int
main (int argc, char **argv)
{
int nt,nzt,nxt,nz,nxo,nxs,ns,nx,nr,is,ixo,ixs;
int ls,jtr,mtr,tracl,mzmax;
off_t nseek;
float ft,fzt,fxt,fz,fx,fxo,fs,fxs,dt,dzt,dxt,dz,dx,dxo,ds,dxs,
ext,ezt,es,ex,ez,xo,s,xs,xg,fpeak;
float v0,dvz;
float fmax,angmax,offmax,rmax,aperx;
float **mig,**migi,***ttab,**tb,**pb,**cosb,**sigb,**tsum,**tt;
char *infile="stdin",*outfile="stdout",*ttfile,*jpfile;
FILE *infp,*outfp,*ttfp,*jpfp;
Wavelet *w;
/* hook up getpar to handle the parameters */
initargs(argc, argv);
requestdoc(1);
/* open input and output files */
if( !getparstring("infile",&infile)) {
infp = stdin;
} else
if ((infp=fopen(infile,"r"))==NULL)
err("cannot open infile=%s\n",infile);
if( !getparstring("outfile",&outfile)) {
outfp = stdout;
} else {
outfp = fopen(outfile,"w");
}
efseeko(infp,(off_t) 0,SEEK_CUR);
warn("Got A");
efseeko(outfp,(off_t) 0,SEEK_CUR);
if( !getparstring("ttfile",&ttfile))
err("must specify ttfile!\n");
if ((ttfp=fopen(ttfile,"r"))==NULL)
err("cannot open ttfile=%s\n",ttfile);
if( !getparstring("jpfile",&jpfile)) {
jpfp = stderr;
} else
jpfp = fopen(jpfile,"w");
/* get information for seismogram traces */
if (!getparint("nt",&nt)) nt = 501;
if (!getparfloat("dt",&dt)) dt = 0.004;
if (!getparfloat("ft",&ft)) ft = 0.0;
if (!getparfloat("fmax",&fmax)) fmax = 1.0/(4*dt);
fpeak = 0.2/dt;
if (!getparint("nxs",&nxs)) nxs = 101;
if (!getparfloat("dxs",&dxs)) dxs = 15;
if (!getparfloat("fxs",&fxs)) fxs = 0.0;
if (!getparint("nxo",&nxo)) nxo = 1;
if (!getparfloat("dxo",&dxo)) dxo = 50;
if (!getparfloat("fxo",&fxo)) fxo = 0.0;
/* get traveltime table parameters */
if (!getparint("nxt",&nxt)) err("must specify nxt!\n");
if (!getparfloat("fxt",&fxt)) err("must specify fxt!\n");
if (!getparfloat("dxt",&dxt)) err("must specify dxt!\n");
if (!getparint("nzt",&nzt)) err("must specify nzt!\n");
if (!getparfloat("fzt",&fzt)) err("must specify fzt!\n");
if (!getparfloat("dzt",&dzt)) err("must specify dzt!\n");
if (!getparint("ns",&ns)) err("must specify ns!\n");
if (!getparfloat("fs",&fs)) err("must specify fs!\n");
if (!getparfloat("ds",&ds)) err("must specify ds!\n");
ext = fxt+(nxt-1)*dxt;
ezt = fzt+(nzt-1)*dzt;
es = fs+(ns-1)*ds;
/* check source and receiver coordinates */
for (ixs=0; ixs<nxs; ++ixs) {
xs = fxs+ixs*dxs;
for (ixo=0; ixo<nxo; ++ixo) {
xg = xs+fxo+ixo*dxo;
if (fs>xs || es<xs || fs>xg || es<xg)
err("shot or receiver lie outside of specified (x,z) grid\n");
}
}
/* get migration section parameters */
