Package gaiasky.util.gaia

Class ConcreteAttitude

java.lang.Object
gaiasky.util.gaia.ConcreteAttitude
All Implemented Interfaces:
Attitude
public class ConcreteAttitude extends Object implements Attitude
This class implements the Attitude interface and contains just the minimum fields necessary to define a unique attitude at a given time, plus a large number of methods to compute quantities that depend only on this attitude and time.

The various scanning laws and specific attitude representations (e.g., using splines, or tables for interpolation) can be implemented as providing attitude objects of this type.

In some cases (in particular for simple analytical scanning laws) there are more direct ways to retrieve some of the quantities for which there are methods in this class (e.g., getHeliotropicAnglesRates()); the present method(s) may then be overridden for efficiency.

  • Constructor Details

    • ConcreteAttitude

      public ConcreteAttitude​(long t, Quaterniond q, boolean withZeroSigmaCorr)
      Construct object from time, and a quaternion. This leaves the time derivative undefined. It can be set later with setQuaternionDot(Quaterniond)
      Parameters:
      t - time of the attitude
      q - quaternion

    • ConcreteAttitude

      public ConcreteAttitude​(long t, Quaterniond q, Quaterniond qDot, boolean withZeroSigmaCorr)
      Construct object from time, quaternion and its derivative.
      Parameters:
      t - time of the attitude
      q - quaternion
      qDot - time derivative of quaternion [1/day]

  • Method Details

    • getTime

      public long getTime()
      Description copied from interface: Attitude
      Get the time that this attitude is valid for as a single long value. The meaning of the time depends on the TimeContext of the AttitudeDataServer that generated the attitude. Use #getGaiaTime() to get the time as an absolute GaiaTime if needed.
      Specified by:
      getTime in interface Attitude
      Returns:
      time time that the attitude is valid for

    • setTime

      public void setTime​(long time)
      Set the time of the attitude. This usually does not make sense as the time is set during construction of the object
      Parameters:
      time - time of the attitude in [ns] since reference epoch

    • getQuaternion

      public Quaterniond getQuaternion()
      Specified by:
      getQuaternion in interface Attitude
      Returns:
      quaternion that represents the attitude

    • setQuaternion

      public void setQuaternion​(Quaterniond q)
      The the quaternion of the attitude. * Set the time of the attitude. This usually does not make sense as the time is set during construction of the
      Parameters:
      q -

    • getQuaternionDot

      public Quaterniond getQuaternionDot()
      Get the time derivative of the attitude.
      Specified by:
      getQuaternionDot in interface Attitude
      Returns:
      time derivative of the attitude quaternion [1/day]

    • setQuaternionDot

      public void setQuaternionDot​(Quaterniond qDot)
      Parameters:
      qDot - quaternion derivative to set - all components in [1/day]

    • getHeliotropicAnglesRates

      public HeliotropicAnglesRates getHeliotropicAnglesRates()

    • getSpinVectorInSrs

      public Vector3d getSpinVectorInSrs()
      Description copied from interface: Attitude
      Get the inertial spin vector in the SRS.
      Specified by:
      getSpinVectorInSrs in interface Attitude
      Returns:
      spin vector in [rad/day] relative to SRS

    • getSpinVectorInIcrs

      public Vector3d getSpinVectorInIcrs()
      Description copied from interface: Attitude
      Get the inertial spin vector in the ICRS (or CoMRS).
      Specified by:
      getSpinVectorInIcrs in interface Attitude
      Returns:
      spin vector in [rad/day] relative to ICRS

    • getFovDirections

      public Vector3d[] getFovDirections()
      Description copied from interface: Attitude
      Get the PFoV and FFoV directions as an array of unit vectors expressed in the ICRS (or CoMRS).
      Specified by:
      getFovDirections in interface Attitude
      Returns:
      array of two (PFoV, FFoV3) vectors

    • getSrsAxes

      public Vector3d[] getSrsAxes​(Vector3d[] xyz)
      Description copied from interface: Attitude
      Get the x, y, z axes of the SRS as an array of three unit vectors expressed in the ICRS (or CoMRS).
      Specified by:
      getSrsAxes in interface Attitude
      Returns:
      array of three (x, y, z) vectors
      See Also:
      Attitude.getSrsAxes(Vector3d[])

    • getAlAcRates

      public double[] getAlAcRates​(double alInstrumentAngle, double acFieldAngle)
      Description copied from interface: Attitude
      Compute the angular speed AL and AC of an inertial direction in the SRS frame, using instrument angles (phi, zeta).
      Specified by:
      getAlAcRates in interface Attitude
      Parameters:
      alInstrumentAngle - (=AL angle phi) of the direction [rad]
      acFieldAngle - (=AC angle zeta) of the direction [rad]
      Returns:
      two-element double array containing the angular speed AL and AC [rad/s]

    • getAlAcRates

      public double[] getAlAcRates​(FOV fov, double alFieldAngle, double acFieldAngle)
      Description copied from interface: Attitude
      Compute the angular speed AL and AC of an inertial direction in the SRS frame, using field angles (fov, eta, zeta).
      Specified by:
      getAlAcRates in interface Attitude
      Parameters:
      fov - FOV (Preceding or Following)
      alFieldAngle - (=AL angle eta) of the direction [rad]
      acFieldAngle - (=AC angle zeta) of the direction [rad]
      Returns:
      two-element double array containing the angular speed AL and AC [rad/s]