2.1-R10 The Calibrator selection component shall provide:
 
  2.1-R10.1 A built-in calibrator catalog;
            Priority: 1 Timescale: D
 
  2.1-R10.2 The ability to import calibrators from a user-supplied source list in
            ASCII format;
            Priority: 1 Timescale: D
 
  2.1-R10.3 The ability to directly input calibrators;
            Priority: 1 Timescale: D
 
  2.1-R10.4 The ability to select the following types of calibrators, based on source
            location, frequency, and array configuration:
 
    2.1-R10.4.1 primary and secondary flux density scale calibrator(s);
                Priority: 1 Timescale: D
 
    2.1-R10.4.2 calibrators for tracking time variable complex gain as a function of
                time ("phase" calibrators);
                Priority: 1 Timescale: D
 
      2.1-R10.4.2.1 there shall be a display to show the distribution of these sources
                    relative to target source location, with associated properties
                    (flux density, position accuracy, flux density vs. frequency,
                    etc...), and to allow for interactive selection of the calibrators
                    to be used;
                    Priority: 2 Timescale: D
 
      2.1-R10.4.2.2 astrometric phase calibrators;
                    Priority: 2 Timescale: E
 
    2.1-R10.4.3 reference pointing calibrator(s);
                Priority: 1 Timescale: D
 
      2.1-R10.4.3.1 it shall be possible to select different reference pointing
                    patterns, either from a menu (showing, e.g., classical 5-point,
                    triangles, shifted triangles, the 'Craig cross', etc...) or via
                    input as an ordered table of offsets and dwell times;
                    Priority: 2 Timescale: E
 
    2.1-R10.4.4 bandpass calibrator(s);
                Priority: 1 Timescale: D
 
    2.1-R10.4.5 polarization calibrator(s);
                Priority: 1 Timescale: D
 
    2.1-R10.4.6 focus calibrator(s);
                Priority: 2 Timescale: E
 
      2.1-R10.4.6.1 it shall be possible to select different focus patterns,
                    either by specifying number of points, focus distance between
                    points, center focus, and dwell time per point, or via input
                    as an ordered table of focus positions and dwell times.
                    Priority: 2 Timescale: E
 
    2.1-R10.4.7 delay calibrator(s).
                Priority: 2 Timescale: E
 
  2.1-R10.5 The ability to have the tool pick all the appropriate calibrators from the
            above list automatically, given the type of observation (e.g., flux
            density and phase calibrators are needed for all, bandpass only for
            spectroscopy, polarization only as needed), the observing band and
            configuration, and the target source location (selection heuristics to be
            provided by NRAO scientific staff);
            Priority: 2 Timescale: E
 
  2.1-R10.6 Output which can be fed automatically into the Observation setup component
            source catalog;
            Priority: 1 Timescale: C
 
  2.1-R10.7 The ability to input a description of the sky brightness distribution for
            any chosen calibrator, via:
 
    2.1-R10.7.1 parametric models of the following types:
 
      2.1-R10.7.1.1 point source (flux density, position, polarization, and the
                    variation of these with frequency);
                    Priority: 1 Timescale: D
 
      2.1-R10.7.1.2 elliptical gaussian (flux density, position, major and minor
                    axis width and position angle, polarization, and the variation
                    of these with frequency);
                    Priority: 1 Timescale: E
 
      2.1-R10.7.1.3 elliptical limb-darkened disk (flux density, position, major
                    and minor axis width and position angle, limb-darkening parameter,
                    polarization, and the variation of these with frequency);
                    Priority: 3 Timescale: E
 
      2.1-R10.7.1.4 combinations of the above simple single sources.
                    Priority: 3 Timescale: E
 
    2.1-R10.7.2 a set of CLEAN components, with polarization and frequency variation
                information;
                Priority: 2 Timescale: E
 
    2.1-R10.7.3 a FITS image, with polarization and frequency variation information;
                Priority: 2 Timescale: E
 
  2.1-R10.8 The ability to do any of the above as a function of date, attaching the
            appropriate date range to the calibrator (for moving target sources).
            Priority: 2 Timescale: D