AIPS HELP file for DIFUV in 31DEC21
As of Tue Oct 26 20:53:42 2021
DIFUV: Task to difference/divide two matching uv data sets
INNAME 1st input UV file name
INCLASS 1st UV file class
INSEQ 0.0 9999.0 1st UV file seq. #
INDISK 0.0 9.0 1st UV file disk #
IN2NAME 2nd UV file name.
IN2CLASS 2nd UV file class.
IN2SEQ 0.0 9999.0 2nd UV file seq. #
IN2DISK 0.0 9.0 2nd UV file disk #
OUTNAME Output UV file name
OUTCLASS Output UV file class
OUTSEQ -1.0 9999.0 Output UV file seq. #
OUTDISK 0.0 9.0 Output UV file disk #.
SOLINT 0.0 How close times must match in
OPTYPE 'DIV'=> divide, else subtract
FQCENTER >= 0 -> center frequency axis
Task: This task writes out the difference or ratio of two UV data
sets. It does very little checking to see if they match. One
purpose of this task would be to difference the two throws of
beam-switched single-dish continuum data. Another use would be
to subtract a residual uv data set from the original to produce
a model uv data set. The division operation could be used to
produce a data set suitable for determining gains.
Tables such as calibration (CL, SN), flag (FG), bandpass (BP),
etc. are not applied to either data set. The tables of the
first data set are copied to the output; the tables of the
second data set are ignored.
INNAME.....First input UV file name (name). Standard defaults.
INCLASS....First input UV file name (class). Standard defaults.
INSEQ......First input UV file name (seq. #). 0 => highest.
INDISK.....First input UV file Disk drive # . 0 => any.
IN2NAME....2nd UV file name subtracted from or divided into the
first data set.
IN2CLASS...2nd UV file class
IN2SEQ.....2nd UV file sequence number.
IN2DISK....2nd UV file sequence number.
OUTNAME....Output UV file name (name). Standard defaults.
OUTCLASS...Output UV file name (class). Standard defaults.
OUTSEQ.....Output UV file name (seq. #). 0 => highest unique
OUTDISK....Disk drive # of output UV file. 0 => highest with
space for the file.
SOLINT.....Data are differenced only if times are close. SOLINT sets
that limit in minutes. 0 => 0.01 sec.
OPTYPE.....'DIV' => do division, else do subtraction.
FQCENTER,..> 0 => Change frequency axis reference pixel to
Nchan / 2 + 1
else => do not change reference pixel