Release of DENISE Black-Edition v1.4

New features:

• Fixed multiple bugs related to importing variable receiver positions for each shot. This allows seismic forward modelling and FWI e.g. for streamer geometries.
• Removed deprecated N_STREAMER option
• Created Python code PythonIO together with a Jupyter Notebook to create input and model files for DENISE Black-Edition allowing a step-by-step definition of all necessary files for seismic forward modelling and FWI. The Jupyter Notebook also checks if the CFL & grid dispersion criteria are satisfied, a reasonable domain decomposition is defined, if sources and receivers are placed outside of the model or inside the PMLs and some FWI parameters are consistent with the acquisition geometry. An example for the Marmousi-2 test problem can be found here
• Fixed failing AC FWI bug found by Albert Zhang when trying to invert hydrophone (pressure) data
• Added acoustic gradients in velocity-pressure formulation according to Hu (2012)
• Added AGC weighted l2-norm objective function to enhance weak reflection events compared to surface waves in the field data
• Oleg Ovcharenko and Vladimir Kazei added an interactive DENISE Python API which not only allows the definition of input and model files, but also runs the forward/FWI code from within a Jupyter notebook. Furthermore, modelled seismic shot gathers and FWI results can be visualized and analyzed. Using Jupyter notebooks together with the API allows to document the changes of input parameters relative to the standard input files for the Marmousi-2 benchmark problem and creates a new set of input files without changing the original files. Therefore, foward modelling and FWI runs can be very effectively documented in a reproducible way. An example for the Marmousi-2 problem can be found here
• Multiple smaller bug fixes

Release of DENISE Black-Edition v1.3

New features:

• added acoustic forward modelling/FWI/RTM module
• added time integration FWI as suggested by Linbin Zhang
• added visco-elastic SH forward modelling/FWI module according to Fabien-Ouellet et al. (2017)
• normalized parameter classes, parameter scaling and diagonal Pseudo-Hessian approximaton for
  the visco-elastic SH FWI problem
• added MODE=3 to compute FD-based gradients for the visco-elastic SH case
• options to suppress model and STF output
• Improved Vaccuum Formulation (IVF) by Zeng et al. (2012) and Pan et al. (2018) for accurate
  modelling of surface waves in the presence of complex topography
• anisotropic Gaussian filter with coherence length adapted to the local S-wave wavelength to impose
  smoothness constraints on gradients
• 2-level parallelization for the PSV module based on domain decomposition and shot parallelization
  by Vladimir Kazei
• Replace data type of objective function from float -> double

The visco-elastic SH FWI is still "work in progress" and shows some significant convergence problems. Therefore, I currently recommend to use the old DENISE-SH code:

https://github.com/daniel-koehn/DENISE-SH

for field data applications.

Release of DENISE Black-Edition v1.2

New features:

• added elastic VTI/TTI PSV seismic modelling/RTM modules
• RTM image output option RTM_SHOT for each shot
• option to read receiver positions for each shot
• added Gauss filter for gradient smoothing

Release of modularized DENISE Black-Edition version

New features:

• strongly improved modularization of the source code
• introduced data structures for forward modelling and FWI
• removed outdated input and inversion parameters
• FWI of x-p/y-p/x-y-p components (QUELLTYPB=5,6,7) by Linbin Zhang
• detached l-BFGS and PCG optimization from PSV forward problem
• added different PCG optimization methods
• added Jupyter notebooks for visualization of FWI/RTM results and wavefield snapshots
• multiple minor and major bug fixes

First major release of DENISE-Black-Edition

v1.0.0

Restrict smooth2 to area below GRADT2