Steptrack; The Sat-Nms Steptrack Algorithm - Calian SatService sat-nms ACU-19V User Manual

Remark for operation in the northern/southern hemisphere:
Look 'through the antenna' to the satellite for the correct orientation of left/right, up/down and
clock/counterclockwise.
axis
azimuth
The center direction to the satellite orbit is 180°. Turning angles are between 0 to 360° | FWD
moves the antenna to the right, the position sensor must increasing the measured value. FWD
moves the antenna 'eastward' The center direction to the satellite orbit is 0°. Turning angles are
between -180 to +180° | | elevation | FWD moves the antenna up, the position sensor must
increasing the measured value. Turning angles are between 0 to 90° | FWD moves the antenna
up, the position sensor must increasing the measured value. Turning angles are between 0 to
90° | | polarization | FWD turns the feed clockwise, the position sensor must increasing the
measured value. Turning angles are between -180 to 180° | FWD turns the feed clockwise, the
position sensor must increasing the measured value. Turning angles are between -180 to 180° |

8.3 Steptrack

sat-nms ACUs having the "ACU-ODM Software Upgrade Step Track" installed are capable to
track a satellite's position. The
algorithm works. Beside plain step track, this option includes the so called
file/program tracking
receiver to be connected to the ACU, the file/program tracking works without any beacon
measurement.

8.3.1 The sat-nms Steptrack Algorithm

The principle of satellite step tracking is quite simple: For each axis, move the antenna a small
amount away from the satellite, move it a small amount to the other site and finally point the
antenna to that position where the signal is the strongest. The sat-nms ACU uses an optimized
variant of this method which lets the tracking find the best pointing ('peak') with a minimum
amount of depointing.
Within one step track cycle on one axis, the ACU does several very small steps. Using the
position and beacon level values of all steps in the cycle, the ACU calculates the peak position by
aligning the approximated antenna pattern to the measured points.
(C) 2022, SatService GmbH
northern hemisphere
FWD moves the antenna to the right, the position sensor must
increasing the measured value. FWD moves the antenna
'westward'
following paragraph
facility as well. While step track and adaptive tracking require a beacon
www.satnms.com
describes how the sat-nms steptrack
adaptive tracking
southern
hemisphere
and a
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