About The Product

GUNDALF is a state of the art Windows or Linux-based airgun modelling package based on many years of research. Airgun array computer modelling is an enormously cost-effective exercise given the cost of downtime of a seismic survey vessel for signature tests or concerns about the effects of drop-out. In the processing centre, simple knowledge of the acquisition geometry and gun types allows an accurate signature to be generated for sophisticated signature deconvolution.

It has taken a number of years to refine understanding of the physics of airgun bubble interaction to its current level but it now offers a genuine alternative to the very costly experimental approach or the uncertainties inherent in near-field extrapolation.

GUNDALF is capable of modelling arrays of up to 128 guns in its present form with full interaction allowed between them. Linear superposition of sub-arrays or even individual guns as is often used is rejected in favour of proper modelling. The power of modern desktop and laptop computers means that this is now entirely feasible. No scientific compromise is made here, the physics at the heart of GUNDALF is capable of accurately modelling the phase locking observed in closely-interacting airguns right down to the edge of the super-foam region. It contains arguably the most advanced physics of its kind anywhere.

GUNDALF is available in two forms both of which use the same state of the art physical modelling engine:

GUNDALF Designer

• Enables the geophysicist to model the signature of up to 128 interacting airguns in an array quickly and accurately.

• Includes most common gun types including injector and sleeve guns in its array construction palette.

• Simple graphical interface to add, edit or delete guns, change the depth of all guns, manipulate sub-arrays and numerous other shortcuts. Each gun can be individually set in position, gun type, volume and operating pressure allowing complete flexibility.

• Signature characteristics such as peak to peak, primary to bubble and bubble period are produced on demand.

• Amplitude spectra and any filtering can be done at the click of a button. The resulting plots are interactive giving an instantaneous check on the amplitude and position with just a click of the mouse.

• Sophisticated handling of the surface reflection ghost and optionally the cable ghost using rough sea surface modelling.

• Import and export of signatures in both text and SEGY format.

• Import and export of arrays in text format allowing full arrays with symmetric sub-arrays to be built quickly and easily, (noting that all interactions are always used when actually modelling the array).

• Zoom in and out.

• Intranet reporting with comprehensive array report produced in a form suitable for a company Intranet including embedded web graphics for the array geometry,maximum bubble radii, signature and amplitude spectrum and colour contour plots of both inline and cross-line directivity.

• Basic drop-out analysis based on signature criteria such as maximum drop in peak-to-peak integrated into the Intranet reporting.

• Quick re-modelling of an array signature if a particular dropout occurs. A few clicks to drop-out the relevant guns and Gundalf issues a warning of which if any of the specified drop-out criteria have been breached. An optional report can be generated. In effect, this means that if a gun goes down during a survey, the effects on the signature can be accurately modelled within a minute - no guesswork and no looking up from tables containing perhaps thousands of combinations. Given that for clustered arrays, the effects of gun drop out are often non-intuitive, this is an invaluable feature.