Ejemplo n.º 1
0
def test_phasing_funcs():
    # these tests are based on a notebook where I tested against the mwa_tools phasing code
    ra_hrs = 12.1
    dec_degs = -42.3
    mjd = 55780.1

    array_center_xyz = np.array([-2559454.08, 5095372.14, -2849057.18])
    lat_lon_alt = uvutils.LatLonAlt_from_XYZ(array_center_xyz)

    obs_time = Time(mjd,
                    format='mjd',
                    location=(lat_lon_alt[1], lat_lon_alt[0]))

    icrs_coord = SkyCoord(ra=Angle(ra_hrs, unit='hr'),
                          dec=Angle(dec_degs, unit='deg'),
                          obstime=obs_time)
    gcrs_coord = icrs_coord.transform_to('gcrs')

    # in east/north/up frame (relative to array center) in meters: (Nants, 3)
    ants_enu = np.array([-101.94, 0156.41, 0001.24])

    ant_xyz_abs = uvutils.ECEF_from_ENU(ants_enu, lat_lon_alt[0],
                                        lat_lon_alt[1], lat_lon_alt[2])
    ant_xyz_rel_itrs = ant_xyz_abs - array_center_xyz
    ant_xyz_rel_rot = uvutils.rotECEF_from_ECEF(ant_xyz_rel_itrs,
                                                lat_lon_alt[1])

    array_center_coord = SkyCoord(x=array_center_xyz[0] * units.m,
                                  y=array_center_xyz[1] * units.m,
                                  z=array_center_xyz[2] * units.m,
                                  frame='itrs',
                                  obstime=obs_time)

    itrs_coord = SkyCoord(x=ant_xyz_abs[0] * units.m,
                          y=ant_xyz_abs[1] * units.m,
                          z=ant_xyz_abs[2] * units.m,
                          frame='itrs',
                          obstime=obs_time)

    gcrs_array_center = array_center_coord.transform_to('gcrs')
    gcrs_from_itrs_coord = itrs_coord.transform_to('gcrs')

    gcrs_rel = (gcrs_from_itrs_coord.cartesian -
                gcrs_array_center.cartesian).get_xyz().T

    gcrs_uvw = uvutils.phase_uvw(gcrs_coord.ra.rad, gcrs_coord.dec.rad,
                                 gcrs_rel.value)

    mwa_tools_calcuvw_u = -97.122828
    mwa_tools_calcuvw_v = 50.388281
    mwa_tools_calcuvw_w = -151.27976

    assert np.allclose(gcrs_uvw[0, 0], mwa_tools_calcuvw_u, atol=1e-3)
    assert np.allclose(gcrs_uvw[0, 1], mwa_tools_calcuvw_v, atol=1e-3)
    assert np.allclose(gcrs_uvw[0, 2], mwa_tools_calcuvw_w, atol=1e-3)

    # also test unphasing
    temp2 = uvutils.unphase_uvw(gcrs_coord.ra.rad, gcrs_coord.dec.rad,
                                np.squeeze(gcrs_uvw))
    assert np.allclose(gcrs_rel.value, temp2)
Ejemplo n.º 2
0
def test_mwa_ecef_conversion():
    '''
    Test based on comparing the antenna locations in a Cotter uvfits file to
    the antenna locations in MWA_tools.
    '''

    test_data_file = os.path.join(DATA_PATH, 'mwa128_ant_layouts.npz')
    f = np.load(test_data_file)

    # From the STABXYZ table in a cotter-generated uvfits file, obsid = 1066666832
    xyz = f['stabxyz']
    # From the East/North/Height columns in a cotter-generated metafits file, obsid = 1066666832
    enh = f['ENH']
    # From a text file antenna_locations.txt in MWA_Tools/scripts
    txt_topo = f['txt_topo']

    # From the unphased uvw coordinates of obsid 1066666832, positions relative to antenna 0
    # these aren't used in the current test, but are interesting and might help with phasing diagnosis in the future
    uvw_topo = f['uvw_topo']
    # Sky coordinates are flipped for uvw derived values
    uvw_topo = -uvw_topo
    uvw_topo += txt_topo[0]

