Maintenance Change in Velocity for Geosynchronous Satellite

This equation computes the change in velocity, `DeltaV`, required to compensate for the East-West drift of a satellite in a geosynchronous orbit and thus maintain the satellite in the vicinity of a specified input longitude, `l_D`. 

The resultant change is in meters/second per year

NOTES

Transverse acceleration caused by resonance with the `J_22` term results in periodic motion about one of the two stable longitudes for a geosynchronous satellite.  The two stable longitudes are at approximately 75 degrees and 225 degrees East longitude.  Satellites tend to orbit the closest of these stable longitudes.

The East-West drift resulting from this orbiting of the closest stable longitude causes drift up to 180 degrees and with a period of up to 900 days.