if (!getparint("nx",&nx)) err("must specify nx!\n");
if (!getparfloat("fx",&fx)) err("must specify fx!\n");
if (!getparfloat("dx",&dx)) err("must specify dx!\n");
if (!getparint("nz",&nz)) err("must specify nz!\n");
if (!getparfloat("fz",&fz)) err("must specify fz!\n");
if (!getparfloat("dz",&dz)) err("must specify dz!\n");
ex = fx+(nx-1)*dx;
ez = fz+(nz-1)*dz;
if(fxt>fx || ext<ex || fzt>fz || ezt<ez)
err(" migration section is out of traveltime table!\n");
if (!getparfloat("v0",&v0)) v0 = 1500;
if (!getparfloat("dvz",&dvz)) dvz = 0;
if (!getparfloat("angmax",&angmax)) angmax = 60.;
if (angmax<0.00001) err("angmax must be positive!\n");
mzmax = dx*sin(angmax*PI/180.)/dz;
if(mzmax<1) mzmax = 1;
if (!getparfloat("aperx",&aperx)) aperx = 0.5*nxt*dxt;
if (!getparint("ls",&ls)) ls = 1;
if (!getparint("mtr",&mtr)) mtr = 100;
fprintf(jpfp,"\n");
fprintf(jpfp," Modeling parameters\n");
fprintf(jpfp," ================\n");
fprintf(jpfp," infile=%s \n",infile);
fprintf(jpfp," outfile=%s \n",outfile);
fprintf(jpfp," ttfile=%s \n",ttfile);
fprintf(jpfp," \n");
fprintf(jpfp," nzt=%d fzt=%g dzt=%g\n",nzt,fzt,dzt);
fprintf(jpfp," nxt=%d fxt=%g dxt=%g\n",nxt,fxt,dxt);
fprintf(jpfp," ns=%d fs=%g ds=%g\n",ns,fs,ds);
fprintf(jpfp," \n");
fprintf(jpfp," nz=%d fz=%g dz=%g\n",nz,fz,dz);
fprintf(jpfp," nx=%d fx=%g dx=%g\n",nx,fx,dx);
fprintf(jpfp," \n");
fprintf(jpfp," nxs=%d fxs=%g dxs=%g\n",nxs,fxs,dxs);
fprintf(jpfp," nxo=%d fxo=%g dxo=%g\n",nxo,fxo,dxo);
fprintf(jpfp," \n");
/* compute reference traveltime and slowness */
offmax = MAX(ABS(fxo),ABS(fxo+(nxo-1)*dxo));
rmax = MAX(es-fxt,ext-fs);
rmax = MIN(rmax,0.5*offmax+aperx);
nr = 2+(int)(rmax/dx);
tb = ealloc2float(nzt,nr);
pb = ealloc2float(nzt,nr);
sigb = ealloc2float(nzt,nr);
cosb = ealloc2float(nzt,nr);
timeb(nr,nzt,dx,dzt,fzt,dvz,v0,tb,pb,sigb,cosb);
fprintf(jpfp," nt=%d ft=%g dt=%g fpeak=%g \n",nt,ft,dt,fpeak);
fprintf(jpfp," v0=%g dvz=%g \n",v0,dvz);
fprintf(jpfp," aperx=%g angmax=%g offmax=%g\n",aperx,angmax,offmax);
fprintf(jpfp," mtr=%d ls=%d\n",mtr,ls);
fprintf(jpfp," ================\n");
fflush(jpfp);
/* allocate space */
mig = ealloc2float(nz,nx);
migi = ealloc2float(nz+2*mzmax,nx);
ttab = ealloc3float(nzt,nxt,ns);
tt = ealloc2float(nzt,nxt);
tsum = ealloc2float(nzt,nxt);
/* make wavelet */
makericker(fpeak,dt,&w);
/* set constant segy trace header parameters */
memset((void *) &tr, 0, sizeof(segy));
tr.trid = 1;
tr.counit = 1;
tr.ns = nt;
tr.dt = 1.0e6*dt;
tr.delrt = 1.0e3*ft;
fprintf(jpfp," read traveltime tables \n");
fflush(jpfp);
/* compute traveltime residual */
for(is=0; is<ns; ++is){
nseek = (off_t) nxt*nzt*is;
efseeko(ttfp,nseek*((off_t) sizeof(float)),SEEK_SET);
fread(ttab[is][0],sizeof(float),nxt*nzt,ttfp);
s = fs+is*ds;
resit(nxt,fxt,dxt,nzt,nr,dx,tb,ttab[is],s);
}
fprintf(jpfp," read migration section \n");
fflush(jpfp);
/* read migration section */
fread(mig[0],sizeof(float),nx*nz,infp);
/* integrate migration section for constructing anti-aliasing
filter */
integ(mig,nz,dz,nx,mzmax,migi);
fprintf(jpfp," start synthesis ... \n");
fprintf(jpfp," \n");
fflush(jpfp);
jtr = 0;
/* loop over shots */
for (ixs=0,xs=fxs,tracl=0; ixs<nxs; ++ixs,xs+=dxs) {
/* loop over offsets */
for (ixo=0,xo=fxo; ixo<nxo; ++ixo,xo+=dxo) {
float as,res;
int is;
xg = xs+xo;
/* set segy trace header parameters */
tr.tracl = tr.tracr = ++tracl;
tr.fldr = 1+ixs;
tr.tracf = 1+ixo;
tr.offset = NINT(xo);
tr.sx = NINT(xs);
tr.gx = NINT(xg);
as = (xs-fs)/ds;
is = (int)as;
if(is==ns-1) is=ns-2;
res = as-is;
if(res<=0.01) res = 0.0;
if(res>=0.99) res = 1.0;
sum2(nxt,nzt,1-res,res,ttab[is],ttab[is+1],tsum);
as = (xg-fs)/ds;
is = (int)as;
if(is==ns-1) is=ns-2;
res = as-is;
if(res<=0.01) res = 0.0;
if(res>=0.99) res = 1.0;
sum2(nxt,nzt,1-res,res,ttab[is],ttab[is+1],tt);
sum2(nxt,nzt,1,1,tt,tsum,tsum);
fflush(jpfp);
/* make one trace */
maketrace(tr.data,nt,ft,dt,xs,xg,mig,migi,aperx,
nx,fx,dx,nz,fz,dz,mzmax,ls,angmax,v0,fmax,w,
tb,pb,sigb,cosb,nr,tsum,nxt,fxt,dxt,nzt,fzt,dzt);
/* write trace */
fputtr(outfp,&tr);
jtr++;
if((jtr-1)%mtr ==0 ){
fprintf(jpfp," generated trace %d\n",jtr);
fflush(jpfp);
}
}
}
fprintf(jpfp," generated %d traces in total\n",jtr);
fprintf(jpfp," \n");
fprintf(jpfp," output done\n");
fflush(jpfp);
efclose(jpfp);
efclose(outfp);
free2float(tsum);
free2float(tt);
free2float(pb);
free2float(tb);
free2float(cosb);
free2float(sigb);
free3float(ttab);
free2float(mig);
free2float(migi);
return(CWP_Exit());
}
int
main (int argc, char **argv)
{
int nr,ir,ls,smooth,ndpfz,ns,ixo,ixm,nxo,nxm,nt,
nx,nz,nxb,nxd,ixd,i,ix,iz,nx1,nx0,nxd1,
verbose,tracl,
*nxz;
float tmin,temp,temp1,
dsmax,fpeak,dx,dz,fx,ex,fx1,ex1,
dxm,dxo,dt,fxm,fxo,ft,xo,xm,vs0,vg0,
xs,xg,ez,
*ar,**xr,**zr,
**vold,**ts,**as,**sgs,**tg,**ag,**sgg,**bas,**bag,
**v,**ts1=NULL,**as1=NULL,**sgs1=NULL,
**tg1=NULL,**ag1=NULL,**sgg1=NULL;
FILE *vfp=stdin;
Reflector *r;
Wavelet *w;
/* hook up getpar to handle the parameters */
initargs(argc,argv);
requestdoc(0);
