Coordinate Projection from Field Boundaries

[GeorgeVassilakis]

Field boundaries are currently approximated as a 2D rectangle. The boundaries and box size can and should be projected to a 3D celestial sphere.

[mcclearyj]

Relatedly, the default plotting function only plots a small subsection of the full image. Trying to expand the region leads to a funny aspect ratio that I can't seem to fix.

[mcclearyj]

At least part of the issue is likely that the declination range is a fraction of a degree, while the RA range is at least 1 degree. However, degrees-arcminutes-arcseconds of declination is not the same as hh:mm:ss of RA. Even in decimal degrees, declination goes from +90 to -90, while RA can go from 0 to 359:59:59. Whatever coordinate transformation is being made in the code doesn't understand this distinction.

Edited to add that I think we should be trying an approach like the ones laid out here:

• https://python4astronomers.github.io/astropy/wcs.html
• https://docs.astropy.org/en/stable/visualization/wcsaxes/index.html#module-astropy.visualization.wcsaxes
• https://docs.astropy.org/en/stable/wcs/reference_api.html#module-astropy.wcs (full astropy.wcs documentation)