AIPS HELP file for EVASN in 31DEC22
As of Sun Feb 5 20:22:55 2023
EVASN: evaluates statistics in SN/CL tables
INNAME UV data (name).
INCLASS UV data (class).
INSEQ 0.0 9999.0 UV data (seq. #). 0 => high
INDISK 0.0 9.0 Disk unit #. 0 => any
INEXT Input'SN' or 'CL' table
INVERS Input table file version no.
SOURCES Source list
QUAL -10.0 Source qualifier -1=>all
TIMERANG Time range to consider
STOKES Stokes type to consider
SELBAND Bandwidth to include (kHz)
SELFREQ Frequency to include (MHz)
FREQID Freq. ID to include, -1=>all
BIF 0.0 100.0 First IF to consider, 0=>1.
EIF 0.0 100.0 Last IF to consider
SUBARRAY 0.0 Subarray to consider: 0 ->1
ANTENNAS Antennas to consider 0=>all
CUTOFF Table weight below which data
will not be considered, 0 =>
DPARM Control parameters
(1) max acceptable deviation
from mean gain amplitude
in (robust) rms's
(2) min acceptable cos of
Use: Examines the statistics in an SN or CL table. It determines
the mean and rms of the amplitude of the gain in a robust
fashion and then determines the number and level of outliers.
It examines the decorrelation on baselines due to the changes
in phase between calibrations. All sources may be considered
in SN tables (or limited with the SOURCES adverb) but only
sources with a non-blank CALCODE will be examined in CL tables.
Note that similar considerations may be used in SNFLG to flag
INNAME.....UV file name (name). Standard defaults.
INCLASS....UV file name (class). Standard defaults.
INSEQ......UV file name (seq. #). 0 => highest.
INDISK.....Disk unit #. 0 => any.
INEXT......'SN' or 'CL' table to be consider
INVERS.....Version number of table to consider, 0=>highest no.
SOURCES....Source list. '*' = all; a "-" before a source name means
all except ANY source named. 'ALL' means to ignore the
source identifier in the SN/CL table and combine all of
them into one "source".
QUAL.......Only sources with a source qualifier number in the SU
table matching QUAL will be used if QUAL is not -1.
TIMERANG...Time range of the data to be considered. In order:
Start day, hour, min. sec, end day, hour, min. sec. Days
relative to reference date.
STOKES.....The desired Stokes type to be considered
'R' = RCP, 'L' = LCP, else the phase difference of R and
L is treated as the data for JUMP or the ratio of
R and L gains is treated as the data for AMP.
SELBAND....Bandwidth of data to be selected. If more than one IF is
present SELBAND is the width of the first IF required.
Units = kHz.
SELFREQ....Frequency of data to be selected. If more than one IF is
present SELFREQ is the frequency of the first IF
required. Units = MHz.
FREQID.....Frequency identifier to select (you may determine which
is applicable from the OPTYPE='SCAN' listing produced by
LISTR). If either SELBAND or SELFREQ are set, their
values overide that of FREQID. However, setting SELBAND
and SELFREQ may result in an ambiguity. In that case,
the task will request that you use FREQID. -1 => all,
0 => first
BIF........Lowest IF to consider. 0 -> 1
EIF........Highest IF to consider. 0 -> highest
ANTENNAS...A list of the antennas to be considered. All 0 => all.
If any number is negative then all antennas listed are
NOT to be considered and all others are.
CUTOFF.....If >= 0, the task will examine the weight column of the
table and if the weight < CUTOFF, the task will consider
that sample to be bad. All samples with weight <= 0 are
considered bad. An FG table entry will be generated for
the time surrounding a bad solution.
DPARM......(1) View as "excess" and gain amplitudes that differ from
the robust mean gain solution be more than DPARM(1)
times the robust rms on a per source, antenna, IF,
and polarization basis. 0 -> 6
The robust mean gain amplitude and its rms are
reported as a function of IF and polarization.
The fraction of samples having excess amplitude and
the average of that excess (in rms's) are reported.
(2) Gain phases are examined between the current and
previous solution time on a per source, antenna, IF,
and polarization basis. If the cosine of the
difference in phase is < DPARM(2), then the
correlation is viwed as low. >= 1, <= -1, 0.0 -> 0.5
Then mean and rms correlation are reported as a
function of IF and polarization. Note that a
correlation of 1.0 is full correlation (Delta phase
= 0). The fraction of samples having a low
correlation and the average of those samples are