LOFAR conversion guide

from importlib.metadata import version
import os

try:
    import xradio

    print("XRADIO version", version("xradio"), "already installed.")
except ImportError as e:
    print(e)
    print("Installing XRADIO")

    os.system("pip install xradio")

    import xradio

    print("xradio version", version("xradio"), " installed.")

XRADIO version 1.1.3 already installed.

Download dataset

import toolviper

toolviper.utils.data.download(file="small_lofar.ms")

[2026-04-20 15:18:36,446]     INFO   toolviper:  Initializing download...
[2026-04-20 15:18:36,447]     INFO   toolviper:  File already exists: /Users/vdesouza/work/xradio/docs/source/measurement_set/guides/small_lofar.ms

Convert to Processing Set

from xradio.measurement_set import convert_msv2_to_processing_set

ms_file = "small_lofar.ms"
main_chunksize = {"frequency": 1, "time": 20}  # baseline, polarization
outfile = "small_lofar.ps.zarr"
convert_msv2_to_processing_set(
    in_file=ms_file,
    out_file=outfile,
    parallel_mode="none",
    persistence_mode='w',
    main_chunksize=main_chunksize,
)

[2026-04-20 15:18:36,738]     INFO   toolviper:  Updated partition scheme used: ['DATA_DESC_ID', 'OBS_MODE', 'OBSERVATION_ID']
[2026-04-20 15:18:36,739]     INFO   toolviper:  Number of partitions: 1
[2026-04-20 15:18:36,739]     INFO   toolviper:  OBSERVATION_ID [0], DDI [0], STATE [0], FIELD [0], SCAN [0], EPHEMERIS [None]
[2026-04-20 15:18:36,805]  WARNING   toolviper:  Source_id is -1. No source information will be included in the field_and_source_xds.

Processing Set

from xradio.measurement_set import open_processing_set

ps_xdt = open_processing_set(ps_store=outfile)
ps_xdt.xr_ps.summary()

	name	scan_intents	shape	execution_block_UID	polarization	scan_name	spw_name	spw_intents	field_name	source_name	line_name	field_coords	session_reference_UID	scheduling_block_UID	project_UID	start_frequency	end_frequency
0	small_lofar_0	[]	(5, 2775, 15, 4)	---	[XX, XY, YX, YY]	[0]	SB-349_0	[UNSPECIFIED]	[BEAM_4_0]	[Unknown]	[]	[fk5, 14h00m00.00s, 86d00m00.00s]	---	---	LC9_007	1.270615e+08	1.272324e+08

