AIPS HELP file for FQTOL in 31DEC18
As of Mon Oct 15 12:00:06 2018
Type: Adverb (Scalar)
Use: Standard data selection adverb, used to define a frequency
tolerance within which data with different frequencies
are assigned the same FQ number. Is mainly used when
merging uv data files together.
Example: if file A has freq #1 and file B has freq #2
then they will be given the same FQ number if
(freq #1 + FQTOL) < freq #2 > (freq #1 + FQTOL).
Null Value: -1
A null value means set FQTOL to be the maximum frequency
difference a source can have in one day, i.e.
FQTOL = ref. freq * (30 km/s) / (30000 km/s)