Tune*

Tune* is a tuning thickness calculator app for Android. The tool is aimed at for geophysical interpreters was made available in the Android Market in July 2011.

Functionality
A straightforward calculator based on the famous wedge model for visualizing seismic resolution problems.

Parameters
The app provides a Ricker wavelet (right). The user optionally provides acoustic properties for the wedge and background, which in turn define the reflectivity of the interface at the top and base of the wedge. This allows the background amplitude to be computed.

The amplitude A of the Ricker wavelet with peak frequency f at time t is computed thus:


 * $$A = (1-2 \pi^2 f^2 t^2) e^{-\pi^2 f^2 t^2} $$

which has minima at


 * $$\pm \frac{\sqrt{3/2}}{f\pi} $$

and these minima have the value


 * $$A_\mathrm{min} = -\frac{2}{e^{3/2}} $$

And we can solve for A = –0.1 to find the time at which tuning starts:


 * $$t \approx \pm \frac{0.66325}{f} $$

Features

 * Computes tuning thickness in time and depth
 * Computes the thickness at which amplitudes start to be perturbed by tuning effects
 * Computes the tuned amplitude difference from the background (untuned amplitude)
 * Offers a linearized function for calculating sub-tuned thickness from amplitude

New in version 0.4

 * You can now optionally use km/s for velocity and g/cm³ for density
 * The reporting of the tuned and untuned amplitudes is more consistent
 * Fixed a bug that caused the app to crash if the frequency field was blank
 * Updated address to the wiki help page
 * Fixed bug causing some European language settings to malfunction

New in version 0.3

 * First public version
 * Emailable form
 * Tap help to visit wiki page

Bugs and deficiencies

 * The app reports the amplitude at the top of the wedge, not the amplitude at the seismic horizon nearest the top of the wedge; we are working on this

For future release

 * Easy/quick enable/disable wedge properties
 * Normalized and non-normalized amplitude on left and right axes
 * More wavelets
 * Save wavelets to a database
 * Save wedge properties to a database
 * Show the wedge and apparent thickness
 * Zooming axes
 * Show tuning frequency as well as tuning thickness
 * Synthetic wedge
 * Interactivity