Flight Dynamics Record Components

Flight Dynamics Record (FDR) components are in a folder in the Components Browser. Each record component represents the state of a satellite at a given point in time. This is a convenient form for doing the following:

Importing this information into the STK/Astrogator^® capability to initialize a satellite
Exporting the information externally from the Ansys Systems Tool Kit^® (STK^®) application for use in the Ansys Orbit Determination Tool Kit (ODTK^®) application

You can also import FDR components from an external file, as described in the Component Browser topic.

When you import an FDR component, the STK software will read the name of the propagator associated with that FDR component. If that exact name does not appear in the Propagators folder of the Component Browser, the software will create a new Propagator component from the FDR information.

Creating a Flight Dynamics Record

You can create a new Flight Dynamics Record component to capture an Astrogator satellite's state at a specific time. In the MCS toolbar, click the "Add Flight Dynamics Record to Component Browser" icon () to open the "Create Flight Dynamics Record" dialog box. You then have the following settings and choices available.

Parameter	Description
Segment	Click next to the text box to choose which MCS segment you want to use to obtain Flight Dynamics Record information from.
Desired Epoch	Choose the method by which the new initial state time is selected. First Point: Uses the first ephemeris point. Closest Point: Uses the data point closest to the Target Epoch. Last Point: Uses the last ephemeris point.
Epoch Selection	Choose the epoch to be used as a starting point for initial state. If you choose a Desired Epoch of Closest Point, you must specify Epoch Selection. If Epoch Selection lies outside the span of the available ephemeris, the closest ephemeris point is used. See the "Time options" section of the STK Time topic page for descriptions of the Epoch Selection options listed.
Record Name	The default is to have the Use Default check box selected, which means that the FDR will have the name that the Astrogator capability automatically sets in the text field. If you want to apply a different name, clear the Use Default check box and enter the name in the text field.
Reset	Click this button to clear the Segment selection and set Desired Epoch to Closest Point.
Preview	Click this button to see the position (Rx, Ry, Rz) and velocity (Vx, Vy, Vz) for the FDR time you chose. The values will appear below the button.
Export	Click this to create a new FDR component in the Component Browser at the time you specified above.

The FDR components you create will appear in the Component Browser as a green component, indicating that you can clone, edit, and delete that component. For editing, you can only edit the Notes text field, with all other parameters being read-only.

Flight Dynamics Record component contents

When you open an FDR component, the following information appears in the record.

Parameter	Description
State Configuration Properties	Click this button to see the values of the satellite state parameters for this FDR component. State parameters include the following: ComponentName Epoch CentralBody CoordinateSystem Position (in X, Y, and Z) Velocity (in X, Y, and Z) DryMass FuelMass CdNominal - nominal drag coefficient CdCorrected - appears when you select a propagator with applied drag stochastic parameters DragCorrection - appears when you select a propagator with applied drag stochastic parameters LongTermDragCorrection - appears when you select a propagator with applied drag stochastic parameters DragArea - the area used in calculating drag force DensityCorrection - appears when you select a propagator with applied drag stochastic parameters CrNominal - nominal solar radiation pressure coefficient CrCorrected - appears when you select a propagator with applied SRP stochastic parameters SRPCorrection - appears when you select a propagator with applied SRP stochastic parameters LongTermSRPCorrection - appears when you select a propagator with applied SRP stochastic parameters SRPArea - solar radiation pressure area Ck - albedo/thermal radiation pressure coefficient RadPressureArea - albedo/thermal radiation pressure cross-sectional area K1Nominal - K1 vaule for nonspherical SRP model K2Nominall - K2 vaule for nonspherical SRP model SourceObjectName StateCovariance - 21 values for Pos-Pos, Pos-Vel, Vel-Vel covariance
Propagator	Displays the name of the propagator that was in use at the epoch time of the FDR.
Propagator Properties	Click this button to open a window that displays the Propagator Functions and Numerical Integrator properties that were in use at the epoch time of the FDR.
Export Propagator to Component Browser	Click this button to create a new Propagator component in the Component Browser having the exact name of the propagator listed in the FDR. If a propagator with that exact name already exists in the Component Browser, then you will have the choice of canceling the export or overwriting the existing Propagator component.
Notes	For FDR components that you create (green color), you can type descriptions or other information in the text field.
Add to Collection	Click this button to add this FDR component to FDR components that are available to use for any scenario in the STK application on your computer.