Example: Schleiz
This example was published by Martin et al. (2020) on the testsite Schleiz. The data and all scripts are accessible on Zenodo. A shallow pyrite-rich blackshale was measured with ABEM Terrameter LS2.
from tdip import TDIP
We read the data as DIP file (from Aarhus Workbench processing). Other possible formats are txt exports from ABEM or Syscal software.
tdip = TDIP("Profile1-DD-4s-new-proc_corr.dip")
print(tdip)
The data set constists of 829 quadrupoles using 42 electrodes. Apparent chargeability is present in 25 gates from 1ms to 3s. The apparent resistivity was shown in Fig. 4 (upper right) of the paper.
tdip.showData();
First, we invert for the resistivity using a rather fine and high-quality mesh with a maximum depth of 12m.
tdip.invertRhoa(paraDepth=12, quality=34.4, paraDX=0.25, verbose=True, show=True)
The result is very similar to Fig. 10, third row left. We fit the decays using a Debye model (only using gates above 100ms) and obtain apparent relaxation times of about 1-2s.
tdip.fitDataDecays(tmin=0.1)
# tdip.generateDataPDF() # produces a multi-page pdf
tdip.showData("tau")
We show all decays for the same AB combination as in Fig. 8.
The function generateDecayPDF() generates a multi-page pdf of all AB.
tdip.showDecay(ab=[26, 27], showFit=True, xscale="log")#, yscale="linear")
if 0: # creates a multi-page pdf file with all AB on separate pages
tdip.generateDecayPDF(showFit=True)
We plot a single apparent chargeability of gate 16 like in Fig. 6 (third row).
tdip.showMa(16, logScale=False);
This gate can be inverted individually.
tdip.invertMa(16, error=0.01)
The result looks similar to the one in Fig. 10, third row, right.
tdip.showChargeability();
We can invert all gates using a Debye approach.
tdip.filter(tmin=0.1)
tdip.invertDebye(verbose=True)
The result is contained in the field modelDebye, but also inside the mesh (tdip.pd) as total chargeability and log-mean tau.
print(tdip.pd, tdip.modelDebye.shape)
tdip.pd.show("TC", factor=1000, cMax=400);
