コード例 #1
0
oskar_VisBlock* oskar_simulator_finalise_block(oskar_Simulator* h,
        int block_index, int* status)
{
    int i, i_active;
    oskar_VisBlock *b0 = 0, *b = 0;
    if (*status) return 0;

    /* The visibilities must be copied back
     * at the end of the block simulation. */

    /* Combine all vis blocks into the first one. */
    i_active = (block_index + 1) % 2;
    b0 = h->d[0].vis_block_cpu[!i_active];
    if (!h->coords_only)
    {
        oskar_Mem *xc0 = 0, *ac0 = 0;
        xc0 = oskar_vis_block_cross_correlations(b0);
        ac0 = oskar_vis_block_auto_correlations(b0);
        for (i = 1; i < h->num_devices; ++i)
        {
            b = h->d[i].vis_block_cpu[!i_active];
            if (oskar_vis_block_has_cross_correlations(b))
                oskar_mem_add(xc0, xc0, oskar_vis_block_cross_correlations(b),
                        oskar_mem_length(xc0), status);
            if (oskar_vis_block_has_auto_correlations(b))
                oskar_mem_add(ac0, ac0, oskar_vis_block_auto_correlations(b),
                        oskar_mem_length(ac0), status);
        }
    }

    /* Calculate baseline uvw coordinates for the block. */
    if (oskar_vis_block_has_cross_correlations(b0))
    {
        const oskar_Mem *x, *y, *z;
        x = oskar_telescope_station_measured_x_offset_ecef_metres_const(h->tel);
        y = oskar_telescope_station_measured_y_offset_ecef_metres_const(h->tel);
        z = oskar_telescope_station_measured_z_offset_ecef_metres_const(h->tel);
        oskar_convert_ecef_to_baseline_uvw(
                oskar_telescope_num_stations(h->tel), x, y, z,
                oskar_telescope_phase_centre_ra_rad(h->tel),
                oskar_telescope_phase_centre_dec_rad(h->tel),
                oskar_vis_block_num_times(b0),
                oskar_vis_header_time_start_mjd_utc(h->header),
                oskar_vis_header_time_inc_sec(h->header) / 86400.0,
                oskar_vis_block_start_time_index(b0),
                oskar_vis_block_baseline_uu_metres(b0),
                oskar_vis_block_baseline_vv_metres(b0),
                oskar_vis_block_baseline_ww_metres(b0), h->temp, status);
    }

    /* Add uncorrelated system noise to the combined visibilities. */
    if (!h->coords_only)
    {
        oskar_vis_block_add_system_noise(b0, h->header, h->tel,
                block_index, h->temp, status);
    }

    /* Return a pointer to the block. */
    return b0;
}
コード例 #2
0
ファイル: oskar_vis_block_lib.c プロジェクト: OxfordSKA/OSKAR
static PyObject* cross_correlations(PyObject* self, PyObject* args)
{
    oskar_VisBlock* h = 0;
    oskar_Mem* m = 0;
    PyObject *capsule = 0;
    PyArrayObject *array = 0;
    npy_intp dims[4];
    if (!PyArg_ParseTuple(args, "O", &capsule)) return 0;
    if (!(h = (oskar_VisBlock*) get_handle(capsule, name))) return 0;

    /* Check that cross-correlations exist. */
    if (!oskar_vis_block_has_cross_correlations(h))
    {
        PyErr_SetString(PyExc_RuntimeError, "No cross-correlations in block.");
        return 0;
    }

    /* Return an array reference to Python. */
    m = oskar_vis_block_cross_correlations(h);
    dims[0] = oskar_vis_block_num_times(h);
    dims[1] = oskar_vis_block_num_channels(h);
    dims[2] = oskar_vis_block_num_baselines(h);
    dims[3] = oskar_vis_block_num_pols(h);
    array = (PyArrayObject*)PyArray_SimpleNewFromData(4, dims,
            (oskar_mem_is_double(m) ? NPY_CDOUBLE : NPY_CFLOAT),
            oskar_mem_void(m));
    return Py_BuildValue("N", array); /* Don't increment refcount. */
}
コード例 #3
0
static void sim_baselines(oskar_Simulator* h, DeviceData* d, oskar_Sky* sky,
        int channel_index_block, int time_index_block,
        int time_index_simulation, int* status)
{
    int num_baselines, num_stations, num_src, num_times_block, num_channels;
    double dt_dump_days, t_start, t_dump, gast, frequency, ra0, dec0;
    const oskar_Mem *x, *y, *z;
    oskar_Mem* alias = 0;

    /* Get dimensions. */
    num_baselines   = oskar_telescope_num_baselines(d->tel);
    num_stations    = oskar_telescope_num_stations(d->tel);
    num_src         = oskar_sky_num_sources(sky);
    num_times_block = oskar_vis_block_num_times(d->vis_block);
    num_channels    = oskar_vis_block_num_channels(d->vis_block);

    /* Return if there are no sources in the chunk,
     * or if block time index requested is outside the valid range. */
    if (num_src == 0 || time_index_block >= num_times_block) return;