/* get required parameters */
if (!getparint("nx",&nx)) err("must specify nx!\n");
if (!getparint("nz",&nz)) err("must specify nz!\n");
/* get optional parameters */
if (!getparint("nxb",&nxb)) nxb = nx;
if (!getparint("nxd",&nxd)) nxd = 1;
if (!getparfloat("dx",&dx)) dx = 100;
if (!getparfloat("fx",&fx)) fx = 0.0;
if (!getparfloat("dz",&dz)) dz = 100;
if (!getparint("nt",&nt)) nt = 101; CHECK_NT("nt",nt);
if (!getparfloat("dt",&dt)) dt = 0.04;
if (!getparfloat("ft",&ft)) ft = 0.0;
if (!getparint("nxo",&nxo)) nxo = 1;
if (!getparfloat("dxo",&dxo)) dxo = 50;
if (!getparfloat("fxo",&fxo)) fxo = 0.0;
if (!getparint("nxm",&nxm)) nxm = 101;
if (!getparfloat("dxm",&dxm)) dxm = 50;
if (!getparfloat("fxm",&fxm)) fxm = 0.0;
if (!getparfloat("fpeak",&fpeak)) fpeak = 0.2/dt;
if (!getparint("ls",&ls)) ls = 0;
if (!getparfloat("tmin",&tmin)) tmin = 10.0*dt;
if (!getparint("ndpfz",&ndpfz)) ndpfz = 5;
if (!getparint("smooth",&smooth)) smooth = 0;
if (!getparint("verbose",&verbose)) verbose = 0;
/* check the ranges of shots and receivers */
ex = fx+(nx-1)*dx;
ez = (nz-1)*dz;
for (ixm=0; ixm<nxm; ++ixm)
for (ixo=0; ixo<nxo; ++ixo) {
/* compute source and receiver coordinates */
xs = fxm+ixm*dxm-0.5*(fxo+ixo*dxo);
xg = xs+fxo+ixo*dxo;
if (fx>xs || ex<xs || fx>xg || ex<xg)
err("shot or receiver lie outside of specified (x,z) grid\n");
}
decodeReflectors(&nr,&ar,&nxz,&xr,&zr);
if (!smooth) breakReflectors(&nr,&ar,&nxz,&xr,&zr);
/* allocate space */
vold = ealloc2float(nz,nx);
/* read velocities */
if(fread(vold[0],sizeof(float),nx*nz,vfp)!=nx*nz)
err("cannot read %d velocities from file %s",nx*nz,vfp);
/* determine maximum reflector segment length */
tmin = MAX(tmin,MAX(ft,dt));
dsmax = vold[0][0]/(2*ndpfz)*sqrt(tmin/fpeak);
/* make reflectors */
makeref(dsmax,nr,ar,nxz,xr,zr,&r);
/* count reflector segments */
for (ir=0,ns=0; ir<nr; ++ir)
ns += r[ir].ns;
/* make wavelet */
makericker(fpeak,dt,&w);
/* if requested, print information */
if (verbose) {
warn("\nSUSYNVXZ:");
warn("Total number of small reflecting segments is %d.\n",ns);
}
/* set constant segy trace header parameters */
memset( (void *) &tr, 0, sizeof(segy));
tr.trid = 1;
tr.counit = 1;
tr.ns = nt;
tr.dt = 1.0e6*dt;
tr.delrt = 1.0e3*ft;
/* allocate space */
nx1 = 1+2*nxb;
ts = ealloc2float(nz,nx1);
as = ealloc2float(nz,nx1);
sgs = ealloc2float(nz,nx1);
tg = ealloc2float(nz,nx1);
ag = ealloc2float(nz,nx1);
sgg = ealloc2float(nz,nx1);
v = ealloc2float(nz,nx1);
bas = ealloc2float(nz,nx1);
