Spherical Mesh Support

Spherical Mesh Support#

We support all cartopy projections, except UTM, for spherical meshes. To be able to support this wide range of projections, with very different projection boundaries, we cull problem cells from the mesh stored internally by the mosaic.Descriptor. We determine the cells that need to be culled based on any of the following three conditions being met for a given cell, after transforming the coordinates to the requested projection:

  1. All verticesOnCell lie outside the projection boundary

  2. Any verticesOnCell is NaN after projection

  3. If the centroid of the projected cell patch does not match the projected cell center position

Unless you are using a very coarse mesh (e.g. QU.960), you will most likely not notice the results of the culling.

Note

This subset of supported projections only applies to spherical meshes. Planar (non-periodic) meshes are not limited to this list and can choose from the full range of cartopy projections.