This is the classic. It picks first breaks, performs ray tracing, and spits out tomographic or layer-cake models. The new iterative reconstruction algorithms are particularly good at handling lateral velocity variations—something older software struggles with. Why Engineers Love It (The Workflow) The magic of SeisImager isn't just the math; it’s the pick correlation .
The problem with traditional refraction is that it only loves velocity increases with depth. If you have a stiff layer sitting on top of a soft layer (a "velocity inversion"), refraction fails. SW uses the dispersive nature of Rayleigh waves to create a 1D S-wave velocity profile. It turns "noise" (ground roll) into valuable data. seisimager
If you have ever spent 4 hours manually picking noisy first breaks, you know the pain. SeisImager’s interactive picker is intuitive. You can see the shot gathers, filter the noise in real-time (bandpass, AGC, or FK filters), and pick with keyboard macros. This is the classic
If you work in geotechnical engineering, environmental consulting, or hydrogeology, you know the struggle: What is actually happening down there ? Why Engineers Love It (The Workflow) The magic
Once the picks are done, the is where the value appears. Instead of assuming horizontal layers, it builds a true velocity field grid. For detecting boulders, paleochannels, or void spaces, tomography beats the layer-cake method every single time. The "SW" Advantage: S-Waves without a Sledgehammer The coolest recent trend is the rise of the MASW (Multichannel Analysis of Surface Waves) method. Because SeisImager/SW is baked into the same interface, you can collect one dataset—12 to 24 channels of geophones—and extract both the P-wave refraction model and the S-wave dispersion model.