geopsy.org

Hi, Marc,

When I loaded one dispersion target, I opened the 'Import Ascii file' window. In the Y column part, I don't know exactly what 'error' and 'weight' are refered to? The f-k procedure I used is somewhat different from yours. So I can't get the variation of the dispersion curve like you did. I just got one single curve like your median dispersion curve. Can I just take the value like 5% of phase velocity over the whole curve as the error. What is the function of 'weight' here? Can I just assume them 1 at all the points? Thanks.

Edward

Hi Edward,

If you don't want to specify the error or the weight, set a column index greater than the number of columns in your file. Default values will be set (0 and 1, respectively).

The weight is the statistical weight, usually the number of time windows used during the FK computation (ambient noise techniques). It is used by 'Average' to combine several curves so that the produced global statistics are equivalent to a FK processing with all time windows.

If you want to set a 5% error over the whole curve, you have to calculate it yourself and put it in a separated column. 'sample.disp' is assumed to have two columns (frequency+slowness or velocity).

'm or km' is set in the dialog box for the slowness/velocity and its error to apply a correction factor. Dinver is always working is meters.