To use DEFLEC12A, an INTD executable and at least one pair (Xi/Eta) of data files must be downloaded. You need only to select those data files that cover your region, and the INTD.EXE (or INTD) program will recognize which files are present.
Program INTD.EXE interpolates deflections of the vertical from data files using user-provided coordinates.
Program XNTD.EXE extracts sub-grids from the binary data files, as well as convert back and forth between binary and ASCII, or just give statistics about a data file.
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