Subject: Marmousi Seismic Data
From: Gary Margrave <margrave>
Date: Fri, 14 Oct 2005 10:57:53 -0500 (CDT)
To: ima-inres@ima.umn.edu

I have prepared a zip archive containing the Marmousi seismic data and
velocity model in Matlab format. In this archive there are five files:
1) procmarm25s_TXxS.mat : a Matlab binary with the seismic data
2) vel_asc_8_33m.grd : an ascii file with the velocity model
3) marmousi_shot.m : a simple m-file that will read any desired shot
record from procmarm25s_TXxS.mat for you
4) mammousi_velocity.m : a simple m-file that reads vel_asc_8_33m.grd and
resamples the velocity matrix to any grid size > 8.33 m
5) vdsample.m : a utility needed by marmousi_velocity.m

You can find the archive at http://www.geo.ucalgary.ca/~gary/ (click on
the "public download" link)
Beware, it is large (60mb).

To use these things, just unload them into your current Matlab working
directory and, at the Matlab prompt, type:
>> help marmousi_shot
or
>> help marmousi_velocity
and follow the instructions.

If you have any questions, just ask.

By the way, plotting seismic data well is non-trivial. If you wish, you
can download a free toolbox of Matlab seismic tools from
http://www.crewes.org/Samples/index-ES.php . Among the many tools in this
kit is a versatile viewer called "plotimage".

Example
after downloading and unpacking both the Marmousi data and the Matlab
seismic toolbox
>> %read shot record 110
>> [seis,t,xr,xs]=marmousi_shot(110);
>> %read the velocity model at a 10m grid
>> [vel,x,z]=marmousi_velocity(10);
>> %display the velocity using imagesc
>> figure;imagesc(x,z,vel);
>> %display the seismic using imagesc (not recommended)
>> figure;imagesc(xr,t,seis);
>> %display the seismic using plotimage (recommended)
>> plotimage(seis,t,xr);
>> %display the velocity model using plotimage after subtracting the mean
>> plotimage(vel-mean(vel(:)),z,x);


Enjoy!
Gary Margrave