    /* Get the time and frequency of the visibility slice being simulated. */
    dt_dump_days = h->time_inc_sec / 86400.0;
    t_start = h->time_start_mjd_utc;
    t_dump = t_start + dt_dump_days * (time_index_simulation + 0.5);
    gast = oskar_convert_mjd_to_gast_fast(t_dump);
    frequency = h->freq_start_hz + channel_index_block * h->freq_inc_hz;

    /* Scale source fluxes with spectral index and rotation measure. */
    oskar_sky_scale_flux_with_frequency(sky, frequency, status);

    /* Evaluate station u,v,w coordinates. */
    ra0 = oskar_telescope_phase_centre_ra_rad(d->tel);
    dec0 = oskar_telescope_phase_centre_dec_rad(d->tel);
    x = oskar_telescope_station_true_x_offset_ecef_metres_const(d->tel);
    y = oskar_telescope_station_true_y_offset_ecef_metres_const(d->tel);
    z = oskar_telescope_station_true_z_offset_ecef_metres_const(d->tel);
    oskar_convert_ecef_to_station_uvw(num_stations, x, y, z, ra0, dec0, gast,
            d->u, d->v, d->w, status);

    /* Set dimensions of Jones matrices. */
    if (d->R)
        oskar_jones_set_size(d->R, num_stations, num_src, status);
    if (d->Z)
        oskar_jones_set_size(d->Z, num_stations, num_src, status);
    oskar_jones_set_size(d->J, num_stations, num_src, status);
    oskar_jones_set_size(d->E, num_stations, num_src, status);
    oskar_jones_set_size(d->K, num_stations, num_src, status);

    /* Evaluate station beam (Jones E: may be matrix). */
    oskar_timer_resume(d->tmr_E);
    oskar_evaluate_jones_E(d->E, num_src, OSKAR_RELATIVE_DIRECTIONS,
            oskar_sky_l(sky), oskar_sky_m(sky), oskar_sky_n(sky), d->tel,
            gast, frequency, d->station_work, time_index_simulation, status);
    oskar_timer_pause(d->tmr_E);

#if 0
    /* Evaluate ionospheric phase (Jones Z: scalar) and join with Jones E.
     * NOTE this is currently only a CPU implementation. */
    if (d->Z)
    {
        oskar_evaluate_jones_Z(d->Z, num_src, sky, d->tel,
                &settings->ionosphere, gast, frequency, &(d->workJonesZ),
                status);
        oskar_timer_resume(d->tmr_join);
        oskar_jones_join(d->E, d->Z, d->E, status);
        oskar_timer_pause(d->tmr_join);
    }
#endif

    /* Evaluate parallactic angle (Jones R: matrix), and join with Jones Z*E.
     * TODO Move this into station beam evaluation instead. */
    if (d->R)
    {
        oskar_timer_resume(d->tmr_E);
        oskar_evaluate_jones_R(d->R, num_src, oskar_sky_ra_rad_const(sky),
                oskar_sky_dec_rad_const(sky), d->tel, gast, status);
        oskar_timer_pause(d->tmr_E);
        oskar_timer_resume(d->tmr_join);
        oskar_jones_join(d->R, d->E, d->R, status);
        oskar_timer_pause(d->tmr_join);
    }

    /* Evaluate interferometer phase (Jones K: scalar). */
    oskar_timer_resume(d->tmr_K);
    oskar_evaluate_jones_K(d->K, num_src, oskar_sky_l_const(sky),
            oskar_sky_m_const(sky), oskar_sky_n_const(sky), d->u, d->v, d->w,
            frequency, oskar_sky_I_const(sky),
            h->source_min_jy, h->source_max_jy, status);
    oskar_timer_pause(d->tmr_K);

    /* Join Jones K with Jones Z*E. */
    oskar_timer_resume(d->tmr_join);
    oskar_jones_join(d->J, d->K, d->R ? d->R : d->E, status);
    oskar_timer_pause(d->tmr_join);

    /* Create alias for auto/cross-correlations. */
    oskar_timer_resume(d->tmr_correlate);
    alias = oskar_mem_create_alias(0, 0, 0, status);

    /* Auto-correlate for this time and channel. */
    if (oskar_vis_block_has_auto_correlations(d->vis_block))
    {
        oskar_mem_set_alias(alias,
                oskar_vis_block_auto_correlations(d->vis_block),
                num_stations *
                (num_channels * time_index_block + channel_index_block),
                num_stations, status);
        oskar_auto_correlate(alias, num_src, d->J, sky, status);
    }

    /* Cross-correlate for this time and channel. */
    if (oskar_vis_block_has_cross_correlations(d->vis_block))
    {
        oskar_mem_set_alias(alias,
                oskar_vis_block_cross_correlations(d->vis_block),
                num_baselines *
                (num_channels * time_index_block + channel_index_block),
                num_baselines, status);
        oskar_cross_correlate(alias, num_src, d->J, sky, d->tel,
                d->u, d->v, d->w, gast, frequency, status);
    }

    /* Free alias for auto/cross-correlations. */
    oskar_mem_free(alias, status);
    oskar_timer_pause(d->tmr_correlate);
}