exportasdm

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

[Description] [Examples] [Development] [Details]

Parameters

• 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

Description

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.

Examples

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)

Development

No additional development details

Parameter Details

Detailed descriptions of each function parameter

vis (path) - Name of input visibility file

Default: none

Example: 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 are

present. If the requested column does not exist,

the task will exit with an error.

archiveid (string='S0') - The X0 in uid://X0/X1/X2

Default: ‘S0’

rangeid (string='X1') - The X1 in uid://X0/X1/X2

Default: ‘X1’

subscanduration (string='24h') - Maximum duration of a subscan in the output ASDM

Default: 24h

sbduration (string='2700s') - Maximum duration of a scheduling block (and therefore

exec block) in the output ASDM

Default: ‘2700s’

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.

apcorrected (bool=False) - Data to be marked as having atmospheric phase correction

Default: False

Options: False|True

verbose (bool=True) - Produce log output?

Default: True

Options: True|False