drift.telescope.focalplane

Functions

beam_circular(angpos, zenith, uv_diameter)

Beam pattern for a circular dish.

gaussian_beam(angpos, pointing, fwhm)

jinc(x)

Classes

FocalPlaneArray([latitude, longitude])

Initialise a telescope object.
class drift.telescope.focalplane.FocalPlaneArray(latitude=45, longitude=0, **kwargs)

Bases: UnpolarisedTelescope

Initialise a telescope object.

Parameters:

  • latitude (scalar) – Position on the Earths surface of the telescope (in degrees).

  • longitude (scalar) – Position on the Earths surface of the telescope (in degrees).

beam(feed, freq)

Beam for a particular feed.

Parameters:

  • feed (integer) – Index for the feed.

  • freq (integer) – Index for the frequency.

Returns:

beam – A Healpix map (of size self._nside) of the beam. Potentially complex.

Return type:

np.ndarray

property feedpositions

Feed positions (all zero in FPA).

property nfeed

The number of feeds.

property u_width

The approximate physical width (in the u-direction) of the dish/telescope etc, for calculating the maximum (l,m).

property v_width

The approximate physical length (in the v-direction) of the dish/telescope etc, for calculating the maximum (l,m).

drift.telescope.focalplane.beam_circular(angpos, zenith, uv_diameter)

Beam pattern for a circular dish.

Parameters:

  • angpos (np.ndarray) – Array of angular positions

  • zenith (np.ndarray) – Co-ordinates of the zenith.

  • uv_diameter (scalar) – Diameter of the dish (in units of wavelength).

Returns:

beam – Beam pattern at each position in angpos.

Return type:

np.ndarray