Initiating A Track On An Inclined Orbit Satellite - RESEARCH CONCEPTS RC2000C Manual

38 RC2000C Polar Tracking Antenna Controller
The Max Track Error and Search Width CONFIG mode items are discussed in section 4.2. The default
values are 10 and 5, respectively. The Max Track Error is specified in tenths of a dB. When initiating a
track on an inclined orbit satellite for the first time, it is probably best to leave these parameters at their
default values. See the section on tracking problems at the end of this chapter for more information on
the Max Track Error parameter.
The Search Enable CONFIG mode item is used to enable or disable the Intelli-Search feature when the
SEARCH sub-mode is active. When disabled, the SEARCH sub-mode will simply prompt the user to
manually jog the antenna (via the front panel) back onto the satellite and hit the ENTER key. When the
ENTER key is pressed, control will transfer to the STEP TRACK sub-mode. The Intelli-Search should be
disabled for transmit applications, or when the RC2000 is interfaced to an antenna which moves very
slowly.
4.4.4

Initiating a Track on an Inclined Orbit Satellite

This section describes the process of initiating a track on an inclined orbit satellite. It is assumed here
that the user has entered the configuration data outlined in sections 4.4.1 through 4.4.3 into the controller,
and that there are no alarm messages flashing on the bottom row of the display. If there are active
alarms, they must be cleared before initiating a track on an inclined orbit satellite.
The steps required to initiate a track are very similar to the procedure used to program a geostationary
satellite into the controller's memory. A track is initiated from SETUP mode as follows:
1. Go to SETUP mode and use the jog keys to manually align the antenna with the satellite. The
polarization can be skewed via the CW and CCW keys.
2. Use the SCROLL keys to select the satellite name. Press ENTER to assign the name to the satellite.
If the name is not in the list, go to step 3.
3. If the satellite name was found, skip this step. If the name was not in the list, select the USER entry.
Then use the SCROLL keys to scroll through the alphanumeric list to key in the name of the satellite.
Press the ENTER key to select each letter/number, and press ENTER at the "*" to terminate the
entry. A blank space can be entered by pressing SCROLL UP once and SCROLL DOWN once.
4. 'IS THIS AN INCLINED ORBIT SAT'. Hit the YES key in response to this question.
5. 'ENTER SAT LON LLL.L'. Use the number keys and the decimal point to enter the numeric portion of
the satellite longitude; i.e., if the longitude is 100.5 West, key in '100.5'. Terminate the entry of the
numeric portion of the satellite longitude by hitting the ENTER key. The BKSP key may be used to
backspace over any incorrectly entered data any time before the ENTER key is pressed.
The user is next prompted to enter the direction associated with the longitude entry. Hit the 4 key to
specify an East longitude, and hit the 6 key for a West longitude. Hit the ENTER key to terminate the
entry.
6. 'SELECT BAND 0-C,1-K,2-C&K,3-L'. If the satellite is a hybrid which has both C and Ku band
transponders, select 2. Otherwise, key in the appropriate band designation.
7. 'SAT INCLINATION (2-16 DEG):' See Appendix G for a list of inclined orbit satellites and a
nomograph which may be used to determine the inclination of the satellite's orbital plane to the
earth's equatorial plane. Key in the appropriate value, followed by ENTER. Note that very few
communications satellites have an inclination greater than 6 degrees. If you are unsure of the
satellite inclination, try 5 degrees.
8. The user is next prompted to specify the horizontal and vertical polarization values for the satellite.
Use the CW and CCW keys to skew the polarization, and the H and V keys to set the polarization.
Values must be specified for the horizontal and vertical polarizations even if the antenna has no
polarization adjustment. In this case, make sure that the Rotating Feed Present CONFIG mode item
is set to NO. The controller will then assume that a polarotor is connected to the antenna. A
polarotor is controlled in an open loop fashion, i.e., the controller sends control signals to the
polarotor and does not receive any feedback (the controller cannot tell whether a polarotor is present
or not). NOTE: The most common mistake made by the user is to set both polarization values at the
same position. Make sure that both values are peaked up on different transponders.
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Chapter 4 Inclined Orbit Satellite