sumigpresp.c

su 的源代码库

/* Copyright (c) Colorado School of Mines, 2006.*/
/* All rights reserved.                       */

/* SUMIGPRESP: $Vision: 1.00 $ ; $Date: 2006/11/07 22:58:42 $*/

#include "su.h"
#include "segy.h"
#include "header.h"
#include <signal.h>


/*********************** self documentation ******************************/
char *sdoc[] = {
"									",
" SUMIGPRESP - The 2-D prestack common-shot split-step Fourier		", 
"		migration 						",
"									",
"   sumigpresp <indata >outfile [parameters]				", 
"									",
" Required Parameters:							",
" nxo=	   number of total horizontal output samples			",
" nxshot=	number of shot gathers to be migrated			",
" nz=	    number of depth sapmles					",
" dx=	    horizontal sampling interval				",
" dz=	    depth sampling interval					",
" vfile=	 velocity profile, it must be binary format.		",
"									",  
" Optional Parameters:						   	",
" fmax=25	The peak frequency of Ricker wavelet used as source wavelet",
" f1=5,f2=10,f3=40,f4=50	 frequencies to build a Hamming window	",
" lpad=9999,rpad=9999	    number of zero traces padded on both    	",
"				sides of depth section to determine the ",
"				migration aperature, the default values ",
"				are using the full aperature.		",
" verbose=0             silent, =1 additional runtime information       ",
"									",  
" Notes:								",
" The input velocity file consists of C-style binary floats.	    	",
" The structure of this file is vfile[iz][ix]. Note that this means that",
" the x-direction is the fastest direction instead of z-direction! Such a",
" structure is more convenient for the downward continuation type	",
" migration algorithm than using z as fastest dimension as in other SU  ",
" programs.								",
"									",
" Because most of the tools in the SU package (such as  unif2, unisam2, ", 
" and makevel) produce output with the structure vfile[ix][iz], you will",
" need to transpose the velocity files created by these programs. You may",
" use the SU program \'transp\' in SU to transpose such files into the  ",
" required vfile[iz][ix] structure.					",
"                                                                       ",
" Also, sx must be monotonically increasing throughout the dataset, and ",
" and gx must be monotonically increasing within a shot. You may resort ",
" your data with \'susort\', accordingly.                               ",
"                                                                       ",
" The scalco header field is honored so this field must be set correctly.",
" See selfdocs of \'susort\', \'suchw\'. Also:   sukeyword scalco       ",
"									",
NULL};

/*
 * Credits: CWP, Baoniu Han, [e-mail], April 19th, 1998
 *          Modified: Chris Stolk, 11 Dec 2005, - changed data input
 *                    to remove erroneous time delay.
 *          Modified: CWP, John Stockwell 26 Sept 2006 - replaced Han's
 *          "goto-loop" in two places with "do { }while loops".
 *          Fixed it so that sx, gx, and scalco are honored.
 *
 *
 * Trace header fields accessed: ns, dt, delrt, d2, sx, gx, scalco
 * Trace header fields modified: ns, dt, delrt
 */

/**************** end self doc *******************************************/

/* Prototypes for functions used internally */
float *ricker(float Freq,float dt,int *Npoint);
void get_sx_gx(float *sx, float *gx);


segy tr;

/* static time_t t1,t2; */

int
main (int argc, char **argv)
{
	int nt;			/* number of time samples		*/
	int nz;			/* number of migrated depth samples	*/
	int nx;			/* number of horizontal samples       	*/
	int nxshot;		/* number of shots to be migrated	*/
	int iz,iw,ix,it,ik;	/* loop counters			*/
        int igx;                /* integerized gx value			*/
	int ntfft,nxfft;	/* fft size				*/
	int nw,truenw,nk;	/* number of wave numbers		*/
	int dip=65;		/* dip angle				*/
	int oldigx=0;		/* old value of integerized gx value	*/
	int oldisx=0;		/* old value of integerized sx value	*/

        float sx,gx;            /* x source and geophone location       */
        float gxmin=0.0,gxmax=0.0; /* x source and geophone location    */
        float min_sx_gx;        /* min(sx,gx)                           */
        float oldgx;            /* old gx position                      */
        float oldgxmin;         /* old gx position                      */
        float oldgxmax;         /* old gx position                      */
        float oldsx=0.0;        /* old sx position                      */

        int isx=0,nxo;          /* index for source and geophone        */
	int ix1,ix2,ix3,ixshot,il=0,ir=0; /* dummy index		*/
	int lpad,rpad; /* padding on both sides of the migrated section */

	float *wl=NULL,*wtmp=NULL;
	float fmax;
	float f1,f2,f3,f4;
	int nf1,nf2,nf3,nf4;
	int ntw;

	float dt=0.004,dz;	/* time and depth sampling interval 	*/
	float dw,dk;		/* wavenumber and frequency sampling interval */
	float fw,fk;		/* first wavenumber and frequency	*/
	float w,k;		/* wavenumber and frequency		*/
	float dx;		/* spatial sampling interval		*/
	float **p=NULL;
	float **cresult=NULL;	/* input, output data			*/
	float v1,vmin;

	double kz1,kz2;
	double phase1;
	float **v=NULL;
	float **vp=NULL;
	complex cshift1,cshift2;
	complex *wlsp=NULL;
	complex **cp=NULL;
	complex **cp1=NULL;
	complex **cq=NULL;
	complex **cq1=NULL;	/*complex input,output*/
	char *vfile="";		/* name of file containing velocities */
	FILE *vfp=NULL;

        int verbose;            /* verbose flag                         */
	

	/* hook up getpar to handle the parameters */
	initargs(argc,argv);
	requestdoc(1);

