AIPS HELP file for BDF2AIPS in 31DEC21
As of Fri Sep 17 14:18:06 2021
BDF2AIPS: Verb to read EVLA ASDM/BDF data into AIPS
DOWAIT -1.0 3.0 > wait for and display output
DOCRT -4.0 132.0 > 0 display output on
terminal, else message file
OBITVERS 0.0 =3 for python3, else 2
ASDMFILE Full path name to ASDM dir.
OUTNAME Output UV file name (name)
blank => BDF2AIPS
OUTCLASS Output UV file name (class)
blank => UVEVLA
OUTDISK 0.0 9.0 Output disk drive #
DOUVCOMP -1.0 1.0 >=0 => write compressed data
CLINT 0.0 CL table interval (min)
0 -> 0.25
CONFIG 0.0 Select this "configuration"
# - see BDFLIST output
NCHAN 0.0 Select only data with this
# spectral channels/window
NIF 0.0 Select only data with this
# spectral windows 0 -> any
BAND Select only frequency band
('L','C',...) blank => any
CALCODE Select only scans with this
value of CALCODE
DOSTOKES -1.0 4.0 Select only scans with
DOSTOKES number of Stokes
ORDER -1.0 IFs to be in frequency order?
DOKEEP -1.0 1.0 > 0 => keep online cal data
Use: The OBIT package of astronomy software written by Bill Cotton
of NRAO Charlottesville is available at some institutions. If
it is available and in your $PATH, then you may use this verb
to load the contents of an ASDM/BDF format data set into AIPS.
Use BDFLIST first to see how to set some of the control
The input adverbs are saved with a TPUT equivalent when this
verb is invoked.
The log and run file for each execution of BDFLIST and BDF2AIPS
will appear in your $HOME area.
DOWAIT.....A log file is written into your $HOME area from the obit
task. If DOWAIT <= 0.0, AIPS does not wait for the OBIT
task BDFIn and you will need to look at the log file with
more, less, cat, or an editor. If 0 < DOWAIT < 2, the
messages from BDFIn will appear as the OBIT task generates
them. If DOWAIT >= 2, AIPS will wait for BDFIn to finish
and then echo the log file under control of DOCRT.
DOCRT......> 0 Use the terminal, the full length of the log file
lines will appear so widen it at least a little.
<= 0 Write log file to message file at level 0 (no echo
to the terminal). Some messages may get truncated.
DOCRT is not used when DOWAIT < 2.
OBITVERS...OBIT now is designed to run on python 3 or 2.7. If you
have a newer version of OBIT (post 01-Apr-2021) then you
may want the python3 version. Set OBITVERS to 3.
Otherwise python2 will be invoked.
ASDMFILE...The full path name to and including the top directory of
the ASDM/BDF data. Two 64-character strings may be used
for long names. The ASDMFILE(2) will be appended to the
non-blank portion of ASDMFILE(1) to generate the name
used. The code will also manage when ASDMFILE(1) begins
with either '$xxxx/' or 'xxxx:' where xxxx is a logical
(environment) variable. The filename sent to OBIT will
be the translation of $xxxx followed by a '/' followed by
an remaining non-blank characters in ASDMFILE(1) followed
OUTNAME....Output UV data file AIPS name - 12 characters.
' ' => 'BDF2AIPS'
OUTCLASS...Output UV data file AIPS name - 6 characters.
' ' => 'UVEVLA'
OUTDISK....Output UV data file AIPS disk.
DOUVCOMP...If true (DOUVCOMP >= 0) the output data are written in
compressed format which can result in a substantial
reduction in disk space needed. This can cause some loss
of spectral dynamic range (storage is integer 0 - 32767)
and a really bad data value can destroy all good data
values. The real differences in weights between IFs and
polarizations and spectral channels within a record are
CLINT......CL table interval in minutes. 0 => 0.25
CONFIG.....ASDM files often contain more than one "configuration"
numbered from 0 to N. Configurations may differ in
observing band, number of spectral windows, number of
spectral channels in the spectral windows, etc. Use
BDFLIST to see what configurations are in your data set.
BDF2AIPS can load only one configuration at a time. Used
with NCHAN and overrides BAND.
NCHAN......If > 0, load only spectral windows containing NCHAN
spectral channels. At present, all spectral windows
contain the same number of spectral channels in any one
configuration. However, this will change. When it does,
BDF2AIPS may have to be run multiple times for a single
configuration to get all spectral windows.
NIF........If > 0, load only configurations with this number of
spectral windows (called "IFs" inside AIPS).
BAND.......If not blank, load only data having the specified
observing band. Recognized values:
Selection by band is risky as EVLA bands overlap which may
result in the exclusion of some data. Note lower case
letters - get them by e.g. BAND='Ka where is
the Enter key.
CALCODE....Select only scans with the specified source calibrator
code if not blank. 'NONE' and '-CAL' => none (i.e. not a
calibrator). '*' => anything other than none (i.e. a
calibrator). Otherwise if any character matches the
first character in the Field Table code, the scan is
DOSTOKES...Selects data having only DOSTOKES values of polarizations.
<= 0 -> take the first value found. Some data sets have
2 and 4 Stokes in the same configuration. This parameter
must then be used: BDFLIST will list this as "nStoke".
ORDER......> 0 => the IFs will be written out in frequency order.
LSB bands (X and Ka) need this to swap the order
of the IFs. BUT - it the AC and BD portions of
the data overlap in frequency, set ORDER <= 0.
<= 0 => the IFs are written to AIPS disk in the order
they are found in the SDM/BDF
DOKEEP.....> 0 => keep data marked as on-line calibration data such
as pointing or phase-up or ??
<= 0 => omit such data
BDF2AIPS is also a stand-alone script you may run outside AIPS. Its
help file is appended below. Note that the stand-alone script does
not offer all the options of the AIPS verb.
Type: Stand-alone service program
Use: BDF2AIPS is a script that will read an EVLA ASDM/BDF format data
area and convert it to an AIPS disk file residing on one of the
AIPS data areas of your current computer. It does this by
invoking a task in the obit software package written by Bill
Cotton. That package must be available on your system and the
script ObitTalk must be in your path. If you do not have obit,
it may be obtained from www.nrao.edu and should install fairly
You should use BDFLIST first to list the contents of your
ASDM/BDF format data. It will provide information on
"configuration number" which is essential in defining which data
you wish to load.
BDF2AIPS is a script that is run at the command line (i.e.,
outside of AIPS). It will ask you a few essential questions.
1. "BDF dir-path :"
Give the full path name to the directory containing the
ASDM and BDF data. These data may be obtained from the
2. "AIPS usrnumb :"
Give the AIPS user number you wish to use for these data.
3. "AIPS outname :"
Give the OUTNAME to be attached to the data file.
4. "AIPS outdisk :"
Give the disk number on which to write these data.
OUTCLASS='UVEVLA'; OUTSEQ=0 will be used.
5. "Only SpWs with this number of channels are selected, others
"Default/blank is the #chans in 1st SpW. #chans select : "
Enter 0 or just hit return and the number of spectral
channels in the selected data will be those of the first
data matching the other keywords. This prompt will be
needed when the number of channels is allowed to vary
between spectral windows within a single "configuration".
6. "ASDM array configuration to select : "
Enter the "configuration number" >= 0 of the desired
configuration (ASDMs often contain multiple sets of
spectral windows of different size, frequency, etc.).
Use BDFLIST to list the contents of your data to tell you
which configuration number to select.
7. "Only scans with this number of SpWs is selected, others
"Default/blank is the #SpWs in 1st scan. #SpWs select : "
This question is asked only if you answer question 6 with
a simple carriage return. Enter the number of spectral
windows (IFs in AIPSpeak) of the data configuration you
want to load. 0 or carriage return => any matching the
8. "Default band is the one in 1st PpW."
"Band select : "
This question is asked only if you answer question 6 with
a simple carriage return. Enter the letter code for the
desired band. Note that bands overlap in the EVLA and the
ASDM does not identify which receiver was used so there is
BDF2AIPS will make the output file including a number of
standard AIPS extension files. The CL table will have an
interval of 15 sec and the data are not compressed. The latter
decision is made to avoid loss of dynamic range which could
arise if there is significant RFI or a very strong spectral
line. Sources with identical names and coordinates but
different CALCODEs will be treated as different. This helps
with calibration, but may cause difficulties when it comes time
to run SPLIT.
BDF2AIPS is a simple script and you may make a copy of it and
modify any of the parameters in your private copy to suit
yourself. You may select output FITS format files instead
(DataType) or change OUTCLASS (outClass), CL interval (calInt),
compression (Compress), or source naming with CALCODEs
(doCode). If you select FITS output you must set x.outFile
to the desired output path name.
BDF2AIPS will write a log file and a run file in your /tmp area
with the time included in the name. This file is echoed to the
screen as BDF2AIPS finishes and will remain in /tmp until it is
automatically deleted by the operating system.
For full details of the BDFIn task, in a regular window (not inside
Note that q is needed to get out of the help and explain.