コード例 #1
0
 def actualSetUp(self, nfreqwin=3, dospectral=True, dopol=False,
                 amp_errors=None, phase_errors=None, zerow=True):
     
     if amp_errors is None:
         amp_errors = {'T': 0.0, 'G': 0.1}
     if phase_errors is None:
         phase_errors = {'T': 1.0, 'G': 0.0}
     
     self.npixel = 512
     self.low = create_named_configuration('LOWBD2', rmax=750.0)
     self.freqwin = nfreqwin
     self.vis_list = list()
     self.ntimes = 1
     self.times = numpy.linspace(-3.0, +3.0, self.ntimes) * numpy.pi / 12.0
     self.frequency = numpy.linspace(0.8e8, 1.2e8, self.freqwin)
     
     if self.freqwin > 1:
         self.channelwidth = numpy.array(self.freqwin * [self.frequency[1] - self.frequency[0]])
     else:
         self.channelwidth = numpy.array([1e6])
     
     if dopol:
         self.vis_pol = PolarisationFrame('linear')
         self.image_pol = PolarisationFrame('stokesIQUV')
         f = numpy.array([100.0, 20.0, -10.0, 1.0])
     else:
         self.vis_pol = PolarisationFrame('stokesI')
         self.image_pol = PolarisationFrame('stokesI')
         f = numpy.array([100.0])
     
     if dospectral:
         flux = numpy.array([f * numpy.power(freq / 1e8, -0.7) for freq in self.frequency])
     else:
         flux = numpy.array([f])
     
     self.phasecentre = SkyCoord(ra=+180.0 * u.deg, dec=-60.0 * u.deg, frame='icrs', equinox='J2000')
     self.blockvis_list = [ingest_unittest_visibility(self.low,
                                                      [self.frequency[i]],
                                                      [self.channelwidth[i]],
                                                      self.times,
                                                      self.vis_pol,
                                                      self.phasecentre, block=True,
                                                      zerow=zerow)
                           for i in range(nfreqwin)]
     
     for v in self.blockvis_list:
         v.data['vis'][...] = 1.0 + 0.0j
     
     self.error_blockvis_list = [copy_visibility(v) for v in self.blockvis_list]
     gt = create_gaintable_from_blockvisibility(self.blockvis_list[0])
     gt = simulate_gaintable(gt, phase_error=0.1, amplitude_error=0.0, smooth_channels=1, leakage=0.0)
     self.error_blockvis_list = [apply_gaintable(self.error_blockvis_list[i], gt)
                                 for i in range(self.freqwin)]
     
     assert numpy.max(numpy.abs(self.error_blockvis_list[0].vis - self.blockvis_list[0].vis)) > 0.0
コード例 #2
0
    def corrupt_vis(vis, gt, **kwargs):
        if isinstance(vis, Visibility):
            bv = convert_visibility_to_blockvisibility(vis)
        else:
            bv = vis
        if gt is None:
            gt = create_gaintable_from_blockvisibility(bv, **kwargs)
            gt = simulate_gaintable(gt, **kwargs)
            bv = apply_gaintable(bv, gt)

        if isinstance(vis, Visibility):
            return convert_blockvisibility_to_visibility(bv)
        else:
            return bv
コード例 #3
0
 def actualSetUp(self, add_errors=False, nfreqwin=7, dospectral=True, dopol=False, zerow=True):
     
     self.npixel = 512
     self.low = create_named_configuration('LOWBD2', rmax=750.0)
     self.freqwin = nfreqwin
     self.vis_list = list()
     self.ntimes = 5
     self.times = numpy.linspace(-3.0, +3.0, self.ntimes) * numpy.pi / 12.0
     self.frequency = numpy.linspace(0.8e8, 1.2e8, self.freqwin)
     
     if self.freqwin > 1:
         self.channelwidth = numpy.array(self.freqwin * [self.frequency[1] - self.frequency[0]])
     else:
         self.channelwidth = numpy.array([1e6])
     
     if dopol:
         self.vis_pol = PolarisationFrame('linear')
         self.image_pol = PolarisationFrame('stokesIQUV')
         f = numpy.array([100.0, 20.0, -10.0, 1.0])
     else:
         self.vis_pol = PolarisationFrame('stokesI')
         self.image_pol = PolarisationFrame('stokesI')
         f = numpy.array([100.0])
     
     if dospectral:
         flux = numpy.array([f * numpy.power(freq / 1e8, -0.7) for freq in self.frequency])
     else:
         flux = numpy.array([f])
     
     self.phasecentre = SkyCoord(ra=+180.0 * u.deg, dec=-60.0 * u.deg, frame='icrs', equinox='J2000')
     self.blockvis_list = [ingest_unittest_visibility(self.low,
                                                      [self.frequency[i]],
                                                      [self.channelwidth[i]],
                                                      self.times,
                                                      self.vis_pol,
                                                      self.phasecentre, block=True,
                                                      zerow=zerow)
                           for i in range(nfreqwin)]
     
     self.vis_list = [convert_blockvisibility_to_visibility(bv) for bv in self.blockvis_list]
     
     self.model_imagelist = [
         create_unittest_model(self.vis_list[i], self.image_pol, npixel=self.npixel, cellsize=0.0005)
         for i in range(nfreqwin)]
     
