Use Case: ProcessBandpass
The Calibration Pipeline reduces bandpass measurements in quasi-real time,
in an automatic way.
Role(s)/Actor(s):
Primary: Calibration Pipeline
Secondary:
Priority: Major
Performance: Seconds
Frequency: Hours
Preconditions:
-
The processing is initiated by the Calibration Pipeline (see Use Case
ProcessCalibrations).
-
One or several observations of a strong point-like source have been obtained,
belonging to one or several contiguous scans.
-
Input:
-
Visibilities for all spectral channels, averaged over the total integration
time.
-
Parameters for frequency smoothing (method, input parameters)
-
Parameters for bandpass fit: frequency or channel method, order of polygons.
Basic Course:
-
Check data consistency.
Exception course: If data not consistent: stop processing and
return a specific error code.
-
If channel method:
-
Derive complex antenna-based bandpasses.
Exception course: If failure: stop processing and return a specific
error code.
-
If frequency method:
-
Optionaly: smooth the data along the frequency axis.
Exception course: If failure: stop processing and return a specific
error code.
-
Derive complex antenna-based bandpasses.
Exception course: If failure: stop processing and return a specific
error code.
-
Verify that result is sensible and set quality code.
Exception course: If failure: stop processing and return a specific
error code.
Alternate Course:
Postconditions:
-
Outputs:
-
For each antenna: complex bandpass, associated fit rms, and quality code.
-
Error code.
-
Results are fed back to the Calibration Pipeline.
Issues to be Determined or Resolved:
-
The Science IPT is still thinking about the bandpass calibration scheme.
Depending on the final decision, all sections of this Use Case may be affected.
Notes:
-
The processing of the bandpass measurements requires the spectral
visibilities.
-
The processing of the bandpass measurements and that of the delays are
coupled.
Owner: Frederic Gueth