Mixed Spherical Coordinate Type

The Mixed Spherical coordinate type uses a variation of the spherical elements that combines Earth-fixed position parameters with inertial velocity parameters. These are also known as DODS elements.

The mixed spherical coordinate type is not available if a Fixed coordinate system is selected.

If you enter the predicted orbital elements and propagate a satellite that is about to launch, it is possible that the launch may not occur at the exact time predicted. A quick way to adjust the elements and repropagate is to switch the Coordinate Type to Mixed Spherical and change the orbit epoch to the new time. The Mixed Spherical coordinate type is independent of the orbit epoch.

Mixed spherical coordinate type elements

Option	Description
Longitude	Measured from -180.0 deg to +360.0 deg
Geodetic Latitude	Measured from -90.0 deg to +90.0 deg. The geodetic latitude of a point is the angle between (1) the normal to the reference ellipsoid that passes through the satellite position and (2) the equatorial plane.
Altitude	The object's position above or below the reference ellipsoid. Altitude is measured along a normal to the surface of the reference ellipsoid.
Flight Path Angle	Horizontal (Hor FPA) or vertical (Ver FPA) flight path angle. The angle between the inertial velocity vector and the radius vector (vertical) or the complement of this angle (horizontal).
Azimuth	The angle in the satellite local horizontal plane between the projection of the inertial velocity vector onto this plane and the local north direction measured as positive in the clockwise direction.
Velocity	The magnitude of the inertial velocity vector.