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Observing with ALMA
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Cycle 0


Steps to observe with ALMA

Please refer to the announced Call for Proposal in the EA ARC ALMA Science Portal. Before starting to write your proposal, check the current capabilities of ALMA in Cycle0 and the Proposer's guide. More technical information can be found in the Technical Guide.

These are the steps in order to get your ALMA observations:

  • Proposal preparation (Phase 1): Enter the information regarding the scientific and technical cases in the Observing Tool (OT) .
  • Proposal review process: Time will be awarded based on the scientific ranking of each proposal and the available time by a peer-reviewed system with a single international committee.
  • Preparing observations (Phase 2): Detail the necessary information of your project into the OT so that your observations can be scheduled.
  • Check status of the observations: Use the Project Tracker in the ALMA Science Portal (need to be logged in).

The key dates are:

  • 31 March 2011: Release of the Call for Proposals for ALMA Early Science Cycle 0 and release of the offline Observing Tool.
  • 29 April 2011: Submission of Notice of Intent.
  • 1 June 2011: Opening of archive for proposal submission and release of the online version of the Observing Tool.
  • 30 June 2011: Proposal Deadline.
  • September 2011: Feedback to proposers on the results from the proposal review process.
  • 30 September 2011: Start of ALMA Cycle 0 observing.
  • 30 June 2012: End of ALMA Cycle 0.

Once observations have been taken, the data can be retrieved from the ALMA archive. The raw data can be processed with CASA.

From the Proposal Preparation to the Scheduling of Observations

Phase 1: Proposals and Review Process

The Phase 1 material of the proposals must be prepared with the Observing Tool (OT), which will allow the users to provide a scientific and technical justification, target specification, time-on-target plus overhead specification, sensitivity and integration time estimation, atmospheric conditions requirements (e.g. transparency and atmospheric conditions), etc. As the EA-ARC staff will form the primary interface between the East Asian community and the ALMA observatory, they will assist users with the preparation of their Phase 1 material. This assistance will cover technical help with the OT, help with the ALMA exposure time calculator, but will also involve consultation regarding observing strategy.

There will be a single Proposal Review Committee (PRC), which will be run by the JAO. Parallel to the ranking based on scientific merit, the Observatory will conduct a 'technical feasibility' review process. The EA-ARC staff will help with the technical assessment of the proposal. This assessment is on a technical basis and will consist of checking the feasibility of the project (for example, check sensitivity calculation, spectral configuration, array configuration, mapping and calibration strategy) and whether for the proposed target, ALMA data already exists.

For any enquiry in the Phase 1 stage, please contact the EA-ARC via the ALMA Helpdesk.

Phase 2: Preparing and Scheduling Observations

The PIs of proposals that successfully pass the technical and scientific evaluation are invited to use the OT to specify the technical details that are required to schedule and execute the proposed observations. The ARC staff will provide support during this phase and will validate all material prepared by the users. The ARC staff is the primary interface between the users and the JAO during this observation preparation phase, consulting with the operations staff as necessary.

Each observing project is splitted into one or more observing unit sets (ObsUnitSets), which in turn consist of sets of scheduling blocks (SBs), each of approximately 45 min of scientific observing. The ARC staff must validate all submitted SBs. After verification of the SBs by the ARC staff, the SBs will be submitted to the ALMA central archive. All material used for validating the SBs (Support Abstract, Support History Log) are submitted to the central archive as well. If problems are found, users will be notified and asked to revise their material. Until such problems are solved, the observations will not be scheduled for execution. Note that the problems can be technical (i.e. user used the OT incorrectly or the OT produced bad results) or operational (i.e. the ARC review reveals a better way to execute the program). Once all Phase 2 material is found to be correct, it will be certified by changing the SBs status from "Defined" to "Ready" and released to ALMA operations in Chile for scheduling and possible execution. A Phase 2 completion deadline shall be established for each scheduling cycle. All projects with incomplete Phase 2 submission at the deadline will not be executed.

Released Scheduling Blocks can be executed at any time without further intervention from users or ARC staff. The project status can be checked through the Project Tracker.

For any enquiry in the Phase 2 stage, please contact the EA-ARC via the ALMA Helpdesk.

Post Processing


Reduction of ALMA data will be performed using Common Astronomy Software Applications (CASA). Instructions for downloading and installing CASA can be found at the following link. Examples of data reduction in CASA can be found in the CASA Guides. If you wish to reduce ALMA data, the ALMA Primer for Early Science can help you understand interferometer data. For hands-on data reduction help, please contact the EA-ARC via the ALMA Helpdesk.

ALMA Pipeline

ALMA data will be processed with an automatic pipeline. The ALMA pipeline will produce science-ready images for basic ALMA observing modes (from late 2012, not available in Cycle 0). The reduced data will be stored in the ALMA archive. Optimization of the data reduction parameters using a cluster computer will be possible in the EA- ARC (not available in Cycle 0).

Information on previous cycles of observations

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