Search Sub-Mode; Step Track Sub-Mode - RESEARCH CONCEPTS RC2000C Manual

RC2000C Az/El Tracking Antenna Controller
5.4.1

SEARCH Sub-mode

The following conditions lead to activation of the SEARCH sub-mode:
1. TRACK mode is entered from AUTO Mode and program track data is not available in the track table
for the current sidereal time;
2. the STEP TRACK sub-mode is active and the satellite transponder goes down;
3. or PROGRAM TRACK mode is active, and the AGC inputs indicate that a satellite signal is not
present when the sidereal time advances to a value for which track data is not available in the track
table.
The behavior of the controller when the SEARCH sub-mode is active is determined by the state of the
Search Enable CONFIG mode item. If the search is disabled, when the SEARCH sub-mode activates,
the controller will prompt the user to manually align the antenna with the satellite (by using the jog keys)
and hit the ENTER key to transfer control to the STEP TRACK sub-mode. If the sidereal time advances
to a value for which track data is available in the track table, control will transfer to the PROGRAM
TRACK sub-mode.
If the Search Enable CONFIG mode item is enabled, the controller will perform a search for the satellite
using the Intelli-Search algorithm. When the search is performed, the controller will sweep the antenna
in a serpentine shaped pattern over the entire region where it has calculated that the satellite may be
found. The width of the search box is controlled by the Search Width CONFIG mode item. If during the
search a signal is detected above the appropriate AGC threshold (either C or K/L) after the entire
search region has been tranversed the antenna will return to the position where the signal was detected
and control will transfer to the STEP TRACK sub-mode. If the search is unsuccessful, the controller will
wait for Search Retry minutes before initiating another search. The Search Retry parameter may be
inspected and modified via the TRACK MENU - Modify menu. Additional information concerning the
Search sub-mode is available in section 4.2.3. Note that for transmit applications it is generally
advisable to disable the automatic search feature.
When the SEARCH sub-mode is active, the following messages will be displayed to the right of the
satellite name on the bottom row of the display.
SEARCH - A search is in progress. If a satellite is found, the STEP track sub-mode activates.
SEARCH IDLE - A search has been performed and a satellite was not found. The controller is waiting
to perform another search. The TRACK MENU function may be invoked to initiate another
search, or to change the Search Retry Interval. If the sidereal time advances to a value for
which track table data is available, the PROGRAM track sub-mode will activate.
5.4.2

STEP TRACK Sub-mode

When the STEP track sub-mode is active, the following actions can occur:
1. The antenna is periodically jogged in elevation and then azimuth to peak up the received signal
strength.
2. The controller compiles the track table.
3. Control will transfer to the PROGRAM track sub-mode if the sidereal time advances to a value for
which track table information is available.
4. If the signal strength indicates that the transponder has powered down, the controller will wait a
short while for the transponder to come back online before activating the SEARCH sub-mode.
5. The TRACK MENU system may be used to immediately trigger a peaking operation. See section
5.4.5 for a description of the TRACK MENU system. A more detailed description of the STEP track
algorithm is given in section 4.2.1.
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Chapter 5 Modes Function Description 43
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