     self.components_list = [create_unittest_components(self.model_imagelist[freqwin],
                                                        flux[freqwin, :][numpy.newaxis, :])
                             for freqwin, m in enumerate(self.model_imagelist)]
     
     self.blockvis_list = [
         predict_skycomponent_visibility(self.blockvis_list[freqwin], self.components_list[freqwin])
         for freqwin, _ in enumerate(self.blockvis_list)]
     
     self.model_imagelist = [insert_skycomponent(self.model_imagelist[freqwin], self.components_list[freqwin])
                             for freqwin in range(nfreqwin)]
     model = self.model_imagelist[0]
     self.cmodel = smooth_image(model)
     if self.persist:
         export_image_to_fits(model, '%s/test_imaging_serial_model.fits' % self.dir)
         export_image_to_fits(self.cmodel, '%s/test_imaging_serial_cmodel.fits' % self.dir)
     
     if add_errors:
         gt = create_gaintable_from_blockvisibility(self.blockvis_list[0])
         gt = simulate_gaintable(gt, phase_error=0.1, amplitude_error=0.0, smooth_channels=1,
                    leakage=0.0, seed=180555)
         self.blockvis_list = [apply_gaintable(self.blockvis_list[i], gt)
                               for i in range(self.freqwin)]
     
     self.vis_list = [convert_blockvisibility_to_visibility(bv) for bv in self.blockvis_list]
     
     self.model_imagelist = [
         create_unittest_model(self.vis_list[i], self.image_pol, npixel=self.npixel, cellsize=0.0005)
         for i in range(nfreqwin)]
コード例 #4
0
 def corrupt_vis(vis, gt, **kwargs):
     if gt is None:
         gt = create_gaintable_from_blockvisibility(vis, **kwargs)
         gt = simulate_gaintable(gt, **kwargs)
     return apply_gaintable(vis, gt)
コード例 #5
0
    def ingest_visibility(self,
                          freq=None,
                          chan_width=None,
                          times=None,
                          add_errors=False,
                          block=True,
                          bandpass=False):
        if freq is None:
            freq = [1e8]
        if chan_width is None:
            chan_width = [1e6]
        if times is None:
            times = (numpy.pi / 12.0) * numpy.linspace(-3.0, 3.0, 5)

        lowcore = create_named_configuration('LOWBD2', rmax=750.0)
        frequency = numpy.array(freq)
        channel_bandwidth = numpy.array(chan_width)

        phasecentre = SkyCoord(ra=+180.0 * u.deg,
                               dec=-60.0 * u.deg,
                               frame='icrs',
                               equinox='J2000')
        if block:
            vt = create_blockvisibility(
                lowcore,
                times,
                frequency,
                channel_bandwidth=channel_bandwidth,
                weight=1.0,
                phasecentre=phasecentre,
                polarisation_frame=PolarisationFrame("stokesI"))
        else:
            vt = create_visibility(
                lowcore,
                times,
                frequency,
                channel_bandwidth=channel_bandwidth,
                weight=1.0,
                phasecentre=phasecentre,
                polarisation_frame=PolarisationFrame("stokesI"))
        cellsize = 0.001
        model = create_image_from_visibility(
            vt,
            npixel=self.npixel,
            cellsize=cellsize,
            npol=1,
            frequency=frequency,
            phasecentre=phasecentre,
            polarisation_frame=PolarisationFrame("stokesI"))
        nchan = len(self.frequency)
        flux = numpy.array(nchan * [[100.0]])
        facets = 4

        rpix = model.wcs.wcs.crpix - 1.0
        spacing_pixels = self.npixel // facets
        centers = [-1.5, -0.5, 0.5, 1.5]
        comps = list()
        for iy in centers:
            for ix in centers:
                p = int(round(rpix[0] + ix * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[0]))), \
                    int(round(rpix[1] + iy * spacing_pixels * numpy.sign(model.wcs.wcs.cdelt[1])))
                sc = pixel_to_skycoord(p[0], p[1], model.wcs, origin=1)
                comp = create_skycomponent(
                    direction=sc,
                    flux=flux,
                    frequency=frequency,
                    polarisation_frame=PolarisationFrame("stokesI"))
                comps.append(comp)
        if block:
            predict_skycomponent_visibility(vt, comps)
        else:
            predict_skycomponent_visibility(vt, comps)
        insert_skycomponent(model, comps)
        self.comps = comps
        self.model = copy_image(model)
        self.empty_model = create_empty_image_like(model)
        export_image_to_fits(
            model, '%s/test_pipeline_functions_model.fits' % (self.dir))

        if add_errors:
            # These will be the same for all calls
            numpy.random.seed(180555)
            gt = create_gaintable_from_blockvisibility(vt)
            gt = simulate_gaintable(gt, phase_error=1.0, amplitude_error=0.0)
            vt = apply_gaintable(vt, gt)

            if bandpass:
                bgt = create_gaintable_from_blockvisibility(vt, timeslice=1e5)
                bgt = simulate_gaintable(bgt,
                                         phase_error=0.01,
                                         amplitude_error=0.01,
                                         smooth_channels=4)
                vt = apply_gaintable(vt, bgt)

        return vt