Angle Display Of Az/El Position Data - RESEARCH CONCEPTS RC2000A DUAL AXIS Instructions Manual

RC2000A Dual Axis Antenna Controller Chapter 3 Installation/Setup 31
non-volatile memory closest to the antenna's present position. With an elevation over azimuth type
mount, however, it is recommended that the user always manually peak up the H and V polarization
values for each satellite.
When the Pol Control? CONFIG mode item is set to something other than None, SETUP mode prompts
the user to specify the band (C, Ku, or hybrid C and Ku) of each satellite stored in non-volatile memory.
Each satellite data entry contains two polarization position values. One normally holds the horizontal
polarization position and the other the vertical polarization position.
If the antenna is equipped with a two port feed and the user specifies either a C band satellite or a Ku
band satellite (i.e. not a hybrid satellite) the user will only be prompted to supply a single polarization
position. For this case, the polarization position supplied by the user is copied to both polarization
positions associated with the satellite data entry.
If the antenna is equipped with a two port feed and the user specifies a hybrid satellite, SETUP mode
prompts the user to specify whether or not he or she wishes to specify unique C and Ku band
polarization values. If the user opts to provide unique C and Ku band polarization values the C band
polarization position is stored in the location commonly employed to store the horizontal polarization
position. The Ku band polarization position is stored in the location normally used to store the vertical
polarization position.
If a modified polar antenna mount is used (see section 3.4.3 - Geo Elevation Position for a discussion of
modified polar mounts) the option of using H/V data from the nearest satellite may be a time saver. For
C band satellites H and V polarities are well coordinated from one satellite to the next (i.e. the H
polarization position for Galaxy 5 are nearly the same as the H polarization position for Galaxy 6 - both
are C band satellites). For Ku band satellites, however, the H and V polarities are not well coordinated
from one satellite to the next. Using the 'H/V polarization data from the nearest satellite' option should
be selected only for the case where the user is using a modified polar mount in a C band only system.
It is recommended that the user first program in a pair of satellites and then use the AUTO mode to
repeatedly position the antenna on one satellite and then the other. This will exercise the controller,
actuators, mount, and position sensors. If the antenna does not return to the peak for each satellite
make sure that the position sensors are properly wired. After the operation of the system has been
verified by testing with two geostationary satellites, the rest of the satellites may be programmed in.
3.7

Angle Display of Az/El Position Data

The RC2000A antenna controller has the capability to display it's azimuth and elevation position in an
angle format. This capability can facilitate the process of locating satellites during system setup for
systems that employ an elevation over azimuth type of antenna mount. This section describes the
procedure for enabling, calibrating, and using the angle display feature. The procedure outlined in this
section makes use of the programs (designed to run on an IBM compatible PC) found on the floppy disk
included with the controller.
The controller can display azimuth and elevation position in a degrees format. When this feature is
enabled, the azimuth position is displayed as a true heading (in degrees - 0 to 360) and the elevation
position is displayed as an angle above the horizon (0 to 90 degrees). This feature is controlled by
parameters specified by the user via CONFIG mode. The scale2.exe program on the floppy disk can be
used to determine these parameters once a pair of satellites has been found.
Another program included on the floppy disk is antenna.exe. This is a general purpose program which
aids the user in locating any satellite. This program prompts the user to enter the antenna longitude
and latitude, the satellite longitude and the satellite inclination angle and calculates the magnetic
heading, true heading and elevation angle above the horizon needed to intercept the satellite. For
geostationary satellites, the satellite inclination angle is 0.
The following step by step procedure can be used to locate geo-stationary satellites. In the process, the
parameters needed to display azimuth and elevation parameters in an angle format will also be
determined.
1. Determine the antenna latitude and longitude. Obtain a satellite guide and identify the pair of
satellites which will be located initially and used to calibrate the angle display. A reasonable
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