Global VLBI 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

global (EVN+VLBA) VLBI observation with: - 5 scans - 2 fields - 2 spw

import toolviper
toolviper.utils.data.download("global_vlbi_gg084b_reduced.ms")

[2026-04-20 15:21:21,727]     INFO   toolviper:  Initializing download...
[2026-04-20 15:21:21,727]     INFO   toolviper:  File already exists: /Users/vdesouza/work/xradio/docs/source/measurement_set/guides/global_vlbi_gg084b_reduced.ms

Convert to Processing Set

from xradio.measurement_set import convert_msv2_to_processing_set

ms_file = "global_vlbi_gg084b_reduced.ms"

main_chunksize = {"frequency": 1, "time": 20}  # baseline, polarization
outfile = "global_vlbi_gg084b_reduced.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 15:21:22,206]     INFO   toolviper:  Updated partition scheme used: ['DATA_DESC_ID', 'OBSERVATION_ID']
[2026-04-20 15:21:22,207]     INFO   toolviper:  Number of partitions: 2
[2026-04-20 15:21:22,207]     INFO   toolviper:  OBSERVATION_ID [0], DDI [0], STATE [None], FIELD [0, 1], SCAN [3, 319, 320, 321, 552], EPHEMERIS [None]
[2026-04-20 15:21:22,399]  WARNING   toolviper:  Source_id is -1. No source information will be included in the field_and_source_xds.
[2026-04-20 15:21:22,801]     INFO   toolviper:  OBSERVATION_ID [0], DDI [1], STATE [None], FIELD [0, 1], SCAN [3, 319, 320, 321, 552], EPHEMERIS [None]
[2026-04-20 15:21:22,981]  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	global_vlbi_gg084b_reduced_0	[None]	(480, 57, 32, 4)	---	[RR, RL, LR, LL]	[3, 319, 320, 321, 552]	spw_0	[UNSPECIFIED]	[EM170817_1, J1311-2329_0]	[Unknown]	[]	Multi-Phase-Center	---	---	GG084B	4.900500e+09	4.916000e+09
1	global_vlbi_gg084b_reduced_1	[None]	(480, 57, 32, 4)	---	[RR, RL, LR, LL]	[3, 319, 320, 321, 552]	spw_1	[UNSPECIFIED]	[EM170817_1, J1311-2329_0]	[Unknown]	[]	Multi-Phase-Center	---	---	GG084B	4.916000e+09	4.931500e+09

