/*
Get_sep:
Calculates the separation between two satellites along
the satellite beam, in the normal- and parallel- to look direction.
Inputs are: a state vector from scene 1, in GEI coordinates;
the name of the ceos for image 2; the slant range and doppler of
the center of the beam; and pointers to the output normal and
parallel baselines.
*/
void get_sep(stateVector stVec1, meta_parameters *meta2,
double range, double dop,double *Bn,double *Bp)
{
double lat,phi,earthRadius;
vector target,up,relPos;
vector upBeam,alongBeam,beamNormal;
double t,timeDelta;
stateVector stVec2;
GEOLOCATE_REC *g;
/*Target is the patch of ground at beam center.*/
/*Initialize the transformation.*/
g=init_geolocate_meta(&stVec1,meta2);
getLoc(g,range,dop,
&lat,&phi,&earthRadius);
free_geolocate(g);
sph2cart(earthRadius,lat,phi,&target);
/*Create beam plane unit vectors.*/
vecSub(stVec1.pos,target,&alongBeam); vecNormalize(&alongBeam);
up=stVec1.pos; vecNormalize(&up);
vecCross(up,alongBeam,&beamNormal); vecNormalize(&beamNormal);
vecCross(alongBeam,beamNormal,&upBeam); vecNormalize(&upBeam);
/*Find the time when the second satellite crosses the first's beam.*/
t=0.0;
stVec2=meta_get_stVec(meta2,t);
timeDelta=1.0;
while (fabs(timeDelta)>0.00001)
{
vecSub(stVec1.pos,stVec2.pos,&relPos);
timeDelta=vecDot(beamNormal,relPos)/vecDot(beamNormal,stVec2.vel);
t+=timeDelta;
if (!quietflag) {
printf(" Time=%f sec, delta=%f sec\n",t,timeDelta);
printf(" Distance from beam plane=%f m\n",vecDot(beamNormal,relPos));
}
stVec2=meta_get_stVec(meta2,t);
}
/*Now we have the second satellite sitting in the plane of the first's beam,
so we just separate that position into components along-beam and across-beam,
and return.*/
vecSub(stVec2.pos,stVec1.pos,&relPos);
*Bp=vecDot(alongBeam,relPos);
*Bn=vecDot(upBeam,relPos);
}
void scan_to_latlon(meta_parameters *meta,
double x, double y, double z,
double *lat_d, double *lon, double *height)
{
double qlat, qlon;
double lat,radius;
vector pos;
meta_projection *proj = meta->projection;
if (z != 0.0) {
// height correction applies directly to y (range direction)
double line, samp;
line = (y-proj->startY)/proj->perY - meta->general->start_line;
samp = (x-proj->startX)/proj->perX - meta->general->start_sample;
double sr = meta_get_slant(meta,line,samp);
double er = proj->param.atct.rlocal;
double ht = meta_get_sat_height(meta,line,samp);
double cos_ang = (sr*sr + er*er - ht*ht)/(2.0*sr*er);
if (cos_ang > 1) cos_ang = 1;
if (cos_ang < -1) cos_ang = -1;
double incid = PI-acos(cos_ang);
x += z*tan(PI/2-incid);
}
if (meta->sar->look_direction=='R')
qlat = -x/proj->param.atct.rlocal; /* Right looking sar */
else
qlat = x/proj->param.atct.rlocal; /* Left looking sar */
qlon = y/(proj->param.atct.rlocal*cos(qlat));
sph2cart(proj->param.atct.rlocal, qlat, qlon, &pos);
rotate_z(&pos,-proj->param.atct.alpha3);
rotate_y(&pos,-proj->param.atct.alpha2);
rotate_z(&pos,-proj->param.atct.alpha1);
cart2sph(pos,&radius,&lat,lon);
*lon *= R2D;
lat *= R2D;
*lat_d = atand(tand(lat) / (1-ecc2(proj->re_minor,proj->re_major)));
*height = z; // FIXME: Do we need to correct the height at all?
