guideline and standards for skytem measurements, processing and ...

(December 2010)
This Annex will be regularly updated so that it follows the development of the SkyTEM system.
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The right part of the table below gives an overview of the main parameters of the super low moment (SLM)
and the three variants of the high moment (HM). Note also that there are two sizes of the transmitter frame.
The left part of the table shows the possible combinations of moment and the investigation depth a given
combination has. In the following tables the different moment specifications are tabulated in detail.
SLM
Tx-area
[m 2 ]
Moment definitions
Number
of turns
1 Tx current
[A]
2 1st gate
time [s]
Two-moment configurations
3 Last
gate
time [ms] A B C D
314 1 10 12 1,0 X X X
494 1 10 15 1,0 X
HM1 314 1 100 30 1,0 X
HM2 314 2 100 35 2,7 X
HM4
314 4 100 70 9,0 X
494 4 90 100 9,0 X
Focus depth:
Deep
Near
surface
/deep
Near
surface
Lateral resolution: Medium Medium High
Very
near
surface
Very
high
4 Approx. depth of investigation [m]: ~300 ~200 ~150 ~100
1 Approx. current.
2 Approx. time for the first usable gate (gate with an acceptable low bias level). Depend on the resistivities of the survey
area.
3 The last gate-center time recorded. The last gate-center time used in the processing will normally be earlier dependent
on the resistivities of the survey area.
4 The depth of investigation is highly dependent on the resistivity distribution in the survey area.
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