    # transpose these arrays to get them into the right shape
    txt_topo = txt_topo.T
    uvw_topo = uvw_topo.T
    enh = enh.T

    # ARRAYX, ARRAYY, ARRAYZ in ECEF frame from Cotter file
    arrcent = f['arrcent']
    lat, lon, alt = uvutils.LatLonAlt_from_XYZ(arrcent)

    # The STABXYZ coordinates are defined with X through the local meridian,
    # so rotate back to the prime meridian
    new_xyz = uvutils.ECEF_from_rotECEF(xyz.T, lon)
    # add in array center to get real ECEF
    ecef_xyz = new_xyz + arrcent

    enu = uvutils.ENU_from_ECEF(ecef_xyz.T, lat, lon, alt)

    nt.assert_true(np.allclose(enu, enh))

    # test other direction of ECEF rotation
    rot_xyz = uvutils.rotECEF_from_ECEF(new_xyz, lon)
    nt.assert_true(np.allclose(rot_xyz.T, xyz))
Ejemplo n.º 3
0
                                        station_types=geo.station_types)
            fnd = fnd_list[0]
            lat = fnd.lat
            lon = fnd.lon
            alt = fnd.elevation

            ant_nums.append(ant_number)
            longitudes.append(lon)
            latitudes.append(lat)
            elevations.append(alt)

# convert to ecef (in meters)
ecef_positions = uvutils.XYZ_from_LatLonAlt(
    np.array(latitudes) * np.pi / 180.,
    np.array(longitudes) * np.pi / 180., elevations)
rotecef_positions = uvutils.rotECEF_from_ECEF(ecef_positions.T,
                                              cofa_loc.lon * np.pi / 180.)

# make an array of antenna positions in the form miriad is expecting
c_ns = const.c.to('m/ns').value
nants = max(ant_nums) + 1
antpos = np.zeros([nants, 3])
for i, ant in enumerate(ant_nums):
    antpos[ant, :] = rotecef_positions[i, :] / c_ns

# make an aa object
freqs = np.array([0.15])
beam = aipy.phs.Beam(freqs)
ants = [aipy.phs.Antenna(a[0], a[1], a[2], beam) for a in antpos]
aa = aipy.phs.AntennaArray(ants=ants, location=location)

# loop over miriad files
Ejemplo n.º 4
0
def test_miriad_location_handling():
    uv_in = UVData()
    uv_out = UVData()
    miriad_file = os.path.join(DATA_PATH, 'zen.2456865.60537.xy.uvcRREAA')
    testdir = os.path.join(DATA_PATH, 'test/')
    testfile = os.path.join(DATA_PATH, 'test/outtest_miriad.uv')
    aipy_uv = aipy.miriad.UV(miriad_file)

    if os.path.exists(testfile):
        shutil.rmtree(testfile)

    # Test for using antenna positions to get telescope position
    uvtest.checkWarnings(
        uv_in.read_miriad, [miriad_file],
        message=[
            'Altitude is not present in Miriad file, using known '
            'location values for PAPER.'
        ])
    # extract antenna positions and rotate them for miriad
    nants = aipy_uv['nants']
    rel_ecef_antpos = np.zeros((nants, 3), dtype=uv_in.antenna_positions.dtype)
    for ai, num in enumerate(uv_in.antenna_numbers):
        rel_ecef_antpos[num, :] = uv_in.antenna_positions[ai, :]

    # find zeros so antpos can be zeroed there too
    antpos_length = np.sqrt(np.sum(np.abs(rel_ecef_antpos)**2, axis=1))

    ecef_antpos = rel_ecef_antpos + uv_in.telescope_location
    longitude = uv_in.telescope_location_lat_lon_alt[1]
    antpos = uvutils.rotECEF_from_ECEF(ecef_antpos, longitude)

