Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Towards an open-source landscape for 3D CSEM modelling   Large-scale modelling of three-dimensional controlled-source electromagnetic
(CSEM) surveys used to be feasible only for large companies and research
consortia. This has changed over the last few years, and today there exists a
selection of different open-source codes available to everyone. Using four
different codes in the Python ecosystem, we perform simulations for
increasingly complex models in a shallow marine setting. We first verify the
computed fields with semi-analytical solutions for a simple layered model. Then
we validate the responses of a more complex block model by comparing results
obtained from each code. Finally we compare the responses of a real world model
with results from the industry. On the one hand, these validations show that
the open-source codes are able to compute comparable CSEM responses for
challenging, large-scale models. On the other hand, they show many general and
method-dependent problems that need to be faced for obtaining accurate results.
Our comparison includes finite-element and finite-volume codes using structured
rectilinear and octree meshes as well as unstructured tetrahedral meshes.
Accurate responses can be obtained independently of the chosen method and the
chosen mesh type. The runtime and memory requirements vary greatly based on the
choice of iterative or direct solvers. However, we have found that much more
time was spent on designing the mesh and setting up the simulations than
running the actual computation. The challenging task is, irrespective of the
chosen code, to appropriately discretize the model. We provide three models,
each with their corresponding discretization and responses of four codes, which
can be used for validation of new and existing codes.

25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph