Martin Desruisseaux created SIS-445:
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Summary: NetCDF store should be robust to localization grid
crossing anti-meridian
Key: SIS-445
URL: https://issues.apache.org/jira/browse/SIS-445
Project: Spatial Information Systems
Issue Type: Task
Components: Referencing, Storage
Reporter: Martin Desruisseaux
Assignee: Martin Desruisseaux
Fix For: 1.0
NetCDF files often have a "longitude" and "latitude" variables (names may vary)
containing longitude and latitude values of every pixels. For raster data in
Pacific ocean, the range of longitude sometime cross the anti-meridian, where
longitude values suddenly drop from +180° to -180°. This discontinuity breaks
our attempt to compute an affine transform approximation in
{{LocalizationGridBuilder}}, produces wrong results when interpolating values
in this area of the grid, and makes more difficult to converge when performing
an inverse transformation.
The proposed fix is to detect when such discontinuity happens, and add or
subtract 360° on one side in order to get continuous values. Inconvenient is
that some values become outside the [-180 … 180] range. In some case it can be
outside the [0 … 360] range too (i.e. the data may turn around the Earth more
than one lap).
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