Editing Seismic task-centric program list (section)

=Modeling=
All methods below deal with acoustic data, unless noted otherwise. Also, to be in the modeling section, a program/chain of programs must produce actual seismograms, not just traveltime curves. Those go into the "Traveltime computation" section.

Programs listed below create time-domain seismic data (wavefield at z=0, i.e. hyperbolas) given a reflectivity model (wavefield at t=0 in the exploding reflector paradigm). Sometimes it is suggestive to plot "shots", i.e. one or several wavefronts at various times. One way to do it with downward-continuation based shot-modeling algorithm is to save the whole wavefield in the time domain, then to extract the slices at the appropriate times. This can get storage-intensive, and slow as it can be IO-bound. Another way is to use a reverse-time procedure and simply save the appropriate time snapshots. This is very CPU-intensive and artifacts can easily appear. The cheapest and the most elegant way is to remember that a wavefront at time t originating from a shot is indistinguishable from the migration impulse response of a spike at time t at the same x location. So to originate a series of wavefronts at intervals dt from a shot at location x and time t, one just has to migrate a sequence of spikes separated by dt at location x. This way, any of the programs in the "migration" section can also be used to create "shots" &ndash; including those programs based on survey-sinking!

==Creating reflectivity models==
* For linear arrivals: [http://reproducibility.org/RSF/sfspike.html spike], followed by [http://reproducibility.org/RSF/sfbandpass.html bandpass] or convolution ([http://reproducibility.org/RSF/sfconv.html conv]) with a wavelet
* Simple 2-D synthetics with crossing plane waves: [http://reproducibility.org/RSF/sfmake.html make]
* Generates the 3-D Qdome model: [http://reproducibility.org/RSF/sfqdome.html qdome]
* Generates the 2-D Sigmoid model: [http://reproducibility.org/RSF/sfsigmoid.html sigmoid]
* Generates the 2-D Synmarine model, spreads it across offsets and applies moveout: [http://reproducibility.org/RSF/sfsynmarine.html synmarine] (bandpass or convolution with a wavelet still needed)
* Generates the 2-D Conflicting Dips model: [http://reproducibility.org/RSF/sfconflict.html conflict]
* Simple synthetics with random reflectivity: [http://reproducibility.org/RSF/sfrandrefl.html randrefl]

==Adding noise==
* Synthetics with bursts of noise: [http://reproducibility.org/RSF/sfburstnoise.html burstnoise]
* Add random noise to the data: [http://reproducibility.org/RSF/sfnoise.html noise]

==Creating falsely irregular data==
* Cut an elliptic hole in data: [http://reproducibility.org/RSF/sfhole.html hole]
* Remove random shot gathers from a 2-D dataset: [http://reproducibility.org/RSF/sfshotholes.html shotholes]

==Creating velocity models==
* Generate 2-D layered velocity model from specified interfaces: [http://reproducibility.org/RSF/sfunif2.html unif2]
* Generate 3-D layered velocity model from specified interfaces: [http://reproducibility.org/RSF/sfunif3.html unif3]

