This document addresses the requirements found in the EVLA e2e Science Software Req'ts (see §2.1-R10 (excerpt)). Comments and/or status are given for the various requirements.

2.1-R10.1 A built-in calibrator catalog

Priority: 1 Timescale: D

Though we will not take this requirement literally, we will honor its spirit. The CSC will be told what database to use to find both observatory and user catalogs. The prototype is doing this now.

2.1-R10.2 The ability to import calibrators from a user-supplied source list in ASCII format

Priority: 1 Timescale: D

The current plan is to pull sources only from a database of source catalogs. However, the Source Catalog Tool (SCT) will have the ability to import sources into that database in one or more text formats.

2.1-R10.3 The ability to directly input calibrators

Priority: 1 Timescale: D

This task has been given to the SCT.

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

What is the algorithm for identifying such calibrators?

2.1-R10.4.2 calibrators for tracking time variable complex gain as a function of time ("phase" calibrators)

Priority: 1 Timescale: D

What is the algorithm for identifying such calibrators?

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

The display in the prototype has a movable "bullseye" centered wherever the user would like and with all nearby calibrators displayed with accurate relative distances.

We need a way to say "set the center of the bullseye to the position of source xyz".

We need a way to select one or more calibrators from the display and communicate those choices to whatever software activated the CSC.

We plan to show details about the source, such as flux density. Do we do this via a pop up box, color / size coding of source, both? Need discussion about this.

2.1-R10.4.2.2 astrometric phase calibrators

Priority: 2 Timescale: E

What is the algorithm for identifying such calibrators?

2.1-R10.4.3 reference pointing calibrator(s)

Priority: 1 Timescale: D

What is the algorithm for identifying such calibrators?

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

The Observation Preparation Tool allows a similar selection when setting up a scan. Is this really a job for the CSC? If so, how does this work?

2.1-R10.4.4 bandpass calibrator(s)

Priority: 1 Timescale: D

What is the algorithm for identifying such calibrators?

2.1-R10.4.5 polarization calibrator(s)

Priority: 1 Timescale: D

What is the algorithm for identifying such calibrators?

2.1-R10.4.6 focus calibrator(s)

Priority: 2 Timescale: E

What is the algorithm for identifying such calibrators?

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

See response to 2.1-R10.4.3.1, above.

2.1-R10.4.7 delay calibrator(s)

Priority: 2 Timescale: E

What is the algorithm for identifying such calibrators?

2.1-R10.5 The ability to have the tool pick all the appropriate calibrators...

Priority: 2 Timescale: E

...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)

2.1-R10.6 Output which can be fed automatically into the Observation setup component source catalog

Priority: 1 Timescale: C

The SCT can do this now. Need to discuss if there is a direct link from OPT to CSC (probable answer: "yes"), or if CSC is linked only to SCT, which is in turn linked to OPT.

2.1-R10.7 The ability to input a description of the sky brightness distribution for any chosen calibrator, via...

2.1-R10.7.1.1 point source (flux density, position, polarization, and the variation of these with frequency)

Priority: 1 Timescale: D

This is part of the Source Model; input is handled by the SCT.

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

This is part of the Source Model; input is handled by the SCT.

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

This is part of the Source Model; input is handled by the SCT.

2.1-R10.7.1.4 combinations of the above simple single sources

Priority: 3 Timescale: E

This is part of the Source Model; input is handled by the SCT. Combinations may be created by either creating multiple subsources of a source, or by creating different brightnesses for a single subsource, but for different frequency ranges.

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

The underlying SourceFilter might operate with a queryDate (need to check), but the prototype has no way to specify this. Need final CSC to allow date input.

Abstract

2.1-R10 The Calibrator Selection Component (CSC)

2.1-R10.1 A built-in calibrator catalog

2.1-R10.2 The ability to import calibrators from a user-supplied source list in ASCII format

2.1-R10.3 The ability to directly input calibrators

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)

2.1-R10.4.2 calibrators for tracking time variable complex gain as a function of time ("phase" calibrators)

2.1-R10.4.3 reference pointing calibrator(s)

2.1-R10.4.4 bandpass calibrator(s)

2.1-R10.4.5 polarization calibrator(s)

2.1-R10.4.6 focus calibrator(s)

2.1-R10.4.7 delay calibrator(s)

2.1-R10.5 The ability to have the tool pick all the appropriate calibrators...

2.1-R10.6 Output which can be fed automatically into the Observation setup component source catalog

2.1-R10.7 The ability to input a description of the sky brightness distribution for any chosen calibrator, via...

2.1-R10.7.1.1 point source (flux density, position, polarization, and the variation of these with frequency)

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)

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)

2.1-R10.7.1.4 combinations of the above simple single sources

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)