ms_xdt = ps_xdt["small_lofar_0"]
ms_xdt

<xarray.DataTree 'small_lofar_0'>
Group: /small_lofar_0
│   Dimensions:                     (time: 5, baseline_id: 2775, frequency: 15,
│                                    polarization: 4, uvw_label: 3)
│   Coordinates:
│     * time                        (time) float64 40B 1.52e+09 ... 1.52e+09
│       field_name                  (time) <U28 560B dask.array<chunksize=(5,), meta=np.ndarray>
│       scan_name                   (time) <U21 420B dask.array<chunksize=(5,), meta=np.ndarray>
│     * baseline_id                 (baseline_id) int64 22kB 0 1 2 ... 2773 2774
│       baseline_antenna1_name      (baseline_id) <U9 100kB dask.array<chunksize=(2775,), meta=np.ndarray>
│       baseline_antenna2_name      (baseline_id) <U9 100kB dask.array<chunksize=(2775,), meta=np.ndarray>
│     * frequency                   (frequency) float64 120B 1.271e+08 ... 1.272e+08
│     * polarization                (polarization) <U2 32B 'XX' 'XY' 'YX' 'YY'
│     * uvw_label                   (uvw_label) <U1 12B 'u' 'v' 'w'
│   Data variables:
│       EFFECTIVE_INTEGRATION_TIME  (time, baseline_id) float64 111kB dask.array<chunksize=(5, 2775), meta=np.ndarray>
│       FLAG                        (time, baseline_id, frequency, polarization) bool 832kB dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>
│       TIME_CENTROID               (time, baseline_id) float64 111kB dask.array<chunksize=(5, 2775), meta=np.ndarray>
│       UVW                         (time, baseline_id, uvw_label) float64 333kB dask.array<chunksize=(5, 2775, 3), meta=np.ndarray>
│       VISIBILITY                  (time, baseline_id, frequency, polarization) complex64 7MB dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>
│       WEIGHT                      (time, baseline_id, frequency, polarization) float32 3MB dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>
│   Attributes:
│       creation_date:     2026-04-20T21:18:36.751211+00:00
│       creator:           {'software_name': 'xradio', 'version': '1.1.3'}
│       data_groups:       {'base': {'correlated_data': 'VISIBILITY', 'date': '20...
│       observation_info:  {'observer': ['unknown'], 'observing_log': '[]', 'proj...
│       processor_info:    {'sub_type': 'LOFAR-COBALT', 'type': 'CORRELATOR'}
│       schema_version:    4.0.0
│       type:              visibility
├── Group: /small_lofar_0/antenna_xds
│       Dimensions:                 (antenna_name: 74, cartesian_pos_label: 3,
│                                    receptor_label: 2)
│       Coordinates:
│         * antenna_name            (antenna_name) <U9 3kB 'CS001HBA0' ... 'IE613HBA'
│           mount                   (antenna_name) <U6 2kB dask.array<chunksize=(74,), meta=np.ndarray>
│           station_name            (antenna_name) <U5 1kB dask.array<chunksize=(74,), meta=np.ndarray>
│           telescope_name          (antenna_name) <U5 1kB dask.array<chunksize=(74,), meta=np.ndarray>
│         * cartesian_pos_label     (cartesian_pos_label) <U1 12B 'x' 'y' 'z'
│         * receptor_label          (receptor_label) <U5 40B 'pol_0' 'pol_1'
│           polarization_type       (antenna_name, receptor_label) <U1 592B dask.array<chunksize=(74, 2), meta=np.ndarray>
│       Data variables:
│           ANTENNA_DISH_DIAMETER   (antenna_name) float64 592B dask.array<chunksize=(74,), meta=np.ndarray>
│           ANTENNA_POSITION        (antenna_name, cartesian_pos_label) float64 2kB dask.array<chunksize=(74, 3), meta=np.ndarray>
│           ANTENNA_RECEPTOR_ANGLE  (antenna_name, receptor_label) float64 1kB dask.array<chunksize=(74, 2), meta=np.ndarray>
│       Attributes:
│           overall_telescope_name:  LOFAR
│           relocatable_antennas:    False
│           type:                    antenna
├── Group: /small_lofar_0/field_and_source_base_xds
│       Dimensions:                       (field_name: 1, sky_dir_label: 2)
│       Coordinates:
│         * field_name                    (field_name) <U28 112B 'BEAM_4_0'
│           source_name                   (field_name) <U7 28B dask.array<chunksize=(1,), meta=np.ndarray>
│         * sky_dir_label                 (sky_dir_label) <U3 24B 'ra' 'dec'
│       Data variables:
│           FIELD_PHASE_CENTER_DIRECTION  (field_name, sky_dir_label) float64 16B dask.array<chunksize=(1, 2), meta=np.ndarray>
│       Attributes:
│           type:     field_and_source
└── Group: /small_lofar_0/pointing_xds
        Dimensions:              (time_pointing: 1, antenna_name: 74,
                                  local_sky_dir_label: 2)
        Coordinates:
          * time_pointing        (time_pointing) float64 8B 1.52e+09
          * antenna_name         (antenna_name) <U9 3kB 'CS001HBA0' ... 'IE613HBA'
          * local_sky_dir_label  (local_sky_dir_label) <U3 24B 'az' 'alt'
        Data variables:
            POINTING_BEAM        (time_pointing, antenna_name, local_sky_dir_label) float64 1kB dask.array<chunksize=(1, 74, 2), meta=np.ndarray>
        Attributes:
            type:     pointing

xarray.DataTree

'small_lofar_0'

• /small_lofar_0/antenna_xds(13)

  • Dimensions:
    • time: 5
    • baseline_id: 2775
    • frequency: 15
    • polarization: 4
    • uvw_label: 3
    • antenna_name: 74
    • cartesian_pos_label: 3
    • receptor_label: 2
  • Coordinates: (7)
    • antenna_name
      (antenna_name)
      <U9
      'CS001HBA0' ... 'IE613HBA'

      array(['CS001HBA0', 'CS001HBA1', 'CS002HBA0', 'CS002HBA1', 'CS003HBA0','CS003HBA1', 'CS004HBA0', 'CS004HBA1', 'CS005HBA0', 'CS005HBA1','CS006HBA0', 'CS006HBA1', 'CS007HBA0', 'CS007HBA1', 'CS011HBA0','CS011HBA1', 'CS013HBA0', 'CS013HBA1', 'CS017HBA0', 'CS017HBA1','CS021HBA0', 'CS021HBA1', 'CS024HBA0', 'CS024HBA1', 'CS026HBA0','CS026HBA1', 'CS028HBA0', 'CS028HBA1', 'CS030HBA0', 'CS030HBA1','CS031HBA0', 'CS031HBA1', 'CS032HBA0', 'CS032HBA1', 'CS101HBA0','CS101HBA1', 'CS103HBA0', 'CS103HBA1', 'CS201HBA0', 'CS201HBA1','CS301HBA0', 'CS301HBA1', 'CS302HBA0', 'CS302HBA1', 'CS401HBA0','CS401HBA1', 'CS501HBA0', 'CS501HBA1', 'RS106HBA', 'RS205HBA','RS208HBA', 'RS210HBA', 'RS305HBA', 'RS306HBA', 'RS307HBA', 'RS310HBA','RS406HBA', 'RS407HBA', 'RS409HBA', 'RS503HBA', 'RS508HBA', 'RS509HBA','DE601HBA', 'DE602HBA', 'DE603HBA', 'DE604HBA', 'DE605HBA', 'SE607HBA','UK608HBA', 'DE609HBA', 'PL610HBA', 'PL611HBA', 'PL612HBA', 'IE613HBA'],dtype='<U9')