ms_xdt = ps_xdt['global_vlbi_gg084b_reduced_0']
ms_xdt

<xarray.DataTree 'global_vlbi_gg084b_reduced_0'>
Group: /global_vlbi_gg084b_reduced_0
│   Dimensions:                     (time: 480, baseline_id: 57, frequency: 32,
│                                    polarization: 4, uvw_label: 3)
│   Coordinates:
│     * time                        (time) float64 4kB 1.527e+09 ... 1.527e+09
│       field_name                  (time) <U32 61kB dask.array<chunksize=(480,), meta=np.ndarray>
│       scan_name                   (time) <U21 40kB dask.array<chunksize=(480,), meta=np.ndarray>
│     * baseline_id                 (baseline_id) int64 456B 0 1 2 3 ... 53 54 55 56
│       baseline_antenna1_name      (baseline_id) <U2 456B dask.array<chunksize=(57,), meta=np.ndarray>
│       baseline_antenna2_name      (baseline_id) <U2 456B dask.array<chunksize=(57,), meta=np.ndarray>
│     * frequency                   (frequency) float64 256B 4.9e+09 ... 4.916e+09
│     * polarization                (polarization) <U2 32B 'RR' 'RL' 'LR' 'LL'
│     * uvw_label                   (uvw_label) <U1 12B 'u' 'v' 'w'
│   Data variables:
│       EFFECTIVE_INTEGRATION_TIME  (time, baseline_id) float64 219kB dask.array<chunksize=(20, 57), meta=np.ndarray>
│       FLAG                        (time, baseline_id, frequency, polarization) bool 4MB dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>
│       TIME_CENTROID               (time, baseline_id) float64 219kB dask.array<chunksize=(20, 57), meta=np.ndarray>
│       UVW                         (time, baseline_id, uvw_label) float64 657kB dask.array<chunksize=(20, 57, 3), meta=np.ndarray>
│       VISIBILITY                  (time, baseline_id, frequency, polarization) complex64 28MB dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>
│       WEIGHT                      (time, baseline_id, frequency, polarization) float32 14MB dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>
│   Attributes:
│       creation_date:     2026-04-20T21:21:22.222037+00:00
│       creator:           {'software_name': 'xradio', 'version': '1.1.3'}
│       data_groups:       {'base': {'correlated_data': 'VISIBILITY', 'date': '20...
│       observation_info:  {'observer': ['GG084B'], 'observing_log': '[]', 'proje...
│       processor_info:    {'sub_type': '', 'type': ''}
│       schema_version:    4.0.0
│       type:              visibility
├── Group: /global_vlbi_gg084b_reduced_0/antenna_xds
│       Dimensions:                 (antenna_name: 14, cartesian_pos_label: 3,
│                                    receptor_label: 2)
│       Coordinates:
│         * antenna_name            (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'BR' 'MK'
│           mount                   (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
│           station_name            (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
│           telescope_name          (antenna_name) <U3 168B dask.array<chunksize=(14,), 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 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
│       Data variables:
│           ANTENNA_DISH_DIAMETER   (antenna_name) float64 112B dask.array<chunksize=(14,), meta=np.ndarray>
│           ANTENNA_POSITION        (antenna_name, cartesian_pos_label) float64 336B dask.array<chunksize=(14, 3), meta=np.ndarray>
│           ANTENNA_RECEPTOR_ANGLE  (antenna_name, receptor_label) float64 224B dask.array<chunksize=(14, 2), meta=np.ndarray>
│       Attributes:
│           overall_telescope_name:  EVN
│           relocatable_antennas:    False
│           type:                    antenna
├── Group: /global_vlbi_gg084b_reduced_0/field_and_source_base_xds
│       Dimensions:                       (field_name: 2, sky_dir_label: 2)
│       Coordinates:
│         * field_name                    (field_name) <U32 256B 'J1311-2329_0' 'EM17...
│           source_name                   (field_name) <U7 56B dask.array<chunksize=(2,), 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 32B dask.array<chunksize=(2, 2), meta=np.ndarray>
│       Attributes:
│           type:     field_and_source
├── Group: /global_vlbi_gg084b_reduced_0/gain_curve_xds
│       Dimensions:                 (antenna_name: 14, poly_term: 3, receptor_label: 2)
│       Coordinates:
│         * antenna_name            (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'BR' 'MK'
│           antenna_id              (antenna_name) int32 56B dask.array<chunksize=(14,), meta=np.ndarray>
│           gain_curve_type         (antenna_name) <U9 504B dask.array<chunksize=(14,), meta=np.ndarray>
│           mount                   (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
│           station_name            (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
│           telescope_name          (antenna_name) <U3 168B dask.array<chunksize=(14,), meta=np.ndarray>
│         * receptor_label          (receptor_label) <U5 40B 'pol_0' 'pol_1'
│           polarization_type       (antenna_name, receptor_label) <U1 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
│       Dimensions without coordinates: poly_term
│       Data variables:
│           GAIN_CURVE              (antenna_name, poly_term, receptor_label) float64 672B dask.array<chunksize=(14, 3, 2), meta=np.ndarray>
│           GAIN_CURVE_INTERVAL     (antenna_name) float64 112B dask.array<chunksize=(14,), meta=np.ndarray>
│           GAIN_CURVE_SENSITIVITY  (antenna_name, receptor_label) float64 224B dask.array<chunksize=(14, 2), meta=np.ndarray>
│       Attributes:
│           measured_date:  2018-05-26T15:33:49.500000000
│           type:           gain_curve
└── Group: /global_vlbi_gg084b_reduced_0/system_calibration_xds
        Dimensions:            (antenna_name: 14, time_system_cal: 10357,
                                receptor_label: 2)
        Coordinates:
          * antenna_name       (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'
            antenna_id         (antenna_name) int32 56B dask.array<chunksize=(14,), meta=np.ndarray>
            mount              (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
            station_name       (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
            telescope_name     (antenna_name) <U3 168B dask.array<chunksize=(14,), meta=np.ndarray>
          * time_system_cal    (time_system_cal) float64 83kB 1.527e+09 ... 1.527e+09
          * receptor_label     (receptor_label) <U5 40B 'pol_0' 'pol_1'
            polarization_type  (antenna_name, receptor_label) <U1 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
        Data variables:
            TSYS               (antenna_name, time_system_cal, receptor_label) float64 2MB dask.array<chunksize=(7, 5179, 1), meta=np.ndarray>
        Attributes:
            type:     system_calibration

