DC-2d forward with only 'Dipole-Dipole' or 'pole-dipole' or 'dipole-pole' or 'pole-pole'?

DC and IP
1

I found that when I created a survey using simpeg for two-dimensional forward modeling,survey_type contains just four types of devices(Dipole-Dipole’ or ‘pole-dipole’ or ‘dipole-pole’ or ‘pole-pole’).I was wondering if we could do other types of devices such as Wenner device or others.

Here are the comments in the code:
def generate_dcip_sources_line(
survey_type,
data_type,
dimension_type,
end_points,
topo,
num_rx_per_src,
station_spacing,
):
“”"
Input:
<<:param str survey_type: ‘dipole-dipole’ | ‘pole-dipole’ |
‘dipole-pole’ | ‘pole-pole’>>

2

dipoe-dipole can handle wenner and other types that you mentioned. it literally means the four electrode system rather than typical dipole dipole array.

2 Likes
3

To add to Seogi’s answer:
Yes, SimPEG can forward and invert any type of electrodes configuration.
However, the util to generate synthetic surveys you are mentioning indeed is limited in what it can create. The best way for you then to create any type of surveys is to use the I/O utils. This means start from a text file (either with a list of ABMN locations or in a UBC format) and load it using the adequate utils. You will find more examples in the documentation, for example:

2 Likes
4

Thank you for your patient answer. In addition, I noticed that direct current forward modeling is based on the survey of a certain device (such as dipole-dipole).

According to the theory of finite element, we can obtain the potential of all underground grid nodes by point source.I want to learn more about how Simpeg does this.

5

I have know how to define a survey form a ABMN file now.
I have one more question , when I use the IO.from_abmn_locations_to_survey to build a dc_survey,I need to assign the data_dc_type,if I assign the datatype to “apparent_resistivity”, how can I generate a “dc_data” form the Simpeg.data using this dc_survey? if I solve the problem using simulation, what is the output of dpred , the dpred is apparent_resistivity or nomalized voltage?

6

Ah, only I don’t know how to change the dipole-pole to a symmetrical quadrupole

7

I want to do symmetric quadrupoles, I tried to set the position of ABMN, but it did not work properly, it was modified on the basis of dipole