    • mount
      (antenna_name)
      <U6
      dask.array<chunksize=(74,), meta=np.ndarray>

      Array Chunk Bytes 1.73 kiB 1.73 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

    • station_name
      (antenna_name)
      <U5
      dask.array<chunksize=(74,), meta=np.ndarray>

      Array Chunk Bytes 1.45 kiB 1.45 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

    • telescope_name
      (antenna_name)
      <U5
      dask.array<chunksize=(74,), meta=np.ndarray>

      Array Chunk Bytes 1.45 kiB 1.45 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

    • cartesian_pos_label
      (cartesian_pos_label)
      <U1
      'x' 'y' 'z'

      array(['x', 'y', 'z'], dtype='<U1')

    • receptor_label
      (receptor_label)
      <U5
      'pol_0' 'pol_1'

      array(['pol_0', 'pol_1'], dtype='<U5')

    • polarization_type
      (antenna_name, receptor_label)
      <U1
      dask.array<chunksize=(74, 2), meta=np.ndarray>

      Array Chunk Bytes 592 B 592 B Shape (74, 2) (74, 2) Dask graph 1 chunks in 2 graph layers Data type

  • Data variables: (3)
    • ANTENNA_DISH_DIAMETER
      (antenna_name)
      float64
      dask.array<chunksize=(74,), meta=np.ndarray>

      type :

      quantity

      units :

      m

      Array Chunk Bytes 592 B 592 B Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

    • ANTENNA_POSITION
      (antenna_name, cartesian_pos_label)
      float64
      dask.array<chunksize=(74, 3), meta=np.ndarray>

      coordinate_system :

      geocentric

      frame :

      ITRS

      origin_object_name :

      earth

      type :

      location

      units :

      m

      Array Chunk Bytes 1.73 kiB 1.73 kiB Shape (74, 3) (74, 3) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

    • ANTENNA_RECEPTOR_ANGLE
      (antenna_name, receptor_label)
      float64
      dask.array<chunksize=(74, 2), meta=np.ndarray>

      type :

      quantity

      units :

      rad

      Array Chunk Bytes 1.16 kiB 1.16 kiB Shape (74, 2) (74, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (3)

    overall_telescope_name :

    LOFAR

    relocatable_antennas :

    False

    type :

    antenna

  /small_lofar_0/field_and_source_base_xds(5)

  • Dimensions:
    • time: 5
    • baseline_id: 2775
    • frequency: 15
    • polarization: 4
    • uvw_label: 3
    • field_name: 1
    • sky_dir_label: 2
  • Coordinates: (3)
    • field_name
      (field_name)
      <U28
      'BEAM_4_0'

      array(['BEAM_4_0'], dtype='<U28')

    • source_name
      (field_name)
      <U7
      dask.array<chunksize=(1,), meta=np.ndarray>

      Array Chunk Bytes 28 B 28 B Shape (1,) (1,) Dask graph 1 chunks in 2 graph layers Data type

    • sky_dir_label
      (sky_dir_label)
      <U3
      'ra' 'dec'

      array(['ra', 'dec'], dtype='<U3')

  • Data variables: (1)
    • FIELD_PHASE_CENTER_DIRECTION
      (field_name, sky_dir_label)
      float64
      dask.array<chunksize=(1, 2), meta=np.ndarray>

      frame :

      fk5

      type :

      sky_coord

      units :

      rad

      Array Chunk Bytes 16 B 16 B Shape (1, 2) (1, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (1)

    type :

    field_and_source

  /small_lofar_0/pointing_xds(5)

  • Dimensions:
    • time: 5
    • baseline_id: 2775
    • frequency: 15
    • polarization: 4
    • uvw_label: 3
    • time_pointing: 1
    • antenna_name: 74
    • local_sky_dir_label: 2
  • Coordinates: (3)
    • time_pointing
      (time_pointing)
      float64
      1.52e+09

      format :

      unix

      scale :

      utc

      type :

      time

      units :

      s

      array([1.520293e+09])

