Release Notes for FreeFlyer 6.11

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New Features in FreeFlyer 6.11


Orbit Determination Enhancements

Added the variational equations method for covariance propagation

oSignificantly improves runtime over the Numeric method

oImproves accuracy over both the Numeric and J2 Semi-Analytic methods

oWorks with the BatchLeastSquaresOD and KalmanFilterOD objects

Added support for solutions in the Equinoctial Element Set

oSupports limited OD solutions, such as constraining the plane of the orbit

oEnables covariance conversion between Cartesian and Equinoctial element sets

oWorks with the BatchLeastSquaresOD, KalmanFilterOD, and UnscentedKalmanFilterOD objects

Addition of Right Ascension and Declination measurement processing

oAdded to the GroundStationObservation and SpacecraftObservation file types

oWorks with the BatchLeastSquaresOD, KalmanFilterOD, and UnscentedKalmanFilterOD objects

Multiple additions to the BatchLeastSquaresOD object

oThe ability to specify how the a priori covariance is used

oOption to compute a best-fit a priori covariance

oCapacity to specify how measurements are edited

oAdded the Levenberg-Marquardt and Quadratic algorithms for limiting state updates to prevent solution divergence

oEnabled the ability to load observation data prior to calling the Iterate method

oImproved compatibility of the Cowell integrator with batch processing to lead to a significant runtime speed improvement when used with variational equations

Improved support of BRTS and TDRS Tracking Data processing

oImproved Universal Tracking Data Format (UTDF) parsing

oSimplified usage model for BRTS observation processing

oAdded BRTS and TDRS observation support to the Tracking Data Editor for processing lists of observations

 

Integrated Development Environment (IDE) Enhancements

Opened up control of the IDE to system administrators

oHas "Full Access" for Mission Plan development and execution

oHas "Execute-Only" for Mission Plan execution only

Configurable with administrator access from the installer, the FreeFlyer GUI, or the command line interface

Allows IDE mode to be set based on User Group security settings

 

Integrator Enhancements

Made many improvements to the Cowell integrator

oThe Cowell integrator is now available for use with all Engineer and Mission licenses

oImproved performance when changing step size

oImproved error control performance

oImproved overall speed

Speed improvements for all integrators in well-posed cases

 

Enhanced User Support

New Sample Mission Plans

New syntax examples throughout the Help File

Updated Station Locations file

Improved error messages

 

Miscellaneous Enhancements

Added min and max functions to FreeForm script

All installers and executables are now signed with a security certificate

FreeFlyer.exe and FF.exe now set exit codes when closing

Added more options for GroundStation and Sensor masking interpolation

Improved the performance of planetary ephemeris processing

Enhanced Database logging and diagnostics

An assortment of bug fixes were made

 

 

Migrating to FreeFlyer 6.11


While we always strive to maintain 100% backwards compatibility in our new releases, our efforts to make FreeFlyer more flexible and consistent in FreeFlyer 6.11 and higher have necessitated a few changes which may require user intervention when migrating your existing Mission Plans. These changes are outlined below.

 

Substantial changes were made to the architecture of the Integrator object and its derived classes (ie. Cowell, J2Mean, Norad, NoradSGP4, NoradSP, and TwoBody) in order to optimize propagation using these integrators. This includes the removal of many properties that were no longer necessary and the addition of new control properties to determine the Integrator object's behavior. For full details on the new list of properties and what they do, see the individual object pages.

 

An issue was fixed where the SystemTime function was reporting a day behind what it was supposed to for time zones that were positive relative to UTC+0. Any adjustments for this behavior in Mission Plans can be removed.

 

The default value for the MatlabInterface property, SharedInstanceFlag, has been changed from 1 (true) to 0 (false) to provide each Matlab usage with its own dedicated instance by default. If you need the shared instance behavior, you will need to explicitly set it to 1 (true) in your Mission Plans.

 

Two new functions were added with this release, min and max, and it is possible that you had objects which use those common names. If you do, you will get an error message when attempting to load those Mission Plans in FreeFlyer 6.11. Simply rename those objects to something besides min or max and your Mission Plan will be fine.

 

The Runge-Kutta ToleranceMode legacy value used to exist so that users could compare the old error tolerance logic against their baseline results if there appeared to be a problem. Because of numerous integrator enhancements in FreeFlyer 6.11, this is no longer possible, and so this mode has been removed. It is recommended to use the default value for the ToleranceMode property, relative-to-step vector for Mission Plans moving forward regardless.

 

Angle data (Az/El and RA/Dec) in GroundStationObservation and SpacecraftObservation file types are now both light-time corrected. This could cause scripts that were simulating non-corrected data and processing corrected data to behave inconsistently.

 

The SpaceraftObservationFile now requires an additional column to specify the data type (Az/El or RA/Dec).

 

The default value for the TreatConsecDelimAsOne and TrimTokens properties of the StringTokenizer object now properly defaults to 0 (false) when the object is created in FreeForm script.

 

Characters that need to be escaped when in regular expressions, such as $, no longer need to be escaped when used as Delimiters within the StringTokenizer object. A delimiter of "\$" will now be treated literally as "\$" instead of as "$" for purposes of tokenizing a String.

 

In supporting estimation of properties in the Equinoctial element set, the element set definition has been changed to not apply the discontinuity / ambiguity at an inclination of 90 degrees, but rather accept a singularity at 180 degrees.

 

Doppler processing has changed for BRTSObservation and TDRSObservation objects. This change only applies when processing data from pre-2000 or when processing simulated data where the simulated data was generated with an older version of FreeFlyer, and it is being processed with FreeFlyer 6.11 or higher.

 

Changed the representation of a TDRS ID as found in the TDRS UTDF file to coincide with the actual value in the file rather than being confined to a maximum of 256. This means that any Mission Plan configured to read the value constrained to a maximum of 256 will need to be updated.

 

The interface by which users interact with BRTSUTDFFile objects has changed in FreeFlyer 6.11. The SetObservedSpacecraft, SetObjectBeingObserved, and AddObserverTDRSRelayLink methods no longer exist on the BRTSUTDFFile object, and the TDRSRelay property of the BRTSObservation object has been removed. To use this functionality, now the user must use the SetObservedTransponder and AddBRTSLink methods of the BRTSUTDFFile object along with the SetRemoveGroundTerminal method of the BRTSObservation object. See the Simulate Tracking Data guide for examples.

 

The EState property of the Spacecraft object has been removed as it was no longer necessary due to the information being reported in a more meaningful way in other properties.

 

The Spacecraft object's EPV method now reports in the Geocentric True of Date rotating reference frame instead of the Earth-fixed reference frame.

 

Various Objects, Properties, Methods, and Functions have been deprecated

oDeprecated Objects, Properties, Methods, and Functions are elements of FreeFlyer which are no longer recommended for use. The description of each deprecated element indicates the new recommended way to achieve the functionality of that element. The complete list of affected elements is given on the Deprecated Objects, Properties, Methods, and Functions page.

 

 

See Also


Release History