O3b Operation and Maintenance from MtsVLink (ACU)
Maintenance Modes
OceanTRx™4-500 O3b System Installation Guide
6-5
6.2.4
O3b Hunt
This is a batch activating Satellite Preset towards the "O3b Hunt" point, then
waiting for the Signal to appear (cross the Threshold level), then invoke Step-
Track
The "O3b Hunt" is a Longitude point on the O3b Satellite Arc calculated as follows:
Antenna GPS Longitude – 180/Number_of_O3b_Satellites
The
O3b Hunt
mode is presented in the Mode List menu only when O3b
Constellation is selected.
6.2.5
Step-Track
Periodically re-peak the Antenna on signal maxima with respect to O3b Satellite Arc
with the Azimuth-Elevation Satellite view angles constantly trigonometrically
recalculated using Altitude and Constellation Period parameters.
If the signal times out below threshold, or Antenna view is blocked,
Search
mode is
automatically invoked.
If the signal is re-acquired (exceeds the threshold by a predefined "epsilon"), the
Antenna reverts back to
Step-track
6.2.6
Peak
Point the Antenna to the Point of maximal reception as found by the last Step-Track or
Program-Track iteration.
Keep Antenna moving on the O3b Satellite Arc. If invoked during Step-Track, calculate
Antenna movement using trigonometry of O3b Trajectory Altitude and Period. If
invoked during Program Track, calculate Antenna movement using TLE math.
6.2.7
Acquired Satellite Preset
This is a batch, activating Satellite Preset and then Step-track modes one after the
other:
Ask for Orbital Longitude (numeric float value in the range of -180.00 to
180.00 degrees)
Calculate Az/El view angles towards the O3b Arc
Point to O3b Arc location
Periodically re-peak the Antenna on signal maxima with respect to O3b
Satellite Arc with the Azimuth-Elevation Satellite view angles constantly
trigonometrically recalculated using Altitude and Constellation Period
parameters.
If the signal times out below threshold,
Search
mode is automatically
invoked.
If the signal is re-acquired (exceeds the threshold by a predefined
"epsilon"), the Antenna reverts back to
Step-track
