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Make sure to have a backup of the entire project before ever attempting to reproject a project.
Re-projecting a project is not trivial. Selecting a reasonable map projection at the beginning of a project and simply correcting for the other reference datum-based data with the Datum tab will largely prevent the need to reproject an entire project.
A map projection is an attempt to portray the curved surface of the earth on a flat piece of paper or computer screen. Map projections have two parts: the reference datum and the coordinate system. The reference datum is a model of zero elevation, which is used to calculate longitude and latitude. The coordinate system essentially is a set of coordinates that transforms latitude and longitude on a globe into XYs on a flat map.
In a sense, these two parts of a map projection (the reference datum and the coordinate system) constitute two separate steps:
- The reference datum, used to calculate LatLons for a location on a globe
- The coordinate system converts this LatLon data into XYs for plotting on a flat map
Changing the reference datum of a project means that the old LatLon points need to be reprojected in order to spot correctly on a map. Since the LatLon data changes, Petra will apply the coordinate system to calculate new XY points.
Changing a project's reference datum is done in two parts:
- Recalculating the LatLon and XY of every well location
- Recalculating the LatLon and XY of all auxiliary files including overlays, grids, XYZ files, and LatLonZ files.
Related Topics
How to Reproject a Project to use a Different Reference Datum
How to Reproject a Project to use a Different Coordinate System (With the Same Datum)
How to Import New LatLon Data
How to Import New XY data
How to Use Map Projection Administrative Options
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