	/* get optional parameters */
	MUSTGETPARINT("nz",&nz);
	MUSTGETPARFLOAT("dz",&dz);
	MUSTGETPARSTRING("vfile", &vfile);
	MUSTGETPARINT("nxo",&nxo);
	MUSTGETPARINT("nxshot",&nxshot);

	if (!getparfloat("fmax",&fmax)) fmax = 25. ;  
	if (!getparfloat("f1",&f1)) f1 = 10.0;
	if (!getparfloat("f2",&f2)) f2 = 20.0;
	if (!getparfloat("f3",&f3)) f3 = 40.0;
	if (!getparfloat("f4",&f4)) f4 = 50.0;
	if (!getparint("lpad",&lpad)) lpad=9999;
	if (!getparint("rpad",&rpad)) rpad=9999;
	if (!getparint("dip",&dip)) dip=65;

        if (!getparint("verbose",&verbose))     verbose = 0;	

	/* allocate space */
	cresult = alloc2float(nz,nxo);
	vp=alloc2float(nxo,nz);

	/* load velocity file */
	vfp=efopen(vfile,"r");
	efread(vp[0],FSIZE,nz*nxo,vfp);
	efclose(vfp);

        /* zero out cresult array */
        memset((void *) cresult[0], 0, nxo*nz*FSIZE);


	if (!gettr(&tr))  err("can't get first trace");
	nt = tr.ns;
        get_sx_gx(&sx,&gx);
        min_sx_gx = MIN(sx,gx);
        sx = sx - min_sx_gx;
        gx = gx - min_sx_gx;

	/* let user give dt and/or dx from command line */
	if (!getparfloat("dt", &dt)) {
		if (tr.dt) { /* is dt field set? */
			dt = ((double) tr.dt)/1000000.0;
		} else { /* dt not set, assume 4 ms */
			dt = 0.004;
			warn("tr.dt not set, assuming dt=0.004");
		}
	}
	if (!getparfloat("dx",&dx)) {
		if (tr.d2) { /* is d2 field set? */
			dx = tr.d2;
		} else {
			dx = 1.0;
			warn("tr.d2 not set, assuming d2=1.0");
		}
	}

        do {    /* begin loop over shots */

 
		/* determine frequency sampling interval*/
		ntfft = npfar(nt);
		nw = ntfft/2+1;
		dw = 2.0*PI/(ntfft*dt);

		/* compute the index of the frequency to be migrated */
		fw=2.0*PI*f1;
		nf1=fw/dw+0.5;
		 
		fw=2.0*PI*f2;
		nf2=fw/dw+0.5;

		fw=2.0*PI*f3;
		nf3=fw/dw+0.5;

		fw=2.0*PI*f4;
		nf4=fw/dw+0.5;  

		/* the number of frequencies to migrated */
		truenw=nf4-nf1+1;
		fw=0.0+nf1*dw;

		if (verbose)
		warn("nf1=%d nf2=%d nf3=%d nf4=%d nw=%d",nf1,nf2,nf3,nf4,truenw);

		/* allocate space */
		wl=alloc1float(ntfft);
		wlsp=alloc1complex(nw);

		/* generate the Ricker wavelet */
		wtmp=ricker(fmax,dt,&ntw);

                /* zero out wl[] array */
                memset((void *) wl, 0, ntfft*FSIZE);

	
		/* CHANGE BY CHRIS STOLK, Dec. 11, 2005 */
		/* The next two lines are the old code, */
		/* it is erroneous because the peak of  */
		/* the wavelet occurs at positive time 	*/
		/* instead of time zero.		*/
		/*
		for(it=0;it<ntw;it++)
	  			wl[it]=wtmp[it];
		*/
		/* New code: we put in the wavelet in a centered fashion */ 
		for(it=0;it<ntw;it++) {
	  		wl[(it-ntw/2+ntfft) % ntfft]=wtmp[it];
	  	/*  warn("%12i    %12f    \n",(it-ntw/2+ntfft) % ntfft,wtmp[it]); */
		}
		/* End of new code */
		free1float(wtmp);

                /* fourier transform wl array */
		pfarc(-1,ntfft,wl,wlsp);

		/* CS TEST: this was used to output the array wlsp
			   (the wavelet in the frequency domain) to the file CSinfo,
			   no longer needed and commented out */
			/*
			FILE *CSinfo;
			CSinfo=fopen("CSinfo","w");
			fprintf(CSinfo,"ntfft=%10i\n",ntfft);
			fprintf(CSinfo,"ntw=%10i\n",ntw);
			for(iw=0;iw<ntfft/2+1;iw++)
			  fprintf(CSinfo,"%12f   %12f   \n",wlsp[iw].r,wlsp[iw].i);
			fclose(CSinfo);
					*/
			/* conclusion from the analysis of this info:
			   the wavelet (whose fourier transform is in wlsp)
			   is not zero phase!!! 
			   so there is a timeshift error!!!
			   Conclusion obtained dec 11 2005 */
			/* CS */


		/* allocate space */
		p = alloc2float(ntfft,nxo);
		cq = alloc2complex(nw,nxo);
	
                /* zero out p[][] array */
                memset((void *) p[0], 0, ntfft*nxo*FSIZE);

		
                /* initialize a number of items before looping over traces */
                nx = 0;
                igx=0;
                oldsx=sx;
                oldgx=gx;
                oldgxmax=gxmax;
                oldgxmin=gxmin;
                do { /* begin looping over traces within a shot gather */

			memcpy( (void *) p[igx], (const void *) tr.data,nt*FSIZE);

                        igx = gx/dx;
			if (igx==oldigx) 
			   warn("repeated igx!!! check dx or scalco value!!!");