casa / casa6 / 4b51cbf9cdd

Commits

Mark Kettenis authored 4b51cbf9cdd 21 Mar 2025

CAS-14540: Use ICRS as default reference frame in importfitsidi

Use ICRS as the default reference frame and interpret FITS-IDI
data that has the epoch/equinox set to J2000 as using ICRS as well.
Add a new coordframe option to the task to allow the user to
override the default.

casatasks/src/private/task_importfitsidi.py

Modified

-1
+import os
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+import shutil
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+import numpy as np
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+from casatools import ms, table
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+from casatasks import casalog
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+from .mstools import write_history
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--
+def importfitsidi(fitsidifile,vis,constobsid=None,scanreindexgap_s=None,specframe=None):
-+
+def importfitsidi(fitsidifile,vis,constobsid=None,scanreindexgap_s=None,specframe=None,coordframe=None):
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+    """Convert FITS-IDI visibility file into a CASA visibility file (MS).
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+    Keyword arguments:
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+    fitsidifile -- Name(s) of input FITS IDI file(s)
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+        default: None; example='3C273XC1.IDI' or ['3C273XC1.IDI1', '3C273XC1.IDI2']
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+    vis -- Name of output visibility file (MS)
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+        default: None; example: vis='3C273XC1.ms'
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+    constobsid -- If True a constant obs id == 0  of is given to all input files
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+        default = False (new obs id for each input file)
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+    scanreindexgap_s --  if > 0., a new scan is started whenever the gap between two
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+        integrations is > the given value (seconds) or when a new field starts
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+        or when the ARRAY_ID changes.
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+        default = 0. (no reindexing)
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+    specframe -- this frame will be used to set the spectral reference frame
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+        for all spectral windows in the output MS
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+        default = GEO (geocentric), other options: TOPO, LSRK, BARY
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+        NOTE: if specframe is set to TOPO, the reference location will be taken from
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+        the Observatories table in the CASA data repository for the given name of
--
+        the observatory. You can edit that table and add new rows.
--
-+
+        the observatory. You can edit that table and add new rows.
-+
-+
+    coordframe -- this frame will be used to set the reference frame
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+        for all source positions in the output MS
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+        default = '' (set based on opeoch/equinox),
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+        other options: ICRS, B1950, J2000
-+
+        NOTE: if the epoch/equinox is set to J2000 in the FITS-IDI file,
-+
+        the reference frame will be set to ICRS. To use FK5/J2000 as the
-+
+        reference frame, set coordframe to J2000.
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+    """
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+    #Python script
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+    try:
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+        casalog.origin('importfitsidi')
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+        casalog.post("")
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+        myms = ms()
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+        mytb = table()
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+        if type(specframe)==str and not specframe=='':
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+            myspecframe=specframe.upper()
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+        else:
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+            myspecframe='GEO'
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+        refframes = {'REST': 0, 'LSRK': 1, 'LSRD': 2, 'BARY': 3, 'GEO': 4, 'TOPO': 5}
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+        if myspecframe not in refframes:
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+            raise ValueError('Value '+myspecframe+' of parameter specframe invalid. Possible values are REST, LSRK, LSRD, BARY, GEO, TOPO')
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-+
+        if type(coordframe)==str and not coordframe=='':
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+            mycoordframe=coordframe.upper()
-+
+        else:
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+            mycoordframe=''
-+
-+
+        if mycoordframe not in ['', 'ICRS', 'B1950', 'J2000']:
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+            raise ValueError('Value '+mycoordframe+' of parameter coordframe invalid. Possible values are ICRS, B1950, J2000')
-+
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+        if(type(fitsidifile)==str):
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+            casalog.post('### Reading file '+fitsidifile, 'INFO')
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+            myms.fromfitsidi(vis,fitsidifile)
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+            myms.close()
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+        elif(type(fitsidifile)==list):
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+            clist = fitsidifile
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+            casalog.post('### Reading file '+clist[0], 'INFO')
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+            myms.fromfitsidi(vis,clist[0])
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+            myms.close()
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+            clist.pop(0)
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+        if myspecframe in refframes:
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+            casalog.post('Setting reference frame for all spectral windows to '+myspecframe, 'INFO')
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+            if myspecframe == 'TOPO':
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+                casalog.post('NOTE: reference position for TOPO frame will be the observatory location', 'WARN')
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+            mytb.open(vis+'/SPECTRAL_WINDOW', nomodify=False)
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+            refcol = mytb.getcol('MEAS_FREQ_REF')
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+            refcol = [refframes[myspecframe]]*len(refcol)
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+            mytb.putcol('MEAS_FREQ_REF', refcol)
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+            mytb.close()
--
-+
-+
+        mytb.open(vis+'/FIELD', nomodify=False)
-+
+        for colname in ['DELAY_DIR', 'PHASE_DIR', 'REFERENCE_DIR']:
-+
+            kwds = mytb.getcolkeywords(colname)
-+
+            if not mycoordframe=='':
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+                kwds['MEASINFO']['Ref'] = mycoordframe
-+
+            # until casacore gets fixed to use ICRS as its default
-+
+            elif mycoordframe=='' and kwds['MEASINFO']['Ref'] == 'J2000':
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+                kwds['MEASINFO']['Ref'] = 'ICRS'
-+
+            mytb.putcolkeywords(colname, kwds)
-+
+        mytb.close()
-+
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+        # write history
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+        try:
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+            param_names = importfitsidi.__code__.co_varnames[:importfitsidi.__code__.co_argcount]
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+            vars = locals( )
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+            param_vals = [vars[p] for p in param_names]
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+            write_history(myms, vis, 'importfitsidi', param_names, param_vals, casalog)
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+        except Exception as instance:
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+            casalog.post("*** Error \'%s\' updating HISTORY" % instance, 'WARN')
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