This is the main directory devoted to illustrating normal moveout
corrections and stacking.  If you are new to SU, start by reading
"The SU User's Manual" and the README in $CWPROOT/src/demos.

To run the demo with X Windows, type:
Xmodel     show the model (X-windows plot)
PSmodel    show the model (PostScript plot)
MakeData   make the synthetic traces for the demo
Xdata      show the data (X-windows plot)
PSdata     show the data (PostScript plot)

Interactive velocity analysis demos to build the parameter file 
necessary for Xnmo. 

Run _only one_ of the following Velan scripts:

Velan_semb   standard semblance analysis -- same as suvelan demo
Velan_nccs   normalized crosscorrelation sum
Velan_nsel   normalized selective correlation sum
Velan_uccs   unnormalized crosscorrelation sum
Velan_usel   unnormalized selective correlation sum

Then perform NMO and NMO stack by running one of these 

Xnmo	   show the nmo and stack (X-windows graphics)
PSnmo	   show the nmo and stack (PostScript graphics)


Clean up the directory:

Clean.sh   remove temporary files created by the demo

File to be saved:
model      necessary for the "model" portions of the demo, do not remove.

You may type:

zap xgraph	to remove all xgraph/suxgraph plots
zap ximage	to remove all ximage/suximage plots
zap xwigb	to remove all xwigb/suwigb plots

Notes:
When you make your velocity picks, you are assuming that the
coefficients were computed as if the model had the constant
velocities (ft/s): 5000.0, 6000.0, 8000.0, 10000.0, 15000.0
in the layers delimited by depths (ft): 0, 1000.0, 2200.0,
3500.0, 5000.0.  However, the modeling program (susynlv)
generates the data according to a linear velocity profile,
here taken as: 5000.0 + 0.002*z. 

Note that you may need or want to tune some of the parameters
in the Velan script you are using. Such parameters as the number
of contours in the contour plot, as well as parameters particular
to each of the suvelan_ programs may be adjusted.

For shell examples used with real data, see the files Velan,
Velan.nmo, and NmoStack in the
	$CWPROOT/src/su/examples subdirectory.



John Stockwell	 | jstockwe@mines.edu
Center for Wave Phenomena (The Home of Seismic Un*x)
Colorado School of Mines
Golden, CO 80401 | http://www.cwp.mines.edu/cwpcodes
voice: (303) 273-3049  |    fax: (303) 273-3478.
