py21cmsense.observatory.Observatory

class py21cmsense.observatory.Observatory(*, antpos, beam, latitude=0, Trcv)

A class defining an interferometric Observatory and its properties.

Parameters

• antpos (array) – An array with shape (Nants, 3) specifying the positions of the antennas. These should be in the ENU (East-North-Up) frame, relative to a central location given by latitude. If not a Quantity, units are assumed to be meters.

• beam (PrimaryBeam instance) – A beam, assumed to be homogeneous across antennas.

• latitude (float or Quantity, optional) – Latitude of the array center. If a float, assumed to be in radians. Note that longitude is not required, as we assume an isotropic sky.

• Trcv (float or Quantity) – Receiver temperature, assumed to be in mK unless otherwise defined.

Methods

__init__(self, \*, antpos, beam[, latitude])	Initialize self.
beamgridder(xcen, ycen, uvgrid, n)	A function for updating a uvgrid with a baseline group
clone(self, \*\*kwargs)	Return a clone of this instance, but change kwargs
from_uvdata(uvdata, beam)	Instantiate an Observatory from a pyuvdata.UVData object or compatible file
from_yaml(yaml_file)	Instantiate an Observatory from a compatible YAML config file.
get_redundant_baselines(self[, bl_min, …])	Determine all baseline groups.
grid_baselines(self, integration_time[, …])	Grid baselines onto a pre-determined uvgrid, accounting for earth rotation.
grid_baselines_coherent(self, \*\*kwargs)	Produce a UV grid of gridded baselines, where different baseline groups are averaged coherently if they fall into the same UV bin.
grid_baselines_incoherent(self, \*\*kwargs)	Produce a UV grid of gridded baselines, where different baseline groups are averaged incoherently if they fall into the same UV bin.
longest_used_baseline(self[, bl_max])	Determine the maximum baseline length kept in the array
projected_baselines(self[, time_offset])	The projected baseline lengths (in wavelengths) phased to a point that has rotated off zenith by some time_offset.
time_offsets_from_obs_int_time(self, …[, …])	Compute a list of time offsets within an LST-bin (i.e.
ugrid(self[, bl_max])	Generate a uv grid out to the maximum used baseline smaller than the given bl_max.

Attributes

baseline_lengths	Lengths of baselines in units of wavelengths, shape (Nant, Nant)
baselines_metres	The raw baseline distances in metres for every pair of antennas (shape (Nant, Nant, 3)).
frequency	Central frequency of the observation
longest_baseline	Longest baseline in units of wavelengths
metres_to_wavelengths	Conversion factor for converting a quantity in m to wavelengths at the fiducial frequency of the observation
n_antennas	Number of antennas in the array
observation_duration	The time it takes for the sky to drift through the FWHM
shortest_baseline	Shortest baseline in units of wavelengths