drift.telescope.gmrt

Functions

`beam_circular`(angpos, zenith, uv_diameter)	Beam pattern for a circular dish.
`jinc`(x)

Classes

`GmrtArray`([pointing])	A Telescope describing an interferometric array of dishes.
`GmrtUnpolarised`([pointing])	Unpolarised GMRT class.

class drift.telescope.gmrt.GmrtArray(pointing=0.0)

Bases: TransitTelescope

A Telescope describing an interferometric array of dishes.

gridu, gridv

Number of dishes in u and v directions.

Type:: integer

dish_width

Width of the dish in metres.

Type:: scalar

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

beamx(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

beamy(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 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).

class drift.telescope.gmrt.GmrtUnpolarised(pointing=0.0)

Bases: GmrtArray, SimpleUnpolarisedTelescope

Unpolarised GMRT class.

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).

drift.telescope.gmrt.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