Receiver Function Forward simulation with Specfem3D_FWATR#
The Specfem3D_FWATR is under developing, so it has not been open accessed.
For RF simulation, we invoked SEM-FK with plane wave injected to compute RFs, So parameter files are same as Specfem3D and SEM-FK, but an additional parameter file is required for RF calculation.
DATA/CMTSOLUTION must exist but its parameters will not work.
src_rec/sources_setXX.dat: Map of source set
XXand event id
YY. The first field is read to define
fwat_params/FWAT.PAR: 4 parameters are required for RF calculation, Others are the same as FWAT.
TSHIFT: Time shift before P
NUM_FILTER: Number of Gaussian filters applied on RFs.
F0: Array of Gaussian factors
MAXIT: Maximum iterations
MINDERR: Minimum residuals
Meshes and Parameters#
Rules of meshes in Specfem3D has introduced how to create meshes and database, but there are still some key points need be highlighted.
Coupling between FK and SEM domain: for high frequency simulation, the abrupt changes of adjacent materials result in wavefield scattering. Thus a taper zone is necessary between FK and SEM, which involved a smooth transition both in velocity and interface topography.
Taper zones are need to be set both along X and Y axis.
The distance between first (last) station and the taper zone should be less than first Fresnel zone radius in effective depth.
Coordinates of initial wavefront: if
ORIGIN_WAVEFRONTis set, the initial wavefront should be out of the SEM domain. We can set up it to 4 bottom corner with different back-azimuth.
sed -i "/LOCAL_PATH =/c\LOCAL_PATH = ./OUTPUT_FILES/DATABASES_MPI" DATA/Par_file sed -i "/LOCAL_PATH =/c\LOCAL_PATH = ./OUTPUT_FILES/DATABASES_MPI" DATA/meshfem3D_files/Mesh_Par_file mpirun -np 4 ./bin/xmeshfem3D mpirun -np 4 ./bin/xgenerate_databases
Go forward simulation#
mpirun -np 4 ./bin/xfwat0_forward_data M00 setXX rf
RFs will be saved into
data/YY with SAC format as