xarray.DataTree

'global_vlbi_gg084b_reduced_0'

• /global_vlbi_gg084b_reduced_0/antenna_xds(13)

  • Dimensions:
    • time: 480
    • baseline_id: 57
    • frequency: 32
    • polarization: 4
    • uvw_label: 3
    • antenna_name: 14
    • cartesian_pos_label: 3
    • receptor_label: 2
  • Coordinates: (7)
    • antenna_name
      (antenna_name)
      <U2
      'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

      array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP','BR', 'MK'], dtype='<U2')

    • mount
      (antenna_name)
      <U16
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • station_name
      (antenna_name)
      <U2
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • telescope_name
      (antenna_name)
      <U3
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 168 B 168 B Shape (14,) (14,) 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=(14, 2), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

  • Data variables: (3)
    • ANTENNA_DISH_DIAMETER
      (antenna_name)
      float64
      dask.array<chunksize=(14,), meta=np.ndarray>

      type :

      quantity

      units :

      m

      Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

    • ANTENNA_POSITION
      (antenna_name, cartesian_pos_label)
      float64
      dask.array<chunksize=(14, 3), meta=np.ndarray>

      coordinate_system :

      geocentric

      frame :

      ITRS

      origin_object_name :

      earth

      type :

      location

      units :

      m

      Array Chunk Bytes 336 B 336 B Shape (14, 3) (14, 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=(14, 2), meta=np.ndarray>

      type :

      quantity

      units :

      rad

      Array Chunk Bytes 224 B 224 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (3)

    overall_telescope_name :

    EVN

    relocatable_antennas :

    False

    type :

    antenna

  /global_vlbi_gg084b_reduced_0/field_and_source_base_xds(5)

  • Dimensions:
    • time: 480
    • baseline_id: 57
    • frequency: 32
    • polarization: 4
    • uvw_label: 3
    • field_name: 2
    • sky_dir_label: 2
  • Coordinates: (3)
    • field_name
      (field_name)
      <U32
      'J1311-2329_0' 'EM170817_1'

      array(['J1311-2329_0', 'EM170817_1'], dtype='<U32')

    • source_name
      (field_name)
      <U7
      dask.array<chunksize=(2,), meta=np.ndarray>

      Array Chunk Bytes 56 B 56 B Shape (2,) (2,) 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=(2, 2), meta=np.ndarray>

      frame :

      fk5

      type :

      sky_coord

      units :

      rad

      Array Chunk Bytes 32 B 32 B Shape (2, 2) (2, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (1)

    type :

    field_and_source

  /global_vlbi_gg084b_reduced_0/gain_curve_xds(13)

  • Dimensions:
    • time: 480
    • baseline_id: 57
    • frequency: 32
    • polarization: 4
    • uvw_label: 3
    • antenna_name: 14
    • poly_term: 3
    • receptor_label: 2
  • Coordinates: (8)
    • antenna_name
      (antenna_name)
      <U2
      'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

      array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP','BR', 'MK'], dtype='<U2')

