DecorrelateALKernelMapper

class lsst.ip.diffim.DecorrelateALKernelMapper(*args, **kwargs)

Bases: lsst.ip.diffim.DecorrelateALKernelTask, lsst.ip.diffim.ImageMapper

Task to be used as an ImageMapper for performing A&L decorrelation on subimages on a grid across a A&L difference image.

This task subclasses DecorrelateALKernelTask in order to implement all of that task’s configuration parameters, as well as its run method.

Methods Summary

run(subExposure, expandedSubExposure, …[, …]) Perform decorrelation operation on subExposure, using expandedSubExposure to allow for invalid edge pixels arising from convolutions.

Methods Documentation

run(subExposure, expandedSubExposure, fullBBox, template, science, alTaskResult=None, psfMatchingKernel=None, preConvKernel=None, **kwargs)

Perform decorrelation operation on subExposure, using expandedSubExposure to allow for invalid edge pixels arising from convolutions.

This method performs A&L decorrelation on subExposure using local measures for image variances and PSF. subExposure is a sub-exposure of the non-decorrelated A&L diffim. It also requires the corresponding sub-exposures of the template (template) and science (science) exposures.

Parameters:
subExposure : lsst.afw.image.Exposure

the sub-exposure of the diffim

expandedSubExposure : lsst.afw.image.Exposure

the expanded sub-exposure upon which to operate

fullBBox : afwGeom.BoundingBox

the bounding box of the original exposure

template : afw.Exposure

the corresponding sub-exposure of the template exposure

science : afw.Exposure

the corresponding sub-exposure of the science exposure

alTaskResult : pipeBase.Struct

the result of A&L image differencing on science and template, importantly containing the resulting psfMatchingKernel. Can be None, only if psfMatchingKernel is not None.

psfMatchingKernel : Alternative parameter for passing the

A&L psfMatchingKernel directly.

preConvKernel : If not None, then pre-filtering was applied

to science exposure, and this is the pre-convolution kernel.

kwargs :

additional keyword arguments propagated from ImageMapReduceTask.run.
Returns:
A `pipeBase.Struct` containing:
* `subExposure` : the result of the subExposure processing.
* `decorrelationKernel` : the decorrelation kernel, currently

not used.

Notes

This run method accepts parameters identical to those of ImageMapper.run, since it is called from the ImageMapperTask. See that class for more information.