    # zero out bad locations (these are checked on read)
    antpos[np.where(antpos_length == 0), :] = [0, 0, 0]
    antpos = antpos.T.flatten() / const.c.to('m/ns').value

    # make new file
    aipy_uv2 = aipy.miriad.UV(testfile, status='new')
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions
    aipy_uv2.init_from_uv(aipy_uv,
                          override={
                              'telescop': 'foo',
                              'antpos': antpos
                          })
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    # close file properly
    del (aipy_uv2)

    uvtest.checkWarnings(
        uv_out.read_miriad, [testfile],
        nwarnings=3,
        message=[
            'Altitude is not present in Miriad file, and '
            'telescope foo is not in known_telescopes. '
            'Telescope location will be set using antenna positions.',
            'Telescope location is not set, but antenna '
            'positions are present. Mean antenna latitude '
            'and longitude values match file values, so '
            'telescope_position will be set using the mean '
            'of the antenna altitudes',
            'Telescope foo is not in known_telescopes.'
        ])

    # Test for handling when antenna positions have a different mean latitude than the file latitude
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy.miriad.UV(miriad_file)
    aipy_uv2 = aipy.miriad.UV(testfile, status='new')
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file latitude
    new_lat = aipy_uv['latitud'] * 1.5
    aipy_uv2.init_from_uv(aipy_uv,
                          override={
                              'telescop': 'foo',
                              'antpos': antpos,
                              'latitud': new_lat
                          })
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    # close file properly
    del (aipy_uv2)

    uvtest.checkWarnings(
        uv_out.read_miriad, [testfile],
        nwarnings=3,
        message=[
            'Altitude is not present in Miriad file, and '
            'telescope foo is not in known_telescopes. '
            'Telescope location will be set using antenna positions.',
            'Telescope location is set at sealevel at the '
            'file lat/lon coordinates. Antenna positions '
            'are present, but the mean antenna latitude '
            'value does not match', 'Telescope foo is not in known_telescopes.'
        ])

    # Test for handling when antenna positions have a different mean longitude than the file longitude
    # this is harder because of the rotation that's done on the antenna positions
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy.miriad.UV(miriad_file)
    aipy_uv2 = aipy.miriad.UV(testfile, status='new')
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file longitude
    new_lon = aipy_uv['longitu'] + np.pi
    aipy_uv2.init_from_uv(aipy_uv,
                          override={
                              'telescop': 'foo',
                              'antpos': antpos,
                              'longitu': new_lon
                          })
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    # close file properly
    del (aipy_uv2)

    uvtest.checkWarnings(
        uv_out.read_miriad, [testfile],
        nwarnings=3,
        message=[
            'Altitude is not present in Miriad file, and '
            'telescope foo is not in known_telescopes. '
            'Telescope location will be set using antenna positions.',
            'Telescope location is set at sealevel at the '
            'file lat/lon coordinates. Antenna positions '
            'are present, but the mean antenna longitude '
            'value does not match', 'Telescope foo is not in known_telescopes.'
        ])

    # Test for handling when antenna positions have a different mean longitude &
    # latitude than the file longitude
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy.miriad.UV(miriad_file)
    aipy_uv2 = aipy.miriad.UV(testfile, status='new')
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file latitude and longitude
    aipy_uv2.init_from_uv(aipy_uv,
                          override={
                              'telescop': 'foo',
                              'antpos': antpos,
                              'latitud': new_lat,
                              'longitu': new_lon
                          })
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    # close file properly
    del (aipy_uv2)

    uvtest.checkWarnings(
        uv_out.read_miriad, [testfile],
        nwarnings=3,
        message=[
            'Altitude is not present in Miriad file, and '
            'telescope foo is not in known_telescopes. '
            'Telescope location will be set using antenna positions.',
            'Telescope location is set at sealevel at the '
            'file lat/lon coordinates. Antenna positions '
            'are present, but the mean antenna latitude and '
            'longitude values do not match',
            'Telescope foo is not in known_telescopes.'
        ])

