AIPS HELP file for TDEPEND in 31DEC24
As of Sat Oct 12 14:07:01 2024
TDEPEND: Procedures to do time-dependent imaging
INPUTS
******** see TDSTEP3 and TDSTEP5 for adverbs *********
HELP SECTION
TDEPEND
Type: Process
Use: TDEPEND is a process involving some procedures which you may
use plus some steps which you are left to do in your favorite
way. To compile the procedures, enter RUN TDEPEND, a command
you need enter only once. The process consists of 3
preliminary steps, plus a pait of steps which may be iterated.
The preliminary process is:
1. Run task SPLIT on your data to create a fully calibrated and
editied single-source data set. Set INNAME, INCLASS, INSEQ,
and INDISK to point at this output data set for inputs to the
later steps.
2. Prepare adverb TD_TIMES which is a list of times in days
indicating the time ranges to be used in breaking up your data.
Thus the I'th time range is from td_times(i) to td_times(i+1).
The procedure TDSSCAN(i,j) will read the index table and find
all scans of source i. It will make j time intervals within
each scan, filling the TD_TIMES adverb. TDSCANS(i) does the
same with simple breaks between scans.
3. TDSTEP3 loops over the time ranges doing:
a. SPLIT to make 'ISPLIT' containing all data for time
range (i)
b. IMAGR of NFIELDS+1 where NFIELDS is the number of
facets required to image the full area and facet
NFIELDS+1 is centered on the time-variable target
source. BOXFILE must include all NFIELDS+1 facets and
should do an UNClean box on the target source wherever
it occurs in facets numbered <= NFIELDS and should do
UNClean boxes surrounding the source in facet
NFIELDS+1. The latter is really only required if you
do auto-boxing.
c. UVSUB subtracts facet NFIELDS+1 from ISPLIT and appends
the data in a file with class 'APPEND'
d. It then deletes ISPLIT and all images and beams.
The iterative process includes:
4. Iterate over:
a. ZAP any previous images from this step
b. IMAGR on APPEND with NFIELDS and the UNClean box
surrounding the time variable source. Use an OUTNAME
to differentiate the output images from those of
TDSTEP1 and TDSTEP3.
c. CALIB on APPEND with these images - always use APPEND
as the input data set since we need to build a total
correction SN table.
d. Flag as needed
Then TACOP the final net SN table to the single-source
input file created in step 1. TAPPE the final FG table to
the previous FG table of the single-source file.
5. TDSTEP5 initially deletes the APPEND file if needed and any
target image files with class 'TRGT*'. It then loops over
the time ranges doing:
a. SPLIT to make 'ISPLIT' containing all data for time
range (i)
b. UVSUB the final model produced in step 4 (and contained
in adverbs NMAPS and IN2NAME, IN2CLASS, etc.) to make
ISOURC containing only the target source visibilities
c. IMAGR on the target source, making NGAUSS images of a
single facet.
d. UVSUB the model found in (c) from ISPLIT and append the
result to APPEND, a data set containing all sources
except the target.
e. Rename the target images from ICL0nn to TRGTnn.
f. It then deletes IUVSUB, ISPLIT, ISOURC, and all beams.
Repeat 4 and 5 until done. Result is 1 set of images of the
time independent full field, plus 1 set of target source
images as a function of time.
EXPLAIN SECTION