A lightweight Xarray extension for managing geospatial coordinate reference systems (CRS) using PROJ/Pyproj.

Current development status: experimental, proof-of-concept.

See the documentation.

• Provide to Xarray geospatial extensions a set of convenient tools for dealing with coordinate reference systems (CRS) in a uniform & flexible way.
• Prevent duplicating CRS-specific logic (e.g., parse, reset, formatting, checking equality, etc.) in each extension ; put it together into one reusable package instead (i.e., a lightweight Xarray extension mostly built on top of pyproj).
• Provide a common end-user API for handling CRS via Xarray accessors.
• Leverage recent Xarray features such as custom indexes. Easily compare, combine or align Xarray datasets or dataarrays based on their CRS (via CRSIndex).
• Consolidate the Xarray geospatial ecosystem (towards better interoperability).

• Being strongly opinionated on how CRS and other information like spatial dimensions should be represented as metadata in Xarray objects and/or in Xarray supported I/O formats. This is left to other Xarray extensions and format specifications.
• Provide a common set of tools (implementations) for re-projecting data. This highly depends on the data type (i.e., raster, vector, etc.) or application and it is best handled by other Xarray extensions. We also see XProj potentially as a lightweight dependency common to those other extensions so we want to restrict XProj's dependencies to the minimum (i.e., Xarray and PyProj).