void oskar_imager_init_dft(oskar_Imager* h, int* status)
{
int num_pixels;
oskar_imager_free_dft(h, status);
if (*status) return;
/* Calculate pixel coordinate grid required for the DFT imager. */
num_pixels = h->image_size * h->image_size;
h->l = oskar_mem_create(h->imager_prec, OSKAR_CPU, num_pixels, status);
h->m = oskar_mem_create(h->imager_prec, OSKAR_CPU, num_pixels, status);
h->n = oskar_mem_create(h->imager_prec, OSKAR_CPU, num_pixels, status);
oskar_evaluate_image_lmn_grid(h->image_size, h->image_size,
h->fov_deg * M_PI/180, h->fov_deg * M_PI/180, 0,
h->l, h->m, h->n, status);
oskar_mem_add_real(h->n, -1.0, status); /* n-1 */
}
void oskar_beam_pattern_generate_coordinates(oskar_BeamPattern* h,
int beam_coord_type, int* status)
{
size_t num_pixels = 0;
int nside = 0;
/* Check if safe to proceed. */
if (*status) return;
/* If memory is already allocated, do nothing. */
if (h->x) return;
/* Calculate number of pixels if possible. */
if (h->coord_grid_type == 'B') /* Beam image */
{
num_pixels = h->width * h->height;
}
else if (h->coord_grid_type == 'H') /* Healpix */
{
nside = h->nside;
num_pixels = 12 * nside * nside;
}
else if (h->coord_grid_type == 'S') /* Sky model */
num_pixels = 0;
else
{
*status = OSKAR_ERR_INVALID_ARGUMENT;
return;
}
/* Create output arrays. */
h->x = oskar_mem_create(h->prec, OSKAR_CPU, num_pixels, status);
h->y = oskar_mem_create(h->prec, OSKAR_CPU, num_pixels, status);
h->z = oskar_mem_create(h->prec, OSKAR_CPU, num_pixels, status);
/* Get equatorial or horizon coordinates. */
if (h->coord_frame_type == 'E')
{
/*
* Equatorial coordinates.
*/
switch (h->coord_grid_type)
{
case 'B': /* Beam image */
{
oskar_evaluate_image_lmn_grid(h->width, h->height,
h->fov_deg[0]*(M_PI/180.0), h->fov_deg[1]*(M_PI/180.0), 1,
h->x, h->y, h->z, status);
break;
}
case 'H': /* Healpix */
{
int num_points, type, i;
double ra0 = 0.0, dec0 = 0.0;
oskar_Mem *theta, *phi;
/* Generate theta and phi from nside. */
num_points = 12 * nside * nside;
type = oskar_mem_type(h->x);
theta = oskar_mem_create(type, OSKAR_CPU, num_points, status);
phi = oskar_mem_create(type, OSKAR_CPU, num_points, status);
oskar_convert_healpix_ring_to_theta_phi(nside, theta, phi, status);
/* Convert theta from polar angle to elevation. */
if (type == OSKAR_DOUBLE)
{
double* theta_ = oskar_mem_double(theta, status);
for (i = 0; i < num_points; ++i)
theta_[i] = 90.0 - theta_[i];
}
else if (type == OSKAR_SINGLE)
{
float* theta_ = oskar_mem_float(theta, status);
for (i = 0; i < num_points; ++i)
theta_[i] = 90.0f - theta_[i];
}
else
{
*status = OSKAR_ERR_BAD_DATA_TYPE;
}
/* Evaluate beam phase centre coordinates in equatorial frame. */
if (beam_coord_type == OSKAR_SPHERICAL_TYPE_EQUATORIAL)
{
ra0 = oskar_telescope_phase_centre_ra_rad(h->tel);
dec0 = oskar_telescope_phase_centre_dec_rad(h->tel);
}
else if (beam_coord_type == OSKAR_SPHERICAL_TYPE_AZEL)
{
/* TODO convert from az0, el0 to ra0, dec0 */
*status = OSKAR_FAIL;
}
else
{
*status = OSKAR_ERR_INVALID_ARGUMENT;
}
/* Convert equatorial angles to direction cosines in the frame
* of the beam phase centre. */
oskar_convert_lon_lat_to_relative_directions(num_points,
phi, theta, ra0, dec0, h->x, h->y, h->z, status);
/* Free memory. */
oskar_mem_free(theta, status);
oskar_mem_free(phi, status);
break;
}
case 'S': /* Sky model */
{
oskar_Mem *ra, *dec;
int type = 0, num_points = 0;
type = oskar_mem_type(h->x);
ra = oskar_mem_create(type, OSKAR_CPU, 0, status);
dec = oskar_mem_create(type, OSKAR_CPU, 0, status);
load_coords(ra, dec, h->sky_model_file, status);
num_points = oskar_mem_length(ra);
oskar_mem_realloc(h->x, num_points, status);
oskar_mem_realloc(h->y, num_points, status);
oskar_mem_realloc(h->z, num_points, status);
oskar_convert_lon_lat_to_relative_directions(
num_points, ra, dec,
oskar_telescope_phase_centre_ra_rad(h->tel),
oskar_telescope_phase_centre_dec_rad(h->tel),
h->x, h->y, h->z, status);
oskar_mem_free(ra, status);
oskar_mem_free(dec, status);
break;
}
default:
*status = OSKAR_ERR_INVALID_ARGUMENT;
break;
};
/* Set the return values. */
h->coord_type = OSKAR_RELATIVE_DIRECTIONS;
h->lon0 = oskar_telescope_phase_centre_ra_rad(h->tel);
h->lat0 = oskar_telescope_phase_centre_dec_rad(h->tel);
}
else if (h->coord_frame_type == 'H')
{
/*
* Horizon coordinates.
*/
switch (h->coord_grid_type)
{
case 'B': /* Beam image */
{
/* NOTE: This is for an all-sky image centred on the zenith. */
oskar_evaluate_image_lmn_grid(h->width, h->height,
M_PI, M_PI, 1, h->x, h->y, h->z, status);
break;
}
case 'H': /* Healpix */
{
int num_points, type;
oskar_Mem *theta, *phi;
num_points = 12 * nside * nside;
type = oskar_mem_type(h->x);
theta = oskar_mem_create(type, OSKAR_CPU, num_points, status);
phi = oskar_mem_create(type, OSKAR_CPU, num_points, status);
oskar_convert_healpix_ring_to_theta_phi(nside, theta, phi, status);
oskar_convert_theta_phi_to_enu_directions(num_points,
theta, phi, h->x, h->y, h->z, status);
oskar_mem_free(theta, status);
oskar_mem_free(phi, status);
break;
}
default:
*status = OSKAR_ERR_INVALID_ARGUMENT;
break;
};
/* Set the return values. */
h->coord_type = OSKAR_ENU_DIRECTIONS;
h->lon0 = 0.0;
h->lat0 = M_PI / 2.0;
}
else
{
*status = OSKAR_ERR_INVALID_ARGUMENT;
}
/* Set the number of pixels. */
h->num_pixels = oskar_mem_length(h->x);
}
