In order to support double-Gaussian smoothing in detection, we need to be able to fit a double-Gaussian approximation to a PSF image. The DoubleShapeletPsfApproxAlgorithm class in meas_modelfit can do this, but will require some changes to make it really usable in this context:
- We need to either make meas_modelfit a dependency of meas_algorithms or move a lot of code between packages.
- We need to support fitting a circular double Gaussian as a configuration option.
- We need an easy way to call the fitter without (directly) setting up a schema, an input/output record, and mocking up a centroid.
- We need a way to easily make a DoubleGaussianPsf from an appropriately constrained MultiShapeletFunction.