==3-D, prestack, v(x,z)==
* Extended split step wavefield extrapolation method: [http://reproducibility.org/RSF/sfsrmod.html srmod]
==3-D, prestack, common-azimuth, v(x,z)==
* Split-step method: [http://reproducibility.org/RSF/sfcamig.html camig]
==3-D, prestack, v(z)==
* Kirchhoff method using analytical Green's functions: [http://reproducibility.org/RSF/sfkirmod3.html kirmod3]
==3-D, zero-offset, v(x,z)==
* Extended split step wavefield extrapolation method: [http://reproducibility.org/RSF/sfsstep2.html sstep2], [http://reproducibility.org/RSF/sfzomig.html zomig]
==3-D, zero-offset, const.v==
* Stolt (F-K) method: [http://reproducibility.org/RSF/sfstolt.html stolt]
==2.5-D, v(z)==
* Kirchhoff method using analytical Green's functions: [http://reproducibility.org/RSF/sfkirmod.html kirmod]
==2-D, prestack, v(x,z)==
* Unknown ray-based method: [http://reproducibility.org/RSF/sfshoot2.html shoot2]
* Second-order cell ray tracing with locally parabolic rays: [http://reproducibility.org/RSF/sfcell2.html cell2].
* Ray tracing by a Runge-Kutta integrator: [http://reproducibility.org/RSF/sfrays2.html rays2]
* Time-domain acoustic FD: [http://reproducibility.org/RSF/sfafmod.html afmod], [http://reproducibility.org/RSF/sfawe.html awe], [http://reproducibility.org/RSF/sfawefd.html awefd], [http://reproducibility.org/RSF/sfawefd1.html awefd1], [http://reproducibility.org/RSF/sfafdm2d.html afdm2d]
* Time-domain acoustic linearized FD: [http://reproducibility.org/RSF/sflwefd.html lwefd], [http://reproducibility.org/RSF/sflwefd1.html lwefd1]
* DSR-based survey-continuation WE method: [http://reproducibility.org/RSF/sfdsr2.html dsr2]
==2-D, prestack, v(x,z), anisotropic media==
* Ray tracing in VTI media by a Runge-Kutta integrator: [http://reproducibility.org/RSF/sfrays2a.html rays2a]
==2-D, prestack, v(z)==
* DSR-based survey-continuation WE method: [http://reproducibility.org/RSF/sfdsr.html dsr]
* [http://reproducibility.org/RSF/sfspike.html spike], [http://reproducibility.org/RSF/sfbandpass.html bandpass], [http://reproducibility.org/RSF/sfinmo.html inmo]
* Analytical traveltime in a linear slowness squared model: [http://reproducibility.org/RSF/sfs2ofz.html s2ofz]

==2-D, prestack, const. v==
* Kirchhoff: [http://reproducibility.org/RSF/sfpreconstkirch.html preconstkirch]
* Stolt (F-K): [http://reproducibility.org/RSF/sfprestolt.html prestolt]
==2-D, zero-offset, v(x,z)==
* Implicit finite-difference method, 15 and 45 degree approximation: [http://reproducibility.org/RSF/sfmig45.html mig45]
* Riemannian Wavefield Extrapolation: [http://reproducibility.org/RSF/sfrwezomig.html rwezomig]
==2-D, zero-offset, v(z)==
* Wavefield-extrapolation, phase-shift method: [http://reproducibility.org/RSF/sfgazdag.html gazdag]
* Kirchhoff with antialiasing: [http://reproducibility.org/RSF/sfkirchnew.html kirchnew]
* 1-D convolution modeling: [http://reproducibility.org/RSF/sfai2refl.html ai2refl]

==Elastic modeling==
* Time-domain 2-D FD method: [http://reproducibility.org/RSF/sfewefd2d.html ewefd2d]
==Anisotropic modeling==
* Time-domain 2-D FD TTI: [http://reproducibility.org/RSF/sfewefd2dtti.html ewefd2dtti]
* [http://reproducibility.org/RSF/sfanifd2d.html anifd2d]

==Unconventional outputs==
* Models PP intercept, PP gradient and PS gradient directly: [http://reproducibility.org/RSF/sfmodrefl2.html modrefl2]
* Outputs PP and PS seismograms in the tau-p domain: [http://reproducibility.org/RSF/sfmodrefl3.html modrefl3]
==Uncertain==
* [http://reproducibility.org/RSF/sfmodrefl.html modrefl] ("Normal reflectivity modeling", according to <tt>sfdoc -k</tt>). Takes as input files with vp, vs and rho, but it is not clear whether it outputs a 2-D or 3-D file, and if modeling is with ray or WE methods.
* 2-D, unknown if prestack or zero-offset, v(x,z), Born modeling: [http://reproducibility.org/RSF/sfaborn.html aborn], [http://reproducibility.org/RSF/sfborn2d.html born2d]