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== Introduction ==
== Introduction ==


This page contains tutorials to guide ALMA users through some common types of data imaging and analysis using CASA with example ALMA datasets.  
This page contains tutorials to guide ALMA users through some common types of data imaging and analysis using CASA with example ALMA datasets. Here are some links to get started:


'''ALMA'''
* [http://almascience.org/ ALMA Science homepage]
* [http://almascience.org/ ALMA Science homepage]
'''CASA'''
* [http://casa.nrao.edu CASA homepage]: includes download and installation information
* [http://casa.nrao.edu CASA homepage]: includes download and installation information
* {{casadocs_6.5.4}}
* {{casadocs_6.5.4}}
  * To cite CASA, please use: [https://ui.adsabs.harvard.edu/abs/2022PASP..134k4501C/abstract  \bibitem<nowiki>[CASA Team et al.(2022)]</nowiki>{2022PASP..134k4501C} CASA Team, Bean, B., Bhatnagar, S., et al.\ 2022, PASP, 134, 114501. doi:10.1088/1538-3873/ac9642]
  * To cite the ALMA pipeline, please use: [https://ui.adsabs.harvard.edu/abs/2023PASP..135g4501H/abstract \bibitem<nowiki>[Hunter et al.(2023)]</nowiki>{2023PASP..135g4501H} Hunter, T.~R., Indebetouw, R., Brogan, C.~L., et al.\ 2023, PASP, 135, 074501. doi:10.1088/1538-3873/ace216]
* [[Getting Started in CASA]]
* [[Getting Started in CASA]]
* [[CASA Tips]]
* [[CASA Tips]]
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* [[First_Look_at_Image_Analysis | Moments and Image Analysis]]
* [[First_Look_at_Image_Analysis | Moments and Image Analysis]]


Older versions of these guides are archived here: [[ALMA_First_Look]]
Older versions of these guides are archived here: [[ALMA First Look]]
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== Reprocessing and Imaging ==
== Restoring and Imaging Calibrated Data ==


=== Considerations before Imaging ===
=== Considerations before Imaging ===
* [[ALMA Renormalization Correction]]
* [[ALMA Renormalization Correction]]
* [[DataWeightsAndCombination]]: A guide to CASA data weights and how to ensure they are correct for data combination.
:- A fix for amplitude calibration issues caused by the ALMA normalization strategy for sources with strong line emission.
* [[DataWeightsAndCombination]]
:- A guide to CASA data weights and how to ensure they are correct for data combination.


=== Pipeline Imaging ===
=== Pipeline Imaging ===


* [[ALMA Imaging Pipeline Reprocessing]]: Create images using pipeline tasks.
* [[ALMA Imaging Pipeline Reprocessing]]
:- Create images using pipeline tasks.


=== Manual Imaging ===
=== Manual Imaging ===


* [[Guide NA ImagingTemplate]]: Create images with a manual template.
* [[Guide to the NA Imaging Template]]
* [[TCLEAN and ALMA]]: Examples of using {{tclean_6.5.4}}, with emphasis on changes from the older "clean" task.
:- Create images with a manual template.
* [[TCLEAN and ALMA]]
:- Examples of using {{tclean_6.5.4}}, with emphasis on changes from the older "clean" task.


=== Automasking ===
=== Automasking ===


* [[Automasking Guide]]
* [[Automasking Guide]]
:- Explanation of parameters used in {{tclean_6.5.4}} to automatically mask clean regions during non-interactive cleaning.


== Manual Calibration and Imaging ==
== Manual Calibration and Imaging ==
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These guides are useful tools for those who would like to learn the process of calibration and imaging in detail. They use publicly-available [https://almascience.nrao.edu/alma-data/science-verification ALMA Science Verification] data that illustrate several different ALMA capabilities. The links below lead to overview pages for each observation. The guides themselves are linked from the overview pages.
These guides are useful tools for those who would like to learn the process of calibration and imaging in detail. They use publicly-available [https://almascience.nrao.edu/alma-data/science-verification ALMA Science Verification] data that illustrate several different ALMA capabilities. The links below lead to overview pages for each observation. The guides themselves are linked from the overview pages.


