Spherical Range Rate Coordinate Type

The Spherical Range Rate coordinate type uses the range to measure the distance of an object from the center point of the coordinate system. The angular location of the object is specified by the right ascension and declination. In contrast to the Spherical and Mixed Spherical coordinate types, the velocity of the object is given in terms of range rate, right ascension rate, and declination rate. The angular elements depend on whether the coordinate system is fixed or inertial.

Spherical Range Rate elements

Option	Description
Right Ascension (inertial)/ Longitude (fixed)	Right Ascension is defined as the angle from the X axis to the projection of the satellite position vector in the equatorial plane measured as positive in the direction of the Y axis.
Declination (inertial)/ Latitude (fixed)	Declination is defined as the angle between the satellite position vector and the inertial equatorial plane measured as positive toward the positive inertial Z axis.
Range	Range is defined as the distance of an object from the center point of the coordinate system.
Right Ascension Rate (inertial)/Longitude Rate (fixed)	Right Ascension Rate is defined as the change of the right ascension angle over time.
Declination Rate (inertial)/Latitude Rate (fixed)	Declination Rate is defined as the change of the declination angle over time.
Range Rate	Range Rate is defined as the change of the range over time.