bag = ealloc2float(nz,nx1);
if(nxd>1) {
/* allocate space for interpolation */
ts1 = ealloc2float(nz,nx1);
as1 = ealloc2float(nz,nx1);
sgs1 = ealloc2float(nz,nx1);
tg1 = ealloc2float(nz,nx1);
ag1 = ealloc2float(nz,nx1);
sgg1 = ealloc2float(nz,nx1);
}
/* loop over offsets and midpoints */
for (ixo=0, tracl=0; ixo<nxo; ++ixo){
xo = fxo+ixo*dxo;
if(ABS(xo)>nxb*dx) err("\t band NXB is too small!\n");
nxd1 = nxd;
for (ixm=0; ixm<nxm; ixm +=nxd1){
xm = fxm+ixm*dxm;
xs = xm-0.5*xo;
xg = xs+xo;
/* set range for traveltimes' calculation */
fx1 = xm-nxb*dx;
ex1 = MIN(ex+(nxd1-1)*dxm,xm+nxb*dx);
nx1 = 1+(ex1-fx1)/dx;
nx0 = (fx1-fx)/dx;
temp = (fx1-fx)/dx-nx0;
/* transpose velocity such that the first row is at fx1 */
for(ix=0;ix<nx1;++ix)
for(iz=0;iz<nz;++iz){
if(ix<-nx0)
v[ix][iz] = vold[0][iz];
else if(ix+nx0>nx-2)
v[ix][iz]=vold[nx-1][iz];
else
v[ix][iz] = vold[ix+nx0][iz]*(1.0-temp)
+temp*vold[ix+nx0+1][iz];
}
if(ixm==0 || nxd1==1){
/* No interpolation */
/* compute traveltimes, propagation angles, sigmas
from shot and receiver respectively */
eiktam(xs,0.,nz,dz,0.,nx1,dx,fx1,v,ts,as,sgs,bas);
eiktam(xg,0.,nz,dz,0.,nx1,dx,fx1,v,tg,ag,sgg,bag);
ixd = NINT((xs-fx)/dx);
vs0 = vold[ixd][0];
ixd = NINT((xg-fx)/dx);
vg0 = vold[ixd][0];
/* make one trace */
ex1 = MIN(ex,xm+nxb*dx);
makeone(ts,as,sgs,tg,ag,sgg,ex1,ez,dx,dz,fx1,vs0,vg0,
ls,w,nr,r,nt,dt,ft,tr.data);
/* set segy trace header parameters */
tr.tracl = tr.tracr = ++tracl;
tr.cdp = 1+ixm;
tr.cdpt = 1+ixo;
tr.offset = NINT(xo);
tr.sx = NINT(xs);
tr.gx = NINT(xg);
/* write trace */
puttr(&tr);
}
else {
/* Linear interpolation */
eiktam(xs,0,nz,dz,0,nx1,dx,fx1,v,ts1,as1,sgs1,bas);
eiktam(xg,0,nz,dz,0,nx1,dx,fx1,v,tg1,ag1,sgg1,bag);
ixd = NINT((xs-fx)/dx);
vs0 = vold[ixd][0];
ixd = NINT((xg-fx)/dx);
vg0 = vold[ixd][0];
xm -= nxd1*dxm;
for(i=1; i<=nxd1; ++i) {
xm += dxm;
xs = xm-0.5*xo;
xg = xs+xo;
fx1 = xm-nxb*dx;
ex1 = MIN(ex+(nxd1-1)*dxm,xm+nxb*dx);
nx1 = 1+(ex1-fx1)/dx;
temp = nxd1-i;
temp1 = 1.0/(nxd1-i+1);
for(ix=0;ix<nx1;++ix)
for(iz=0;iz<nz;++iz){
if(i==nxd1){
ts[ix][iz] = ts1[ix][iz];
tg[ix][iz] = tg1[ix][iz];
sgs[ix][iz] = sgs1[ix][iz];
ag[ix][iz] = ag1[ix][iz];
sgg[ix][iz] = sgg1[ix][iz];
as[ix][iz] = as1[ix][iz];
}
else{
ts[ix][iz] = (temp*ts[ix][iz]
+ts1[ix][iz])*temp1;
tg[ix][iz] = (temp*tg[ix][iz]
+tg1[ix][iz])*temp1;
as[ix][iz] = (temp*as[ix][iz]
+as1[ix][iz])*temp1;
sgs[ix][iz] = (temp*sgs[ix][iz]
+sgs1[ix][iz])*temp1;
ag[ix][iz] = (temp*ag[ix][iz]
+ag1[ix][iz])*temp1;
