Patent Description:
The present disclosure generally relates to systems and methods for displaying terminal area procedure charts on a cockpit display system of an aircraft. More particularly, the present disclosure relates to systems and methods for calculating temperature compensated altitude values (e.g. for computing temperature compensated trajectories) for inclusion in terminal area procedure charts.

When a flight is executed in non-standard atmospheric conditions as defined by the International Standard Atmosphere (ISA), the aircraft is either lower or higher than the indicated barometric altitude based on whether the external temperature is lower or higher than the assumed ISA conditions. Consequently, there is a risk that the specified clearance above an obstacle or specified clearance of an aircraft from another aircraft is no longer sufficient.

Aeronautical Information Publications (AIPs) are issued by, or with the authority of, a state (on behalf of the respective civil aviation administration) according to International Civil Aviation Organization (ICAO) standards and contain aeronautical information details of regulations, procedures and other information pertinent to flying aircraft in the particular country to which it relates. Terminal Procedure Publications (TPPs) are an important component of the AIPs. Included in the Terminal Procedures Publications as diagrammatic charts are: Instrument Approach Procedure (IAP) Charts, Departure Procedure (DP) Charts, Standard Terminal Arrival (STAR) Charts, Charted Visual Flight Procedures (CVFP) and Airport Diagrams (AD).

The nomenclature and symbology indicated on the Terminal Procedure Publications, henceforth simplistically referred to as the Procedure Charts or Terminal Area procedure charts, is standardized by the International Civil Aviation Organization (ICAO) to be used across the globe and independent of prevailing environmental conditions of weather and temperature at the designated terminal or enroute region which can vary over a period of time. Altitude values printed on the procedure charts are Mean Sea Level (MSL) altitudes or Above Ground Level (AGL) altitudes. Flight Instruments like the Primary Flight Display (PFD) indicate altitude in Mean Sea Level (MSL) reference.

The International Standard Atmosphere (ISA) is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations. The International Organization for Standardization (ISO) publishes the ISA as an international standard, e.g. ISO <NUM>:<NUM>. Most flight instruments indicate altitude in Mean Sea Level (MSL) assuming ISA conditions. ICAO PANS OPS (e.g. Doc <NUM>) requires that "The calculated minimum safe altitudes/heights must be adjusted when the ambient temperature on the surface is much lower than that predicted by the standard atmosphere". The most efficient means to mitigate the effect of non-standard atmospheric conditions is to quantify the effect of the difference from ISA in the form of a correction that should be added to the minimum flight altitudes/heights to ensure the appropriate clearance above obstacles and terrain. ATS Authorities are responsible to develop and establish the necessary corrections for the cold temperature effect on altimetry and provide the air traffic control the values for minimum flight altitudes/minimum vectoring to be used in cold temperature conditions.

A Temperature Deviation is defined as the difference between the Actual Temperature either sensed by the aircraft or measured at the closest airfield and the International Standard Atmosphere Temperature at a given altitude (ISADEV = (Actual Temperature - International Standard Atmosphere Temperature)). According to the PAN OPS (Doc <NUM>), the following logic is applied for temperature compensation for non-standard atmospheric conditions: For temperatures above -<NUM>, an approximate correction is <NUM> percent height increase for every <NUM> below standard temperature as measured at the altimeter setting source and this is safe for all altimeter setting source altitudes. For temperatures below -<NUM>, the temperature correction is defined by the below equation (equation <NUM>, which is disclosed in the following) which produces results that are within <NUM>% of the accurate correction for altitudes between <NUM> and <NUM> feet above that source. However, more accurate corrections may also be computed based on the equations specified in the PAN OPS document. For temperatures colder than -<NUM> degrees, a more accurate correction may be obtained according to the guidance provided in the 'Temperature corrections' section of the document.

Historically, pilots are always required to carry printed approach and terminal procedure charts for reference in their flight bag. These would refresh every Aeronautical Information Regulation And Control (AIRAC) cycle (typically <NUM> days) and the charts would be reprinted for pilots to be replaced in their flight bags. Pilots would keep open these printed charts into operating airports for reference. With the advent of the Electronic Flight Bag (EFB) or the Electronic Flight Bags (Portable Tablets or Fixed Tertiary Cockpit Displays), printed charts were no longer required. Electronic format of the charts (scanned PDF or Raster Images) replaced the print media on the EFB, but altitude values are defined with respect to ISA conditions (including temperature) and are not editable.

The documents <CIT> and <CIT> disclose the calculation of a temperature-compensated altitude for an aircraft. The document <CIT> discloses a system for presenting navigation chart information on a display unit of an aircraft.

