STK Aircraft Mission Modeler

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STK Aircraft Mission Modeler

Tom Neely


Introduction

About the author and inventor – Tom Neely

• F-14 Tomcat Radar Intercept Officer– 850 flight hours

– 170+ carrier arrested landings

• US Naval Postgraduate School– Aerospace Engineering

– Electrical Engineering

• Analytical Graphics– Development project leader

– Author of STK/Radar and STK/Matlab


Agenda

• Intro to Aircraft Mission Modeler– What is Aircraft Mission Modeler?– Rapid mission modeling in 3D– Terrain following– Detailed Mission Modeling

• Sites & procedures• Performance Models• Phases• Catalogs

• Under the hood


Aircraft Mission Modeler

• New aircraft object propagator

• Significantly enhanced over great arc aircraft

• Based on aircraft performance characteristics– Airspeed

– Climb rate

– Roll rate

– Bank angle

• Aircraft types– Pre-defined

– Customizable


Aircraft Mission Modeler (cont.)

• Quickly create fundamental mission models– 3D Editing– One-click maneuvers– Smart aircraft performance defaults– Numerous models– Catalogs

• Ability to design advanced mission models– Aircraft models– Build complex, multi-segment mission models


3D editing

• Inserting a site

• Procedure control points

• Move, rotate and stretch holding patterns

• Alter heading and climb angle at a waypoint

• Move waypoint/runway


Aircraft

• Defined by a family of performance models

• Performance model categories in STK 7.0:– Climb– Cruise– Descend– Accelerate (turn)– Takeoff– Land– Terrain Following


Aircraft (cont.)

• Contain default performance models

• Users can design new performance models

• Procedures and performance define flight path

• Aircraft and performance models are extensible


Sites

• Waypoints and runways

• Every procedure refers to a site

• Sites constrain the type of procedure

• Sites can be saved to a catalog

• Sites are extensible


Procedures

• Procedure types included in STK 7– Takeoff and landing– Various point-to-point– Various holding

• Architecture is extensible


Mission modeling

• Aircraft with defined performance models

• One or more phases– Use specific performance models for each phase

• Each phase has procedures

• A procedure refers to a site

• Sites constrain procedure types


Mission Modeler UI

• Supports rapid setup

• Aircraft-specific performance

• Combines procedures– Takeoff– Enroute– Arc– Acceleration (turn)– Holding patterns– Landing

• Configurable, graphical feedback


Aircraft performance models

• User-configurable aircraft models

• Unlimited number of performance models per aircraft

• Linked to 3D visual model

• Built-in models with user-selectable parameters

• Extensible via API


Catalogs

• Maintain a collection of objects for reuse– Aircraft– Waypoints

• User defined• DAFIF

– Runways• User defined• DAFIF

• Catalog is extensible


Catalog UIs

• User-configurable catalogs for:– Aircraft models

– Way points

– Runways

• Catalog interface for aircraft procedures


Aircraft Mission Modeler

• Creating performance models

• Modeling a multi-phase mission

• Using the catalogs


Under the hood

The following discussion of features and capabilities for Aircraft Mission Modeling includes information

subject to pending patent applications


Under the hood

• Aircraft Mission Modeler– Data-driven system– Designed to be used by non-experts– Analytic curves parameterized by well known aircraft

performance values• Well known aircraft performance values

– roll rate, bank angle, climb rate, airspeed

– Building blocks for constructing complex missions• Sites• Procedures


Sites

• Runways– Lat/lon values– Runway altitude– Runway heading

• True/magnetic

– Length– Catalog

• Create & save• Use DAFIF data

• Waypoints– Lat/lon– Catalog


Procedures

• Takeoff– Choose runway

heading– Departure Altitude– Departure point

range– Use runway terrain


Procedures

• Arc– Turn direction– Set altitude– Bearing– Arc radius– Turn angle


Procedures

• Circular holding pattern– Turn direction– Level off maneuver– Bearing– Range– Number of turns– Time per turn


Procedures

• Figure-8 holding pattern– Level off maneuver– Bearing– Range– Width– Length– Number of turns– Time per turn


Procedures

• Racetrack holding pattern– Turn direction– Level off maneuver– Bearing– Range– Width– Length– Number of turns– Time per turn


Procedures

• Landing– Approach altitude– Level off maneuver– Initial approach fix range– Glideslope– Use runway terrain


Point to point flight

• Procedures employ point to point flight– Holding and Arc procedures

• Fly from end of the previous procedure– To holding point– To start of Arc

• Procedures over-fly waypoints– Specify heading at waypoint


Point to point flight

• Position/heading to position/heading

• Turns computed to minimize total heading change

• Acceleration performance model– Determines bank angle for level, steady turns

• Turns– Constant radius– First turn– Second turn– Turn radius

• Turn bank angle– May vary


Translating a great arc aircraft

• New aircraft from an existing great arc aircraft

• Position and velocity vectors computed the same

• Attitude window is used– Moving average algorithm


Performance models and procedures

• Procedure/performance model exceptions– GtArc Procedure

• Same logic as “old” great arc propagator

– Basic Point to Point• Unconstrained behavior desired

– Constant hold segment speed• Speed at which aircraft arrives at holding point• Specified time per holding turn


Earth surface height model

• Major analysis capability improvements– Objects close to surface– WGS84 and MSL surfaces differ by tens of meters

• AMM uses Mean Sea Level as altitude reference

• WGS84 or MSL globe options– Set the globe surface to MSL!


DAFIF

• Obtain DAFIF– Limited distribution– Versions 7 & 8 supported

• DAFIF location– Tools–Options–File Find–DAFIF

• Verify your DAFIF


Scripting and customization

• Connect is supported– Connect is documented

• COM is supported– Native implementation– All interaction is through COM interfaces– Custom user interfaces created with 4DX


Coordinate system

• Current procedures– Generated in a flat earth coordinate system– Altitude is referenced to MSL– Mapping preserves great arc motion– Mapped to ECF coordinates

• Extensibility model– Does not require a flat earth– Any coordinate system is supported


Level off maneuvers

• Desired altitude unattainable

• Vertical spiral

• Override automatic LOM logic

• Delay climb and descent


Vertical plane motion

• Arbitrary climb and descent profiles– Smooth curve

• Terrain Following– Same type of curve for vertical trajectory

• Other vertical plane maneuvers– Constant radius arcs– Straight line segments


Climb and descent transitions

• Performance models– Generate individual climb, cruise and descent profiles

• “Stitched” together by procedures

• Climb/descent angle– Intercepted using a constant radius arc

• Trajectory follows the climb/descent angle– Aircraft changes velocity

• Determined by acceleration performance model


Bank angle

• Accounts for the total aircraft acceleration– Horizontal turn radius– Vertical plane acceleration– Speed– Climb angle


Validation & verification

• Performed by Sensis Corporation– Generated 747-200 external performance model

• BADA• Compared to flight trajectory generated by STK

– Feedback– Implementation


Future

• Business partnership– Aircraft performance model catalogs

• New procedures and performance model categories

• V/STOL - T/O, Hover and Landing

• Carrier T/O and Landing

• Formation Flight

• Aerial Refueling

• Air Intercept

• Guided Missiles

Documents

STK Aircraft Mission Modeler