gusucode.com > DSISoft是由加拿大地质调查局发布的用于垂直地震剖面(VSP)数据处理的免费软件包 > dsisoftv3/dsisoftv3/dsisoftv3/main/intvel.m
function [dataout,depth,vel]=intvel(datain,winsize,rec,method); %function [dataout,depth,vel]=intvel(datain,winsize,rec,method); % %This function computes the interval velocity log from a DSI dataset % %datain = dsisoft variable sorted into components (header word 4) %winsize = length of the window to use for averaging (in number of receiver levels) %rec = record on which to perform the analysis %Method == 0 uses a sliding mean window %Method == 1 uses a regional linear regression % %dataout = dsisoft variable updated with velocities in header word 64 %depth = depth vector for the interval velocity log %vel = actual velocity values (m/s) for each of the depth location specified in depth % %$Id: intvel.m,v 3.0 2000/06/13 19:20:32 gilles Exp $ %$Log: intvel.m,v $ %Revision 3.0 2000/06/13 19:20:32 gilles %*** empty log message *** % % %Copyright (C) 1998 Seismology and Electromagnetic Section/ %Continental Geosciences Division/Geological Survey of Canada % %This library is free software; you can redistribute it and/or %modify it under the terms of the GNU Library General Public %License as published by the Free Software Foundation; either %version 2 of the License, or (at your option) any later version. % %This library is distributed in the hope that it will be useful, %but WITHOUT ANY WARRANTY; without even the implied warranty of %MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU %Library General Public License for more details. % %You should have received a copy of the GNU Library General Public %License along with this library; if not, write to the %Free Software Foundation, Inc., 59 Temple Place - Suite 330, %Boston, MA 02111-1307, USA. % %DSI Consortium %Continental Geosciences Division %Geological Survey of Canada %615 Booth St. %Ottawa, Ontario %K1A 0E9 % %email: dsi@cg.nrcan.gc.ca disp('[dataout,depth,vel]=intvel(datain,winsize,rec,method);'); dataout=datain; %loop over the receiver until the center of the last window for i=1:datain.fh{13}-(winsize-1) %control flow on the method to use if method==0 %computing the time difference between end samples of the window deltat((i-1)+(round(winsize/2)))=(datain.th{rec}(15,i+(winsize-1))-datain.th{rec}(15,i)); %computing the average velocity over the window using wireline depth vel((i-1)+(round(winsize/2)))=(datain.th{rec}(53,i+(winsize-1))-datain.th{rec}(53,i))/deltat((i-1)+(round(winsize/2))); %real depth %depth((i-1)+(round(winsize/2)))=datain.th{1}(39,(i-1)+(round(winsize/2))); %wireline depth vector corresponding to velocity values depth((i-1)+(round(winsize/2)))=datain.th{1}(53,(i-1)+(round(winsize/2))); %putting the velocities in trace header word 64 dataout.th{rec}(64,(i-1)+(round(winsize/2)))=vel((i-1)+(round(winsize/2))); elseif method==1 %grabbing the time values corresponding to the window deltat=(datain.th{rec}(15,i:i+(winsize-1))); %grabbing the wireline depth values corresponding to the window deltad=(datain.th{rec}(53,i:i+(winsize-1))); %computing the linear regression for depth and time parametersover the window samples reg=polyfit(deltad,deltat,1); %velocity = 1/slope of the regression vel((i-1)+(round(winsize/2)))=1/reg(1); %creating wireline depth vector depth((i-1)+(round(winsize/2)))=datain.th{1}(53,(i-1)+(round(winsize/2))); %putting the velocities in trace header word 64 dataout.th{rec}(64,(i-1)+(round(winsize/2)))=vel((i-1)+(round(winsize/2))); end end %plotting sequence plot(vel(round(winsize/2):length(vel)),depth(round(winsize/2):length(depth)),'.-r') set(gca,'ydir','reverse') grid on title('Interval Velocity Profile') xlabel('Interval Velocity (m/s)') ylabel('Wireline Depth (m)')