It is not really necessary to have drive rate control, if the position
update rate is sufficiently high. This is much simpler and has the same
effect. If you really need the drive rates (eg.g for a PID type control
algorithm) they can be obtained by numerical differentiation of the
positions inside the TCS. The path of a satellite across the sky is
described by a trigonometric function. The first derivative of this
function is again a trigonometric function. Drive rate control would
only conserve bandwith (lower the bandwith requirement), if the new
function has less curvature (not so wobbly). This only happens if
the pole of the telescope mount is nearby the pole of the satellite
path. In the late fifthies and sixties, satellite tracking telescopes
have been built with such adaptable mounts to alleviate the control
problem and to avoid the excessive drive rates necessary if the
satellite comes near the pole of the mount (known as Dobsons hole by
amateur astronomers).

The problem with the MEADE LX-200 TCS is the insufficient update rate of
2Hz and the use of fixed drive rates. Btw. it might be possible to get
a better result if the slew drive rate of the
MEADE TCS would be intelligently reprogrammed with respect to the distance.
Mels TCS works at 18.2Hz and has an almost infinite range of drive rates.
Professional systems at modern telescopes have bandwiths of around 100Hz.
A pentium class system is capable of computing the position of a
single satellite every 55ms with enough time left to control the motors.

Markus Kempf