Difference between revisions of "Dispersion curve inversion"
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* Load this [[File:Dinverdc_no_variance.disp|dispersion curve]]. It is a theoretical curve computed using this [[Computing a theoretical dispersion curve|tutorial]]. | * Load this [[File:Dinverdc_no_variance.disp|dispersion curve]]. It is a theoretical curve computed using this [[Computing a theoretical dispersion curve|tutorial]]. | ||
* Select the fundamental curve (use [[Dispersion curve target#Browsing curves|these tips]] to identify it). | * Select the fundamental curve (use [[Dispersion curve target#Browsing curves|these tips]] to identify it). | ||
| + | * Re-sample it from 2 to 20 Hz on log scale (menu '''Actions/Resample'''). | ||
| + | * Cut it from 2 to 20 Hz (menu '''Actions/Cut'''). | ||
| + | * Select the first higher mode curve (use [[Dispersion curve target#Browsing curves|these tips]] to identify it). | ||
| + | * Remove it (menu '''Actions/Remove'''). | ||
| + | |||
| + | Achieving a good frequency sampling is an art, for a better understanding see [[Curve sampling]]. | ||
| + | |||
| + | At this step, the [[Dispersion curve target]] should contain only one curve, the fundamental mode. Make sure the [[Dispersion curve target#Modes|mode table]] contains only one item like this: | ||
| + | |||
| + | [[Image:Dinverdc_fundamental_mode.png]] | ||
Revision as of 22:29, 26 November 2008
This tutorial shows how to invert a dispersion curve measured for surface waves. It is based on dinverdc module used inside dinver framework.
Getting ready
Start Dinver with Surface Wave Inversion module.
At first glance, the interface might look a little bit messy. If it is the first time you start dinver, you'd better close all windows until having an empty workspace. The various tools will be displayed one by one and explained in this tutorial, in a logical order.
Importing the dispersion curve to fit
- Activate the Target panel in menu Tools.
- Select the Dispersion option. Leave the Misfit weigth and the Min. misfit to their default values, 1 and 0, respectively.
- Click on Set to load the dispersion curve, the Dispersion curve target is displayed.
Load a dispersion curve and fix its frequency sampling:
- Load this dispersion curve. It is a theoretical curve computed using this tutorial.
- Select the fundamental curve (use these tips to identify it).
- Re-sample it from 2 to 20 Hz on log scale (menu Actions/Resample).
- Cut it from 2 to 20 Hz (menu Actions/Cut).
- Select the first higher mode curve (use these tips to identify it).
- Remove it (menu Actions/Remove).
Achieving a good frequency sampling is an art, for a better understanding see Curve sampling.
At this step, the Dispersion curve target should contain only one curve, the fundamental mode. Make sure the mode table contains only one item like this:
