Peak jitter threshold --- If the jitter value of at least one axis exceeds this threshold, the
ACU raises an 'model fault'. If this happens three consecutive times, the ACU resets the
models of both axes. Adaptive tracking will be possible not until 6 hours after this
happens.During adaptive tracking, the ACU evaluates for each axis a figure called jitter. The
jitter value describes standard deviation of the measured peak positions with respect to the
positions calculated from the (currently selected) model. The figure is also expressed as a
percentage of the antenna's beamwidth, low values indicate, that the model ideally describes
the antenna's path. High values indicate that's something wrong. The step track results may
be to noisy at low amplitudes or the model does not fit at all. This may be the case if a
satellite gets repositioned in the orbit.A typical threshold value is 20%, this will detect very
early that a model does not fit to describe the satellite's motion. If this value causes false
alarms too often, you may want to raise the threshold to 50%. Setting it to 0 switches the
threshold monitoring completely off.
Prediction Parameters
I11 Ephemerides --- The ACU provides 99 named memory places (numbered 1..99) to
store Intelsat 11 parameter sets. With this parameter you address the number of the I11
parameter set to be used with the 'I11' or 'STEP-I11' tracking modes and for the 'I11' intitial
pointing mode as well. The setting is a reference to the memory location where the I11
parameter are stored, hence, if the parameters at this location are changed the ACU
automatically uses the changed parameters.
TLE Ephemerides --- The ACU provides 99 named memory places (numbered 1..99) to
store TLE ephemerides sets. With this parameter you address the number of the TLE
parameter set to be used with the 'TLE' or 'STEP-TLE' tracking modes and for the 'TLE'
intitial pointing mode as well. The setting is a reference to the memory location where the
TLE parameter are stored, hence, if the parameters at this location are changed the ACU
automatically uses the changed parameters.
max. TLE/I11 age --- If the epoch of a TLE or I11 parameter set which is actually in use
('TLE' or 'I11' tracking modes) is older than the time specified here, a TLE-OUTDATED or
I11-OUTDATED fault is raised. This has no impact on the TLE/I11 tracking but signals, that
the ephemeris data should be updated for an optimal antenna pointing
Target azimuth offset / Target elevation offset --- The offsets specified here are added
to any antenna pointing which is calculated from ephemeris data or from an orbit position
and also to the pointing angles read from a file in PROGRAM tracking mode. The offsets can
be used to compensate for differences between measured and calculated angles, e.g. if the
azimuth axis of the antenna is not exactly vertical. The buttons at the bottom of the target
editor page let you either save the edited value, save the edited values to another memory
location or you may leave the editor without saving the changes.
CANCEL --- This abadons the editing process, leaves the stored values unchanged. You are
returned to the target selection page
SAVE --- This saves the edited values and returns to the target selection page. The updated
target memory is not recalled, not applied to the 'live' settings. If you want this, you have to
click 'go' for this target memory at the target selection page.
SAVETO --- This saves the edited values to the memory location set at the entry field right
beside the button. The value in this field is preset with the target number for which the editor
has been opened. It has to be changed if the editor shall save the edited target to another
location. After saving the ACU returns to the target selection page. Like with 'SAVE', the
saved target memory is not recalled, not applied to the 'live' settings.
All three buttons work immediately when clicked, there is no 'do you really want' query before the
clicked action is executed.
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