    • antenna_name
      (antenna_name)
      <U9
      'CS001HBA0' ... 'IE613HBA'

      array(['CS001HBA0', 'CS001HBA1', 'CS002HBA0', 'CS002HBA1', 'CS003HBA0','CS003HBA1', 'CS004HBA0', 'CS004HBA1', 'CS005HBA0', 'CS005HBA1','CS006HBA0', 'CS006HBA1', 'CS007HBA0', 'CS007HBA1', 'CS011HBA0','CS011HBA1', 'CS013HBA0', 'CS013HBA1', 'CS017HBA0', 'CS017HBA1','CS021HBA0', 'CS021HBA1', 'CS024HBA0', 'CS024HBA1', 'CS026HBA0','CS026HBA1', 'CS028HBA0', 'CS028HBA1', 'CS030HBA0', 'CS030HBA1','CS031HBA0', 'CS031HBA1', 'CS032HBA0', 'CS032HBA1', 'CS101HBA0','CS101HBA1', 'CS103HBA0', 'CS103HBA1', 'CS201HBA0', 'CS201HBA1','CS301HBA0', 'CS301HBA1', 'CS302HBA0', 'CS302HBA1', 'CS401HBA0','CS401HBA1', 'CS501HBA0', 'CS501HBA1', 'RS106HBA', 'RS205HBA','RS208HBA', 'RS210HBA', 'RS305HBA', 'RS306HBA', 'RS307HBA', 'RS310HBA','RS406HBA', 'RS407HBA', 'RS409HBA', 'RS503HBA', 'RS508HBA', 'RS509HBA','DE601HBA', 'DE602HBA', 'DE603HBA', 'DE604HBA', 'DE605HBA', 'SE607HBA','UK608HBA', 'DE609HBA', 'PL610HBA', 'PL611HBA', 'PL612HBA', 'IE613HBA'],dtype='<U9')

    • local_sky_dir_label
      (local_sky_dir_label)
      <U3
      'az' 'alt'

      array(['az', 'alt'], dtype='<U3')

  • Data variables: (1)
    • POINTING_BEAM
      (time_pointing, antenna_name, local_sky_dir_label)
      float64
      dask.array<chunksize=(1, 74, 2), meta=np.ndarray>

      frame :

      fk5

      type :

      sky_coord

      units :

      rad

      Array Chunk Bytes 1.16 kiB 1.16 kiB Shape (1, 74, 2) (1, 74, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (1)

    type :

    pointing

• Dimensions:
  • time: 5
  • baseline_id: 2775
  • frequency: 15
  • polarization: 4
  • uvw_label: 3
• Coordinates: (9)
  • time
    (time)
    float64
    1.52e+09 1.52e+09 ... 1.52e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 2.00278016, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09])

  • field_name
    (time)
    <U28
    dask.array<chunksize=(5,), meta=np.ndarray>

    Array Chunk Bytes 560 B 560 B Shape (5,) (5,) Dask graph 1 chunks in 2 graph layers Data type

  • scan_name
    (time)
    <U21
    dask.array<chunksize=(5,), meta=np.ndarray>

    scan_intents :

    ['']

    Array Chunk Bytes 420 B 420 B Shape (5,) (5,) Dask graph 1 chunks in 2 graph layers Data type

  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 ... 2771 2772 2773 2774

    array([   0,    1,    2, ..., 2772, 2773, 2774], shape=(2775,))

  • baseline_antenna1_name
    (baseline_id)
    <U9
    dask.array<chunksize=(2775,), meta=np.ndarray>

    Array Chunk Bytes 97.56 kiB 97.56 kiB Shape (2775,) (2775,) Dask graph 1 chunks in 2 graph layers Data type

  • baseline_antenna2_name
    (baseline_id)
    <U9
    dask.array<chunksize=(2775,), meta=np.ndarray>

    Array Chunk Bytes 97.56 kiB 97.56 kiB Shape (2775,) (2775,) Dask graph 1 chunks in 2 graph layers Data type

  • frequency
    (frequency)
    float64
    1.271e+08 1.271e+08 ... 1.272e+08

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 12207.03125, 'dims': []}

    observer :

    TOPO

    reference_frequency :

    {'attrs': {'observer': 'TOPO', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 127148437.5, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    SB-349_0

    type :

    spectral_coord

    units :

    Hz

    array([1.270615e+08, 1.270737e+08, 1.270859e+08, 1.270981e+08, 1.271103e+08,
           1.271225e+08, 1.271347e+08, 1.271469e+08, 1.271591e+08, 1.271713e+08,
           1.271835e+08, 1.271957e+08, 1.272079e+08, 1.272202e+08, 1.272324e+08])

  • polarization
    (polarization)
    <U2
    'XX' 'XY' 'YX' 'YY'

    array(['XX', 'XY', 'YX', 'YY'], dtype='<U2')

  • uvw_label
    (uvw_label)
    <U1
    'u' 'v' 'w'

    array(['u', 'v', 'w'], dtype='<U1')

• Data variables: (6)
  • EFFECTIVE_INTEGRATION_TIME
    (time, baseline_id)
    float64
    dask.array<chunksize=(5, 2775), meta=np.ndarray>

    type :

    quantity

    units :

    s

    Array Chunk Bytes 108.40 kiB 108.40 kiB Shape (5, 2775) (5, 2775) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • FLAG
    (time, baseline_id, frequency, polarization)
    bool
    dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>

    Array Chunk Bytes 812.99 kiB 54.20 kiB Shape (5, 2775, 15, 4) (5, 2775, 1, 4) Dask graph 15 chunks in 2 graph layers Data type bool numpy.ndarray

