int main (int argc, char **argv) {
SpiceDouble lt;
SpiceDouble ang;
SpiceDouble v[3];
SpiceDouble pos[3];
int i;
furnsh_c("/home/barrycarter/BCGIT/ASTRO/standard.tm");
// spkezp_c(299,0,"ITRF93","LT+S",399,v,<);
// printf("POS: %f,%f,%f\n",v[0],v[1],v[2]);
// exit(0);
// abq roughly
georec_c (-106.5*rpd_c(), 35.05*rpd_c(), 1.609344, 6378.137,
(6378.137-6356.7523)/6378.137, pos);
for (i=0; i<=86400; i+=3600) {
// pos of sun from IAU_EARTH
spkezp_c(10,i,"ITRF93","LT+S",399,v,<);
printf("POS(%d): %f,%f,%f\n",i,v[0],v[1],v[2]);
// angle between abq vector and sun vector (0 = zenith)
ang = vsep_c (v,pos);
// printf("%d %f\n",i,r2d(ang));
}
return 0;
}
static VALUE georec(VALUE self, VALUE longitude, VALUE latitude, VALUE altitude, VALUE radius_equatorial, VALUE flattening) {
double vector[3];
georec_c(NUM2DBL(longitude), NUM2DBL(latitude), NUM2DBL(altitude), NUM2DBL(radius_equatorial), NUM2DBL(flattening), vector);
if(spice_error(SPICE_ERROR_SHORT)) return Qnil;
return rb_nmatrix_dense_create(FLOAT64, (size_t *) VECTOR_SHAPE, 2, (void *) vector, 3);
}
double bc_elev(double lat, double lon, double et, char *target) {
double pos[3], radii[3], normal[3], state[6], lt;
int n;
// the Earth's 3 radii
bodvrd_c ("EARTH", "RADII", 3, &n, radii);
double flat = (radii[2]-radii[0])/radii[0];
// rectangular coordinates of position (ITRF93)
georec_c (lon, lat, 0, radii[0], flat, pos);
// surface normal vector to ellipsoid at latitude/longitude (this is
// NOT the same as pos!)
surfnm_c(radii[0], radii[1], radii[2], pos, normal);
// printf("POS: %f %f %f\n", pos[0], pos[1], pos[2]);
// printf("NORMAL: %f %f %f\n", normal[0], normal[1], normal[2]);
// printf("ET = %f\n", et);
// printf("POS: %f %f %f\n", pos[0], pos[1], pos[2]);
// position of Sun in ITRF93
spkcpo_c("Sun", et, "ITRF93", "OBSERVER", "CN+S", pos, "Earth", "ITRF93", state, <);
// printf("STATE: %f %f %f\n", state[0], state[1], state[2]);
double el = halfpi_c() - vsep_c(state, normal);
// printf("DEBUG: %f,%f,%f,%f,%f\n", lat, lon, 0., el, et);
// return halfpi_c() - vsep_c(normal, state);
return el;
}