=== Antennae Galaxy Merger ===
=== Mosaic Imaging ===


* [[AntennaeBand7]] (NGC 4038/4039)
* [[AntennaeBand7]]
* Band 7 (0.87 mm)
:- Band 7 (345 GHz, 0.87 mm)
* North and South mosaics
:- CO 3-2 spectral line
:- Antennae Galaxy Merger (NGC 4038/4039)
:- North and South mosaics


=== Protostellar Cluster IRAS16293-2422 ===
=== High Frequency Calibration ===


* [[IRAS16293Band9]]
* [[IRAS16293Band9]]
* Band 9 (0.45 mm)
:- Band 9 (650 GHz, 0.46 mm)
* Mosaic
:- Protostellar Cluster
:- High frequency techniques
:- Mosaic


=== M100 Single Dish and Array Combination ===
=== Single Dish and Array Image Combination ===


* [[M100_Band3]]
* [[M100_Band3]]
* Band 3 (?? mm)
:- Band 3 (100 GHz, 3 mm)
* Total Power (Single Dish) calibration and imaging
:- Total Power (Single Dish) calibration and imaging
* Combining 12m-array, 7m-array, and Total Power data
:- Combining 12m-array, 7m-array, and Total Power data


=== 3C286 Full Polarization ===
=== Full Polarization ===


* [[3C286_Polarization]]
* [[3C286_Polarization]]
* Band 3 (?? mm)
:- Band 6 (230 GHz, 1.3 mm)
* Continuum polarization
:- Continuum polarization


=== Sunspot ===
=== Solar Observing ===


* [[Sunspot_Band6]]
* [[Sunspot_Band6]]
* Band 6 (1.25mm)
:- Band 6 (230 GHz, 1.3 mm)
* Solar observing techniques
:- Solar observing techniques
* Calibration and imaging
:- Calibration and imaging
* Helper scripts
:- Helper scripts


== Simulation ==
== Simulation ==


* [[Guide To Simulating ALMA Data]]: An overview of simulation as it pertains to ALMA.
* [[Guide To Simulating ALMA Data]]
* [[Simulating Observations in CASA]]: All simulation guides (for all telescopes) are here.
:- An overview of simulation as it pertains to ALMA.
* [[Simulating Observations in CASA]]
:- All simulation guides (for ALMA, VLA, ngVLA, etc.)


== Legacy Guides ==
== Legacy Guides ==


* [[Archived ALMA CASAguides]]: These guides and scripts use Science Verification data and have been validated for older versions of CASA, but will not continue to be updated for new CASA releases.
These guides and scripts use Science Verification data and have been validated for older versions of CASA, but will not continue to be updated for new CASA releases:
* [[Archived ALMA CASAguides]]


=== Cycle 0 ===
=== Cycle 0 ===


* [[Guide To Processing ALMA Data for Cycle 0]]
* [[Guide To Processing ALMA Data for Cycle 0]]
* Last checked in CASA 4.2
:- Last checked in CASA 4.2
* Helpful hints for downloading the data
:- Helpful hints for downloading the data
* Imaging, self-calibration, and image analysis
:- Imaging, self-calibration, and image analysis


You can also get a look at example data calibration scripts used for Cycle 0 data at the following links.  These were written for CASA version 3.4.
Example data calibration scripts used for Cycle 0 data (CASA 3.4):
* TDM (128 channels/spw) [[File:TDM.example.ms.scriptForCalibration.py]]
* [[File:TDM.example.ms.scriptForCalibration.py]]: TDM (128 channels/spw)
* FDM (3840 channels/spw) [[File:FDM.example.ms.scriptForCalibration.py]]
* [[File:FDM.example.ms.scriptForCalibration.py]]: FDM (3840 channels/spw)
* If you need to update 3.4 scripts to 4.2 or later, see more information here [[Updating a script to work with CASA 4.2]]
* [[Updating a script to work with CASA 4.2]]: Update 3.4 scripts to 4.2 or later.


== Resources ==
== Resources ==
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* [https://almascience.nrao.edu/processing/science-pipeline ALMA Pipeline webpage]
* [https://almascience.nrao.edu/processing/science-pipeline ALMA Pipeline webpage]
  * To cite the ALMA pipeline, please use: [https://ui.adsabs.harvard.edu/abs/2023PASP..135g4501H/abstract \bibitem<nowiki>[Hunter et al.(2023)]</nowiki>{2023PASP..135g4501H} Hunter, T.~R., Indebetouw, R., Brogan, C.~L., et al.\ 2023, PASP, 135, 074501. doi:10.1088/1538-3873/ace216]
* [[ALMA Pipeline Known Issues]]
* [[ALMA Pipeline Known Issues]]


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* [[ADMIT Products and Usage]]: This guide discusses how to use the ALMA Data-Mining Toolkit (ADMIT) and customize it for your data.
* [[ADMIT Products and Usage]]: This guide discusses how to use the ALMA Data-Mining Toolkit (ADMIT) and customize it for your data.
* [[Analysis Utilities]]: A Python module containing utilities for analysis and plotting.  
* [[Analysis Utilities]]: A Python module containing utilities for analysis and plotting.  
* [[Solar System Models in CASA 4.0]]


=== Other Telescopes ===
=== Other Telescopes ===
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* [[Past MM/Submm Guides]]: These are not currently being maintained.
* [[Past MM/Submm Guides]]: These are not currently being maintained.


