SYNOPSIS
PERL PROGRAM NAME:
AUTHOR: Juan Lorenzo (Perl module only)
DATE:
DESCRIPTION:
Version:
USE
NOTES
Examples
SYNOPSIS
SEISMIC UNIX NOTES ADDRVL3D - Add a random velocity layer (RVL) to a gridded
v(x,y,z) velocity model
addrvl3d <infile n1= n2= >outfile [parameters]
Required Parameters:
n1= number of samples along 1st dimension
n2= number of samples along 2nd dimension
Optional Parameters:
n3=1 number of samples along 3rd dimension
mode=1 add single layer populated with random vels
=2 add nrvl layers of random thickness and vel
seed=from_clock random number seed (integer)
---->New layer geometry info
i1beg=1 1st dimension beginning sample
i1end=n1/5 1st dimension ending sample
i2beg=1 2nd dimension beginning sample
i2end=n2 2nd dimension ending sample
i3beg=1 3rd dimension beginning sample
i3end=n3 3rd dimension ending sample
---->New layer velocity info
vlsd=v/3 range (std dev) of random velocity in layer,
where v=v(0,0,i1) and i1=(i1beg+i1end)/2
add=1 add random vel to original vel (v_orig) at that point
=0 replace vel at that point with (v_orig+v_rand)
how=0 random vels can be higher or lower than v_orig
=1 random vels are always lower than v_orig
=2 random vels are always higher than v_orig
cvel=2000 layer filled with constant velocity cvel
(overides vlsd,add,how params)
---->Smoothing parameters (0 = no smoothing)
r1=0.0 1st dimension operator length in samples
r2=0.0 2nd dimension operator length in samples
r3=0.0 3rd dimension operator length in samples
slowness=0 =1 smoothing on slowness; =0 smoothing on velocity
nrvl=n1/10 number of const velocity layers to add
pdv=10. percentage velocity deviation (max) from input model
Notes:
1. Smoothing radii usually fall in the range of [0,20].
2. Smoothing radii can be used to set aspect ratio of random velocity
anomalies in the new layer. For example (r1=5,r2=0,r3=0) will
result in vertical vel streaks that mimick vertical fracturing.
3. Smoothing on slowness works better to preserve traveltimes relative
to the unsmoothed case.
4. Default case is a random velocity (+/-30%) near surface layer whose
thickness is 200f the total 2D model thickness.
5. Each layer vel is a random perturbation on input model at that level.
6. The depth dimension is assumed to be along axis 1.
Example:
1. 2D RVL with no smoothing
makevel nz=250 nx=200 | addrvl3d n1=250 n2=200 | ximage n1=250
2. 3D RVL with no smoothing
makevel nz=250 nx=200 ny=220 |
addrvl3d n1=250 n2=200 n3=220 |
xmovie n1=250 n2=200
Author: Saudi Aramco: Chris Liner Jan/Feb 2005
Based on smooth3d (CWP: Zhenyue Liu March 1995)User's notes (Juan Lorenzo) untested
CHANGES and their DATES
Import packages
instantiation of packages
Encapsulated hash of private variables
sub Step
collects switches and assembles bash instructions by adding the program name
sub note
collects switches and assembles bash instructions by adding the program name
sub clear
sub add
sub cvel
sub how
sub i1beg
sub i1end
sub i2beg
sub i2end
sub i3beg
sub i3end
sub mode
sub n1
sub n2
sub n3
sub nrvl
sub nz
sub pdv
sub r1
sub r2
sub r3
sub seed
sub slowness
sub v
sub vlsd
sub get_max_index
max index = number of input variables -1