Hence, it is desirable to provide systems and methods for compensating for the effect of the temperature variation from ISA conditions in terminal area procedure charts to ensure that all applications, and pilots, reference the corrected altitudes. More specifically, it is desirable to provide methods and systems that facilitate accurate and informative temperature compensated altitude values. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Methods and systems are provided for generating a data driven digital chart. The methods and systems retrieve a data driven chart for a requested terminal area procedure chart from a database of data driven charts. The data driven charts describe digital terminal area procedure charts by way of data elements for each terminal area procedure chart including geodetic straights, arcs, text elements and symbols defined with respect to location. Some of the data elements are further defined with respect to altitude values defined assuming a standard atmospheric temperature value. The systems and methods include calculating compensated altitude values for the data elements of the retrieved data driven chart based on a deviation between the outside air temperature value and the standard atmospheric temperature value. The methods and systems include generating a presentation for a display device of the aircraft of the terminal area procedure chart including the compensated altitude values.

The systems and methods described herein are for providing temperature compensated displays of terminal area procedure charts including vertical profiles and altitude references on electronic chart display applications based on the prevailing atmospheric conditions. The present disclosure deals with an inherent limitation in the way the terminal area procedure charts either in print or digital format are coded and used by the pilots and, more specifically, deals with the altitude representations on Procedure Charts.

Described herein are techniques for applying temperature compensation on the true altitude references used in digital terminal area procedure charting applications. Based on the user or pilot configuration, computational pre-processing can be applied to all the altitude references (vertical situation display, minimum sector altitude, decision altitudes, altitude constraints, etc.) on a digital procedure chart in electronic format to render a temperature compensated terminal area procedure chart for pilot use on Electronic Flight Bag or Interactive Navigation applications. The temperature compensation may be calculated based on the below model, by way of a look up table or some other model relating altitude correction to temperature deviation from ISA temperature.

In most current day usage, terminal area procedure charts are digitized and electronic versions are made available on Electronic Flight Bags (EFBs) or on Integrated Navigation (INAV) Display applications. These terminal area procedure charts may be in PDF or raster format, which does not lend itself to determining compensated altitude values. The systems and methods described herein process all altitude references on a digital electronic procedure chart depiction and apply a temperature compensation as indicated by the logic defined above. The terminal area procedure charts are stored in a database, with each chart made up of data elements including data fields for altitude, thereby making the altitude values available for altitude compensation calculations and correction. The digital or electronic procedure charts are then rendered using the new corrected or compensated altitude references on the target applications.

In order to ensure that the pilot has access to both the compensated and non-compensated versions of the procedure charts, an option can be provided to the pilot to select options for applying temperature compensation or removing an applied temperature compensation. Additionally, the Outside Air Temperature (OAT) to be used for the compensation algorithms may be entered by the pilot based on the airfield temperature or even automatically consumed from the temperature sensors on board or from another source.

Indications can be made on the procedure charts about the ISA temperature, the OAT, the ISA deviation and the computed correction altitude. Controls can be provided for the pilot to also apply or cancel a temperature compensation for the barometric altitude values depicted on the procedure charts. The OAT can be automatically populated or be allowed for the pilot to enter or tailor.

Various exemplary use cases for the systems and methods described herein are described. In one exemplary use case, the vertical map or vertical descent profile depicted on the procedure chart is adjusted. The descent profile is typically depicted using Mean Sea Level (MSL) altitudes considering standard atmospheric conditions. If the OAT were significantly lower than the ISA temperature on a specific day, a temperature compensated digital procedure chart will be a significant safety benefit for the pilot for terminal area operations. On a profile view, several elements of altitude are referenced with respect to MSL assuming ISA conditions, for example: procedure notes associated with the profile view, minimum altitude when executing a procedure turn, tracks with corresponding crossing altitudes, flight tracks with associated altitude levels, etc. These altitude values can be temperature compensated. Further, not only can displayed numeric altitude values be temperature compensated but associated graphics can be correspondingly adjusted in position (such as a vertical profile).

Another example of an exemplary use case is the Approach Briefing section at the top of an Approach plate. Example elements in the Approach briefing section include Glideslope Clearing Altitude for precision approaches, Decision Altitude (DA) or Minimum Decision Altitude (MDA), Missed Approach Procedure, Airport or procedure transition level and altitude, etc. Typically, these altitude references are defined with respect to MSL altitudes assuming standard atmospheric conditions. The temperature compensation can be applied to all altitude references other than the ones which represent elevation levels above ground level to present a modified digital procedure chart to the pilot. A different color coding can be used to indicate to the pilot that a compensation has been applied.

Another exemplary use case of altitude references in procedure charts are the ones used to specify the Minimum Sector Altitudes (MSA) or Minimum Safe Altitudes on instrument charts, which provide <NUM> feet of obstacle clearance within a <NUM> radius from the navigation facility upon which MSA is predicated. MSA altitudes are also indicated as MSL altitudes assuming ISA conditions. The systems and methods of the present disclosure can intelligently apply the temperature corrections and display compensated MSA representation on the electronic charts such as the minimum safe altitude in each defined sector as depicted on the procedure chart.

Another exemplary use case is circling minimums, which are charted on the procedure charts when a circling OCA (H) or MDA (H) is provided by the procedure source. Again, the charted altitude values are non-compensated altitude values above MSL assuming ISA conditions. In such scenarios, the present disclosure presents compensated MSL altitudes on the Circling minimums table along with as-is AGL values if any.

