RockWorks stores grid models in a combination text (XML) and encrypted file format, with an ".RwGrd" file name extension. Note that all real number coordinates are listed in the files using a US number format.
Here is an example of the contents of an RwGrd file:
<?xml version="1.0" encoding="utf-8"?>
<RWGRD VERSION="16.0">
<DIMENSIONS>
<X_MIN>481875.0</X_MIN>
<Y_MIN>4399725.0</Y_MIN>
<X_NODES>61</X_NODES>
<Y_NODES>61</Y_NODES>
<X_SPACING>5.0</X_SPACING>
<Y_SPACING>5.0</Y_SPACING>
</DIMENSIONS>
<UNITS>
<XY_UNITS>Units_Undefined</XY_UNITS>
<Z_UNITS>Units_Undefined</Z_UNITS>
</UNITS>
<PROJECTIONS>
<LCS_LON>0.0</LCS_LON>
<LCS_LAT>0.0</LCS_LAT>
<SPC_ZONE>0</SPC_ZONE>
<UTM_DATUM>0</UTM_DATUM>
<UTM_ZONE>0</UTM_ZONE>
</PROJECTIONS>
<GRID>
(encrypted data blocks here)
</GRID>
<NOTES/>
</RWGRD>
As of November 2004, the grid file format now supports an optional block of data that contains fault segment information. This fault "block" consists of a header, a list of fault segment endpoints, and a terminator.
This block is automatically appended to grid models by gridding algorithms that support faulting (e.g. inverse-distance). This information is then used by programs that process grid models, including grid-smoothing, solid-fill color contouring, grid contouring, and fault plotting.
! Note: The fault block must be positioned after the normal grid data.
See also: Grid Nodes versus Grid Cells