  • TIME_CENTROID
    (time, baseline_id)
    float64
    dask.array<chunksize=(5, 2775), meta=np.ndarray>

    format :

    unix

    scale :

    utc

    type :

    time

    units :

    s

    Array Chunk Bytes 108.40 kiB 108.40 kiB Shape (5, 2775) (5, 2775) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • UVW
    (time, baseline_id, uvw_label)
    float64
    dask.array<chunksize=(5, 2775, 3), meta=np.ndarray>

    frame :

    fk5

    type :

    uvw

    units :

    m

    Array Chunk Bytes 325.20 kiB 325.20 kiB Shape (5, 2775, 3) (5, 2775, 3) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • VISIBILITY
    (time, baseline_id, frequency, polarization)
    complex64
    dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>

    type :

    quanta

    units :

    unkown

    Array Chunk Bytes 6.35 MiB 433.59 kiB Shape (5, 2775, 15, 4) (5, 2775, 1, 4) Dask graph 15 chunks in 2 graph layers Data type complex64 numpy.ndarray

  • WEIGHT
    (time, baseline_id, frequency, polarization)
    float32
    dask.array<chunksize=(5, 2775, 1, 4), meta=np.ndarray>

    Array Chunk Bytes 3.18 MiB 216.80 kiB Shape (5, 2775, 15, 4) (5, 2775, 1, 4) Dask graph 15 chunks in 2 graph layers Data type float32 numpy.ndarray

• Attributes: (7)

  creation_date :

  2026-04-20T21:18:36.751211+00:00

  creator :

  {'software_name': 'xradio', 'version': '1.1.3'}

  data_groups :

  {'base': {'correlated_data': 'VISIBILITY', 'date': '2026-04-20T21:18:36.778659+00:00', 'description': "Data group derived from the data column 'VISIBILITY' of an MSv2 converted to MSv4", 'field_and_source': 'field_and_source_base_xds', 'flag': 'FLAG', 'uvw': 'UVW', 'weight': 'WEIGHT'}}

  observation_info :

  {'observer': ['unknown'], 'observing_log': '[]', 'project_UID': 'LC9_007', 'release_date': '2019-03-06T11:42:02.753978729'}

  processor_info :

  {'sub_type': 'LOFAR-COBALT', 'type': 'CORRELATOR'}

  schema_version :

  4.0.0

  type :

  visibility

ms_xdt.xr_ms.get_field_and_source_xds()

<xarray.DatasetView> Size: 23kB
Dimensions:                       (field_name: 1, sky_dir_label: 2,
                                   baseline_id: 2775, frequency: 15,
                                   polarization: 4, time: 5, uvw_label: 3)
Coordinates:
  * field_name                    (field_name) <U28 112B 'BEAM_4_0'
    source_name                   (field_name) <U7 28B dask.array<chunksize=(1,), meta=np.ndarray>
  * sky_dir_label                 (sky_dir_label) <U3 24B 'ra' 'dec'
  * baseline_id                   (baseline_id) int64 22kB 0 1 2 ... 2773 2774
  * frequency                     (frequency) float64 120B 1.271e+08 ... 1.27...
  * polarization                  (polarization) <U2 32B 'XX' 'XY' 'YX' 'YY'
  * time                          (time) float64 40B 1.52e+09 ... 1.52e+09
  * uvw_label                     (uvw_label) <U1 12B 'u' 'v' 'w'
Data variables:
    FIELD_PHASE_CENTER_DIRECTION  (field_name, sky_dir_label) float64 16B dask.array<chunksize=(1, 2), meta=np.ndarray>
Attributes:
    type:     field_and_source

xarray.DatasetView

• Dimensions:
  • field_name: 1
  • sky_dir_label: 2
  • baseline_id: 2775
  • frequency: 15
  • polarization: 4
  • time: 5
  • uvw_label: 3
• Coordinates: (8)
  • field_name
    (field_name)
    <U28
    'BEAM_4_0'

    array(['BEAM_4_0'], dtype='<U28')

  • source_name
    (field_name)
    <U7
    dask.array<chunksize=(1,), meta=np.ndarray>

    Array Chunk Bytes 28 B 28 B Shape (1,) (1,) Dask graph 1 chunks in 2 graph layers Data type

  • sky_dir_label
    (sky_dir_label)
    <U3
    'ra' 'dec'

    array(['ra', 'dec'], dtype='<U3')

  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 ... 2771 2772 2773 2774

    array([   0,    1,    2, ..., 2772, 2773, 2774], shape=(2775,))

  • frequency
    (frequency)
    float64
    1.271e+08 1.271e+08 ... 1.272e+08

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 12207.03125, 'dims': []}

    observer :

    TOPO

    reference_frequency :

    {'attrs': {'observer': 'TOPO', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 127148437.5, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    SB-349_0

    type :

    spectral_coord

    units :

    Hz

    array([1.270615e+08, 1.270737e+08, 1.270859e+08, 1.270981e+08, 1.271103e+08,
           1.271225e+08, 1.271347e+08, 1.271469e+08, 1.271591e+08, 1.271713e+08,
           1.271835e+08, 1.271957e+08, 1.272079e+08, 1.272202e+08, 1.272324e+08])