    • antenna_id
      (antenna_name)
      int32
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 56 B 56 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type int32 numpy.ndarray

    • gain_curve_type
      (antenna_name)
      <U9
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 504 B 504 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • mount
      (antenna_name)
      <U16
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • station_name
      (antenna_name)
      <U2
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • telescope_name
      (antenna_name)
      <U3
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 168 B 168 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • 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=(14, 2), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

  • Data variables: (3)
    • GAIN_CURVE
      (antenna_name, poly_term, receptor_label)
      float64
      dask.array<chunksize=(14, 3, 2), meta=np.ndarray>

      Array Chunk Bytes 672 B 672 B Shape (14, 3, 2) (14, 3, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

    • GAIN_CURVE_INTERVAL
      (antenna_name)
      float64
      dask.array<chunksize=(14,), meta=np.ndarray>

      type :

      quantity

      units :

      s

      Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

    • GAIN_CURVE_SENSITIVITY
      (antenna_name, receptor_label)
      float64
      dask.array<chunksize=(14, 2), meta=np.ndarray>

      type :

      quantity

      units :

      K/Jy

      Array Chunk Bytes 224 B 224 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (2)

    measured_date :

    2018-05-26T15:33:49.500000000

    type :

    gain_curve

  /global_vlbi_gg084b_reduced_0/system_calibration_xds(10)

  • Dimensions:
    • time: 480
    • baseline_id: 57
    • frequency: 32
    • polarization: 4
    • uvw_label: 3
    • antenna_name: 14
    • time_system_cal: 10357
    • receptor_label: 2
  • Coordinates: (8)
    • antenna_name
      (antenna_name)
      <U2
      'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

      array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP','BR', 'MK'], dtype='<U2')

    • antenna_id
      (antenna_name)
      int32
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 56 B 56 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type int32 numpy.ndarray

    • mount
      (antenna_name)
      <U16
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • station_name
      (antenna_name)
      <U2
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • telescope_name
      (antenna_name)
      <U3
      dask.array<chunksize=(14,), meta=np.ndarray>

      Array Chunk Bytes 168 B 168 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

    • time_system_cal
      (time_system_cal)
      float64
      1.527e+09 1.527e+09 ... 1.527e+09

      format :

      unix

      scale :

      utc

      type :

      time

      units :

      s

      array([1.527340e+09, 1.527340e+09, 1.527340e+09, ..., 1.527406e+09,1.527406e+09, 1.527406e+09], shape=(10357,))

    • 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=(14, 2), meta=np.ndarray>

      Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

  • Data variables: (1)
    • TSYS
      (antenna_name, time_system_cal, receptor_label)
      float64
      dask.array<chunksize=(7, 5179, 1), meta=np.ndarray>

      type :

      quantity

      units :

      K

      Array Chunk Bytes 2.21 MiB 283.23 kiB Shape (14, 10357, 2) (7, 5179, 1) Dask graph 8 chunks in 2 graph layers Data type float64 numpy.ndarray

  • Attributes: (1)

    type :

    system_calibration

• Dimensions:
  • time: 480
  • baseline_id: 57
  • frequency: 32
  • polarization: 4
  • uvw_label: 3
• Coordinates: (9)
  • time
    (time)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 1.0, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527341e+09, 1.527341e+09, 1.527341e+09, ..., 1.527405e+09,
           1.527405e+09, 1.527405e+09], shape=(480,))

  • field_name
    (time)
    <U32
    dask.array<chunksize=(480,), meta=np.ndarray>

    Array Chunk Bytes 60.00 kiB 60.00 kiB Shape (480,) (480,) Dask graph 1 chunks in 2 graph layers Data type

  • scan_name
    (time)
    <U21
    dask.array<chunksize=(480,), meta=np.ndarray>

    scan_intents :

    ['None']

    Array Chunk Bytes 39.38 kiB 39.38 kiB Shape (480,) (480,) Dask graph 1 chunks in 2 graph layers Data type

  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 5 6 ... 51 52 53 54 55 56

    array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
           18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
           36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
           54, 55, 56])

  • baseline_antenna1_name
    (baseline_id)
    <U2
    dask.array<chunksize=(57,), meta=np.ndarray>

    Array Chunk Bytes 456 B 456 B Shape (57,) (57,) Dask graph 1 chunks in 2 graph layers Data type

  • baseline_antenna2_name
    (baseline_id)
    <U2
    dask.array<chunksize=(57,), meta=np.ndarray>

    Array Chunk Bytes 456 B 456 B Shape (57,) (57,) Dask graph 1 chunks in 2 graph layers Data type

  • frequency
    (frequency)
    float64
    4.9e+09 4.901e+09 ... 4.916e+09

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 500000.0, 'dims': []}

    observer :

    gcrs

    reference_frequency :

    {'attrs': {'observer': 'gcrs', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 4900500000.0, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    spw_0

    type :

    spectral_coord

    units :

    Hz

    array([4.9005e+09, 4.9010e+09, 4.9015e+09, 4.9020e+09, 4.9025e+09, 4.9030e+09,
           4.9035e+09, 4.9040e+09, 4.9045e+09, 4.9050e+09, 4.9055e+09, 4.9060e+09,
           4.9065e+09, 4.9070e+09, 4.9075e+09, 4.9080e+09, 4.9085e+09, 4.9090e+09,
           4.9095e+09, 4.9100e+09, 4.9105e+09, 4.9110e+09, 4.9115e+09, 4.9120e+09,
           4.9125e+09, 4.9130e+09, 4.9135e+09, 4.9140e+09, 4.9145e+09, 4.9150e+09,
           4.9155e+09, 4.9160e+09])

  • polarization
    (polarization)
    <U2
    'RR' 'RL' 'LR' 'LL'

    array(['RR', 'RL', 'LR', 'LL'], 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=(20, 57), meta=np.ndarray>

    type :

    quantity

    units :

    s

    Array Chunk Bytes 213.75 kiB 8.91 kiB Shape (480, 57) (20, 57) Dask graph 24 chunks in 2 graph layers Data type float64 numpy.ndarray

  • FLAG
    (time, baseline_id, frequency, polarization)
    bool
    dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>

    Array Chunk Bytes 3.34 MiB 4.45 kiB Shape (480, 57, 32, 4) (20, 57, 1, 4) Dask graph 768 chunks in 2 graph layers Data type bool numpy.ndarray

  • TIME_CENTROID
    (time, baseline_id)
    float64
    dask.array<chunksize=(20, 57), meta=np.ndarray>

    format :

    unix

    scale :

    utc

    type :

    time

    units :

    s

    Array Chunk Bytes 213.75 kiB 8.91 kiB Shape (480, 57) (20, 57) Dask graph 24 chunks in 2 graph layers Data type float64 numpy.ndarray

  • UVW
    (time, baseline_id, uvw_label)
    float64
    dask.array<chunksize=(20, 57, 3), meta=np.ndarray>

    frame :

    fk5

    type :

    uvw

    units :

    m

    Array Chunk Bytes 641.25 kiB 26.72 kiB Shape (480, 57, 3) (20, 57, 3) Dask graph 24 chunks in 2 graph layers Data type float64 numpy.ndarray

  • VISIBILITY
    (time, baseline_id, frequency, polarization)
    complex64
    dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>

    type :

    quanta

    units :

    unkown

    Array Chunk Bytes 26.72 MiB 35.62 kiB Shape (480, 57, 32, 4) (20, 57, 1, 4) Dask graph 768 chunks in 2 graph layers Data type complex64 numpy.ndarray

  • WEIGHT
    (time, baseline_id, frequency, polarization)
    float32
    dask.array<chunksize=(20, 57, 1, 4), meta=np.ndarray>

