Use Case: ReduceSingleField

This Use Case describes the on-line data reduction operations for the Single Field interferometry mapping mode.

Role(s)/Actor(s)
Primary: The AOS, or the observer
Secondary:

Priority: Major

Performance: Need to feed back data nearly in real time.

Frequency: At least once per program, possibly after breakpoints, after a session or for every scan.

Preconditions: The user input parameters have been input and have been made available to the pipeline, preferably in the data headers

Basic Course:

  1. For each available observation, the current system temperatures are computed using total power on sky and ambient load (previously measured).
  2. When the bandpass scan is available, the bandpass calibration is computed (UC ReduceBandPass)
  3. Whenever a new phase calibrator scan is available, the phase rms is computed, the antenna based amplitudes are checked against the known calibrator flux.
  4. At the end of the session:
    1. the phase calibration is computed and applied to all target scans by interpolation.

      2. Alternate Course: the phase calibration is computed and applied on the fly, as soon a sufficient number of calibration scans are available
    2. the amplitude calibration is computed and applied to all target scans by interpolation.

      3. Alternate Course: the amplitude calibration is computed and applied on the fly, as soon a sufficient number of calibration scans are available
  5. Optionally, the UV data is
  6. Optionally the data cube is archived
 Postconditions:
  1. ...

Issues to be Determined or Resolved: ...

Notes:

  1. we assume that the pointing and focus scans reduction is described in another Use Case
  2. we assume that online displays to be regularly updated are described in another Use Case.
  3. if resources allow maps may be computed and displayed at more frequent intervals, for diagnostic purposes.
  4. Interim results are probably not stored in the archive or at least they should be flagged as being only intermediate results.
Last modified: 2000/07/28 R. Lucas, 2000/11/10 D. Muders