Another exemplary use case is that of the display of the Segment Minimum Altitudes in the profile view of the procedure chart. Such a presentation may include sector minimum altitudes for different segments of the approach procedure and are indicated in MSL altitude assuming ISA conditions in the database and corresponding temperature compensated altitude values in a temperature compensated presentation as described herein.

Current systems only present raw digitized information, which include altitude references in Mean Sea Level (MSL) in accordance with ISA assumptions. The cockpit system applications like the Flight Management Systems (FMS) and Autopilot systems have capabilities to compensate for temperature when they generate an altitude profile or predict one. The pilot in the terminal area is mostly reliant on the procedure charts for safe execution of flight maneuvers with respect to the terminal area constraints. A pilot referencing procedure chart and trying to compare it with a lateral or vertical profile displayed on the cockpit system from a flight management system is often confused and unable to relate the values presented on the display system with the ones referenced in the terminal area procedure charts. Printed or Digital charts like the ones on electronic flight bags or on INAV display systems currently do not have any capabilities to provide temperature compensated values for altitude profiles. The systems and methods described herein provide a novel technique and data format, which can be applied to a digital or electronic chart application to enhance safety in the terminal area and ensure adherence to safe separation and clearance altitudes. The overall safety of the flight, and also the operational efficiency of the flight, is enhanced by the automation provided by the present disclosure.

The present disclosure enhances the whole experience of the integrated information presented to the pilot in an intuitive way on the advanced electronic flight bag chart application or on the cockpit system display applications. The described solution also enhances safety of terminal area operations and increases operational efficiency due to automation of temperature compensation of reference altitudes.

Prior solutions assume a RASTER image or a PDF (non-editable) depiction of the terminal area procedure chart, which does not allow temperature compensation. The systems and methods described herein begins with encoding the terminal area procedure charts into Data Driven Charts (DDC). In the disclosed DDCs or digital charting applications, all data elements of the chart are coded in a database in the form of a combination of straights, arcs, points, text, thumbnail elements, symbols, etc.. The data elements are then rendered on a digital display to provide the same visualization as that of a conventional RASTER image or PDF but using temperature compensated altitude values when required and optionally when requested by a user. The fact that there is a backend database that drives these digital charting applications (DDC), temperature compensation can be applied on all data elements that contain an altitude reference including graphical and alphanumeric data elements. In some embodiments, one can present non-compensated and compensated lateral and vertical profiles and other chart elements like MSA (minimum sector altitude) etc. in dependence on a user or system selection.

The digital charting display rendering system disclosed herein is driven by a Data Driven Chart (DDC) database wherein discrete component elements of the terminal area procedure chart are stored as geodetic points, straights, arcs, text elements, thumbnails, symbols, etc rather than a database of raster images or PDF, which are non-editable and thus not able to be subject to temperature compensation. The Data Driven Charts (DDC), or sometimes synonymously quoted as just Digital Charts, for the terminal area procedure charts facilitate temperature compensated, advanced displays that are better integrated with other temperature compensated displays in the cockpit. Instead of storing the terminal procedure charts as a raster image or PDF into which the user or a computer system or software has limited control, a database of elements coded in a DDC database is used to generate the terminal area procedure chart. In embodiments, constituent elements of the terminal area procedure chart are coded in the DDC database with plural combinations of straight lines, arcs, text boxes, symbols, thumbnails, alphanumerics, etc. A display rendering module described herein aggregates the discrete database elements depictions on a canvas to produce a terminal area procedure chart visualization. The charts so accomplished allow for much user control and friendliness including simple elements like controlling visualization based on ambient light or much complex elements like dynamic rendering of only must and essential elements of the chart based on prevailing aircraft conditions. Further, and in accordance with embodiments described herein, the charts include a significant advancement whereby temperature compensated profiles and other altitude referenced features are presented.

The display rendering module of embodiments of the present disclosure, visualizes an approach chart or a terminal area procedure chart by regenerating discrete elements coded into a database including by drawing straights, arcs, text, symbols, etc in 3D space. Straights would be represented in the database at a minimum with a start and end position (latitude/longitude pair) and optionally an altitude and other parameters. Arcs would be represented in the database with start and end position values along with radius as distance and optionally an altitude and other parameters. Symbols, text boxes, thumbnails and other graphic features will be stored in their image equivalents with an associated position (which may include altitude) at which they will need to be placed. Each terminal procedure chart will have a combination of these in the database. These are only exemplary coding formats and one can accomplish the database coding in other alternative forms. The display rendering module is able to regenerate the chart by using the data specified in the database, which is a combination of multiple discrete elements. The terminal procedure charts described herein need not be 2D only. 3D visualizations are envisaged, which are represented on 2D displays with capabilities of rotating and visualizing the chart in all perspectives.

<FIG> is a schematic diagram of a display system <NUM> of an aircraft <NUM>. The display system <NUM> includes a DDC database <NUM>, a source of flight plan data <NUM>, a source of temperature data <NUM>, a user interface <NUM>, a processing system <NUM> and a display device <NUM>. It should be understood that <FIG> is a simplified representation of the display system <NUM>, and <FIG> is not intended to limit the application or scope of the subject matter in any way. In practice, the display system <NUM> will include numerous other devices and components for providing additional functions and features, as will be appreciated in the art.

