Coordinate Type (Orbital Elements)

STK supports several different coordinate types. Each coordinate type is a unique representation of the position and velocity of a vehicle. Available coordinate types depend on which STK capabilities you are licensed for and the propagator selected. The parameters that you must define and the data that you must provide depend on the coordinate type that you choose.

Coordinate Type	Description
Classical / Keplerian	Uses the traditional Keplerian orbital elements to specify the shape and size of an orbit.
Cartesian	Enter the initial X, Y and Z position and velocity components of the satellite.
Equinoctial	Uses the center of the central body as the origin and the plane of the vehicle's orbit as the reference plane.
Delaunay Variables	Uses a set of canonical action-angle variables that is commonly used in general perturbation theories.
Mixed Spherical	Uses a variation of the spherical elements that combines central body-fixed position parameters with inertial velocity parameters.
Spherical	Define the path of an orbit using polar rather than rectangular coordinates.
Spherical Range Rate	This is a variation of the spherical elements that uses range rate, right ascension rate, and declination rate to describe the velocity elements of a vehicle.
Geodetic	This is available when using a Fixed coordinate system.
Target Vector Incoming Asymptote	Used for hyperbolic arrival trajectories.
Target Vector Outgoing Asymptote	Used for hyperbolic departure trajectories.
B Plane	Used to target a specific position for hyperbolic arrival trajectories

Reports and graphs are available for the above coordinate types, as well as for Kozai-Izsak and Brouwer-Lyddane Mean Elements.