Introduce Area weighted, Distance weighted methods in support of LFRic data

[j-opatz]

Describe the New Feature

As requested by Met Office, there is a desire to see more interpolation methods that can be utilized by LFRic data, an unstructured gridded (UGRID) dataset.

An option to consider when forming the Bilinear method is when interpolating to point obs lat/lon, we could figure out the “face” in which the point falls. Each face is defined by 3 or more vertices. When the user requests bilinear interpolation, we could consider implementing that as a distance-weighted mean of the values at the vertices which define that face.

This also raises the question of if there is more of a desire to have a distance weighted interpolation, rather than bilinear (which relies on a traditional rectangle grid).

Acceptance Testing

Met Office will need to supply test data, as well as be the reviewing body that confirms these interpolation methods are working as requested.

Time Estimate

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Issues should represent approximately 1 to 3 days of work.

Sub-Issues

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Relevant Deadlines

This work needs to be completed before the end of the PoP for PRJ014176, which is August 30th 2026.

Funding Source

PRJ014176

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