sgg[ix][iz] = (temp*sgg[ix][iz]
+sgg1[ix][iz])*temp1;
}
}
/* make one trace */
ex1 = MIN(ex,xm+nxb*dx);
makeone(ts,as,sgs,tg,ag,sgg,ex1,ez,dx,dz,fx1,vs0,vg0,
ls,w,nr,r,nt,dt,ft,tr.data);
/* set segy trace header parameters */
tr.tracl = tr.tracr = ++tracl;
tr.cdp = 1+ixm-nxd1+i;
tr.cdpt = 1+ixo;
tr.offset = NINT(xo);
tr.d2=dxm;
tr.f2=fxm;
tr.sx = NINT(xs);
tr.gx = NINT(xg);
/* write trace */
puttr(&tr);
}
}
/* set skip parameter */
if(ixm<nxm-1 && ixm>nxm-1-nxd1) nxd1 = nxm-1-ixm;
}
warn("\t finish offset %f\n",xo);
}
free2float(vold);
free2float(ts);
free2float(bas);
free2float(sgs);
free2float(as);
free2float(v);
free2float(tg);
free2float(bag);
free2float(sgg);
free2float(ag);
if(nxd>1) {
free2float(ts1);
free2float(as1);
free2float(sgs1);
free2float(tg1);
free2float(ag1);
free2float(sgg1);
}
return(CWP_Exit());
}
int
main (int argc, char **argv)
{
int nr,er,ob,sp,ir,ixz,ls,smooth,ndpfz,ns,
ixo,ixsm,nxo,nxs,nxm,nt,nxsm,
shots,midpoints,verbose,tracl,
*nxz;
float x0,z0,v00,gamma,dvdx,dvdz,vmin,tmin,tminr,
x,z,v,t,dsmax,fpeak,
dxs,dxm,dxo,dt,fxs,fxm,fxo,ft,dxsm,
xs,zs,xg,zg,
*xo,*ar,**xr,**zr;
Reflector *r;
Wavelet *w;
/* hook up getpar to handle the parameters */
initargs(argc,argv);
requestdoc(0);
/* get parameters */
if (!getparint("nt",&nt)) nt = 101; CHECK_NT("nt",nt);
if (!getparfloat("dt",&dt)) dt = 0.04;
if (!getparfloat("ft",&ft)) ft = 0.0;
if ((nxo=countparval("xo"))!=0) {
xo = ealloc1float(nxo);
getparfloat("xo",xo);
} else {
if (!getparint("nxo",&nxo)) nxo = 1;
if (!getparfloat("dxo",&dxo)) dxo = 0.05;
if (!getparfloat("fxo",&fxo)) fxo = 0.0;
xo = ealloc1float(nxo);
for (ixo=0; ixo<nxo; ++ixo)
xo[ixo] = fxo+ixo*dxo;
}
shots = (getparint("nxs",&nxs) ||
getparfloat("dxs",&dxs) ||
getparfloat("fxs",&fxs));
midpoints = (getparint("nxm",&nxm) ||
getparfloat("dxm",&dxm) ||
getparfloat("fxm",&fxm));
if (shots && midpoints)
err("cannot specify both shot and midpoint sampling!\n");
if (shots) {
if (!getparint("nxs",&nxs)) nxs = 101;
if (!getparfloat("dxs",&dxs)) dxs = 0.05;
if (!getparfloat("fxs",&fxs)) fxs = 0.0;
nxsm = nxs;
dxsm = dxs;
} else {
midpoints = 1;
if (!getparint("nxm",&nxm)) nxm = 101;
if (!getparfloat("dxm",&dxm)) dxm = 0.05;
if (!getparfloat("fxm",&fxm)) fxm = 0.0;
nxsm = nxm;
dxsm = dxm;
}
if (!getparint("nxm",&nxm)) nxm = 101;
if (!getparfloat("dxm",&dxm)) dxm = 0.05;
if (!getparfloat("fxm",&fxm)) fxm = 0.0;
if (!getparfloat("x0",&x0)) x0 = 0.0;
if (!getparfloat("z0",&z0)) z0 = 0.0;