In embodiments, the aircraft <NUM> includes a cockpit, one or more engines, and a fuselage. The aircraft <NUM> can be a multicopter (or rotary-wing), fixed-wing or a tilt-wing aircraft. The aircraft <NUM> can be an airplane or a helicopter or other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors. The display system <NUM> is located in the cockpit of the aircraft <NUM>, although the display device <NUM> may be transportable.

In embodiments, the source of flight plan data <NUM> may be a flight management system, which manages the flight control of the aircraft <NUM>. In other embodiments, the source of flight plan data <NUM> is a file stored in memory, which is user created or system created. The source of flight plan data <NUM> may be omitted in some embodiments and destination data may be user entered. For instance, the flight management system implements, manages, and/or controls a flight mode, flight path, flight plan, flight trajectory, etc. for the aircraft <NUM>. The flight management system receives an input from a user via the user interface <NUM>. The flight management system can be configured to implement one or more flight mode(s), flight plans, etc. of the aircraft <NUM> selected by user input and display information associated with the one or more flight mode(s) on display device <NUM>. In embodiments, a navigation function of the flight management system allows a route to be programmed by a user through the user interface <NUM>. A flight director (not shown) and an auto-pilot system (not shown) can steer the aircraft <NUM> along the desired course to an active waypoint. When the aircraft reaches an active waypoint, the flight management system automatically sequences to the next waypoint in the route, unless waypoint sequencing is suspended. The flight management system outputs destination data <NUM> defining a target airport or runway for the aircraft <NUM>. The processing system <NUM> may receive the destination data <NUM> and generate airport or runway specific display data <NUM> including a terminal area procedure chart. For example, the destination runway included in the destination data <NUM> may be centered in the rendered terminal area procedure chart and a predetermined or variably defined area around the destination runway can be included in the presentation of the terminal area procedure chart. The processing system <NUM> may be configured to automatically render the terminal area procedure chart in response to data from the FMS indicating a certain closeness to the destination airport or in response to a request from a user submitted via the user interface <NUM>.

In embodiments, the user interface <NUM> is located in the cockpit or is associated with the display device <NUM> (e.g. as a touchscreen of an EFB device) and provides input to one or more system(s) of the aircraft <NUM>. The user interface <NUM> includes any device suitable to accept input from a user for interaction with the systems of the aircraft <NUM>. For example, the user interface <NUM> includes one or more of a keyboard, joystick, multi-way rocker switches, mouse, trackball, touch screen, touch pad, data entry keys, a microphone suitable for voice recognition, and/or any other suitable device. The user interface <NUM> allows the user to interact with a graphic and/or textual data element provided for display on the display device <NUM>. In particular embodiments, the user interface <NUM> can be controlled by a user to submit a request for a terminal area procedure chart, to receive responsive interactions to the terminal area procedure chart (e.g. selection of just one type of presentation such as a vertical profile view, to zoom in on a part of a presentation, to display another type of presentation, to rotate the presentation with respect to one or more axes, etc.), to submit or cancel a request to temperature compensate altitude values, to enter OAT, among other uses. The user selection data <NUM> from the user interface <NUM> is taken as an input to the processing system <NUM>, which responds by adjusting the rendered presentation of the terminal area procedure chart.

In embodiments, the source of temperature data <NUM> provides temperature data <NUM>, which includes OAT. In embodiments, the OAT relates to the temperature at or near the airport. The source of temperature data <NUM> may be an OAT sensor of the aircraft <NUM>, satellite weather data, uplinked weather data, user entered via the user interface <NUM>, combinations thereof, etc. The temperature data <NUM> is used by the processing system <NUM> to generate compensated altitude values, which are included in compensated terminal area procedure charts as described further herein.

The DDC database <NUM> is a data driven chart database <NUM> that includes terminal area procedure charts for many airports. Unlike prior art systems where the terminal area procedure charts are defined as a whole by a raster or PDF data format, the terminal area procedure charts of the DDC database are each defined by a combination of data elements <NUM>. The data elements include various different types of data elements <NUM> including straights (or straight lines)14a, arcs (or arced lines) 14b, symbols 14c, points 14d, text (or alphanumeric) boxes 14e, shapes (not shown), text 14f, numeric values <NUM>, thumbnails/icons <NUM>, etc. Some or all of the data elements <NUM> are defined with respect to a location including an altitude. The altitude is defined in the DDC database <NUM> assuming ISA conditions including ISA temperature. In the case of straights 14a, arcs 14b, points 14d, text boxes 14e, shapes, thumbnails/icons <NUM>, these may be defined geodetically using longitude, latitude and, in many cases, altitude in real world coordinates. Straights may be defined in terms of start and end points. Arcs may be defined in terms of start and end points and a degree or radius of curvature. Text boxes and other rectangular shapes may be defined in terms of three corner points. Symbols or thumbnails/icons or other graphical features may be defined as images with a location corresponding to a center point. The points in the fields of the DDC database <NUM> that are used to define a number of data elements <NUM> may be geodetically defined and often include altitude values. The processing system <NUM> may interrogate the DDC database <NUM> for the data elements <NUM> associated with a particular destination location (e.g. a runway) or a destination region (e.g. defined by a certain geofence). The retrieved data elements <NUM> are arranged according to, at least in part, location and combined when rendering the terminal area procedure chart. In embodiments, the processing system <NUM> retrieves data elements <NUM> making up a terminal area procedure chart based on destination data <NUM> so that only a relevant airport or region within an airport is rendered.

