On Fri, 30 Nov 2018 07:15:34 -0700, Chris L Peterson
wrote:
On Fri, 30 Nov 2018 01:36:04 -0800 (PST), StarDust

wrote:

https://www.youtube.com/watch?v=rIesWBTUeiI

It's called Geostationary Oscillation. Not all geo sats are
directly above the equator, they can be slightly inclined whether by
design or insertion failure. The satellite's gyros will compensate
for the movement to keep the footprint centered. Sirius XM sats do a
huge "figure 8" from North to South and back to ensure a uniform
footprint for moving vehicles. A. Kemp - Lockheed Martin
Astronautics?

By definition, all geostationary satellites are above the equator,
and
do not oscillate. If they are inclined, by have a 24 hour orbit,
they
are called geosynchronous, and show that north/south oscillation.

If so, geostationary satellites do not exist since it is impossible
to keep a satellite exactly above the equator at all times. There
will always be some small deviations.

All geostationary satellites are geosynchronous, but not all
geosynchronous satellites are geostationary.