ABEM Terrameter SAS 4000 / SAS 1000
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The specified depth is in this case be the midpoint of each layer. Blank model cells should be
entered as asterisks (*). If IP data is available it can be included as indicated, the square
parantheses [] indicate that it is optional. The IP parameter/unit line would similar to the
corresponding line in the DAT files.
Alternatively the RHO-2 format can be used:
RHO-2 [IP]
x(1) alt(1)
nd(1)
rho(1,1) Depth(1,1) [ip(1,1)]
rho(1,2) Depth(1,2) [ip(1,2)]
...
rho(1,nd-1) Depth(1,nd-1) [ip(1,nd-1)]
rho(nd) [ip(nd)]
x(2) alt(2)
nd(2)
rho(2,1) Depth(2,1) [ip(2,1)]
rho(2,2) Depth(2,2) [ip(2,2)]
...
rho(2,nd-1) Depth(2,nd-1) [ip(2,nd-1)]
rho(2,nd) [ip(2,nd)]
...
...
...
...
x(nx) alt(nx)
nd(nx)
rho(nx,1) Depth(nx,1) [ip(nx,1)]
rho(nx,2) Depth(nx,2) [ip(nx,1)]
...
rho(nx,nd-1) Depth(nx,nd-1) [ip(nx,nd-1)]
rho(nx,nd). [ip(nx,nd)]
/Model residuals:
[optional]
/Inversion type header:
[optional]
/IP parameter/unit
[optional]
The RHO-2 format has been added since it is advantageous in cases with strong gradients in
the topography. The depth is in this case the bottom of each layer. There is a built-in RHO-2
format conversion tool in Erigraph for conversion from XYZ files saved by Res2dinv (do not
use negative depths). This conversion tool is only designed for models inverted with
topography.
For both model formats an unlimited number of comment lines may be added at the end of the
file, where each comment line should start with a slash (/). This can be useful for saving
information on e.g. inversion parameters together with the model.
Res2dinv has an option for exporting inverted models in Lund-format, which will in the
present version use the old version of the RHO-1 format. In some versions of Res2dinv there
is a bug so it will export non-sense models.
17.4
TOPOGRAPHY
If a data file is opened and an associated inverted model is plotted selecting "2D section", the
models will be plotted with topography provided the DAT-file contains topography (please
consult the Res2dinv manual for details). Alternatively, the topography may be saved in a file
with ALT extension (see above). However, in any case it is necessary to open a datafile and