Use Case: Quick Look Pipeline: Monitor Calibration Data

Quick Look Calibration Monitor Use Case for ALMA (based on ALMA SW Memo 11, Science Requirements and Use Cases, modified to include detailed Quick Look calibration monitoring requirements). The Quick Look calibration monitor is activated after every calibration observation of any type and runs in quasi real time.

Goal:   Provide monitoring information on results from telescope calibration operations.

Contact Authors:   C. Wilson, R. Lucas

Role(s)/Actor(s):
Primary: Pipeline Subsystem, quick look calibration monitor; TelCal Subsystem
Secondaries:

• Telcal Subsystem - Activates quick look calibration monitor; provides results of on-line calibration directly to the pipeline
  
• Pipeline Subsystem - plots results of the various calibration measurements, both the most recent result and as a function of time for the current observing session. Saves all calibration results until the end of the current observing session.
• Operator, Staff Astronomer, Interactive Observer - inspects plots, controls plotting parameters, reacts to alarms.
  
• Archive - receives processed results as plots or tables. Keeps results for a period of one week after the end of an observing session and then plots are deleted automatically.
  
  

Priority:   Critical

Performance:   Need to feedback data and results in a 'timely fashion.' Exact timing requirements TBD, but could need to display results of pointing and focus scans in very near real time so that operator can decide if measurement needs to be repeated. At a minimum, will need to complete processing of previous calibration measurement(s) before it is activated for the next batch of data.

Frequency of Use:   Minutes to seconds. Perform this Quick Look Calibration Monitor Use Case after each calibration measurement by ALMA. This Calibration Monitor will normally be activated several times per scheduling block.

Preconditions:

1. A TelCal event activates the Quick Look Calibration Monitor when a calibration scan is completed.
2. Calibration Data are available from the Telescope Calibration subsystem running in parallel.

Basic Course:

1. Quick-Look Calibration Monitor retrieves the most recent calibration result using methods provided by the TelCal subsystem after receiving the appropriate TelCal event.
   
2. The Quick Look Calibration Monitor plots the results of the most recent calibration scan using the default parameters for that type of calibration scan.
   Alternate course: the most recent scan is plotted using parameters specified by the Operator, Staff Astronomer or Interactive Observer.

   The Quick Look Calibration Monitor plots the results of the cumulative results of this type of calibration scan using the default parameters for that type of calibration scan.

   Alternate course: the most recent scan is plotted using parameters specified by the Operator, Staff Astronomer or Interactive Observer.

   The Quick Look Calibration Monitor plots the calibration results for this observing session as a function of time, if appropriate, using the default parameters.

   Alternate course: calibration results versus time are plotted using parameters specified by the Operator, Staff Astronomer or Interactive Observer.

Postconditions:

1. The Quick Look Calibration Monitor adds the most recent calibration results to a temporary database holding all the calibration results from the current observing session. This database is emptied at the end of the current observing session.
2. Standard plots and summary tables of calibration monitoring to this point are sent to the archive.
3. The Observer is notified (by email) that calibration monitoring plots are available.

Issues to be Determined or Resolved:  

1. How often do we want to email the obsevers that calibration monitoring plots are available? We want to avoid sending 100 emails per observing session, but once per session may not be enough. Maybe they should just be given a URL (that they can monitor) at observing startup.
   
2. How often do we want to send calibration monitoring plots and summary tables to the archive? At a minimum they must be sent at the end of the session. To allow monitoring during the session, perhaps once per scheduling block would be frequent enough? Depends a bit on how interactive a remote observer wants to be what the program is. Perhaps the user can set this as a parameter (with reasonable limits). Some guidance from operations on this would be helpful.
   
3. It might be useful if the ALMA offline system could regenerate plots from the summary tables stored in the archive.

Notes:  

1. This Use Case was created by C. Wilson to help define Quick Look requirements. Relevant SSR Use Case from SSR Memo 11 is 4.5.2 (Process Quick Look Data) (parts of it) by R. Lucas.
   
2. An Observer must be able to look at the Pipeline results of recently observed Programmes without downgrading the Quick Look peformance on the currently observed Programme.
   

   Last modified: 12aug03