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41 | 41 | "\n", |
42 | 42 | "**Summary:** Here, we use the [simpeg.electromagnetics.static.induced_polarization](xref:simpeg#simpeg.electromagnetics.static.induced_polarization) module to simulate 3D DC induced polarization (IP) data on a tree mesh. This approach is ideal when the local geology doesn't change along the strike direction, as we can leverage the symmetry of the problem to reduce computational cost.\n", |
43 | 43 | "\n", |
44 | | - "Because the same survey geometry, mesh and topography that are used to simulate DC resistivity data are used simulate IP data, almost all of the fundamental functionality used in this tutorial is described in detail in the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial. In this tutorial, we focus primarily on functionality related to the simulation of IP data. More specifically, we discuss:\n", |
| 44 | + "Because the same survey geometry, mesh and topography that are used to simulate DC resistivity data are used simulate IP data, almost all of the fundamental functionality used in this tutorial is described in detail in the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial. In this tutorial, we focus primarily on functionality related to the simulation of IP data. More specifically, we discuss:\n", |
45 | 45 | "\n", |
46 | 46 | "- Defining the chargeability model\n", |
47 | 47 | "- How to simulate IP data\n", |
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205 | 205 | "source": [ |
206 | 206 | "## Define the IP Survey\n", |
207 | 207 | "\n", |
208 | | - "A full description of elements required to define DC and IP surveys was presented in the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial. Here, we take the same approach. The only difference is that our receivers are defined to measure apparent chargeabilities. Because SimPEG uses a linearized formulation for simulating IP data; see [Simulation3DCellCentered](xref:simpeg#simpeg.electromagnetics.static.induced_polarization.Simulation3DCellCentered) or [Simulation3DNodal](xref:simpeg#simpeg.electromagnetics.static.induced_polarization.Simulation3DNodal), the units of the apparent chargeability data are the same as the units chosen to represent the subsurface chargeabilities..\n", |
| 208 | + "A full description of elements required to define DC and IP surveys was presented in the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial. Here, we take the same approach. The only difference is that our receivers are defined to measure apparent chargeabilities. Because SimPEG uses a linearized formulation for simulating IP data; see [Simulation3DCellCentered](xref:simpeg#simpeg.electromagnetics.static.induced_polarization.Simulation3DCellCentered) or [Simulation3DNodal](xref:simpeg#simpeg.electromagnetics.static.induced_polarization.Simulation3DNodal), the units of the apparent chargeability data are the same as the units chosen to represent the subsurface chargeabilities..\n", |
209 | 209 | "\n", |
210 | 210 | "Here, the survey consists of 5 IP lines that use a dipole-dipole electrode configuration; 1 line along the East-West direction and 2 lines along the North-South direction. Each line is 2000 m in length and has an electrode spacing of 100 m." |
211 | 211 | ] |
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316 | 316 | "source": [ |
317 | 317 | "## Design a (Tree) Mesh\n", |
318 | 318 | "\n", |
319 | | - "Here, we generate a tree mesh based on the survey geometry. We use the same mesh that was generated for the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial. The best-practices for generating meshes for DC/IP simulations is presented in the [2.5D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_2d.ipynb) tutorial." |
| 319 | + "Here, we generate a tree mesh based on the survey geometry. We use the same mesh that was generated for the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial. The best-practices for generating meshes for DC/IP simulations is presented in the [2.5D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_2d.ipynb) tutorial." |
320 | 320 | ] |
321 | 321 | }, |
322 | 322 | { |
|
398 | 398 | "source": [ |
399 | 399 | "## Define the Background Conductivity/Resistivity\n", |
400 | 400 | "\n", |
401 | | - "In order to simulate IP data, we require the background conductivity/resistivity defined on the entire mesh. You can generate this directly, or apply the appropriate mapping to different parameterization of the conductivity/resistivity. Here, we generate the same conuductivity model that was used for the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial." |
| 401 | + "In order to simulate IP data, we require the background conductivity/resistivity defined on the entire mesh. You can generate this directly, or apply the appropriate mapping to different parameterization of the conductivity/resistivity. Here, we generate the same conuductivity model that was used for the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial." |
402 | 402 | ] |
403 | 403 | }, |
404 | 404 | { |
|
669 | 669 | "source": [ |
670 | 670 | "## Project Electrodes to Discretized Topography\n", |
671 | 671 | "\n", |
672 | | - "As explained in the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial, we use the [drape_electrodes_on_topography](xref:simpeg#simpeg.electromagnetics.static.resistivity.Survey.drape_electrodes_on_topography) method to project the electrodes to the discrete surface topography." |
| 672 | + "As explained in the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial, we use the [drape_electrodes_on_topography](xref:simpeg#simpeg.electromagnetics.static.resistivity.Survey.drape_electrodes_on_topography) method to project the electrodes to the discrete surface topography." |
673 | 673 | ] |
674 | 674 | }, |
675 | 675 | { |
|
875 | 875 | "source": [ |
876 | 876 | "### Plot Individual Lines in 2D Pseudosection\n", |
877 | 877 | "\n", |
878 | | - "For conventional DC resistivity surveys, the electrodes are located along a set of survey lines. If we know which the survey line associated with each datum, we can parse the 3D survey into a set of 2D survey lines. Then we can plot individual pseudosections for each survey line. This was detailed in the [3D Forward Simulation of DC Resistivity Data](../05-dcr/fwd_dcr_3d.ipynb) tutorial. Here, we have 6 survey lines, each of which has the same number of data. So assigning a line ID to each datum is easy. You may need to do something more sophisticated in other cases." |
| 878 | + "For conventional DC resistivity surveys, the electrodes are located along a set of survey lines. If we know which the survey line associated with each datum, we can parse the 3D survey into a set of 2D survey lines. Then we can plot individual pseudosections for each survey line. This was detailed in the [3D Forward Simulation of DC Resistivity Data](../dc-resistivity/fwd_dcr_3d.ipynb) tutorial. Here, we have 6 survey lines, each of which has the same number of data. So assigning a line ID to each datum is easy. You may need to do something more sophisticated in other cases." |
879 | 879 | ] |
880 | 880 | }, |
881 | 881 | { |
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