if (!getparfloat("v00",&v00)) v00 = 2.0;
if (!getparfloat("gamma",&gamma)) gamma = 1.0;
if (!getparfloat("dvdx",&dvdx)) dvdx = 0.0;
if (!getparfloat("dvdz",&dvdz)) dvdz = 0.0;
if (!getparfloat("fpeak",&fpeak)) fpeak = 0.2/dt;
if (!getparint("ls",&ls)) ls = 0;
if (!getparint("er",&er)) er = 0;
if (!getparint("ob",&ob)) ob = 1;
if (!getparint("sp",&sp)) sp = 1;
if (!getparfloat("tmin",&tmin)) tmin = 10.0*dt;
if (!getparint("ndpfz",&ndpfz)) ndpfz = 5;
if (!getparint("smooth",&smooth)) smooth = 0;
if (!getparint("verbose",&verbose)) verbose = 0;
decodeReflectors(&nr,&ar,&nxz,&xr,&zr);
if (!smooth) breakReflectors(&nr,&ar,&nxz,&xr,&zr);
/* convert velocity v(x0,z0) to v(0,0) */
v00 -= dvdx*x0+dvdz*z0;
/* determine minimum velocity and minimum reflection time */
for (ir=0,vmin=FLT_MAX,tminr=FLT_MAX; ir<nr; ++ir) {
for (ixz=0; ixz<nxz[ir]; ++ixz) {
x = xr[ir][ixz];
z = zr[ir][ixz];
v = v00+dvdx*x+dvdz*z;
if (v<vmin) vmin = v;
t = 2.0*z/v;
if (t<tminr) tminr = t;
}
}
/* determine maximum reflector segment length */
tmin = MAX(tmin,MAX(ft,dt));
dsmax = vmin/(2*ndpfz)*sqrt(tmin/fpeak);
/* make reflectors */
makeref(dsmax,nr,ar,nxz,xr,zr,&r);
/* count reflector segments */
for (ir=0,ns=0; ir<nr; ++ir)
ns += r[ir].ns;
/* make wavelet */
makericker(fpeak,dt,&w);
/* if requested, print information */
if (verbose) {
warn("\nSYNLVCW:");
warn(
"Minimum possible reflection time (assuming sources\n"
"and receivers are at the surface Z=0) is %g s.\n"
"You may want to adjust the \"minimum time of \n"
"interest\" parameter.",tminr);
warn(
"Total number of small reflecting\n"
"segments is %d.",ns);
}
/* set constant segy trace header parameters */
memset( (void *) &tr, 0, sizeof(segy));
tr.trid = 1;
tr.counit = 1;
tr.ns = nt;
tr.dt = 1.0e6*dt;
tr.delrt = 1.0e3*ft;
/* loop over shots or midpoints */
for (ixsm=0,tracl=0; ixsm<nxsm; ++ixsm) {
/* loop over offsets */
for (ixo=0; ixo<nxo; ++ixo) {
/* compute source and receiver coordinates */
if (shots)
xs = fxs+ixsm*dxs;
else
xs = fxm+ixsm*dxm-0.5*xo[ixo];
zs = 0.0;
xg = xs+xo[ixo];
zg = 0.0;
/* set segy trace header parameters */
tr.tracl = tr.tracr = ++tracl;
if (shots) {
tr.fldr = 1+ixsm;
tr.tracf = 1+ixo;
} else {
tr.cdp = 1+ixsm;
tr.cdpt = 1+ixo;
}
tr.offset = NINT(1000.0*(dxsm>0.0?xo[ixo]:-xo[ixo]));
tr.sx = NINT(1000.0*xs);
tr.gx = NINT(1000.0*xg);
/* make one trace */
makeone(v00,dvdx,dvdz,ls,er,ob,sp,w,gamma,
xs,zs,xg,zg,
nr,r,nt,dt,ft,tr.data);
/* write trace */
puttr(&tr);
}
}
return(CWP_Exit());
}