In embodiments, the display device <NUM> includes a head down display (HDD), a head up display (HUD), a wearable HUD, a portable display or any combination thereof. The display device <NUM> may be a cockpit integrated display or an EFB device. The display device <NUM> outputs one of various terminal area procedure related presentations such as those described with reference to <FIG> in the following. The terminal area procedure presentations are rendered using a combination of many discrete data elements <NUM>. When temperature compensated altitudes are to be applied, the processing system <NUM> adjusts the altitude values associated with the data elements <NUM> to render the temperature compensated terminal area procedure presentations.

In embodiments, the processing system <NUM> implements functions of the display system <NUM> of <FIG> and steps of the method <NUM> of <FIG>. The processing system <NUM> includes one or more processor(s) <NUM>, one or more memory device(s) <NUM>, one or more computer programs <NUM>, a compensation module <NUM> and a rendering module <NUM>. The processor <NUM> can include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, logic device, or other suitable processing device. The one or more memory device(s) <NUM> can include one or more computer-readable media, including, but not limited to, non-transitory computer-readable media, RAM, ROM, hard drives, flash drives, or other memory devices.

The one or more memory device(s) <NUM> can store information accessible by the processor <NUM>, including one or more computer program(s) <NUM>, which include computer-readable instructions that can be executed by the processor <NUM>. The instructions can be any set of instructions that, when executed by the processor <NUM>, cause the processor <NUM> to perform operations corresponding to functions and method steps described herein. The instructions can be software written in any suitable programming language or can be implemented in hardware. In some embodiments, the instructions can be executed by the processor <NUM> to cause the processor <NUM> to perform operations, such as the operations for temperature compensating altitude values and generating presentations of terminal area procedure charts as described herein.

The memory device(s) <NUM> can further store data that can be accessed by the processor <NUM>. For example, the data can include a navigational database, data associated with a navigation system(s), data associated with the control mechanisms, data indicative of a flight plan associated with the aircraft <NUM>, data associated with flight director mode selection, data associated with a flight management system, and/or any other data associated with aircraft <NUM>, as described herein. The data can include one or more table(s), function(s), algorithm(s), model(s), equation(s), etc. for navigating the aircraft <NUM>. Although the compensation module <NUM> and the rendering module <NUM> are shown separately from the computer programs <NUM>, these modules would, in practice, be implemented by computer executable program instructions embodied by the computer programs <NUM>. Further, computer programs <NUM> are shown separately from memory <NUM>, but may be stored within memory <NUM>.

The compensation module <NUM> receives altitude values and OAT as inputs and outputs temperature compensated altitude values (or an amount of correction to be applied). The compensation module <NUM> may compensate altitude for other non-ISA prevailing conditions such as air pressure, which can be provided as a further input. The compensation module <NUM> may utilize a model based on equation <NUM> above, another model or even a look-up table or other data format defining a relationship between input OAT and altitude corrections. In embodiments, the compensation module <NUM> calculates temperature compensated altitudes based on a deviation between OAT and the reference temperature for the altitude values in the DDC database <NUM>.

The rendering module <NUM> receives a request for rendering a terminal area procedure chart, optionally any user selections including a request for temperature compensation of altitude values and any additional user requirements (e.g. a particular portion of the terminal area procedure chart data, a zoom selection, a rotation selection, etc.) and optionally destination data <NUM>. The rendering module <NUM> retrieves a destination specific terminal area procedure chart from the DDC database <NUM> based on the destination data <NUM>, which includes combinations of many data elements <NUM>. When a request for temperature compensation is also received, the altitude values associated with the data elements <NUM> that are defined with respect to ISA (or other reference standard) temperature are extracted and converted to temperature compensated altitude values based on OAT using the compensation module <NUM>. The ISA altitude values included in some or all of the data elements <NUM> are thus supplemented with, or replaced by, temperature compensated altitude values. The rendering module <NUM> renders display data <NUM> by combining data elements <NUM> to produce the various presentations of terminal area procedure charts described herein. When the data elements <NUM> have altitude compensated values, these altitude compensated values will be utilized, which may mean that graphic features are positionally adjusted in the presentations such as the position of straights, arcs, symbols, icons, thumbnails, alphanumeric boxes, shapes, points, etc. Further, numeric altitude values are adjusted to the compensated altitude values.

