Ticket #2114 (new design issue)

Opened 7 years ago

Last modified 7 years ago

Consider making it possible to run AstrometryTask without an Exposure

Reported by: rhl Owned by: rowen
Priority: normal Milestone:
Component: pipe_tasks Keywords:
Cc: price, ktl, rhl Blocked By:
Blocking: Project: LSST
Version Number: 5.0
How to repeat:

not applicable

Description

With the current design, you need to create an Exposure before you can run the AstrometryTask. For use within the pipeline this is fine, but there are other places where this functionality is useful (e.g. looking at photometric quality in Stripe82 processing).

The Exposure appears to be only used because it is a convenient container. It is possible to create a "FakeExposure" object that carries its wcs, size, filterName, and distortion, but this is clumsy. Passing all this information as a set of arguments is clumsy too, so designing the correct interface is a little tricky. We have made an Exposure a grab-bag of lots of related stuff, and maybe that's the real issue here?

Change History

comment:1 Changed 7 years ago by DefaultCC Plugin

  • Cc price, ktl, rhl added

comment:2 Changed 7 years ago by rowen

I would often find it useful to have just the WCS and parent bbox of an exposure, and wish there was an object that carried that information. (I'm not convinced all the other metadata, such as filter and calibration, should be packaged in the same object, though I suppose an Exposure could be a MaskedImage + ExposureMetadata?).

In any case, it would presumably suffice to unpackage the needed arguments -- this could be done without any redesign of Exposure.

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