Related Software and Terrain Data
InnerTC and LaserTC are designed to calculate terrain corrections
due to terrain very close to a gravity station. At greater distances, more
traditional terrain correction programs, such as that of
Plouff (1966), are typically utilized. A version of
Plouff's program called OuterTC
is available for download. Terrain data for the lower 48 states of the
United States are also available for download (12.9
Mb file!), though such data will have to be reformatted somewhat in
order to be used by Plouff's code. A code called MAPFILE
that will perform a particular reformatting is provided here, as well.
Additionally, the 30-m DEMs that are most commonly used in conjunction
with InnerTC are now available -- for a limited time -- for FREE
from the U. S. Geological Survey. The catch is that these DEMs have been
reformatted into the new Spatial Data Transfer Standard
(SDTS), which is utterly incompatible with the previous format.
However, a conversion code is available
here, which will convert the SDTS-formatted DEMs into the original format,
thus permitting the SDTS-formatted DEMs to be used with InnerTC.
More details of the code are
available here, as well.