Source code for pyuvdata.telescopes

# -*- mode: python; coding: utf-8 -*-
# Copyright (c) 2018 Radio Astronomy Software Group
# Licensed under the 2-clause BSD License

"""Telescope information and known telescope list."""
import numpy as np
from astropy.coordinates import Angle

from . import uvbase
from . import parameter as uvp

__all__ = ["Telescope", "known_telescopes", "get_telescope"]

# center_xyz is the location of the telescope in ITRF (earth-centered frame)
    "PAPER": {
        "center_xyz": None,
        "latitude": Angle("-30d43m17.5s").radian,
        "longitude": Angle("21d25m41.9s").radian,
        "altitude": 1073.0,
        "citation": (
            "value taken from capo/cals/, "
            "comment reads KAT/SA  (GPS), altitude from"
    "HERA": {
        "center_xyz": None,
        "latitude": Angle("-30.72152612068925d").radian,
        "longitude": Angle("21.42830382686301d").radian,
        "altitude": 1051.69,
        "diameters": 14.0,
        "citation": (
            "value taken from hera_mc script "
            "(using hera_cm_db_updates under the hood.)"
    "MWA": {
        "center_xyz": None,
        "latitude": Angle("-26d42m11.94986s").radian,
        "longitude": Angle("116d40m14.93485s").radian,
        "altitude": 377.827,
        "citation": "Tingay et al., 2013",
    "SMA": {
        "center_xyz": None,
        "latitude": Angle("19d49m27.13895s").radian,
        "longitude": Angle("-155d28m39.08279s").radian,
        "altitude": 4083.948144,
        "citation": "Ho, P. T. P., Moran, J. M., & Lo, K. Y. 2004, ApJL, 616, L1",

[docs]class Telescope(uvbase.UVBase): """ A class for defining a telescope for use with UVData objects. Attributes ---------- citation : str text giving source of telescope information telescope_name : UVParameter of str name of the telescope telescope_location : UVParameter of array_like telescope location xyz coordinates in ITRF (earth-centered frame). antenna_diameters : UVParameter of float Optional, antenna diameters in meters. Used by CASA to construct a default beam if no beam is supplied. """ def __init__(self): """Create a new Telescope object.""" # add the UVParameters to the class # use the same names as in UVData so they can be automatically set self.citation = None self._telescope_name = uvp.UVParameter( "telescope_name", description="name of telescope " "(string)", form="str" ) desc = ( "telescope location: xyz in ITRF (earth-centered frame). " "Can also be set using telescope_location_lat_lon_alt or " "telescope_location_lat_lon_alt_degrees properties" ) self._telescope_location = uvp.LocationParameter( "telescope_location", description=desc, acceptable_range=(6.35e6, 6.39e6), tols=1e-3, ) desc = ( "Antenna diameters in meters. Used by CASA to " "construct a default beam if no beam is supplied." ) self._antenna_diameters = uvp.UVParameter( "antenna_diameters", required=False, description=desc, expected_type=np.float, tols=1e-3, # 1 mm ) # possibly add in future versions: # Antenna positions (but what about reconfigurable/growing telescopes?) super(Telescope, self).__init__()
[docs]def known_telescopes(): """ Get list of known telescopes. Returns ------- list of str List of known telescope names. """ return list(KNOWN_TELESCOPES.keys())
[docs]def get_telescope(telescope_name, telescope_dict_in=None): """ Get Telescope object for a telescope in telescope_dict. Parameters ---------- telescope_name : str Name of a telescope telescope_dict_in: dict telescope info dict. Default is None, meaning use KNOWN_TELESCOPES (other values are only used for testing) Returns ------- Telescope object The Telescope object associated with telescope_name. """ if telescope_dict_in is None: telescope_dict_in = KNOWN_TELESCOPES telescope_list = list(telescope_dict_in.keys()) uc_telescope_list = [item.upper() for item in telescope_list] if telescope_name.upper() in uc_telescope_list: telescope_index = uc_telescope_list.index(telescope_name.upper()) telescope_dict = telescope_dict_in[telescope_list[telescope_index]] obj = Telescope() obj.citation = telescope_dict["citation"] obj.telescope_name = telescope_list[telescope_index] if telescope_dict["center_xyz"] is not None: obj.telescope_location = telescope_dict["center_xyz"] else: if ( telescope_dict["latitude"] is None or telescope_dict["longitude"] is None or telescope_dict["altitude"] is None ): raise ValueError( "either the center_xyz or the " "latitude, longitude and altitude of the " "telescope must be specified" ) obj.telescope_location_lat_lon_alt = ( telescope_dict["latitude"], telescope_dict["longitude"], telescope_dict["altitude"], ) obj.check(run_check_acceptability=True) if "diameters" in telescope_dict.keys(): obj.antenna_diameters = telescope_dict["diameters"] else: # no telescope matching this name return False return obj