}
static void ll_ac(meta_projection *proj, char look_dir, double lat_r, double lon, double *c1, double *c2)
{
double qlat, qlon;
double lat,radius;
vector pos;
lat = atan(tan(lat_r)*(1 - ecc2(proj->re_minor,proj->re_major)));
sph2cart(proj->param.atct.rlocal,lat,lon,&pos);
rotate_z(&pos,proj->param.atct.alpha1);
rotate_y(&pos,proj->param.atct.alpha2);
rotate_z(&pos,proj->param.atct.alpha3);
cart2sph(pos,&radius,&qlat,&qlon);
*c1 = qlon*proj->param.atct.rlocal*cos(qlat);
if (look_dir=='R')
*c2 = -1.0*qlat*proj->param.atct.rlocal; /* right looking */
else
*c2 = qlat * proj->param.atct.rlocal; /* left looking */
}
/** Kernel L2P operation
* r += Op(L, t) where L is the local expansion and r is the result
*
* @param[in] L The local expansion
* @param[in] center The center of the box with the local expansion
* @param[in] target The target of this L2P operation
* @param[in] result The result to accumulate into
* @pre L includes the influence of all sources outside its box
*/
void L2P(const local_type& L, const point_type& center,
const target_type& target, result_type& result) const {
complex Ynm[4*P*P], YnmTheta[4*P*P];
point_type dist = target - center;
point_type gradient[4]; // = {0.,0.,0.,0.};
gradient[0] = point_type(0.);
gradient[1] = point_type(0.);
gradient[2] = point_type(0.);
gradient[3] = point_type(0.);
point_type cartesian(0);
real r, theta, phi;
cart2sph(r,theta,phi,dist);
evalMultipole(r,theta,phi,Ynm,YnmTheta);
#ifdef STRESSLET
double scale = 1./6;
#else
double scale = 1.;
#endif
for( int n=0; n!=P; ++n ) {
int nm = n * n + n;
int nms = n * (n + 1) / 2;
result[0] += scale*std::real(L[0][nms] * Ynm[nm]);
result[1] += scale*std::real(L[1][nms] * Ynm[nm]);
result[2] += scale*std::real(L[2][nms] * Ynm[nm]);
real factor = 1. / r * n;
gradient[0][0] += std::real(L[0][nms] * Ynm[nm]) * factor;
gradient[0][1] += std::real(L[0][nms] * YnmTheta[nm]);
gradient[1][0] += std::real(L[1][nms] * Ynm[nm]) * factor;
gradient[1][1] += std::real(L[1][nms] * YnmTheta[nm]);
gradient[2][0] += std::real(L[2][nms] * Ynm[nm]) * factor;
gradient[2][1] += std::real(L[2][nms] * YnmTheta[nm]);
gradient[3][0] += std::real(L[3][nms] * Ynm[nm]) * factor;
gradient[3][1] += std::real(L[3][nms] * YnmTheta[nm]);
for( int m=1; m<=n; ++m ) {
nm = n * n + n + m;
nms = n * (n + 1) / 2 + m;
result[0] += scale * 2 * std::real(L[0][nms] * Ynm[nm]);
result[1] += scale * 2 * std::real(L[1][nms] * Ynm[nm]);
result[2] += scale * 2 * std::real(L[2][nms] * Ynm[nm]);
gradient[0][0] += 2 * std::real(L[0][nms] * Ynm[nm]) * factor;
gradient[0][1] += 2 * std::real(L[0][nms] * YnmTheta[nm]);
gradient[0][2] += 2 * std::real(L[0][nms] * Ynm[nm] * CI) * m;
gradient[1][0] += 2 * std::real(L[1][nms] * Ynm[nm]) * factor;
gradient[1][1] += 2 * std::real(L[1][nms] * YnmTheta[nm]);
gradient[1][2] += 2 * std::real(L[1][nms] * Ynm[nm] * CI) * m;
gradient[2][0] += 2 * std::real(L[2][nms] * Ynm[nm]) * factor;
gradient[2][1] += 2 * std::real(L[2][nms] * YnmTheta[nm]);
gradient[2][2] += 2 * std::real(L[2][nms] * Ynm[nm] * CI) * m;
gradient[3][0] += 2 * std::real(L[3][nms] * Ynm[nm]) * factor;
gradient[3][1] += 2 * std::real(L[3][nms] * YnmTheta[nm]);
gradient[3][2] += 2 * std::real(L[3][nms] * Ynm[nm] * CI) * m;
}
}
sph2cart(r,theta,phi,gradient[0],cartesian);
cartesian *= -target[0];
gradient[0] = cartesian;
sph2cart(r,theta,phi,gradient[1],cartesian);
cartesian *= -target[1];
gradient[1] = cartesian;
sph2cart(r,theta,phi,gradient[2],cartesian);
cartesian *= -target[2];
gradient[2] = cartesian;
sph2cart(r,theta,phi,gradient[3],cartesian);
gradient[3] = cartesian;
result[0] += scale*(gradient[0][0]+gradient[1][0]+gradient[2][0]+gradient[3][0]);
result[1] += scale*(gradient[0][1]+gradient[1][1]+gradient[2][1]+gradient[3][1]);
result[2] += scale*(gradient[0][2]+gradient[1][2]+gradient[2][2]+gradient[3][2]);
}
