- exportasdm(vis, asdm='', datacolumn='data', archiveid='S0', rangeid='X1', subscanduration='24h', sbduration='2700s', apcorrected=False, verbose=True)
Convert a CASA visibility file (MS) into an ALMA or EVLA Science Data Model
vis (path) - Name of input visibility file
asdm (path=’’) - >Name of output ASDM directory (on disk)
datacolumn (string=’data’) - Which data column(s) to process.
archiveid (string=’S0’) - The X0 in uid://X0/X1/X2
rangeid (string=’X1’) - The X1 in uid://X0/X1/X2
subscanduration (string=’24h’) - Maximum duration of a subscan in the output ASDM
sbduration (string=’2700s’) - Maximum duration of a scheduling block (and therefore exec block) in the output ASDM
apcorrected (bool=False) - Data to be marked as having atmospheric phase correction
verbose (bool=True) - Produce log output
This task serves to convert a CASA visibility file (MS) into an ALMA or EVLA Science Data Model dataset. They are mostly identical and mostly use the general SDM and ALMA ASDM terms interchangibly. A description of the SDM format can be found here.
The main purpose of creating this task was to (a) enable the creation of simulated ASDMs and (b) facilitate the testing of (A)SDM to MS conversion. The user may think of other purposes.
The sbduration parameter controls the number of execution blocks (EBs) into which exportasdm subdivides the visibilities from your input MS. If the total observation time in the MS is shorter than what is given in sbduration, a single EB will be created.
Note: exportasdm will first create a temporary time-sorted reference MS using the name of the vis parameter plus “-tsorted”. If such a file or directory already exists with that name, it will be removed without warning.
Note: exportasdm requires that all rows in the MAIN table of the input MS (vis) have the same value for the PROCESSOR_ID column (only a single PROCESSOR can be exported). The split task can be used to produce such an MS, often by chosing appropriate SPWs.
Note concerning ALMA data: exportasdm presently is only able to export from MSs containing processor type “CORRELATOR” data (e.g. WVR data can not be exported). If you attempt to export other types you will receive an error message saying that you can only export data of processor type “CORRELATOR”. It will also try to give you the list of SPWs which contain CORRELATOR data, but that list is almost certain to be empty because of the requirement noted earlier that the main table of the MS only references one PROCESSOR_ID.
Also EVLA data can be exported. Note here that exportasdm does not produce online flags and that a subsequent re-import of the data must be done with online=False.
To produce an ASDM named ‘uid___S021_X1418_X1’ using the datacolumn ‘corrected’ in the MS ‘ngc4826.ms’ with minimal log output:
exportasdm(vis=’ngc4826.ms’, asdm=’uid___S021_X1418_X1’, datacolumn=’corrected’, archiveid=’S021’, rangeid=’X1418’, verbose=False)
No additional development details
- Parameter Details
Detailed descriptions of each function parameter
vis (path)- Name of input visibility fileDefault: noneExample: vis=’ngc5921.ms’
asdm (path='')- Name of output ASDM directory (on disk)Default: none
datacolumn (string='data')- Which data column(s) to use for processing(case-insensitive).Default: ‘corrected’Options: ‘data’, ‘model’, ‘corrected’,‘all’,’float_data’, ‘lag_data’,‘float_data,data’, ‘lag_data,data’Example: datacolumn=’data’NOTE: ‘all’ = whichever of the above that arepresent. If the requested column does not exist,the task will exit with an error.
archiveid (string='S0')- The X0 in uid://X0/X1/X2Default: ‘S0’
rangeid (string='X1')- The X1 in uid://X0/X1/X2Default: ‘X1’
subscanduration (string='24h')- Maximum duration of a subscan in the output ASDMDefault: 24h
sbduration (string='2700s')- Maximum duration of a scheduling block (and thereforeexec block) in the output ASDMDefault: ‘2700s’The sbduration parameter controls the number ofexecution blocks (EBs) into which exportasdmsubdivides the visibilities from your inputMS. If the total observation time in the MS isshorter than what is given in sbduration, asingle EB will be created.
apcorrected (bool=False)- Data to be marked as having atmospheric phase correctionDefault: FalseOptions: False|True
verbose (bool=True)- Produce log output?Default: TrueOptions: True|False