movement based on the sidereal time with a time offset. The amplitude is defined by the
inclination. The time offset can be calculated from the tracking data look angles and
dynamic.
The summary of these three terms will provided at least the polarization value.
As we see from above definition, it will necessary to have some additional information to initiate a
polarization prediction. Therefore it will be necessary to provide the sat-nms ACU the following
parameter in the ??Tracking Parameter' menu:
Target orbit position: This Parameter should define the nominal Orbit position of the
satellite. This value should be available from the satellite operator. Remark : In the
Polarization prediction setting ??ADAPTIVE?? this value will be recalculated after get a valid
medium model, but only small changes are allowed per calculation cycle to the bases value
(+/-0.5??). Therefore the start orbit position have to set within this range.
Inclination: The actual inclination value of the satellite. This value should be also available
from the satellite operator.Remark : In the Polarization prediction setting ??ADAPTIVE?? this
value will be recalculated after get a valid medium model, but only small changes are allowed
per calculation cycle to the bases value (+/-0.5??). Therefore the start inclination have to set
within this range.
Satellite Pol offset: The linear polarization offset of the satellite. This value should be also
available from the satellite operator or have to be measured.
Since we need from the tracking also the dynamic of the satellite (movement up or down),
the sat-nms ACU cannot start the polarization prediction immediately after setting the
polarization prediction to ??ON?? or ??ADAPTIVE??, it need some tracking cycles to clearly
identify the direction of movement (15min.). If the main tracking mode is ??I11?? or ??TLE??
the polarization prediction will start immediately because the movement of the satellite is
already defined by the satellite ephemerides.
There are different faults which could occur during operation. Please also refer to chapter
Operation
. Below is a collection of all this faults.
There are the following cases for a fault of one axis. 'TIMEOUT' and 'FAULT' are releasable
during a tracking cycle. A 'STOPPED' fault have to be released with the RESET button:
Jump Values of angle encoder; 5?? in azimuth and elevation or 10?? in polarisation
('STOPPED')
Antenna moves 5sec into the wrong position ('STOPPED')
Motor timeout occur because of no antenna movement within the entered time ('TIMEOUT')
Motor fault input triggered for example from frequency converter ('FAULT')
There are the following cases for a 'STOPPED' fault of all axes together, which have to be
released with the RESET button:
Trigger emergency stop input
Click the STOP button on the web interface
All faults are released by clicking the RESET button on the web interface or by sending the
remote command mrst=0. The RESET button activates the 'MOTOR RESET' outputs of all three
axes for a quarter second and delete the fault flags. All target angles are set to the actual value
to suppress an immediate movement of the antenna.
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ACU2-19V2-UM-2209 Page 98/99
