AvL Proprietary and Confidential
Content is Subject to Change without Notice
Page
164
of
195
When one of these signal sources is selected for acquisition, the AAQ will move directly to the “AZ
Line Scan” starting point based on the pointing solution for the target satellite and initiate a raster
scan. The AZ line scan is stopped immediately upon target satellite signal detection
(modem/receiver lock indication) and the AAQ shifts directly into peaking mode. The AAQ does not
normally execute a SATTANT when the Signal Source is Modem or Beacon Receiver since
neighboring satellites that lie on or close to the AZ line scan will be ignored by these signal sources.
7.4.9 Peaking on the Signal
After acquisition is complete, the AAQ peaks on the satellite signal in two stages; referred to as
Coarse Peaking and Fine Peaking. The objectives for Coarse Peaking are to (1) insure that the
system is peaking on the main beam of the antenna’s pattern and not a “side lobe” and (2) position
the antenna such that the peak of the main beam is closely aligned with the satellite. The objective
for Fine Peaking is to precisely align the antenna with the target satellite.
The following Sections, describe the default (recommended) mode for Coarse and Fine Peaking on
the Target Satellite signal. In reality, either of the modes described here (Cross Peaking and Step
Peaking) may be used. Additionally, Coarse and/or Fine Peaking may be skipped entirely if that is
the Integrator’s choice. All of these options are configurable via the AAQ Profile System parameter
settings described in Chapters 4 & 5.
7.4.10
Coarse Peaking
At the completion of the acquisition process, the antenna is aligned close enough to the satellite’s
location to receive a signal that meets or exceeds the user settable minimum detection threshold.
The next step involves reliably moving the center of the antenna’s main beam (boresight) to an
angle that aligns closely with the target satellite. This is usually accomplished by executing cross
scans as illustrated in Figure 7.4.9.