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Very Fast Simulated Annealing global optimization of zero offset CRS parameters (VFSA)

This program is available in the Madagascar package! Version 3.0

The Very Fast Simulated Annealing (VFSA) algorithm optimizes the global search of the CRS parameters (RNIP, RN and BETA) throughout fitting the reflection data with the non-hiperbolic common reflection surface (CRS) approximation surface. The algorithm uses the semblance between the CRS approximation surface and the reflection surface in the seismic data as a convergence criterion. The main assumption of this algorithm is that the CRS parameters, RN, RNIP, and BETA that produce the best fit between these surfaces will be the optimized ones.

The program sfvfsacrsnh uses VFSA global optimization to obtain the CRS parameters. This program uses the non-hyperbolic CRS traveltime approximation in the process to fit the data. After CRS parameters inversion, sfnhcrssurf program can be used to build the non-hyperbolic CRS surface that best fits the data for RN, RNIP, and BETA given.

If you need more details about VFSA and non-hyperbolic CRS, please read "what is VFSA?" and "What is non-hyperbolic CRS?" sections of this wiki.

Install dependencies

The vfsa programs are designed for the Madagascar seismic processing package. In order to use them, you should install the actual Madagascar stable version in your computer and you should also install the vfsa package in your local version of Madagascar if it is not already available.

If you have any doubt about how to add new programs to your Madagascar installation, you can refer to the official documentation in Adding new programs to Madagascar, follow this video tutorial on YouTube (Portuguese, English subtitles) or follow the steps bellow to install the vfsa:

• Usually, Madagascar keeps the path of the source files of your Madagascar local version in the $RSFSRC environment variable. You can show that on a bash terminal using 'echo' command:

~$ echo "$RSFSRC"

And Madagascar will install binary executable files on your $RSFROOT directory. You can show that environment variable with 'echo' too:

~$ echo "$RSFROOT"

Madagascar stores user programs in $RSFSRC/user directory. So, you can create a new directory on $RSFSRC/user or put vfsa repository inside $RSFSRC/user. In vfsa repository, such as every user's repository in Madagascar, we have a compilation SConstruct that compile the C programs of this package. Run 'scons' on your $RSFSRC/user/vfsa repository to compile it:

~$ scons

And run 'scons install' in the top directory of your local Madagascar installation (the directory path in your $RSFSRC variable):

~$ sudo scons install