by logical extension, this also indicates that the forecast overpressure event can likely be averted by a relatively modest deceleration of the A/C prior to reaching this juncture in the flight path. 
     Several numerical readouts  104 ,  106 ,  108 ,  110  are further presented on VNAV display  36 . Numerical readouts  104 ,  106 ,  108   110  are expressed as Mach speeds in this example, but may be expressed in a different format (e.g., as airspeeds) in alternative embodiments. As shown in  FIG. 4 , numerical readout  108  expresses the predicted speed of the A/C corresponding to icon  80  at the TRM waypoint; hence, the positioning of readout  108  adjacent symbol  84 . Comparatively, numerical readouts  104 ,  106 ,  110  specify the approximate maximum speed at which the A/C represented by icon  80  can travel, when located at corresponding AGL altitudes indicated by boom floor graphic  102 , without triggering or inducing an overpressure event. Numerical readouts  104 ,  106 ,  110  can be generated at any suitable junctures or intervals along the anticipated vertical flight path of the A/C. In the illustrated embodiment, readouts  104  and  110  are generated at junctures corresponding to forecast overpressure events, while readout  106  is generated at a juncture corresponding to a prolonged dip or nadir of boom floor graphic  102 . In certain embodiments, readouts  104 ,  106 ,  110  can be color coded in a manner indicative of the disparity between the values of readouts  104 ,  106 ,  110  and the current or predicted speed of the A/C represented by icon  80 , as previously indicated. 
     Boom floor graphic  102  and the above-described numeral readouts may be determined by avionic display system  10  through a series of “what-if” or “if-then” queries, as taken along the trajectory of the A/C represented by icon  80  ( FIG. 4 ). At least two data types may be requested utilizing “if-then” data queries transmitted from avionic display system  10  to a remote entity, such as a cloud-based forecasting service, in wireless communication with display system  10 . First, a series of “if-then” data queries may identify minimum AGL altitudes at which an A/C is permitted to fly at specified supersonic speeds, while ensuring that the reference magnitudes of any anticipated sonic boom(s) remain below the corresponding boom tolerance threshold; that is, without triggering an overpressure event. Similarly, a second series of “if-then” data queries can be submitted to identify maximum (e.g., Mach) speeds suitably flown by an A/C at specified altitudes, while further avoiding the generation of overpressure events. In such embodiments, the “if-then” altitude requests submitted by avionic display system  10  ( FIG. 1 ) may be based on standard or reduced vertical separation minima (RVSM). Avionic display system  10  may then deem the lowest response within an acceptable level as the minimum acceptable boom altitude. Avionic display system  10  may then generate boom floor graphic  102 , as shown in  FIG. 4 , as a visualization of the altitude floor given each trajectory point (e.g., Mach) speed at which occurrence of an overpressure event can be avoided. 
     In various embodiments, advisory messages can further be produced on one or more of displays  34 ,  36 ,  37  to convey suggested preemptive actions suitably performed to avoid occurrence of a forecast overpressure event. In such embodiments, avionic display system  10  may search and present such preemptive actions through “if-then” data queries of the type described above or utilizing a different approach. Display system  10  advantageously prioritizes the preemptive actions based upon selected performance criteria, such as timeliness, fuel efficiency, or emission levels. Consider, for example,  FIG. 5  presenting one possible hierarchy of suggested preemptive actions. Here, solutions to decelerate to lower speeds are first searched (BLOCK  114 ) as such solutions can typically be implemented with minimal impact on fuel consumption and timeliness. If found, the solution may be presented on one or more of displays  34 ,  36 ,  37  as, for example, a text annunciation specifying a (e.g., Mach) speed to which the A/C would ideally decelerate ahead of the anticipated overpressure event. Instead, if no such solutions are found at BLOCK  114 , avionic display system  10  next determines whether a forecast overpressure event can be avoided by climbing to particular AGL altitude or FL, if unoccupied by other A/C (BLOCK  116 ). Again, such solutions are presented if found. Otherwise, display system  10  may next consider solutions involving A/C deceleration to sub-Mach speeds (BLOCK  118 ), which may be prioritized below changes in altitude due to the fuel expenditure typically required to regain supersonic speeds. Finally, if necessary, other solutions may be searched and presented by display system  10 , such as recommendations to reroute the A/C (BLOCK  120 ). Finally, if no solutions are found at this stage in the process, a visual alert may be generated on the avionic display(s) notifying a viewer of avionic displays  34 ,  36 ,  37  of the impending overpressure event. 