    # Test for handling when antenna positions are far enough apart to make the
    # mean position inside the earth

    good_antpos = np.where(antpos_length > 0)[0]
    rot_ants = good_antpos[:len(good_antpos) / 2]
    rot_antpos = uvutils.rotECEF_from_ECEF(ecef_antpos[rot_ants, :],
                                           longitude + np.pi)
    modified_antpos = uvutils.rotECEF_from_ECEF(ecef_antpos, longitude)
    modified_antpos[rot_ants, :] = rot_antpos
    # zero out bad locations (these are checked on read)
    modified_antpos[np.where(antpos_length == 0), :] = [0, 0, 0]
    modified_antpos = modified_antpos.T.flatten() / const.c.to('m/ns').value

    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy.miriad.UV(miriad_file)
    aipy_uv2 = aipy.miriad.UV(testfile, status='new')
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use modified absolute antenna positions
    aipy_uv2.init_from_uv(aipy_uv,
                          override={
                              'telescop': 'foo',
                              'antpos': modified_antpos
                          })
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    # close file properly
    del (aipy_uv2)

    uvtest.checkWarnings(
        uv_out.read_miriad, [testfile],
        nwarnings=3,
        message=[
            'Altitude is not present in Miriad file, and '
            'telescope foo is not in known_telescopes. '
            'Telescope location will be set using antenna positions.',
            'Telescope location is set at sealevel at the '
            'file lat/lon coordinates. Antenna positions '
            'are present, but the mean antenna position '
            'does not give a telescope_location on the '
            'surface of the earth.',
            'Telescope foo is not in known_telescopes.'
        ])
Ejemplo n.º 5
0
def test_miriad_location_handling(paper_miriad_master, tmp_path):
    uv_in = paper_miriad_master
    uv_out = UVData()

    testfile = str(tmp_path / "outtest_miriad.uv")
    aipy_uv = aipy_extracts.UV(paper_miriad_file)

    if os.path.exists(testfile):
        shutil.rmtree(testfile)

    # Test for using antenna positions to get telescope position
    # extract antenna positions and rotate them for miriad
    nants = aipy_uv["nants"]
    rel_ecef_antpos = np.zeros((nants, 3), dtype=uv_in.antenna_positions.dtype)
    for ai, num in enumerate(uv_in.antenna_numbers):
        rel_ecef_antpos[num, :] = uv_in.antenna_positions[ai, :]

    # find zeros so antpos can be zeroed there too
    antpos_length = np.sqrt(np.sum(np.abs(rel_ecef_antpos) ** 2, axis=1))

    ecef_antpos = rel_ecef_antpos + uv_in.telescope_location
    longitude = uv_in.telescope_location_lat_lon_alt[1]
    antpos = uvutils.rotECEF_from_ECEF(ecef_antpos, longitude)

    # zero out bad locations (these are checked on read)
    antpos[np.where(antpos_length == 0), :] = [0, 0, 0]
    antpos = antpos.T.flatten() / const.c.to("m/ns").value

    # make new file
    aipy_uv2 = aipy_extracts.UV(testfile, status="new")
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions
    aipy_uv2.init_from_uv(aipy_uv, override={"telescop": "foo", "antpos": antpos})
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    aipy_uv2.close()

    with uvtest.check_warnings(
        UserWarning,
        [
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Altitude is not present ",
            "Telescope location is not set, but antenna "
            "positions are present. Mean antenna latitude "
            "and longitude values match file values, so "
            "telescope_position will be set using the mean "
            "of the antenna altitudes",
            "Telescope foo is not in known_telescopes.",
            "The uvw_array does not match the expected values given the antenna "
            "positions.",
        ],
    ):
        uv_out.read(testfile)

