Importing Data into CASA: Difference between revisions

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{{Using CASA Hints Tips Tricks}}
[[Category: CASA Basics]]
To manipulate your data in CASA, it will have to be in measurement set format. But how do you get it into a measurement set?
To manipulate your data in CASA, it will have to be in measurement set format. But how do you get it into a measurement set?
__FORCETOC__
== For EVLA Data ==


Please see a complete description in the [[Loading Data]] CASA Guide.


* '''For EVLA Data:''' Go to the NRAO archive and find the data set you'd like to download. Navigate to the "Download Archive Data Files" page, which will look something like this:
<!-- Go to the NRAO archive and find the data set you'd like to download. Navigate to the "Download Archive Data Files" page, which will look something like this:


[[Image:archive_import.png|900px|"Download Archive Data Files".]]
[[Image:archive_import.png|900px|"Download Archive Data Files".]]
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Unpack the tar ball with a <tt>tar -xvf</tt>. Fire up CASA in your working directory.
Unpack the tar ball with a <tt>tar -xvf</tt>. Fire up CASA in your working directory.


Now it's time to use the CASA task [[importevla]] to convert this SDM into a measurement set.  
Now it's time to use the CASA task {{importevla}} to convert this SDM into a measurement set.  


[[Image:importevla_import.png|700px|Importevla Parameters.]]
[[Image:importevla_import.png|700px|Importevla Parameters.]]
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The second way to download your data is easier for the user, but may place a large burden on the archive and delay your data's arrival. Simply select "CASA MS" format on the "Download Archive Data Files" page of the archive. You'll probably want to still create a tar file, and you may or may not want to apply telescope flags. What flagging steps are included in this "Apply flags generated during observing" is in flux currently, so you may want to exercise caution here. Wait for your email from the archive stating that the data has been copied, download it, un-tar it, and voila! You have a measurement set ready for use in CASA.
The second way to download your data is easier for the user, but may place a large burden on the archive and delay your data's arrival. Simply select "CASA MS" format on the "Download Archive Data Files" page of the archive. You'll probably want to still create a tar file, and you may or may not want to apply telescope flags. The flagging steps included in this "Apply flags generated during observing" command is currently in flux, so you may want to exercise caution here. Wait for your email from the archive stating that the data set has been copied, download it, un-tar it, and voila! You have a measurement set ready for use in CASA. -->


== For Historical VLA Data ==
Download the data from the archive as you normally would (note that the format has not changed!), selecting the naming style that is most convenient ("Original Style", "AIPS Friendly", or "User Specify"). Wait for the email to arrive from the archive saying your data has been copied, and download it into your working directory. Now fire up CASA.


* '''For Historical VLA Data:''' Download the data from the archive as you normally would, selecting the naming style that is most convenient ("Original Style", "AIPS Friendly", or "User Specify"). Wait for the email to arrive from the archive saying your data has been copied, and download it into your working directory. Now fire up CASA.
You will use the CASA task {{importvla}} to import these historical data:
 
You will use the CASA task [[importvla]] to import these historical data:


[[Image:importvla_import.png|700px|Importvla Parameters.]]
[[Image:importvla_import.png|700px|Importvla Parameters.]]


Set '''archivefiles''' to the name(s) of the files you just downloaded, and set '''vis''' to the name of the measurement set you'd like to produce (make sure you add a ".ms" to the end of the name!). Type <tt>go</tt>, check the logger output periodically, and you should end up with a nice measurement set as output.
Set '''archivefiles''' to the name(s) of the files you just downloaded, and set '''vis''' to the name of the measurement set you'd like to produce (make sure you add a ".ms" to the end of the name!). Type <tt>go</tt>, check the logger output periodically, and you should end up with a nice measurement set as output.
== For CARMA and SMA Data ==
Your data should be imported in FITS format using {{importuvfits}}. Check out these tutorials ([[SMA_CO_Line_Data|SMA]], [[Importing_and_Calibrating_a_Mosaicked_Spectral_Line_Dataset|CARMA]]) for more specifics.
[[Main Page | &#8629; '''CASAguides''']] <br>


--[[User:Lchomiuk|Laura Chomiuk]] 21:57, 6 June 2010 (UTC)
--[[User:Lchomiuk|Laura Chomiuk]] 21:57, 6 June 2010 (UTC)

Latest revision as of 16:17, 20 April 2012

Hints, Tips, and Tricks

To manipulate your data in CASA, it will have to be in measurement set format. But how do you get it into a measurement set?

For EVLA Data

Please see a complete description in the Loading Data CASA Guide.


For Historical VLA Data

Download the data from the archive as you normally would (note that the format has not changed!), selecting the naming style that is most convenient ("Original Style", "AIPS Friendly", or "User Specify"). Wait for the email to arrive from the archive saying your data has been copied, and download it into your working directory. Now fire up CASA.

You will use the CASA task importvla to import these historical data:

Importvla Parameters.

Set archivefiles to the name(s) of the files you just downloaded, and set vis to the name of the measurement set you'd like to produce (make sure you add a ".ms" to the end of the name!). Type go, check the logger output periodically, and you should end up with a nice measurement set as output.


For CARMA and SMA Data

Your data should be imported in FITS format using importuvfits. Check out these tutorials (SMA, CARMA) for more specifics.

CASAguides

--Laura Chomiuk 21:57, 6 June 2010 (UTC)