KNS Ku-BAND RX, Installation And Operation Manual

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4. Theory
4.1 Self-Disciplining Algorithm
The greatest difference of the SAMYUNG ENC antenna system from other stabilized
antennas is its superbly designed algorithm. Pin-point accuracy can be easily obtained
with a spectrum analyzer during satellite cut-over. The key reason for this pin-point
accuracy is to guarantee the capacity for self-discipline, whereby the algorithm constantly
calculates the difference between theoretic and real-time values and disciplines itself
accordingly. This algorithm requires very complex computations, and the SAMYUNG
ENC antenna system uses the 32-bit DSP process with 150 MHz of clock when it
performs the calculation at nano-second (10
-9
) speeds (i.e. a thousand times faster than a
micro-second).
The motioning patterns in land-mobile and maritime applications are very different. For
example, dramatic acceleration or deceleration occurs in land-mobile applications,
whereas pitch-roll-yawl motions occur in maritime applications.
Some vendor stabilized systems may have up to two different sets of algorithms specific
to land-mobile and maritime applications. The SAMYUNG ENC stabilizer uses a single
algorithm for land-mobile and maritime applications simply because the motion sampling
process of the DSP is far faster than any actual motioning condition.
4.2 Searching and Tracking Reference
VS61 antenna uses the “tuning” and “fine tuning” methods. Searching is a “tuning”
process which tries to find the satellite by covering a wide range of elevation and azimuth
motions; tracking is a “fine tuning” process which optimizes the pointing by a “Dish Scan”
mode after searching for the signal of the target satellite.
There are seven searching references, as follows: DVB C/N(Carrier to Noise)
Threshold; DVB AGC Threshold; RSSD Threshold; DVB Carrier Lock Bit; External Lock
Bit; External AGC Threshold; External Lock Bit & DVB C/N Threshold. And, there are
three tracking references: DVB Tuner AGC Level; DVB C/N Ratio; and RSSD Level. The
ACU can be configured by the operator to function in any combination of Searching and
Tracking references.
NOTE : With the threshold searching references the antenna will perform a search
pattern until the receive level measured by the RSSD or DVB tuners exceeds the pre-
configured threshold level.