  • polarization
    (polarization)
    <U2
    'XX' 'XY' 'YX' 'YY'

    array(['XX', 'XY', 'YX', 'YY'], dtype='<U2')

  • time
    (time)
    float64
    1.52e+09 1.52e+09 ... 1.52e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 2.00278016, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09])

  • uvw_label
    (uvw_label)
    <U1
    'u' 'v' 'w'

    array(['u', 'v', 'w'], dtype='<U1')

• Data variables: (1)
  • FIELD_PHASE_CENTER_DIRECTION
    (field_name, sky_dir_label)
    float64
    dask.array<chunksize=(1, 2), meta=np.ndarray>

    frame :

    fk5

    type :

    sky_coord

    units :

    rad

    Array Chunk Bytes 16 B 16 B Shape (1, 2) (1, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (1)

  type :

  field_and_source

ms_xdt.antenna_xds

<xarray.DataTree 'antenna_xds'>
Group: /small_lofar_0/antenna_xds
    Dimensions:                 (time: 5, baseline_id: 2775, frequency: 15,
                                 polarization: 4, uvw_label: 3, antenna_name: 74,
                                 cartesian_pos_label: 3, receptor_label: 2)
    Coordinates:
      * antenna_name            (antenna_name) <U9 3kB 'CS001HBA0' ... 'IE613HBA'
        mount                   (antenna_name) <U6 2kB dask.array<chunksize=(74,), meta=np.ndarray>
        station_name            (antenna_name) <U5 1kB dask.array<chunksize=(74,), meta=np.ndarray>
        telescope_name          (antenna_name) <U5 1kB dask.array<chunksize=(74,), meta=np.ndarray>
      * cartesian_pos_label     (cartesian_pos_label) <U1 12B 'x' 'y' 'z'
      * receptor_label          (receptor_label) <U5 40B 'pol_0' 'pol_1'
        polarization_type       (antenna_name, receptor_label) <U1 592B dask.array<chunksize=(74, 2), meta=np.ndarray>
    Inherited coordinates:
      * baseline_id             (baseline_id) int64 22kB 0 1 2 3 ... 2772 2773 2774
      * frequency               (frequency) float64 120B 1.271e+08 ... 1.272e+08
      * polarization            (polarization) <U2 32B 'XX' 'XY' 'YX' 'YY'
      * time                    (time) float64 40B 1.52e+09 1.52e+09 ... 1.52e+09
      * uvw_label               (uvw_label) <U1 12B 'u' 'v' 'w'
    Data variables:
        ANTENNA_DISH_DIAMETER   (antenna_name) float64 592B dask.array<chunksize=(74,), meta=np.ndarray>
        ANTENNA_POSITION        (antenna_name, cartesian_pos_label) float64 2kB dask.array<chunksize=(74, 3), meta=np.ndarray>
        ANTENNA_RECEPTOR_ANGLE  (antenna_name, receptor_label) float64 1kB dask.array<chunksize=(74, 2), meta=np.ndarray>
    Attributes:
        overall_telescope_name:  LOFAR
        relocatable_antennas:    False
        type:                    antenna

xarray.DataTree

'antenna_xds'

• Dimensions:
  • time: 5
  • baseline_id: 2775
  • frequency: 15
  • polarization: 4
  • uvw_label: 3
  • antenna_name: 74
  • cartesian_pos_label: 3
  • receptor_label: 2
• Coordinates: (7)
  • antenna_name
    (antenna_name)
    <U9
    'CS001HBA0' ... 'IE613HBA'

    array(['CS001HBA0', 'CS001HBA1', 'CS002HBA0', 'CS002HBA1', 'CS003HBA0',
           'CS003HBA1', 'CS004HBA0', 'CS004HBA1', 'CS005HBA0', 'CS005HBA1',
           'CS006HBA0', 'CS006HBA1', 'CS007HBA0', 'CS007HBA1', 'CS011HBA0',
           'CS011HBA1', 'CS013HBA0', 'CS013HBA1', 'CS017HBA0', 'CS017HBA1',
           'CS021HBA0', 'CS021HBA1', 'CS024HBA0', 'CS024HBA1', 'CS026HBA0',
           'CS026HBA1', 'CS028HBA0', 'CS028HBA1', 'CS030HBA0', 'CS030HBA1',
           'CS031HBA0', 'CS031HBA1', 'CS032HBA0', 'CS032HBA1', 'CS101HBA0',
           'CS101HBA1', 'CS103HBA0', 'CS103HBA1', 'CS201HBA0', 'CS201HBA1',
           'CS301HBA0', 'CS301HBA1', 'CS302HBA0', 'CS302HBA1', 'CS401HBA0',
           'CS401HBA1', 'CS501HBA0', 'CS501HBA1', 'RS106HBA', 'RS205HBA',
           'RS208HBA', 'RS210HBA', 'RS305HBA', 'RS306HBA', 'RS307HBA', 'RS310HBA',
           'RS406HBA', 'RS407HBA', 'RS409HBA', 'RS503HBA', 'RS508HBA', 'RS509HBA',
           'DE601HBA', 'DE602HBA', 'DE603HBA', 'DE604HBA', 'DE605HBA', 'SE607HBA',
           'UK608HBA', 'DE609HBA', 'PL610HBA', 'PL611HBA', 'PL612HBA', 'IE613HBA'],
          dtype='<U9')

