Proposed enhancements from LSST SSSC

[mkelley]

The LSST Solar System Science Collaboration has proposed a few enhancements for sbpy. This issue is to track the status of the proposal and the progress of the tasks, if selected.

The top-level goals are to enhance the sbpy Python module by completing the following:

1. Create a module for sbpy that, given an arbitrary filter transmission curve (e.g., a custom VR filter, PanSTARRS w' band, ATLAS c' or o' band) and an assumed object spectrum, can compute equivalent magnitudes in LSST bands from magnitudes measured in the arbitrary filter, or vice versa, with reasonable performance at large scales, with the goal of providing a means for linking LSST data with other photometric data from other surveys.
2. Improve sbpy installation infrastructure to better align with the Rubin Science Platform, e.g., make it conda-installable. See Add sbpy to conda-forge and the astropy channel #250, WIP: add conda recipe #264.
3. Convert key sbpy code (e.g., for fitting disk-integrated phase functions) from Python to Cython to improve performance when applied to LSST-scale datasets, and potentially identify and address other primary performance bottlenecks in sbpy code as time allows.

Task 1. could have some overlap with the main developer tasks over the next two years, and if this is the case, who does what can be negotiated in the future. sbpy developers tasks might be considered as baseline functionality and the above task as an extension to create a high-level interface.

[Yeqzids]

Improve sbpy installation infrastructure to better align with the Rubin Science Platform, e.g., make it conda-installable. See Add sbpy to conda-forge and the astropy channel #250, WIP: add conda recipe #264.

Isn't sbpy already available through conda-forge? https://anaconda.org/conda-forge/sbpy

[mkelley]

Interesting, thanks for pointing that out. Our task will be to be sure that it remains there, working with future versions.

[Yeqzids]

Interesting, thanks for pointing that out. Our task will be to be sure that it remains there, working with future versions.

Thanks. In case anybody is reading, the conda-forge version is apparently up to date, but be aware that it will not check for dependency/compatibility with astropy (see #312; sbpy 0.2.2 needs astropy<4.0). So what I do is to set up another conda environment with astropy<4.0 and sbpy will run smoothly.

The dependency is probably mentioned somewhere in the README but I didn't see it...

[mkelley]

@Yeqzids , with v0.3.0 out now and on conda-forge, the dependency issues should be addressed.