    # Test for handling when antenna positions have a different mean latitude
    # than the file latitude
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy_extracts.UV(paper_miriad_file)
    aipy_uv2 = aipy_extracts.UV(testfile, status="new")
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file latitude
    new_lat = aipy_uv["latitud"] * 1.5
    aipy_uv2.init_from_uv(
        aipy_uv, override={"telescop": "foo", "antpos": antpos, "latitud": new_lat}
    )
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    aipy_uv2.close()

    with uvtest.check_warnings(
        UserWarning,
        [
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Telescope location is set at sealevel at the "
            "file lat/lon coordinates. Antenna positions "
            "are present, but the mean antenna latitude "
            "value does not match",
            "drift RA, Dec is off from lst, latitude by more than 1.0 deg",
            "Telescope foo is not in known_telescopes.",
            "The uvw_array does not match the expected values given the antenna "
            "positions.",
        ],
    ):
        uv_out.read(testfile)

    # Test for handling when antenna positions have a different mean longitude
    # than the file longitude
    # this is harder because of the rotation that's done on the antenna positions
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy_extracts.UV(paper_miriad_file)
    aipy_uv2 = aipy_extracts.UV(testfile, status="new")
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file longitude
    new_lon = aipy_uv["longitu"] + np.pi
    aipy_uv2.init_from_uv(
        aipy_uv, override={"telescop": "foo", "antpos": antpos, "longitu": new_lon}
    )
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    aipy_uv2.close()

    with uvtest.check_warnings(
        UserWarning,
        [
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Telescope location is set at sealevel at the "
            "file lat/lon coordinates. Antenna positions "
            "are present, but the mean antenna longitude "
            "value does not match",
            "drift RA, Dec is off from lst, latitude by more than 1.0 deg",
            "Telescope foo is not in known_telescopes.",
            "The uvw_array does not match the expected values given the antenna "
            "positions.",
        ],
    ):
        uv_out.read(testfile)

    # Test for handling when antenna positions have a different mean longitude &
    # latitude than the file longitude
    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy_extracts.UV(paper_miriad_file)
    aipy_uv2 = aipy_extracts.UV(testfile, status="new")
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use absolute antenna positions, change file latitude and longitude
    aipy_uv2.init_from_uv(
        aipy_uv,
        override={
            "telescop": "foo",
            "antpos": antpos,
            "latitud": new_lat,
            "longitu": new_lon,
        },
    )
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    aipy_uv2.close()

    with uvtest.check_warnings(
        UserWarning,
        [
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Telescope location is set at sealevel at the "
            "file lat/lon coordinates. Antenna positions "
            "are present, but the mean antenna latitude and "
            "longitude values do not match",
            "drift RA, Dec is off from lst, latitude by more than 1.0 deg",
            "Telescope foo is not in known_telescopes.",
            "The uvw_array does not match the expected values given the antenna "
            "positions.",
        ],
    ):
        uv_out.read(testfile)

    # Test for handling when antenna positions are far enough apart to make the
    # mean position inside the earth

    good_antpos = np.where(antpos_length > 0)[0]
    rot_ants = good_antpos[: len(good_antpos) // 2]
    rot_antpos = uvutils.rotECEF_from_ECEF(ecef_antpos[rot_ants, :], longitude + np.pi)
    modified_antpos = uvutils.rotECEF_from_ECEF(ecef_antpos, longitude)
    modified_antpos[rot_ants, :] = rot_antpos
    # zero out bad locations (these are checked on read)
    modified_antpos[np.where(antpos_length == 0), :] = [0, 0, 0]
    modified_antpos = modified_antpos.T.flatten() / const.c.to("m/ns").value

    # make new file
    if os.path.exists(testfile):
        shutil.rmtree(testfile)
    aipy_uv = aipy_extracts.UV(paper_miriad_file)
    aipy_uv2 = aipy_extracts.UV(testfile, status="new")
    # initialize headers from old file
    # change telescope name (so the position isn't set from known_telescopes)
    # and use modified absolute antenna positions
    aipy_uv2.init_from_uv(
        aipy_uv, override={"telescop": "foo", "antpos": modified_antpos}
    )
    # copy data from old file
    aipy_uv2.pipe(aipy_uv)
    aipy_uv2.close()

    with uvtest.check_warnings(
        UserWarning,
        [
            "Altitude is not present in Miriad file, and "
            "telescope foo is not in known_telescopes. "
            "Telescope location will be set using antenna positions.",
            "Altitude is not present ",
            "Telescope location is set at sealevel at the "
            "file lat/lon coordinates. Antenna positions "
            "are present, but the mean antenna position "
            "does not give a telescope_location on the "
            "surface of the earth.",
            "Telescope foo is not in known_telescopes.",
            "The uvw_array does not match the expected values given the antenna "
            "positions.",
        ],
    ):
        uv_out.read(testfile)