    Array Chunk Bytes 13.36 MiB 17.81 kiB Shape (480, 57, 32, 4) (20, 57, 1, 4) Dask graph 768 chunks in 2 graph layers Data type float32 numpy.ndarray

• Attributes: (7)

  creation_date :

  2026-04-20T21:21:22.222037+00:00

  creator :

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

  data_groups :

  {'base': {'correlated_data': 'VISIBILITY', 'date': '2026-04-20T21:21:22.257881+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': ['GG084B'], 'observing_log': '[]', 'project_UID': 'GG084B', 'release_date': '2018-05-26T13:11:00.500000000'}

  processor_info :

  {'sub_type': '', 'type': ''}

  schema_version :

  4.0.0

  type :

  visibility

ant_xds = ms_xdt.antenna_xds   # or ms_xdt["antenna_xds"]
ant_xds

<xarray.DataTree 'antenna_xds'>
Group: /global_vlbi_gg084b_reduced_0/antenna_xds
    Dimensions:                 (time: 480, baseline_id: 57, frequency: 32,
                                 polarization: 4, uvw_label: 3, antenna_name: 14,
                                 cartesian_pos_label: 3, receptor_label: 2)
    Coordinates:
      * antenna_name            (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'BR' 'MK'
        mount                   (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
        station_name            (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
        telescope_name          (antenna_name) <U3 168B dask.array<chunksize=(14,), 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 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
    Inherited coordinates:
      * baseline_id             (baseline_id) int64 456B 0 1 2 3 4 ... 53 54 55 56
      * frequency               (frequency) float64 256B 4.9e+09 ... 4.916e+09
      * polarization            (polarization) <U2 32B 'RR' 'RL' 'LR' 'LL'
      * time                    (time) float64 4kB 1.527e+09 1.527e+09 ... 1.527e+09
      * uvw_label               (uvw_label) <U1 12B 'u' 'v' 'w'
    Data variables:
        ANTENNA_DISH_DIAMETER   (antenna_name) float64 112B dask.array<chunksize=(14,), meta=np.ndarray>
        ANTENNA_POSITION        (antenna_name, cartesian_pos_label) float64 336B dask.array<chunksize=(14, 3), meta=np.ndarray>
        ANTENNA_RECEPTOR_ANGLE  (antenna_name, receptor_label) float64 224B dask.array<chunksize=(14, 2), meta=np.ndarray>
    Attributes:
        overall_telescope_name:  EVN
        relocatable_antennas:    False
        type:                    antenna

xarray.DataTree

'antenna_xds'

• Dimensions:
  • time: 480
  • baseline_id: 57
  • frequency: 32
  • polarization: 4
  • uvw_label: 3
  • antenna_name: 14
  • cartesian_pos_label: 3
  • receptor_label: 2
• Coordinates: (7)
  • antenna_name
    (antenna_name)
    <U2
    'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

    array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP',
           'BR', 'MK'], dtype='<U2')

  • mount
    (antenna_name)
    <U16
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • station_name
    (antenna_name)
    <U2
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • telescope_name
    (antenna_name)
    <U3
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 168 B 168 B Shape (14,) (14,) 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=(14, 2), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

• Inherited coordinates: (5)
  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 5 6 ... 51 52 53 54 55 56

    array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
           18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
           36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
           54, 55, 56])

  • frequency
    (frequency)
    float64
    4.9e+09 4.901e+09 ... 4.916e+09

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 500000.0, 'dims': []}

    observer :

    gcrs

    reference_frequency :

    {'attrs': {'observer': 'gcrs', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 4900500000.0, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    spw_0

    type :

    spectral_coord

    units :

