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  1. Data Management
  2. DM-7102

Add centroid reliability flag or improve Centroid_flag behavior

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      The current base_SdssCentroid_flag does not incorporate as much detail about the "goodness" of the centroid fit as I would like. For example, for a random HSC image, I find a non-zero list of objects with centroid_flag False and interpolated, saturated, and/or edge True:

      ipdb> dataRef.dataId
      DataId(initialdata={'taiObs': '2006-06-02T09:07:28.22', 'extension': 13, 'object': 'D3', 'visit': 850587, 'filter': 'r', 'state': 'p', 'runId': '06AL01', 'tract': 0, 'date': '2006-06-02', 'ccd': 12, 'expTime': 300.181}, tag=set([]))
      ipdb> cent = src['slot_Centroid_flag']
      ipdb> sat = src['base_PixelFlags_flag_saturated']
      ipdb> interp = src['base_PixelFlags_flag_interpolated']
      ipdb> edge = src['base_PixelFlags_flag_edge'] 
      ipdb> (sat & ~cent).sum()
      52
      ipdb> (interp & ~cent).sum()
      173
      ipdb> (edge & ~cent).sum()
      5
      

      I do not have any cases where the centroid values or sigmas are non-finite and Centroid_flag is False, but those were claimed to have been found in some CFHT data in the past.

      I would propose that a Centroid_isReliable (or similar name) flag be defined as follows, with fields removed if they are already incorporated into Centroid_flag.

      all(
      not centroidFlag,
      isfinite(centroid),
      isfinite(sigma),
      ok covariance (somehow defined),
      not saturated,
      not interpolatedCenter,
      not edge
      )
      

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            swinbank John Swinbank added a comment -

            Reviewed for DM-CCB, 2020-06-02.

            And it made me wonder somewhat about the semantics of flags, but not enough to distract from other work that's currently in progress.

            Show
            swinbank John Swinbank added a comment - Reviewed for DM-CCB, 2020-06-02. And it made me wonder somewhat about the semantics of flags, but not enough to distract from other work that's currently in progress.

              People

              Assignee:
              Unassigned Unassigned
              Reporter:
              Parejkoj John Parejko
              Watchers:
              Chris Morrison [X] (Inactive), Jim Bosch, John Parejko, John Swinbank, Russell Owen, Simon Krughoff
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