Satellite: Position Covariance in Axes: VVLH(Earth)

Reports data about position covariance matrix including orientation of its principal axes relative to the VVLH(Earth) axes and dimensions of the associated sigma scaled equal probability density ellipsoid. Any set of axes defined in the Vector Geometry Tool is available for use, including user defined sets. The data requires position covariance to be defined for the object.

Name Dimension Type Description
Time DateFormat Real Number Time.
Sigma x DistanceUnit Real Number Square root of the first diagonal component of the scaled covariance matrix.
Sigma y DistanceUnit Real Number Square root of the second diagonal component of the scaled covariance matrix.
Sigma z DistanceUnit Real Number Square root of the third diagonal component of the scaled covariance matrix.
Correlation xy Unitless Real Number XY correlation coefficient of the scaled covariance matrix.
Correlation xz Unitless Real Number XZ correlation coefficient of the scaled covariance matrix.
Correlation yz Unitless Real Number YZ correlation coefficient of the scaled covariance matrix.
CovMtx xx Area Real Number XX Component of the Position Covariance Matrix
CovMtx yx Area Real Number YX Component of the Position Covariance Matrix
CovMtx yy Area Real Number YY Component of the Position Covariance Matrix
CovMtx zx Area Real Number ZX Component of the Position Covariance Matrix
CovMtx zy Area Real Number ZY Component of the Position Covariance Matrix
CovMtx zz Area Real Number ZZ Component of the Position Covariance Matrix
1/(Inverted Sigma x) DistanceUnit Real Number Square root of the inverse of the first diagonal element of the inverse of the scaled covariance matrix.
1/(Inverted Sigma y) DistanceUnit Real Number Square root of the inverse of the second diagonal element of the inverse of the scaled covariance matrix.
1/(Inverted Sigma z) DistanceUnit Real Number Square root of the inverse of the third diagonal element of the inverse of the scaled covariance matrix.
YPR321 yaw AngleUnit Real Number Yaw angle between the two sets of axes. Defines rotation about the z-axis of the reference set, which occurs first when using 321 (or YPR) sequence in YPR angles representation.
YPR321 pitch AngleUnit Real Number Pitch angle between the two sets of axes. Defines rotation about the y-axis of the reference set, which occurs second when using 321 (or YPR) sequence in YPR angles representation.
YPR321 roll AngleUnit Real Number Roll angle between the two sets of axes. Defines rotation about the x-axis of the reference set, which occurs third when using 321 (or YPR) sequence in YPR angles representation.
Euler323 precession AngleUnit Real Number Precession angle between the two sets of axes. Defines rotation about the z-axis of the reference set, which occurs first when using 323 sequence in Euler angles representation.
Euler323 nutation AngleUnit Real Number Nutation angle between the two sets of axes. Defines rotation about the y-axis of the set rotated through precession, which occurs second when using 323 sequence in Euler angles representation.
Euler323 spin AngleUnit Real Number Spin angle between the two sets of axes. Defines rotation about the z-axis of the set rotated through precession and nutation, which occurs third when using 323 sequence in Euler angles representation.
q1 Unitless Real Number First element of quaternion (and of its vector part) representing orientation between the two sets of axes.
q2 Unitless Real Number Second element of quaternion (and of its vector part) representing orientation between the two sets of axes.
q3 Unitless Real Number Third element of quaternion (and of its vector part) representing orientation between the two sets of axes.
q4 Unitless Real Number Fourth element of quaternion (its scalar part) representing orientation between the two sets of axes.
Major Sigma DistanceUnit Real Number Square root of the maximum eigenvalue of the projected covariance matrix.
Intermediate Sigma DistanceUnit Real Number Square root of the intermediate eigenvalue of the scaled covariance matrix.
Minor Sigma DistanceUnit Real Number Square root of the minimum eigenvalue of the projected covariance matrix.
Major Sigma Dir x Unitless Real Number First component of the unit vector along the major axis of the scaled ellipsoid.
Major Sigma Dir y Unitless Real Number Second component of the unit vector along the major axis of the scaled ellipsoid.
Major Sigma Dir z Unitless Real Number Third component of the unit vector along the major axis of the scaled ellipsoid.
Minor Sigma Dir x Unitless Real Number First component of the unit vector along the minor axis of the scaled ellipsoid.
Minor Sigma Dir y Unitless Real Number Second component of the unit vector along the minor axis of the scaled ellipsoid.
Minor Sigma Dir z Unitless Real Number Third component of the unit vector along the minor axis of the scaled ellipsoid.
Volume Volume Real Number Volume of the scaled equal probability density ellipsoid defined by the scaled covariance matrix.
SEP DistanceUnit Real Number Spherical error probable - statistically equivalent spherical representation for the equal probability density ellipsoid defined by the covariance matrix.
Approx SEP DistanceUnit Real Number Fast approximation of "spherical error probable".

STK Programming Interface 11.0.1