Conical scan tracking system employing a large antenna

摘要

A conical scan tracking system for spacecraft and radio sources employing a large antenna detects small sinusoidal modulation in received power from a source that is off target with a frequency equal to a very low scan rate, an amplitude proportional to angular deviation of the source from the target, and a phase directly related to the direction the source is off target. The sinusoid is digitally correlated with inphase and out-of-phase (90 DEG ) scan sinusoids to obtain azimuth/elevation and hour angle/declination signals which are digitally integrated over exactly one scan period (e.g., 10 to 100 sec) to obtain correction signals for an antenna pointing subsystem.