CoordinateSystem#

class ansys.stk.core.stkutil.CoordinateSystem#

IntEnum

Overview#

UNKNOWN

Represents coordinate system not supported by the Object Model.

ALIGNMENT_AT_EPOCH

Alignment at Epoch: an inertial system coincident with ECF at the Coord Epoch. Often used to specify launch trajectories.

B1950

B1950: X points toward the mean vernal equinox and Z points along the mean rotation axis of the Earth at the beginning of the Besselian year 1950 and corresponds to 31 December 1949 22:09:07.2 or JD 2433282.423.

FIXED

Fixed: X is fixed at 0 deg longitude, Y is fixed at 90 deg longitude, and Z is directed toward the north pole.

J2000

J2000: X points toward the mean vernal equinox and Z points along the mean rotation axis of the Earth on 1 Jan 2000 at 12:00:00.00 TDB, which corresponds to JD 2451545.0 TDB.

MEAN_OF_DATE

Mean of Date: X points toward the mean vernal equinox and Z points along the mean rotation axis of the Earth at the Orbit Epoch.

MEAN_OF_EPOCH

Mean of Epoch: X points toward the mean vernal equinox and Z points along the mean rotation axis of the Earth at the Coord Epoch.

TEME_OF_DATE

TEME of Date: X points toward the mean vernal equinox and Z points along the true rotation axis of the Earth at the Orbit Epoch.

TEME_OF_EPOCH

TEME of Epoch: X points toward the mean vernal equinox and Z points along the true rotation axis of the Earth at the Coord Epoch.

TRUE_OF_DATE

True of Date: X points toward the true vernal equinox and Z points along the true rotation axis of the Earth at the Orbit Epoch.

TRUE_OF_EPOCH

True of Epoch: X points toward the true vernal equinox and Z points along the true rotation axis of the Earth at the Coord Epoch.

TRUE_OF_REFERENCE_DATE

True of Ref Date: A special case of True of Epoch. Instead of the Coord Epoch, this system uses a Reference Date defined in the Integration Control page of the scenario’s PODS properties.

ICRF

ICRF: International Celestial Reference Frame.

MEAN_EARTH

Mean Earth.

FIXED_NO_LIBRATION

uses an analytic formula not modeling lunar libration.

FIXED_IAU2003

Fixed_IAU2003.

PRINCIPAL_AXES421

PrincipalAxes_421.

PRINCIPAL_AXES403

PrincipalAxes_403.

INERTIAL

Inertial.

J2000_ECLIPTIC

The mean ecliptic system evaluated at the J2000 epoch. The mean ecliptic plane is defined as the rotation of the J2000 XY plane about the J2000 X axis by the mean obliquity defined using FK5 IAU76 theory.

TRUE_ECLIPTIC_OF_DATE

The true ecliptic system, evaluated at each given time. The true ecliptic plane is defined as the rotation of the J2000 XY plane about the J2000 X axis by the true obliquity defined using FK5 IAU76 theory.

PRINCIPAL_AXES430

PrincipalAxes_430.

TRUE_OF_DATE_ROTATING

TrueOfDateRotating: Like the Fixed system, but ignores pole wander. The XY plane is the same as the XY plane of the TrueOfDate system, and the system rotates about the TrueOfDate Z-axis.

ECLIPTIC_J2000ICRF

EclipticJ2000ICRF: An ecliptic system that is a fixed offset of the ICRF system, found by rotating the ICRF system about its X-axis by the mean obliquity at the J2000 epoch (i.e., 84381.448 arcSecs). The ecliptic plane is the XY-plane of this system.

Import detail#

from ansys.stk.core.stkutil import CoordinateSystem