  • mount
    (antenna_name)
    <U6
    dask.array<chunksize=(74,), meta=np.ndarray>

    Array Chunk Bytes 1.73 kiB 1.73 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

  • station_name
    (antenna_name)
    <U5
    dask.array<chunksize=(74,), meta=np.ndarray>

    Array Chunk Bytes 1.45 kiB 1.45 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

  • telescope_name
    (antenna_name)
    <U5
    dask.array<chunksize=(74,), meta=np.ndarray>

    Array Chunk Bytes 1.45 kiB 1.45 kiB Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type

  • cartesian_pos_label
    (cartesian_pos_label)
    <U1
    'x' 'y' 'z'

    array(['x', 'y', 'z'], dtype='<U1')

  • receptor_label
    (receptor_label)
    <U5
    'pol_0' 'pol_1'

    array(['pol_0', 'pol_1'], dtype='<U5')

  • polarization_type
    (antenna_name, receptor_label)
    <U1
    dask.array<chunksize=(74, 2), meta=np.ndarray>

    Array Chunk Bytes 592 B 592 B Shape (74, 2) (74, 2) Dask graph 1 chunks in 2 graph layers Data type

• Inherited coordinates: (5)
  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 ... 2771 2772 2773 2774

    array([   0,    1,    2, ..., 2772, 2773, 2774], shape=(2775,))

  • frequency
    (frequency)
    float64
    1.271e+08 1.271e+08 ... 1.272e+08

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 12207.03125, 'dims': []}

    observer :

    TOPO

    reference_frequency :

    {'attrs': {'observer': 'TOPO', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 127148437.5, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    SB-349_0

    type :

    spectral_coord

    units :

    Hz

    array([1.270615e+08, 1.270737e+08, 1.270859e+08, 1.270981e+08, 1.271103e+08,
           1.271225e+08, 1.271347e+08, 1.271469e+08, 1.271591e+08, 1.271713e+08,
           1.271835e+08, 1.271957e+08, 1.272079e+08, 1.272202e+08, 1.272324e+08])

  • polarization
    (polarization)
    <U2
    'XX' 'XY' 'YX' 'YY'

    array(['XX', 'XY', 'YX', 'YY'], dtype='<U2')

  • time
    (time)
    float64
    1.52e+09 1.52e+09 ... 1.52e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 2.00278016, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09])

  • uvw_label
    (uvw_label)
    <U1
    'u' 'v' 'w'

    array(['u', 'v', 'w'], dtype='<U1')

• Data variables: (3)
  • ANTENNA_DISH_DIAMETER
    (antenna_name)
    float64
    dask.array<chunksize=(74,), meta=np.ndarray>

    type :

    quantity

    units :

    m

    Array Chunk Bytes 592 B 592 B Shape (74,) (74,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • ANTENNA_POSITION
    (antenna_name, cartesian_pos_label)
    float64
    dask.array<chunksize=(74, 3), meta=np.ndarray>

    coordinate_system :

    geocentric

    frame :

    ITRS

    origin_object_name :

    earth

    type :

    location

    units :

    m

    Array Chunk Bytes 1.73 kiB 1.73 kiB Shape (74, 3) (74, 3) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • ANTENNA_RECEPTOR_ANGLE
    (antenna_name, receptor_label)
    float64
    dask.array<chunksize=(74, 2), meta=np.ndarray>

    type :

    quantity

    units :

    rad

    Array Chunk Bytes 1.16 kiB 1.16 kiB Shape (74, 2) (74, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (3)

  overall_telescope_name :

  LOFAR

  relocatable_antennas :

  False

  type :

  antenna

ms_xdt.pointing_xds

<xarray.DataTree 'pointing_xds'>
Group: /small_lofar_0/pointing_xds
    Dimensions:              (time: 5, baseline_id: 2775, frequency: 15,
                              polarization: 4, uvw_label: 3, time_pointing: 1,
                              antenna_name: 74, local_sky_dir_label: 2)
    Coordinates:
      * time_pointing        (time_pointing) float64 8B 1.52e+09
      * antenna_name         (antenna_name) <U9 3kB 'CS001HBA0' ... 'IE613HBA'
      * local_sky_dir_label  (local_sky_dir_label) <U3 24B 'az' 'alt'
    Inherited coordinates:
      * baseline_id          (baseline_id) int64 22kB 0 1 2 3 ... 2772 2773 2774
      * frequency            (frequency) float64 120B 1.271e+08 ... 1.272e+08
      * polarization         (polarization) <U2 32B 'XX' 'XY' 'YX' 'YY'
      * time                 (time) float64 40B 1.52e+09 1.52e+09 ... 1.52e+09
      * uvw_label            (uvw_label) <U1 12B 'u' 'v' 'w'
    Data variables:
        POINTING_BEAM        (time_pointing, antenna_name, local_sky_dir_label) float64 1kB dask.array<chunksize=(1, 74, 2), meta=np.ndarray>
    Attributes:
        type:     pointing

xarray.DataTree

'pointing_xds'