<FIG> is an exemplary presentation <NUM> of a terminal area procedure chart. The presentation <NUM> is shown on the display device <NUM> based on display data <NUM>, which is produced by processing system <NUM> as described above. The presentation <NUM> includes various sections including approach briefing information <NUM>, minimum sector altitudes (MSA) <NUM>, landing minimums <NUM>, approach plan view <NUM> and approach profile view <NUM>. In some embodiments, a user may select, via the user interface <NUM>, one of the sections in order to render a full screen view of just that section. In other embodiments, a user may select, via the user interface <NUM>, to zoom in or out of the various sections and/or to rotate a view such as the plan or approach profile view. The presentation <NUM> (or approach plate) may be generated for the whole airport or for a particular runway at an airport based on the specificity of the location defined in the destination data <NUM>. The presentation <NUM> may include an apply compensation button <NUM>, which is user selectable, via the user interface <NUM>, to cause altitude values in the various sections of the presentation <NUM> to be temperature compensated by compensation processing and new rendering by the processing system <NUM> as described above. The apply compensation button may be a physical or virtual button. After compensation has been applied, the presentation <NUM> may include a cancel button (not shown) so that that the user can go back to the non-compensated view. In some embodiments, presentation <NUM> additionally includes at least one of: an indication of the reference (or ISA) temperature <NUM>, an indication of OAT <NUM> and an indication of temperature deviation <NUM> between the reference temperature and the OAT. In the exemplary embodiment of <FIG>, the various sections are vertically separated in the presentation <NUM> so that the approach briefing information <NUM> is located above the approach planview <NUM>, which is located above the approach profile view, which is located above the landing minimums <NUM>.

<FIG> includes a presentation <NUM> of non-compensated approach profile view and a presentation <NUM> of a compensated approach profile view. The presentations <NUM>, <NUM> both include vertical profiles of the instrument approach procedure. The presentations <NUM>, <NUM> include the published descent profile and graphical depiction of the vertical path using facilities, intersections, fixes, etc. identified in the procedure to the destination runway. A profile view of the procedure track is shown. The approach track begins toward the top of the primary facility line, unless otherwise dictated by the procedure, and descends to where the final approach ends and the missed approach begins. The presentations <NUM>, <NUM> include various symbols, lines, shapes, numeric values, label icons, etc. Although both the non-compensated and compensated presentations <NUM>, <NUM> are shown together in <FIG>, this is by way of illustration. Both versions could be displayed together, but it is preferred that non-compensated presentation <NUM> be displayed when compensation has not been user or system selected and compensated presentation <NUM> be displayed when compensation has been user or system selected. In the presentation <NUM> of compensated approach profile views, various compensated altitude values <NUM> are shown overlaid or replacing the non-compensated altitude values <NUM>. In some embodiments, the non-compensated and compensated altitude values <NUM>, <NUM> could be displayed next to each other. In embodiments, the compensated altitude values <NUM> are shown in a different color, font style, boldness or other visually differentiable manner than the non-compensated altitude values <NUM>. Further, compensated approach profile lines <NUM> are shown to graphically reflect adjusted altitude values in the lines of the vertical path. In the exemplary embodiment of <FIG>, both non-compensated and compensated lines making up the vertical path are shown (albeit visually differentiated by coloring or lines style). However, just the compensated approach profiles lines <NUM> may be shown. Further, when symbols, label icons, text boxes, shapes, etc. in the presentation <NUM> of compensated approach profile view are associated with altitude values in the DDC database <NUM>, these data elements <NUM> may also be adjusted in vertical position based on temperature compensated altitude values and the re-drawing of each data element <NUM>.

<FIG> includes a presentation <NUM> of non-compensated approach briefing information and a presentation <NUM> of compensated approach briefing information, in accordance with an exemplary embodiment. As with the other embodiments of <FIG> and <FIG>, it is not necessary or preferred (but it is possible) that both non-compensated and compensated presentations <NUM>, <NUM> are shown at the same time. Prior to user or system selection to apply temperature compensation, non-compensate altitude values <NUM> are displayed. After user or system selection to apply temperature compensation, compensated values <NUM> are displayed, optionally in a visually different manner.

<FIG> includes a presentation <NUM> of non-compensated Minimum Sector (or Safe) Altitude (MSA) and a presentation <NUM> of compensated Minimum Sector Altitude (MSA), in accordance with an exemplary embodiment. In <FIG>, the MSA section <NUM> is shown laterally adjacent the approach briefing information <NUM>. However, the MSA may also be included in the approach planview section <NUM>. MSAs are published for emergency use on IAP charts. The MSA is based on the primary NAVAID, waypoint, or airport reference point on which the IAP is predicated. The MSA depiction on the approach chart contains the identifier of the NAVAID/waypoint/airport used to determine the MSA altitudes. MSAs are expressed in feet above mean sea level and normally have a <NUM> radius; however, this radius may be expanded to <NUM> if necessary, to encompass the airport landing surfaces. MSAs provide <NUM>,<NUM> feet clearance over all obstructions. The MSA altitude values are shown non-compensated in the presentation <NUM>. Compensated altitude values <NUM> for the MSA are included in the presentation <NUM>, which is rendered when the user of the system selects to apply compensation. The compensated altitude values <NUM> are shown in a visually different format than the non-compensated altitude values <NUM>.

<FIG> includes a presentation of non-compensated circling minimums <NUM> and a presentation of compensated circling minimums <NUM>, in accordance with an exemplary embodiment. The circle to land minimums, circling minimums or landing minimums section <NUM> may be positioned below the approach profile view in <FIG>. This section gives the pilot the lowest altitude and visibility requirements for the approach. There are two types of landing minimums: Straight-in landing or Circling. Straight in landing minimums are the Minimum Descent Altitude (MDA) and visibility, or Decision Height (DH) and visibility, required for a straight-in landing on a specified runway. Circling minimums are the MDA and visibility required for the circle-to-land maneuver. Although circling minimums are exemplified in <FIG>, altitude compensation could similarly be applied for straight-in landing minimums. The presentation <NUM> includes non-compensated altitude values <NUM> and the presentation <NUM> includes compensated altitude values <NUM>, which are rendered when a user or system selection has been made to apply altitude compensation. In the example of <FIG>, the presentation <NUM> includes a compensation applied indicator <NUM> that appears when temperature compensated altitude values are display. In the example of <FIG>, the presentation <NUM> additionally or alternatively includes a temperature deviation indicator <NUM> showing a deviation between OAT and the reference temperature for the altitude values in the DDC database <NUM>. Such indicators could be included in the other presentations of <FIG> and <FIG>.

<FIG> includes a non-compensated presentation <NUM> of Segment Minimum Altitudes (SMAs) <NUM> and a compensated presentation <NUM> of SMAs. SMAs provide required obstacle clearance for a given segment of the approach. It is a minimum Instrument Flight Rules (IFR) altitude established by the procedure designer and meant to be a "do not descend below" altitude. SMAs must not be violated. In the depicted example of <FIG>, the MSAs are depicted as shaded blocks (or other graphical element) <NUM>, <NUM> in association with numeric altitude values <NUM>, <NUM>. The presentation <NUM> includes one or more non-compensated graphical elements <NUM> in the form of a shaded block having a height determined by the non-compensated altitude values <NUM>, which are also displayed in or adjacent the graphical elements <NUM>. In the DDC database <NUM>, the non-compensated graphical element <NUM> may be stored as a shape data element <NUM> in association with an ISA altitude value. The compensated presentation <NUM> of SMAs is displayed after a compensation apply selection is made by the processing system <NUM> or the user. The compensated presentation <NUM> includes compensated altitudes values <NUM> that are shown in a visually different format or color than the non-compensated altitude values <NUM>. Further, the compensated presentation <NUM> includes compensated graphical elements <NUM> in the form of shaded blocks having an adjusted height (altitude) as compared to the non-compensated graphical elements <NUM>. The corresponding data element <NUM> in the DDC database <NUM> (e.g. a rectangle shape) has a height set by the non-compensated altitude value. When the altitude value is changed by the compensation module <NUM>, the height of the data element <NUM> is also changed, thereby rendering the compensated graphical element <NUM>. In <FIG>, there are also compensated altitude values <NUM> associated with the vertical path profile. Although not highlighted in <FIG>, the straight lines (which are a data element <NUM> in the DDC database <NUM>) making up the vertical profile also have a vertical position set by ISA (or other reference standard) altitude values in the DDC database <NUM>. The vertical position of the straight lines of the vertical profile are adjusted in the compensated presentation <NUM> in the same manner to that described with respect to <FIG>.

Although the presentations of <FIG> are depicted separately, these presentations can be shown on the same screen in the corresponding sections of <FIG> or a similar combined view. When the compensation is selected, the altitude numeric values and the position or height of graphical elements (e.g. straights, shapes, etc.) are adjusted in all of the presentations (where compensated altitude values are relevant) in each section of the presentation of a terminal procedure chart <NUM> (or approach plate). This provides an intuitive way to visualize altitude compensations for IAPs and provides enhanced integration with automated altitude compensations applied in other displays based on FMS data such as primary flight displays, multi-functional displays, etc. It should be appreciated that static publications are being compensated according to the present disclosure rather than real-time data relating specifically to the current flight and its progress from the FMS and other aircraft systems. Yet further, the present disclosure provides a data format for the storage of terminal area procedure charts (or approach plates) that allows the altitude values and associated graphical indications to be adjusted based on prevailing atmospheric conditions including temperature. As such, flight safety can be improved.

<FIG> is a process flow chart detailing a method <NUM> for rendering and display a presentation of a terminal area procedure chart. The order of operation within the method <NUM> is not limited to the sequential execution as illustrated in the figure, but may be performed in one or more varying orders as applicable and in accordance with the present disclosure. Steps of the of method <NUM> are performed by the one or more processors <NUM> of the processing system <NUM> executing computer programming instructions of the one or more computer programs <NUM>. Method <NUM> may be instigated when a selection is made by a user through the user interface <NUM> to temperature compensate altitude values in a displayed terminal area procedure chart. Additionally or alternatively, method <NUM> may be automatically instigated by the processing system <NUM> such as when the temperature deviation between the reference temperature and the OAT at the destination exceeds a certain threshold.

