Systems for comparing and ranking a plurality of signal inputs

DETAILED DESCRIPTION A system is provided for comparing the signals from a plurality of sources to a reference signal and for gating out of the system the best quality signal and for updating the reference signal to reflect the best quality signal.
The signals from the plurality of sources are sequentially provided to one input of a comparator.
At the second input of the comparator a second signal is provided which is indicative of the previous best quality signal.
The comparator is responsive to the signal level at the first input indicating a higher quality signal at the signal input for gating the higher quality signal out of the system and providing a new reference signal indicative of the new higher quality signal to the second input of the comparator.