• Dimensions:
  • time: 5
  • baseline_id: 2775
  • frequency: 15
  • polarization: 4
  • uvw_label: 3
  • time_pointing: 1
  • antenna_name: 74
  • local_sky_dir_label: 2
• Coordinates: (3)
  • time_pointing
    (time_pointing)
    float64
    1.52e+09

    format :

    unix

    scale :

    utc

    type :

    time

    units :

    s

    array([1.520293e+09])

  • antenna_name
    (antenna_name)
    <U9
    'CS001HBA0' ... 'IE613HBA'

    array(['CS001HBA0', 'CS001HBA1', 'CS002HBA0', 'CS002HBA1', 'CS003HBA0',
           'CS003HBA1', 'CS004HBA0', 'CS004HBA1', 'CS005HBA0', 'CS005HBA1',
           'CS006HBA0', 'CS006HBA1', 'CS007HBA0', 'CS007HBA1', 'CS011HBA0',
           'CS011HBA1', 'CS013HBA0', 'CS013HBA1', 'CS017HBA0', 'CS017HBA1',
           'CS021HBA0', 'CS021HBA1', 'CS024HBA0', 'CS024HBA1', 'CS026HBA0',
           'CS026HBA1', 'CS028HBA0', 'CS028HBA1', 'CS030HBA0', 'CS030HBA1',
           'CS031HBA0', 'CS031HBA1', 'CS032HBA0', 'CS032HBA1', 'CS101HBA0',
           'CS101HBA1', 'CS103HBA0', 'CS103HBA1', 'CS201HBA0', 'CS201HBA1',
           'CS301HBA0', 'CS301HBA1', 'CS302HBA0', 'CS302HBA1', 'CS401HBA0',
           'CS401HBA1', 'CS501HBA0', 'CS501HBA1', 'RS106HBA', 'RS205HBA',
           'RS208HBA', 'RS210HBA', 'RS305HBA', 'RS306HBA', 'RS307HBA', 'RS310HBA',
           'RS406HBA', 'RS407HBA', 'RS409HBA', 'RS503HBA', 'RS508HBA', 'RS509HBA',
           'DE601HBA', 'DE602HBA', 'DE603HBA', 'DE604HBA', 'DE605HBA', 'SE607HBA',
           'UK608HBA', 'DE609HBA', 'PL610HBA', 'PL611HBA', 'PL612HBA', 'IE613HBA'],
          dtype='<U9')

  • local_sky_dir_label
    (local_sky_dir_label)
    <U3
    'az' 'alt'

    array(['az', 'alt'], dtype='<U3')

• Inherited coordinates: (5)
  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 ... 2771 2772 2773 2774

    array([   0,    1,    2, ..., 2772, 2773, 2774], shape=(2775,))

  • frequency
    (frequency)
    float64
    1.271e+08 1.271e+08 ... 1.272e+08

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 12207.03125, 'dims': []}

    observer :

    TOPO

    reference_frequency :

    {'attrs': {'observer': 'TOPO', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 127148437.5, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    SB-349_0

    type :

    spectral_coord

    units :

    Hz

    array([1.270615e+08, 1.270737e+08, 1.270859e+08, 1.270981e+08, 1.271103e+08,
           1.271225e+08, 1.271347e+08, 1.271469e+08, 1.271591e+08, 1.271713e+08,
           1.271835e+08, 1.271957e+08, 1.272079e+08, 1.272202e+08, 1.272324e+08])

  • polarization
    (polarization)
    <U2
    'XX' 'XY' 'YX' 'YY'

    array(['XX', 'XY', 'YX', 'YY'], dtype='<U2')

  • time
    (time)
    float64
    1.52e+09 1.52e+09 ... 1.52e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 2.00278016, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09, 1.520272e+09])

  • uvw_label
    (uvw_label)
    <U1
    'u' 'v' 'w'

    array(['u', 'v', 'w'], dtype='<U1')

• Data variables: (1)
  • POINTING_BEAM
    (time_pointing, antenna_name, local_sky_dir_label)
    float64
    dask.array<chunksize=(1, 74, 2), meta=np.ndarray>

    frame :

    fk5

    type :

    sky_coord

    units :

    rad

    Array Chunk Bytes 1.16 kiB 1.16 kiB Shape (1, 74, 2) (1, 74, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (1)

  type :

  pointing

ps_xdt.xr_ps.plot_antenna_positions_2d()

ps_xdt.xr_ps.plot_phase_centers()