Pitney Bowes MapInfo Vertical Mapper - Manual (Page 150)

Using the Reproject Tool
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Vertical Mapper 3.7
The Table will display the list of open tables.
The Class Column will display the list of columns in the selected table which are of type character.
The Value Column will display list of columns in the selected table which are of type numeric.
Clicking on OK in this dialog will update the values in the Class Value column in the Classified to
Numeric Grid converter dialog.
Using the Reproject Tool
The Reproject tool enables you to transform a grid from its existing coordinate system to another
MapInfo Professional supported system, which results in the interpolation of new values for each
new grid cell. The process involves a complex coordinate transformation that makes use of
quadratic surfaces to transform x, y locations in the original grid to the new coordinate system using
four cell blocks. The procedure has been engineered to be accurate to within five percent of the new
grid cell size at any location across the new grid extent. For example, if the new cell size is 100
metres, the cell location will be accurate to within ±5 metres. The process uses a variation of the
bilinear interpolator to recalculate new cell values at each transformed grid cell.
1. In the Grid Manager, click the Tools button and choose the Reproject command.
2. In the Reproject Grid dialog box, choose a grid from the Grid list and click the Projection button.
3. In the Choose Projection dialog box, choose a projection category and category member and
click the OK button.
4. Click the OK button to close the Information dialog box containing a suggested range of cell size
values.
This range of values represents the minimum and maximum cell sizes to which any of the
original grid cells will be transformed over the area of the new reprojected grid. If you select a
new cell size for the reprojected grid that is less than half as small as the minimum
recommended value, then the process will return a warning message stating that “This cell size
is not recommended.” This warning is meant to ensure that grid cells in the new reprojected file
approximate as closely as possible the size of the original cells. The same warning message will
appear if you select a new cell size for the reprojected grid that is greater than twice the
maximum recommended value.
5. In the File name field of the Reproject Grid dialog box, type a new file name or accept the
default.
6. Click the OK button.