OCTAVE REFPLOT

This program can be used to both plot and measure apparent velocities of refraction arrival time picks. It is up to the user to know how to determine which arrivals are refractions. The first arrival picks must have been done first and inserted into the *.seg file headers (see programs segpic.m, BDAT, BPIC, PICRESTORE).

 Start an octave session, then type
     refplot

One is prompted for the file name. For example:
     k008.seg

Choose either stations or offsets
Pick a segment to get started,
Click yes
Then 3 mouse clicks, click a near offset
then a far offset limit, a line will be
fit (OLS), a third click will print the
estimated velocity and 95% confidence
values where you click on the plot.
Chi^2 info GUI, then choose to do another
segment or not.

When picking the near and far offset
limits, only the horizontal, x-axis
position of the mouse matters.

A Postscript output file, plot.ps, is created and
can be viewed with ghostscript.

Figure 13: OCTAVE REFPLOT: Plots first break picks which have been added to headers with BPIC. Then use mouse to pick line segment (start,end), followed by a mouse click to plot refractor apparent velocity result. See section 8.4.6, estimating a cross-over distance for program BREF.
\includegraphics[scale=0.65]{Figure13.pdf}