     The above-described navigational solutions or preemptive actions may be automatically presented on avionic displays  34 ,  36 ,  37 ; or, instead, only presented when receiving additional user input via interface  18  ( FIG. 1 ). For example, in one embodiment, such preemptive actions may be presented when a pilot or other user selects symbology on one of displays  34 ,  36 ,  37  by, for example, hovering a cursor over a particular symbol. Similarly, in other embodiments, additional information pertaining to a particular overpressure event or sonic boom prediction may be presented to a pilot or other viewer when a particular symbol or graphic is selected. For example, in one embodiment, a user can hover a cursor over any chosen section of boom floor graphic  102  ( FIG. 4 ) to summon a window or other graphic specifying the maximum permissible Mach speed and minimum permissible AGL altitude at the selected location along the A/C flight path. As previously indicated, color coding can be utilized to indicate or emphasize whether an A/C can accelerate (e.g., as may be indicated by a first predetermined informational color, such as green), should maintain on the current planned speed (e.g., as may be indicated by a second predetermined informational color, such as white), or should decelerate to avoid a forecast overpressure event (e.g., as may be indicated by a predetermined caution color, such as amber) at a particular moment in time. 
     CONCLUSION 
     The foregoing has thus provided avionic display systems and methods utilized in the generation of avionic displays including symbology relating the potential occurrence of overpressure events and, perhaps, other graphical elements aiding in the avoidance of overpressure events. The avionic display system may not perform sonic boom forecasting itself, but rather retrieve relevant sonic boom forecast data from a remote source and subsequently analyze the sonic boom forecast data to carry-out the above-described process steps. In other embodiments, the avionic display system may perform such forecasting algorithms on an independent basis. The provision of such forecast overpressure event symbology thus supports decision making during supersonic A/C flight to reduce the likelihood and severity of overpressure events. Further, the forecast overpressure event symbology may aid in such decision making on behalf of pilots operating manned or unmanned A/C capable of supersonic flight, as well as in the decision making of air traffic control authorities (e.g., ATC personnel) directing or advising the supersonic flight of at least one A/C. Finally, as further explained above, the sonic boom-related symbology described above can be generated on any number and type of avionic displays. Such avionic displays may include vertical navigation and horizontal navigation displays of the type described above, exocentric 3D displays (e.g., displays depicting the 3D flight environment of an A/C from a point external to the A/C), PFDs, and other 2D and 3D avionic displays. 
     In certain embodiments, the avionic display system includes a display device on which an avionic display is generated, a controller architecture operably coupled to the display device, and storage media containing computer-readable instructions. When executed by the controller architecture, the computer-readable instructions cause the avionic display system to perform the operations of: (i) determining when an overpressure event is forecast to occur due to the generation of a sonic boom having a magnitude exceeding a boom tolerance threshold; and (ii) generating symbology on the avionic display indicative of the forecast overpressure event when determining that an overpressure event is forecast to occur. In certain embodiments, the computer-readable instructions, when executed by the controller architecture, may further cause the avionic display system to: (iii) identify a geographical location corresponding to the forecast sonic boom; and (iv) assign a value to the boom tolerance threshold based, at least in part, on the identified geographical location. In such embodiments, the geographical location corresponding to the forecast sonic boom can be projected origin of the sonic boom or a location at which the sonic boom is projected to impact the earth. Similarly, in embodiments, the avionic display system may further include a database storing multiple georeferenced values for the boom tolerance threshold; and the avionic display system may assign a particular value to the boom tolerance threshold based, at least in part, on which of the multiple georeferenced values corresponds to the identified geographical location. In other embodiments, the avionic display system may identify and visually express a maximum reduced speed to which the aircraft can decelerate and/or a minimum altitude to which the aircraft can climb to avert a forecast overpressure event. 
     Terms such as “comprise,” “include,” “have,” and variations thereof are utilized herein to denote non-exclusive inclusions. Such terms may thus be utilized in describing processes, articles, apparatuses, and the like that include one or more named steps or elements, but may further include additional unnamed steps or elements. While at least one exemplary embodiment has been presented in the foregoing Detailed Description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing Detailed Description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. Various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set-forth in the appended Claims.