SpicePosition Other Functionality

What is this document?

This is the companion to the core SpicePosition requirements document. This document contains every public method that is not mentioned in the other document. This will be an evolving document where we can collect what each method does, where it is used, and why it is used.

Methods

Time Bias (Candidate For Removal)

• SetTimeBias(double timeBias)
  • Used by MocNarrowAngleCamera and MocWideAngleCamera
  • NOT used. There is a function with this name used from SpiceRotation, but SpicePosition's is not used.
• GetTimeBias() const
  • Only used within SpicePosition! We could potentially eliminate this from the API, as it is only used within SpicePosition.

LightTime and Aberration Correction

• SetAberrationCorrection(const QString &correction)
  • Used by SpacecraftPosition, Spice, gllssical/main, LoHighCamera, LoMediumCamera, Mariner10Camera
• QString GetAberrationCorrection()
  • Not used anywhere (SpacecraftPosition has something similar and should probably use it but doesn't)
• GetLightTime()
  • Not used anywhere (SpacecraftPosition has something similar and should probably use it but doesn't)

GetCenterCoordinate

• GetCenterCoordinate()
  • Used by BundleObservation
  • Gets the gets the mid point in time between the start and end of the cached position data, and returns that coordinate
  • Used to get the center position of the instrument when looking at a section of ephemeris data

HasVelocity (Candidate For Removal)

• HasVelocity()
  • Not used, the private variable is getting accessed directly from within SpicePosition
  • Returns the private variable p_hasVelocity from a SpicePosition object
  • Doesn't provide any functionality at the moment

IsCached

• IsCached()
  • Used by Spice
  • Checks if there is something stored within the cache
  • Used to determine whether or not to read/write from and to cache

SetPolynomialDegree

• SetPolynomialDegree(int degree)
  • Used by BundleObservation
  • Sets the degree of the internal polynomial state
  • Used to set and change the polynomials degree, consequently expanding or reducing the polynomial if the polynomials have been "applied"(?)

GetSource

• GetSource()
  • Used by Spice
  • Returns the private variable p_source from a SpicePosition object
  • Used to determine how the data in SpicePosition is stored

Base Time and Time Scaling

• ComputeBaseTime()
  • Only used within SpicePosition
  • Computes the base time based on the private variable p_override
  • Adjust the p_basetime and p_timescale variables in SpicePosition when SetPolynomial is run or when memcache2hermitecache is run
• GetBaseTime()
  • Used in BundleObservation
  • Returns the private variable p_basetime
  • Used to get the current base time for fit equations
• SetOverrideBaseTime(double baseTime, double timeScale)
  • Used in BundleObservation
  • Sets the p_overrideBaseTime to the given baseTime, sets p_overrideTimeScale to the given time scale, and sets p_override to timeScale
  • Used in LoadCache to set the above variables if p_source is not a PolyFunction
• GetTimeScale()
  • Used in BundleObservation
  • Returns the private variable p_timeScale
  • Used to set a variable in BundleObservation::initializeExteriorOrientation

DPolynomial

• DPolynomial(const int coeffIndex)
  • Only used within SpicePosition

Extrapolate

• Extrapolate(double timeEt)
  • Used in SpkSegment

HermiteCoordinate()

• HermiteCoordinate
  • Not used