    Hz

    array([4.9005e+09, 4.9010e+09, 4.9015e+09, 4.9020e+09, 4.9025e+09, 4.9030e+09,
           4.9035e+09, 4.9040e+09, 4.9045e+09, 4.9050e+09, 4.9055e+09, 4.9060e+09,
           4.9065e+09, 4.9070e+09, 4.9075e+09, 4.9080e+09, 4.9085e+09, 4.9090e+09,
           4.9095e+09, 4.9100e+09, 4.9105e+09, 4.9110e+09, 4.9115e+09, 4.9120e+09,
           4.9125e+09, 4.9130e+09, 4.9135e+09, 4.9140e+09, 4.9145e+09, 4.9150e+09,
           4.9155e+09, 4.9160e+09])

  • polarization
    (polarization)
    <U2
    'RR' 'RL' 'LR' 'LL'

    array(['RR', 'RL', 'LR', 'LL'], dtype='<U2')

  • time
    (time)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 1.0, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527341e+09, 1.527341e+09, 1.527341e+09, ..., 1.527405e+09,
           1.527405e+09, 1.527405e+09], shape=(480,))

  • 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=(14,), meta=np.ndarray>

    type :

    quantity

    units :

    m

    Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • ANTENNA_POSITION
    (antenna_name, cartesian_pos_label)
    float64
    dask.array<chunksize=(14, 3), meta=np.ndarray>

    coordinate_system :

    geocentric

    frame :

    ITRS

    origin_object_name :

    earth

    type :

    location

    units :

    m

    Array Chunk Bytes 336 B 336 B Shape (14, 3) (14, 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=(14, 2), meta=np.ndarray>

    type :

    quantity

    units :

    rad

    Array Chunk Bytes 224 B 224 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (3)

  overall_telescope_name :

  EVN

  relocatable_antennas :

  False

  type :

  antenna

ant_xds.antenna_name.values

array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT',
       'KP', 'BR', 'MK'], dtype='<U2')

ms_xdt.baseline_antenna2_name.values

array(['BD', 'HH', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YS', 'SC',
       'HN', 'GB', 'NL', 'FD', 'SC', 'HN', 'GB', 'NL', 'FD', 'HN', 'GB',
       'NL', 'FD', 'GB', 'NL', 'FD', 'NL', 'FD', 'FD', 'YY', 'LA', 'PT',
       'KP', 'BR', 'MK', 'YY', 'LA', 'PT', 'KP', 'BR', 'MK', 'LA', 'PT',
       'KP', 'BR', 'MK', 'PT', 'KP', 'BR', 'MK', 'KP', 'BR', 'MK', 'BR',
       'MK', 'MK'], dtype='<U2')

ms_xdt.xr_ms.get_field_and_source_xds()

<xarray.DatasetView> Size: 5kB
Dimensions:                       (field_name: 2, sky_dir_label: 2,
                                   baseline_id: 57, frequency: 32,
                                   polarization: 4, time: 480, uvw_label: 3)
Coordinates:
  * field_name                    (field_name) <U32 256B 'J1311-2329_0' 'EM17...
    source_name                   (field_name) <U7 56B dask.array<chunksize=(2,), meta=np.ndarray>
  * sky_dir_label                 (sky_dir_label) <U3 24B 'ra' 'dec'
  * baseline_id                   (baseline_id) int64 456B 0 1 2 3 ... 54 55 56
  * frequency                     (frequency) float64 256B 4.9e+09 ... 4.916e+09
  * polarization                  (polarization) <U2 32B 'RR' 'RL' 'LR' 'LL'
  * time                          (time) float64 4kB 1.527e+09 ... 1.527e+09
  * uvw_label                     (uvw_label) <U1 12B 'u' 'v' 'w'
Data variables:
    FIELD_PHASE_CENTER_DIRECTION  (field_name, sky_dir_label) float64 32B dask.array<chunksize=(2, 2), meta=np.ndarray>
Attributes:
    type:     field_and_source

xarray.DatasetView

• Dimensions:
  • field_name: 2
  • sky_dir_label: 2
  • baseline_id: 57
  • frequency: 32
  • polarization: 4
  • time: 480
  • uvw_label: 3
• Coordinates: (8)
  • field_name
    (field_name)
    <U32
    'J1311-2329_0' 'EM170817_1'

    array(['J1311-2329_0', 'EM170817_1'], dtype='<U32')

