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SPECFEM / specfem2d

SPECFEM2D simulates forward and adjoint seismic wave propagation in two-dimensional acoustic, (an)elastic, poroelastic or coupled acoustic-(an)elastic-poroelastic media, with Convolution PML absorbing conditions.
https://specfem.org
GNU General Public License v3.0
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Does SPEFCEM2D scale kernels? #1188

Closed AbolfazlKhanMo closed 1 year ago

AbolfazlKhanMo commented 1 year ago

Hi everyone,

I did a little experiment; two exact simulations but two different source amp_factor. The kernels are precisely the same.

src_amp_factor = 1e20 proc000000_rhop_alpha_beta_kernel_1E20

src_amp_factor = 1e10 proc000000_rhop_alpha_beta_kernel_1E10

Why are these kernels the same? Shouldn't they be different? Does SPECFEM2D scale the kernels based on the source amplification factor?

danielpeter commented 1 year ago

As a general remark, the sensitivity kernels depend on the adjoint source(s) you use.

in your case, I assume that you used adjoint sources for traveltime misfits. for such traveltime sensitivity kernels, the sensitivity is independent of the source amplitude. That is, you did a nice validation test to check whether the numerical results are indeed independent of the source amplitude factor :)