 
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Latest revision as of 20:27, 10 September 2024

Introduction

This page contains tutorials to guide ALMA users through some common types of data imaging and analysis using CASA with example ALMA datasets. Here are some links to get started:

ALMA

CASA

  * To cite CASA, please use: \bibitem[CASA Team et al.(2022)]{2022PASP..134k4501C} CASA Team, Bean, B., Bhatnagar, S., et al.\ 2022, PASP, 134, 114501. doi:10.1088/1538-3873/ac9642
  * To cite the ALMA pipeline, please use: \bibitem[Hunter et al.(2023)]{2023PASP..135g4501H} Hunter, T.~R., Indebetouw, R., Brogan, C.~L., et al.\ 2023, PASP, 135, 074501. doi:10.1088/1538-3873/ace216

CARTA

Guides that have been updated to demonstrate the CARTA image viewer will include this statement near the top:

This guide features CARTA, the “Cube Analysis and Rendering Tool for Astronomy,” which is the new NRAO visualization tool for images and cubes. The CASA viewer (imview) has not been maintained for a few years and will be removed from future versions of CASA. We strongly recommend using CARTA, as it provides a much more efficient, stable, and feature rich user experience. A comparison of the CASA viewer and CARTA, as well as instructions on how to use CARTA at NRAO, is provided in the CARTA section of the CASA docs.

First Look (TW Hydra)

ALMA data are delivered to users with calibrations applied and they are ready for imaging. The following "First Look" tutorials provide short examples of common next steps a user may take with their calibrated data. These guides use an example ALMA observation of TW Hydra.

Older versions of these guides are archived here: ALMA First Look

Restoring and Imaging Calibrated Data

Considerations before Imaging

- A fix for amplitude calibration issues caused by the ALMA normalization strategy for sources with strong line emission.
- A guide to CASA data weights and how to ensure they are correct for data combination.

Pipeline Imaging

- Create images using pipeline tasks.

Manual Imaging

- Create images with a manual template.
- Examples of using tclean, with emphasis on changes from the older "clean" task.

Automasking

- Explanation of parameters used in tclean to automatically mask clean regions during non-interactive cleaning.

Manual Calibration and Imaging

These guides are useful tools for those who would like to learn the process of calibration and imaging in detail. They use publicly-available ALMA Science Verification data that illustrate several different ALMA capabilities. The links below lead to overview pages for each observation. The guides themselves are linked from the overview pages.

Mosaic Imaging

- Band 7 (345 GHz, 0.87 mm)
- CO 3-2 spectral line
- Antennae Galaxy Merger (NGC 4038/4039)
- North and South mosaics

High Frequency Calibration

- Band 9 (650 GHz, 0.46 mm)
- Protostellar Cluster
- High frequency techniques
- Mosaic

Single Dish and Array Image Combination

- Band 3 (100 GHz, 3 mm)
- Total Power (Single Dish) calibration and imaging
- Combining 12m-array, 7m-array, and Total Power data

Full Polarization

- Band 6 (230 GHz, 1.3 mm)
- Continuum polarization

Solar Observing

- Band 6 (230 GHz, 1.3 mm)
- Solar observing techniques
- Calibration and imaging
- Helper scripts

Simulation

- An overview of simulation as it pertains to ALMA.
- All simulation guides (for ALMA, VLA, ngVLA, etc.)

Legacy Guides

These guides and scripts use Science Verification data and have been validated for older versions of CASA, but will not continue to be updated for new CASA releases:

Cycle 0

- Last checked in CASA 4.2
- Helpful hints for downloading the data
- Imaging, self-calibration, and image analysis

Example data calibration scripts used for Cycle 0 data (CASA 3.4):

Resources

Pipeline

  * To cite the ALMA pipeline, please use: \bibitem[Hunter et al.(2023)]{2023PASP..135g4501H} Hunter, T.~R., Indebetouw, R., Brogan, C.~L., et al.\ 2023, PASP, 135, 074501. doi:10.1088/1538-3873/ace216

Tools

Other Telescopes