    # cleanup
    aipy_uv.close()
Ejemplo n.º 6
0
def get_aa_from_uv(uvd, freqs=[0.15]):
    '''
    Generate an AntennaArray object from a pyuvdata UVData object.

    This function creates an AntennaArray object from the metadata
    contained in a UVData object. It assumes that the antenna_positions
    array in the UVData object is in earth-centered, earth-fixed (ECEF)
    coordinates, relative to the center of the array, also given in
    ECEF coordinates. We must add these together, and then rotate so that
    the x-axis is aligned with the local meridian (rotECEF). rotECEF is the
    coordinate system for Antenna objects in the AntennaArray object (which
    inherits this behavior from MIRIAD). It is also expected that distances
    are given in nanoseconds, rather than meters, also because of the
    default behavior in MIRIAD.

    Arguments
    =================
    uvd: a pyuvdata UVData object containing the data.
    freqs (optional): list of frequencies to pass to aa object. Defaults to single frequency
        (150 MHz), suitable for computing redundancy and uvw info.

    Returns
    ====================
    aa: AntennaArray object that can be used to calculate redundancies from
       antenna positions.
    '''
    assert AIPY, "you need aipy to run this function"
    # center of array values from file
    cofa_lat, cofa_lon, cofa_alt = uvd.telescope_location_lat_lon_alt
    location = (cofa_lat, cofa_lon, cofa_alt)

    # get antenna positions from file
    antpos = {}
    for i, antnum in enumerate(uvd.antenna_numbers):
        # we need to add the CofA location to the relative coordinates
        pos = uvd.antenna_positions[i, :] + uvd.telescope_location
        # convert from meters to nanoseconds
        c_ns = const.c.to('m/ns').value
        pos = pos / c_ns

        # rotate from ECEF -> rotECEF
        rotECEF = uvutils.rotECEF_from_ECEF(pos, cofa_lon)

        # make a dict for parameter-setting purposes later
        antpos[antnum] = {'x': rotECEF[0], 'y': rotECEF[1], 'z': rotECEF[2]}

    # make antpos_ideal array
    nants = np.max(list(antpos.keys())) + 1
    antpos_ideal = np.zeros(shape=(nants, 3), dtype=float) - 1
    # unpack from dict -> numpy array
    for k in list(antpos.keys()):
        antpos_ideal[k, :] = np.array([antpos[k]['x'], antpos[k]['y'], antpos[k]['z']])
    freqs = np.asarray(freqs)
    # Make list of antennas.
    # These are values for a zenith-pointing antenna, with a dummy Gaussian beam.
    antennas = []
    for i in range(nants):
        beam = aipy.fit.Beam(freqs)
        phsoff = {'x': [0., 0.], 'y': [0., 0.]}
        amp = 1.
        amp = {'x': amp, 'y': amp}
        bp_r = [1.]
        bp_r = {'x': bp_r, 'y': bp_r}
        bp_i = [0., 0., 0.]
        bp_i = {'x': bp_i, 'y': bp_i}
        twist = 0.
        antennas.append(aipy.pol.Antenna(0., 0., 0., beam, phsoff=phsoff,
                                         amp=amp, bp_r=bp_r, bp_i=bp_i, pointing=(0., np.pi / 2, twist)))

    # Make the AntennaArray and set position parameters
    aa = AntennaArray(location, antennas, antpos_ideal=antpos_ideal)
    pos_prms = {}
    for i in list(antpos.keys()):
        pos_prms[str(i)] = antpos[i]
    aa.set_params(pos_prms)
    return aa