09_gravity_calculations.tex

\chapter{Gravity integral calculations for the gravity field of the Earth}


SPECFEM can now compute the gravity field as well as its derivatives (i.e., gravity gradiometry)
generated by any given 3D Earth model at the height
of an observation satellite, for instance GOCE\newline
(see e.g. en.wikipedia.org/wiki/Gravity\_Field\_and\_Steady-State\_Ocean\_Circulation\_Explorer).\newline
That feature is still experimental but should work just fine.\newline


\noindent
To see how it is implemented and to use it, type this in the root directory of the code:
\begin{verbatim}
grep -i GRAVITY_INTEGRALS src/*/*
\end{verbatim}
All main gravity field computations can be found in file \texttt{src/meshfem3d/gravity\_integrals.F90}.
Please make sure you compile the code with double-precision, i.e., use flag \texttt{{-}{-}enable-double-precision} for the
configuration of the package.