abem Terrameter LS, Instruction Manual

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ABEM Terrameter LS
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10. Make a copy of the file COLLATE_2D_TO_3D.TXT (can be found in the
Res2dinv program directory) and change filenames and coordinates according to
the present survey. Start Res2dinv and use the option “File/Collate data into
Res3dinv format” to merge the files.
11. Start Res3dinv and invert the merged data file.
X axis
Y
a
x
is
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Start
End
Start
End
Start
End
Start End
Start
End
Start End
Start End
Start End
Start End
Figure 50 . This example shows a survey consisting of 9 parallel lines oriented in the
x-direction.
6.7 3D Imaging by Electrode Grid Layouts
In some cases a roll-along procedure as described above is not sufficient for 3D
surveys, in which case a grid of electrodes can be used. Since the built-in relay switch
of a single Terrameter LS can switch 64 electrodes the maximum layout size is 8 x 8
electrodes. For larger electrode layouts external relay switches can be connected to
Terrameter LS.
6.8 Borehole-borehole Tomography
Borehole measurements require electrode cables designed for this purpose, standard
Lund Imaging System electrode cables are not suitable. Cable description (address)
files must be designed to suit the particular hardware configuration of these cables,
and sequence (protocol) files should use array code 12 (tomography). See “Appendix
C. Spread and Measuring Sequence Files” for more information on spread / address
and measuring sequence / protocol files. The roll-along feature will not work for this
type of measurements.