AIPS HELP file for VLBAAMP in 31DEC21
As of Fri Dec 4 4:32:29 2020
VLBAAMP: Applies a-priori amplitude corrections
INNAME Input file name
INCLASS Input file class
INSEQ Input file sequence number
INDISK Disk number for input file
SUBARRAY Subarray to correct. 0=>ALL
DOFIT Fit for opacity correction
BADDISK Disks to avoid for scratch
VLBAAMP is defined in the VLBAUTIL run file.
Use: VLBAAMP is a procedure that applies post-bandpass and delay
calibration amplitude correction and a-priori amplitude corrections.
These corrections are added to the corrections in the highest
numbered CL table.
VLBAAMP assumes that you already have GC and TY tables and that you
have at least one CL table.
Type RUN VLBAUTIL to define the VLBAAMP procedure.
INNAME.....The name of the file to be corrected. Wildcard characters are
INCLASS....The class of the file to be corrected. Wildcard characters are
INSEQ......The sequence number of the file to be corrected. Zero defaults
to the highest sequence number of a file matching INNAME,
INCLASS, and INDISK.
INDISK.....The disk drive number of the file to be corrected. Zero defaults
to any disk.
SUBARRAY...The subarray to correct. Zero defaults to doing all.
DOFIT......Do opacity correction in APCAL. This is recommended
for high frequency experiments (freq >= 15~GHz) if the
accuray of the source flux is important.
BADDISK....A list of disks on which scratch files are not to
be placed. This will not affect the output file.
VLBAAMP: Procedure to apply a-priori amplitude corrections
Documentor: Amy Mioduszewski
Related Programs: VLBAUTIL, ACSCL, SNSMO, APCAL, CLCAL
VLBAAMP determines the post-bandpass and delay calibration amplitude
correction and a-priori amplitude corrections from the gain curves and
system temperature measurements, and applies these corrections to the
highest numbered calibration (CL) table attached to the input file.
Note that interpolation type 'SELF' is used for the a-priori amplitude
calibration, to avoid interpolating between sources at different
elevations, among other things.
You should run VLBAAMP after loading any gain curves or system temperature
data for non-VLBA antennas using ANTAB.
VLBAAMP should be used along with (and after) VLBAACOR and VLBAPASS instead
of VLBACALA. This redesign of the amplitude calibration path is based on
VLBA Scientific Memo #37 (Craig Walker). VLBAAMP should NEVER be used with
VLBACALA. The new recommended steps for amplitude calibration are:
1) Do preliminary calibration steps that are necessary (e.g., VLBAFIX,
2) VLBACCOR -- digital sampling corrections
3) VLBAMPCL (or VLBAPCOR) -- remove instrumental delay
4) VLBABPSS -- do bandpass
5) VLBAAMP -- correct auto-correlations and a priori amplitude calibration
6) Continue with calibration.