satellites drifts east/west and north/south in a 24 hour cyclus.
satellites drifts within a box of +/-0.05 degrees. Some within as
as +/-0.01 degrees
Astra 1B over a 24H period ( figure linked from www.coolstf.com ).
With some old satellites the lifetime can be prolonged by saving
fuel for orbital
north/south manouvers which result the satellite drifting in the
Latitude. In the extreme some satellites
is 15 degrees inclined which means they moves inside a +/-15
degree box not a +/-0.03 degree box
like in the Astra 1B example.
At http://www.lyngsat.com/tracker/europe.shtml there is sat
can show the current inclination for all satellites including the
Inclined Orbit. It is imortant that the computers clock is
correct. The tracker uses GMT
time which is derived from the computers local timeoffset so it's
OK to use local time as long as
correect timezone is selected.
SatTracker is developed by Rod Hewitt and the official WEB site
located at http://www.coolstf.com/sattracker/index.html
Ephemeris data can be downloaded online for Thor ,Intelsat and
satellites. The antenna pointing angles can be calculated at
170 hour listing can be generated. Se example for Intelsat 707 - London 2.11.2002 to
to do cheap manually Inclined Orbit Tracking ?
motorised systems only can be controlled in the east/west
direction (single axisis). This angle is called the
hourangle ( X-ANGLE on the drawing below)
the north/east direction should be adjusted by a motor an
actuator has to be installed to control the polar axis angle
is simply the north/south direction.
actuator can in most cases be fitted to do this job. Some
welding/drilling might have to be carried out on the existing
The actuator can be controlled my a manually +/-36V powersupply
or a positioner.
makes polarmounts which have actuator for north/south direction. SMR1224 EL.
More Jaeger info
receivers like the old Chapparal Monterey 140 receiver is capable
of controlling dual axis ( two actuators)
and authomaticly track the satellite based on the signal level
from a defined channel. Also some old Drake analog receivers
have possibility of dual axis control.
the manual tracking method works well in home systems and it also
gives better performance of normal satellites if the
polarmount is not 100% correctly tracking the arc. For bigger
antennas (>2m) it's nice to have manually north/south tracking
as it's more likely the polarmount will not track 100% in Ku-band..
Inclined Orbit links:
20©02 Jens T. Satre