The method <NUM> includes step <NUM> of receiving a request to display a terminal area procedure chart. The request may be received by the processing system <NUM> in response to a user selection through the user interface <NUM> or may be received automatically based on proximity to the destination.

In step <NUM>, a data driven chart is retrieved by the processing system <NUM> from the DDC database <NUM>. The data driven chart includes data elements <NUM> that are aggregated in order to produce a presentation of the terminal area procedure chart. The data elements <NUM> relevant to the retrieved data driven chart may be selected based on destination, e.g. only those data elements <NUM> within a proximity of a destination runway or airport are selected, which may be determined based on location information associated with each data element <NUM>. At least some of the data elements <NUM> are associated with altitude values that are defined with respect to standard atmospheric conditions including a reference temperature. The rendering module <NUM> renders a presentation of the terminal area procedure chart, such as the outline of the presentation <NUM> of <FIG>, thereby displaying the terminal area procedure chart according to step <NUM>. The presentation <NUM> may include an apply compensation button <NUM> to allow a user to select, through the user interface <NUM>, to apply temperature compensation to displayed altitude values and any graphical features that are positionally or size defined with respect to altitude values.

In step <NUM>, a request to temperature compensate altitude values is received by the processing system <NUM>, e.g. in response to a user selection of the apply compensation button <NUM> or based on a system request such as the processing system <NUM> determining that the OAT deviates from the reference temperature by an amount greater than a threshold.

In step <NUM>, the OAT is received by the processing system <NUM>. OAT can be sensed by one or more onboard temperature sensing devices of the aircraft <NUM>, can be received from other aircraft, can be uplinked from a ground station, can be provided through a satellite communication, can be provided by a manual entry through the user interface <NUM>, can be provided by an application providing predicted or historical OATs or in any other suitable way. In embodiments, the OAT is received for different position values (longitude and/latitude) covered by the data driven chart to be drawn. The OAT for the various geographic locations included in the chart are sensed or measured or predicted or estimated. In some embodiments, step <NUM> encompasses computing a three-dimensional grid of interpolated OAT values for all points in the procedure chart to be drawn. Step <NUM> includes, in one embodiment, calculating the OAT values for all the designated points on the procedure chart for which the correction is desired at the corresponding geographic location. Since it may not be practical to measure OAT at every geographic position combination in the region of interest corresponding to the procedure chart, interpolation helps estimate the best temperature estimate at any desired position.

In step <NUM>, the processing system <NUM>, specifically the compensation module <NUM>, temperature compensates the altitude values associated with the retrieved data elements <NUM> based on a deviation between the reference temperature and the OAT.

In step <NUM>, the display elements are re-rendered based on the temperature compensated altitude values. In embodiments, compensated numeric altitude values are included in the compensated presentation of the terminal area procedure chart. Further, position or size or otherwise adjusted graphical features are included in the compensated presentation, with the adjustments being made based on the compensate altitude values. In particular, the vertical position of straights in an approach profile view are adjusted to fit the compensated altitude values as shown in <FIG> and/or the height of shape elements representing the SMAs are adjusted as shown in <FIG>. Other adjustments of graphical features may be made including position of symbols, icons, thumbnails, points, text boxes, etc.. These various graphical elements are included in the DDC database <NUM> and are defined with respect to an altitude at standard atmospheric conditions and are re-defined when the altitude is adjusted based on prevailing atmospheric conditions.

In step <NUM>, the compensated presentation of the terminal area procedure chart is displayed per one or any combination of the compensated presentations shown in <FIG>.

Although not illustrated in the figures, the terminal area procedure charts may additionally include at least one of: a Notice to Airmen (NOTAM) or Temporary Flight Restriction (TFR) in textual or graphical representation, a speech transcribed instruction from the Air Traffic Controller (ATC) or the Airline Operations Center (AOC) in textual or graphical representation, and a depiction of neighboring terminal area aircraft traffic. Altitude values associated with these features may also be temperature compensated per the teaching described herein.

Claim 1:
A data driven digital chart display system for an aircraft, the display system comprising:
a display device;
a database of data driven charts describing digital terminal area procedure charts, wherein each digital terminal area procedure chart is constructed by data elements included in the database, the data elements including geodetic straights, arcs, text elements and symbols defined with respect to location, wherein at least some of the data elements are further defined with respect to altitude values assuming a standard atmospheric temperature value;
at least one processor in operable communication with the display device and the database, the at least one processor configured to execute program instructions, wherein the program instructions are configured to cause the at least one processor to:
receive an outside air temperature value;
receive a request to generate and render a display of a terminal area procedure chart;
retrieve the data driven chart for the requested terminal area procedure chart including the data elements;
calculate compensated altitude values for the at least some of the data elements of the retrieved data driven chart based on the altitude values assuming the standard atmospheric temperature value and a deviation between the outside air temperature value and the standard atmospheric temperature value; and
generate a presentation, for the display device, of the terminal area procedure chart including the compensated altitude values for the at least some of the data elements of the retrieved data driven chart.