AIPS HELP file for PHASE in 31DEC22
As of Wed Nov 30 8:09:03 2022
PHASE: Baseline dependent time averaging of "BT" order uv data
INNAME Input UV data (name)
INCLASS Input UV data (class)
INSEQ Input UV data (seq. #)
INDISK Input UV data disk #
OUTNAME Output uvdata name (name)
OUTCLASS Output uv data class
OUTDISK Output uvdata disk #
OUTSEQ -1.0 32000.0 Output seq. no.
APARM (1) Max Coherent ave time
(2) Max SNR deviation to pass
(4) Min Vector/Scalar ratio
(5)>0 = Coherent Average `
(6) Interval to write out
(10) Prtlev, (# baselines)
BADDISK Disk #'s to avoid
Type: WARNING, WARNING, Verrry Experimental Task WARNING.
Use: Baseline dependent estimation of coherence time,
automatic flagging of data and coherenct time averaging
NB: data must be sorted to 'BT' order before running.
INNAME.....Input UV data file (name). Standard defaults.
INCLASS....Input UV data file (class). Standard defaults.
INSEQ......Input UV data file (seq. #). 0 => highest.
INDISK.....Input UV data file disk #. 0 => any.
OUTNAME....Output UV data name (name). Standard defaults.
OUTCLASS...Output UV data file (class).
OUTDISK....The disk # of output data. 0 => highest
OUTSEQ.....Output sequence number. 0 => new file.
APARM.....Task enrichment parameters.
(1) This gives the maximum averaging time in
seconds, 0=> infinite.
This parameter may be necessary if subsequent
editing or self calibration is required.
(2) Max SNR deviation to pass. While calculating
the coherence time, the mean and rms of each
baseline is calculated. If the value of a
visibility exceed A(2) times the RMS, the correlator
(3) No longer used.
(4) Min Vector/Scalar amplitude ratio. The ratio of
the vector to scalar amplitude of the real and
imaginary parts of the correlator output is calculated
for the average of a few visibilities. When the
ratio becomes less than A(4) the coherence time is
said to be exceeded. A(4) = 0.9 is good for many
(5) if A(5) > 0 then the output data are averaged
(smoothed) over the coherence time for the baseline
(6) Interval to write out data. The data should
be written out at an interval of 1/2 the coherence
BADDISK...Disk #'s to avoid for scratch files
Documentor: Glen Langston
An output of PHASE is the minimum coherence time for all
baselines. This result is placed in the output uvdata header.