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The process of transforming mouse coordinates to raster coordinates to status bar coordinates may be complex. If that chain involves a datum change, then the results have an uncertainty which can be anything between a few millimeters to a kilometer. If the uncertainty is smaller than the precision of coordinates shown in the status bar, then the accuracy is not provided. But if user zooms enough, the coordinate precision may become finer than positional accuracy. In that case a text such "± 1 m" appears. Screenshot below is an example with the status bar showing coordinates in a Mercator projection. A 3 kilometers uncertainty seems high, but it is because no datum shift information is available in this example, in which case Apache SIS assumes a worst case scenario.

Raster reprojection

The Coordinate Reference System (CRS) can be selected among the list of CRS supported by Apache SIS. This list is available only if the EPSG geodetic dataset has been installed, which is not the case by default for licensing reason (a future version may provide a plugin download mechanism for easier installation). The dialog box shows a warning in red if the selected CRS does not have a domain of validity intersecting the raster geographic area.

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