burgpr.m

基于matlab的反演程序,用于地球物理勘探中射线追踪及偏移成像程序.

function pfilt=burgpr(trin,lc)

% pfilt= burgpr(trin,lc)
%
% returns an lc length Burg prediction error filter (unit lag)
%
% trin= input trace 
% lc= number of points in prediction filter 
% pfilt= Burg prediction error filter
%
%
% adapted from Claerbout 1976: Fundamentals of Geophysical Data
% Processing, p 137
%
% by G.F. Margrave, May 1991
%
% NOTE: It is illegal for you to use this software for a purpose other
% than non-profit education or research UNLESS you are employed by a CREWES
% Project sponsor. By using this software, you are agreeing to the terms
% detailed in this software's Matlab source file.
 
% BEGIN TERMS OF USE LICENSE
%
% This SOFTWARE is maintained by the CREWES Project at the Department
% of Geology and Geophysics of the University of Calgary, Calgary,
% Alberta, Canada.  The copyright and ownership is jointly held by 
% its author (identified above) and the CREWES Project.  The CREWES 
% project may be contacted via email at:  [e-mail]
% 
% The term 'SOFTWARE' refers to the Matlab source code, translations to
% any other computer language, or object code
%
% Terms of use of this SOFTWARE
%
% 1) Use of this SOFTWARE by any for-profit commercial organization is
%    expressly forbidden unless said organization is a CREWES Project
%    Sponsor.
%
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%    CREWES Project Sponsorship agreement.
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%    use this SOFTWARE subject to the following terms and conditions:
%    - this SOFTWARE is for teaching or research purposes only.
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% END TERMS OF USE LICENSE

if lc>length(trin)
	error(' Please check input parameters again');
else

s=[];

% set defaults
 n=round(length(trin)/2+1);
 %
 specb=zeros(1,n);
 cpr=zeros(1,lc-1);
 a=[1.0 zeros(1,lc-1)];
 c=zeros(1,lc);
 em=trin;
 ep=trin;
 lx=length(trin);
 for j=2:lc
   bot=ep(j:lx)*ep(j:lx)'+em(1:lx-j+1)*em(1:lx-j+1)';
   top=ep(j:lx)*em(1:lx-j+1)';
   c(j)=2.*top/bot;
   epp=[ep(1:j-1) ep(j:lx)-c(j)*em(1:lx-j+1)];
   em=[em(1:lx-j+1)-conj(c(j))*ep(j:lx) em(lx-j+2:lx)];
   ep=epp;
   s(1:j)=a(1:j)-c(j)*conj(a(j:-1:1));
   a(1:j)=s(1:j);
 end
 pfilt=s;
end