Research Concepts RC4000 - Manual (Page 138)

RC4000 Antenna Controller Chapter 4 Support
130
The azimuth scale factor is obtained by noting the difference in the azimuth pointing solution angles
between two satellites and the pulse counts when on the satellites. For best results, use satellites that
are as far apart as possible and make sure you have positively identified the satellites.
Example : Kansas City (38’56N,94’45W) heading of 180.0
SATELLITE AZIMUTH POINTING
SOLUTION ANGLE
PULSE
COUNT
SPACENET 2 (69.0W) -37.5 33333
SATCOM C5 (135.0W) 53.4 11000
Difference 90.9 22333
(22333 / 90.9) * 57.29 = 14075 pulses/radian
SCALE FACTOR FOR RESOLVER SYSTEMS
The RC4000 uses the actual digitized resolver count in the same way it uses a pulse count. The RC4000
utilizes a 16 bit resolver to digital converter which generates a count value from 0 to 65,535. Typically the
resolver sensor rotates with the antenna. The resulting “pulse scale factor” therefore is:
65536 reslover counts / ( 360 degrees * 1 radian/57.29 degrees) = 10430.2 “pulses” / radian
The default scale factor for a resolver system is therefore rounded up to 10431.
The constants are entered via the azimuth pulse drive (3.3.1.7) and elevation pulse drive (3.3.1.10)
configuration item screens.