Added some initial FAQs to the documentation.

docs/source/examples_2D.rst

@@ -4,6 +4,8 @@
 
 This section provides some general example models in 2D that demonstrate how to use certain features of gprMax. Each example comes with an input file which you can download and run.
 
+.. _example-2D-Ascan:
+
 A-scan with a Hertzian dipole source
 ====================================
 

docs/source/faqs.rst

@@ -2,4 +2,31 @@
 FAQs
 ****
 
-This section will provide answers to frequently asked questions about gprMax and its uses.
+This section provides answers to frequently asked questions about gprMax and its uses.
+
+**What applications can gprMax simulate?**
+gprMax is electromagnetic wave simulation software that is based on the Finite-Difference Time-Domain (FDTD) method. Many of its features have been designed to benefit simulating Ground Penetrating Radar (GPR), however it can be used to simulate many other applications in areas such as engineering, geophysics, archaeology, and medicine.
+
+**Why does gprMax not have a GUI?**
+We considered developing a CAD-based graphical user interface (GUI) but, for now, decided against it. There were two guiding principals behind this design decision: firstly, users most often perform a series of related simulations with varying parameters to solve or optimize a particular problem; and secondly, we decided the limited resources we had were best concentrated on developing advanced modelling features for GPR within software that could easily be interfaced with other tools. Although a CAD-based GUI is useful for creating single simulations it becomes increasingly cumbersome for a series of simulations or where simulations contain heterogeneities, e.g. a model of a soil with stochastically varying electrical properties.
+
+**How is gprMax licensed?**
+gprMax is released under the GNU General Public License v3 or higher (http://www.gnu.org/copyleft/gpl.html). This means when distributing derived works, the source code of the work must be made available under the same license.
+
+**Do I need to learn Python to use gprMax?**
+No, but it can be beneficial to know a little Python. We have made it easier to create more complex simulations in gprMax through scripting in the input file. This is achieved by allowing blocks of Python code to be written in the input file which are executed when the file is read by gprMax.
+
+**Can I still do all my pre/post-processing for gprMax in MATLAB?**
+Yes, we have provided tools to help you read the new HDF5-based output file in MATLAB.
+
+**But converting my input file from the old version of gprMax will be really painful**
+Hopefully not! We have provided a Python script to help you convert input files from the old version of gprMax to use syntax introduced in the version.
+
+**How do I choose a spatial resolution for my simulation?**
+Spatial resolution should be chosen to mitigate numerical dispersion and to adequately resolve geometry in your simulation. :ref:`A 2D example of modelling a metal cylinder in a dielectric <example-2D-Ascan>` provides guidance on how to determine spatial resolution.
+
+**I specified a certain piece of geometry but I don’t see when I view my geometry file.**
+gprMax builds objects in a model in the order the objects were specified in the input file, using a layered canvas approach. This means, for example, a cylinder object which comes after a box object in the input file will overwrite the properties of the box object at any locations where they overlap. This approach allows complex geometries to be created using basic object building blocks.
+
+**Can I run gprMax on my HPC/cluster?**
+Yes. gprMax has been parallelised using OpenMP and features a task farm based on MPI. For more information read the :ref:`section on parallelism. <openmp_mpi>`

docs/source/gprmodelling.rst

@@ -84,12 +84,12 @@ The actual positions of field components for a given set of space coordinates (x
 Hertzian dipole sources as well as other electric field excitations (i.e. voltage sources, transmission lines) are located at the corresponding electric field components.
 
 
-Discretisation
-==============
+Spatial discretisation
+======================
 
-There is no specific guideline for choosing the right discretization for a given problem. In general, it depends on the required accuracy, the frequency content of the source pulse and the size of the targets. Obviously, all targets present in a model must be adequately resolved. This means, for example, that a cylinder with radius equal to one or two spatial steps does not really look like a cylinder!
+There is no specific guideline for choosing the right spatial discretization for a given problem. In general, it depends on the required accuracy, the frequency content of the source pulse and the size of the targets. Obviously, all targets present in a model must be adequately resolved. This means, for example, that a cylinder with radius equal to one or two spatial steps does not really look like a cylinder!
 
-An other important factor which influences the discretization is the errors associated with numerical induced dispersion. This means that contrary to the real world where electromagnetic waves propagate with the same velocity irrespectively of their direction and frequency (assuming no dispersive media and far-field conditions) in the discrete one this is not the case. This error (details can be found in [GIA1997]_ and [KUN1993]_) can be kept in a minimum if the following *rule-of-thumb* is satisfied:
+An other important factor which influences the spatial discretization is the errors associated with numerically induced dispersion. This means that contrary to the real world where electromagnetic waves propagate with the same velocity irrespectively of their direction and frequency (assuming no dispersive media and far-field conditions) in the discrete one this is not the case. This error (details can be found in [GIA1997]_ and [KUN1993]_) can be kept in a minimum if the following *rule-of-thumb* is satisfied:
 
 **The discretization step should be at least ten times smaller than the smallest wavelength of the propagating electromagnetic fields.**
 

docs/source/index.rst

@@ -18,8 +18,12 @@ gprMax User Guide
     input
     geometry_snapshots
     output
-    openmp_mpi
 
+.. toctree::
+    :maxdepth: 2
+    :caption: Advanced topics
+
+    openmp_mpi
 
 .. toctree::
     :maxdepth: 2