Zhao, Jun-Hui

10:13 AM (5 minutes ago) On Thu, Sep 12, 2013

to BumHyun, smamiriad
> Are there some difference between SMA-miriad and other miriad version (i.e. carma) in Task 'INVERT' and 'UVLIN' ?

The latest SMA-miriad beta version was based on early miriad_cvs version 4.1.3 in Nov 2009 when we implemented patches for
double-band while the latest carma version should be miriad_cvs version 4.3.5 or newer.

In addition, for the SMA-miriad beta, we added a routine (a debugging feature) to examine the headers prior to processing
the visibility in some of the tasks that involved handling uv data and were easy to be (often) collapsed in the end-to-end (e2e)
data handling routine (scripte) due to wrong header variables or badly calibrated spectral channel vis in the uv-data which were produced by
users with their own Miriad; some of them used very old versions of Miriad. The default for those tasks is only to handle uv data produced
from the e2e process with SMA-miriad beta. In the relevant tasks, options=nochk is given to disable this function. Other than that,
these tasks should be identical to those in miriad_cvs version 4.1.3 imported from carma CVS.

I checked, both invert and uvlin are among the tasks:

%uvlin
%help
....
Keyword: options
This gives extra processing options. Several options can be given,
each separated by commas. They may be abbreivated to the minimum
needed to avoid ambiguity. Possible options are:
sun With this options, the OFFSET keyword is ignored,
and a shift appropriate for the Sun is determined
This can be useful to eliminate solar interference.
twofit If either the OFFSET parameter is set, or the SUN
option invoked, this options instructs UVLIN to
perform a simultaneous polynomial fit for a emission
both at the phase centre and at the appropriate
offset.
nowindow Normally uvlin processes the different windows separatel
This will usually give the best result when the differen
windows are at quite different frequencies. However when
the windows are at similar frequencies, or perhaps even
abutting, then it is better to perform a single fit over
all windows simultaneously. The "nowindow" option causes
uvlin to do a single fit over all windows.
lpropc The line shape is constant throughout the data-set,
and the intensity is proportional to the continuum
strength. This cannot be used together with
the "twofit" option.
relax Normally UVLIN attempts to avoid overfitting the
data by reducing the order of the fit. It does this
if a significant number of channels are flagged
(more than 40% bad) or if it believes there is
inadequate data to perform the fit (less than
5*(order+1) channels). You can overwrite this
conservatism, if you know what you are doing, with
the "relax" option.
The following options can be used to turn off calibration corrections.
The default is to apply any calibration present.
nocal Do not apply the gains table.
nopass Do not apply bandpass corrections. It is unwise
to turn off bandpass correction, as the continuum
estimation process will be confused by a bandpass
which is not flat.
nopol Do not apply polarization corrections.
nochk Diable head variable check (for SMA only). <--
uvlin%

invert%
....
Keyword: options
This gives extra processing options. Several options can be
given (abbreviated to uniqueness), and separated by commas:
nocal Do not apply gains table calibration to the data.
nopol Do not apply polarisation leakage corrections.
nopass Do not apply bandpass table calibration to the data.
double Normally INVERT makes the beam patterns the same
size as the output image. This option causes the
beam patterns to be twice as large.
systemp Weight each visibility in inverse proportion to the
noise variance. Normally visibilities are weighted in
proportion to integration time. Weighting based on the
noise variance optimises the signal-to-noise ratio
(provided the measures of the system temperature are
reliable!).
mfs Perform multi-frequency synthesis. The causes all the
channel data to be used in forming a single map. The
frequency dependence of the uv coordinate is thus used to
give better uv coverage and/or avoid frequency
smearing. For this option to produce useful maps, the
intensity change over the frequency band must be small.
You should set the ``line'' parameter to select the
channels that you wish to grid.
sdb Generate the spectral dirty beam as well as the normal
beam, when MFS processing. The default is to only create
the normal beam. If the spectral dirty beam is created,
this is saved as an extra plane in the beam dataset.
mosaic Process multiple pointings, and generate a linear
mosaic of these pointings.
imaginary Make imaginary image for non-Hermitian data (holography).
amplitude Produce a image using the data amplitudes only. The
phases of the data are set to zero.
phase Produce an image using the data phase only. The amplitudes
of the data are set to 1.
nochk Diable head variable check (for SMA only). <--
....
invert%

Similar questions from users have been archived in a SMA Miriad webpage under the SMA website, for example,
http://www.cfa.harvard.edu/sma/miriad/download/QandA/GlenPetitpas2012jun28.html

>I guess that SMA-miriad has special functions and tasks in calibrations steps. Is it right?
Yes, we have implemented many special features for handling interferometer array data at
submillimeter concerning the calibrators at submillimeters become weak (often run out S/N budget) for QSOs and/or
strong but resolved for solar planets, sophisticated SMA correlators, and many SMA data errors
due to frequently updated SMA online software since spring 2004. These features are coded in the SMA special programs with
prefix "sma". These programs are located in two special areas in $MIRSRC/prog/sma and/or $SMASUBS in
both miriad_cvs and SMA beta distributions.
JHZ

2013-Sep-13, JHZ: "$MIRSUBS" instead of "$SMASUBS" in the last sentence above.

On Thu, Sep 12, 2013 at 12:36 AM, BumHyun Lee wrote:

Dear Zhao, Jun-Hui
I have another question related with SMA-miriad.
Are there some difference between SMA-miriad and other miriad version (i.e. carma) in Task 'INVERT' and 'UVLIN' ?
I mean that I am wondering if there is special function in Task 'INVERT' and 'UVLIN' of SMA-miriad.
Usually, I do calibration steps in MIR_IDL and I do imaging steps in MIRIAD or AIPS.
I guess that SMA-miriad has special functions and tasks in calibrations steps. Is it right?

Thank you.
Best regards,
Bumhyun Lee

2013/8/15 BumHyun Lee

Dear Zhao, Jun-Hui
Thank you for your kind answer.

Best regards,
Bumhyun Lee

2013/8/2 Zhao, Jun-Hui

please download the SMA original data (not calibrated) from SMA archive
and follow the procedure for one of the examples given for the observing modes
that we have been supporting (see http://www.cfa.harvard.edu/sma/miriad/spec/SMAscripts/).

JHZ

On Fri, Aug 2, 2013 at 4:51 AM, BumHyun Lee wrote:

Hi, my name is Bumhyun Lee.
I tried to use 'sma_miriad' ubuntu version.
However, I have some problem for some tasks.
(i.e. uvlin & invert)
Also, I find same problem of other user.
http://www.cfa.harvard.edu/sma/miriad/download/QandA/cDedes29jul2011.html

When I try to do uvlin task, I can see the error message :

uvlin vis=12n4522.miriad out=12n4522.lin order=1 chans=5,10,90,95 options=nowin
UvLin: version beta 11jan10
### Fatal Error [uvlin]:

And, when I try to do invert task, I can see no data after doing invert task.

How can I fix these two problems?

Could you give me a tip for these problem?

Best regards,

Bumhyun Lee