Observation Simulations

>>> from nenupy.astro.target import FixedTarget
>>> from nenupy.astro.skymodel import HpxGSM
>>> from nenupy.instru import NenuFAR

>>> from astropy.time import Time, TimeDelta
>>> import astropy.units as u
>>> import numpy as np

Time profile

>>> vira = FixedTarget.from_name("Vir A")

>>> vira_transit = vira.next_meridian_transit(Time("2021-01-01 00:00:00"))
>>> vira_transit
<Time object: scale='utc' format='iso' value=2021-01-01 05:38:42.551>
>>> dt = TimeDelta(2*60, format="sec")
>>> times = vira_transit - TimeDelta(1800, format="sec") + np.arange(31)*dt

>>> vira_transit_pointing = Pointing.target_transit(
        target=vira,
        t_min=Time("2021-01-01 00:00:00"),
        duration=TimeDelta(7200, format="sec"),
        azimuth=180*u.deg
    )
>>> analog_pointing = Pointing.target_tracking(
        target=vira,
        time=times,
        duration=dt,
    )
>>> whole_sky = HpxSky(
        resolution=0.5*u.deg,
        frequency=50*u.MHz,
        polarization=Polarization.NW,
        time=times
    )
>>> nenufar = NenuFAR()
>>> beam = nenufar.beam(
        sky=whole_sky,
        pointing=vira_transit_pointing,
        analog_pointing=analog_pointing
    )

>>> skymodel = HpxGSM.shaped_like(beam)

>>> sky_through_beam = beam * skymodel
>>> print(sky_through_beam)
<class 'nenupy.astro.sky.HpxSky'> instance
    value: (12, 1, 1, 196608)
        * time: (12,)
        * frequency: (1,)
        * polarization: (1,)
        * coordinates: (196608,)

>>> profile = np.nanmean(sky_through_beam.value, axis=(1, 2, 3))

>>> plt.plot(times.datetime, 10*np.log10(t_profile))
>>> plt.ylabel("Amplitude (dB)")
>>> plt.xlabel(f"Time (since {times[0].isot})")
>>> plt.title(f"Vir A transit simulation ({beam.frequency[0]})")

Blbla.