  • source_name
    (field_name)
    <U7
    dask.array<chunksize=(2,), meta=np.ndarray>

    Array Chunk Bytes 56 B 56 B Shape (2,) (2,) 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 5 6 ... 51 52 53 54 55 56

    array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
           18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
           36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
           54, 55, 56])

  • frequency
    (frequency)
    float64
    4.9e+09 4.901e+09 ... 4.916e+09

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 500000.0, 'dims': []}

    observer :

    gcrs

    reference_frequency :

    {'attrs': {'observer': 'gcrs', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 4900500000.0, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    spw_0

    type :

    spectral_coord

    units :

    Hz

    array([4.9005e+09, 4.9010e+09, 4.9015e+09, 4.9020e+09, 4.9025e+09, 4.9030e+09,
           4.9035e+09, 4.9040e+09, 4.9045e+09, 4.9050e+09, 4.9055e+09, 4.9060e+09,
           4.9065e+09, 4.9070e+09, 4.9075e+09, 4.9080e+09, 4.9085e+09, 4.9090e+09,
           4.9095e+09, 4.9100e+09, 4.9105e+09, 4.9110e+09, 4.9115e+09, 4.9120e+09,
           4.9125e+09, 4.9130e+09, 4.9135e+09, 4.9140e+09, 4.9145e+09, 4.9150e+09,
           4.9155e+09, 4.9160e+09])

  • polarization
    (polarization)
    <U2
    'RR' 'RL' 'LR' 'LL'

    array(['RR', 'RL', 'LR', 'LL'], dtype='<U2')

  • time
    (time)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 1.0, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527341e+09, 1.527341e+09, 1.527341e+09, ..., 1.527405e+09,
           1.527405e+09, 1.527405e+09], shape=(480,))

  • 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=(2, 2), meta=np.ndarray>

    frame :

    fk5

    type :

    sky_coord

    units :

    rad

    Array Chunk Bytes 32 B 32 B Shape (2, 2) (2, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (1)

  type :

  field_and_source

ms_xdt.gain_curve_xds

<xarray.DataTree 'gain_curve_xds'>
Group: /global_vlbi_gg084b_reduced_0/gain_curve_xds
    Dimensions:                 (time: 480, baseline_id: 57, frequency: 32,
                                 polarization: 4, uvw_label: 3, antenna_name: 14,
                                 poly_term: 3, receptor_label: 2)
    Coordinates:
      * antenna_name            (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'BR' 'MK'
        antenna_id              (antenna_name) int32 56B dask.array<chunksize=(14,), meta=np.ndarray>
        gain_curve_type         (antenna_name) <U9 504B dask.array<chunksize=(14,), meta=np.ndarray>
        mount                   (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
        station_name            (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
        telescope_name          (antenna_name) <U3 168B dask.array<chunksize=(14,), meta=np.ndarray>
      * receptor_label          (receptor_label) <U5 40B 'pol_0' 'pol_1'
        polarization_type       (antenna_name, receptor_label) <U1 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
    Inherited coordinates:
      * baseline_id             (baseline_id) int64 456B 0 1 2 3 4 ... 53 54 55 56
      * frequency               (frequency) float64 256B 4.9e+09 ... 4.916e+09
      * polarization            (polarization) <U2 32B 'RR' 'RL' 'LR' 'LL'
      * time                    (time) float64 4kB 1.527e+09 1.527e+09 ... 1.527e+09
      * uvw_label               (uvw_label) <U1 12B 'u' 'v' 'w'
    Dimensions without coordinates: poly_term
    Data variables:
        GAIN_CURVE              (antenna_name, poly_term, receptor_label) float64 672B dask.array<chunksize=(14, 3, 2), meta=np.ndarray>
        GAIN_CURVE_INTERVAL     (antenna_name) float64 112B dask.array<chunksize=(14,), meta=np.ndarray>
        GAIN_CURVE_SENSITIVITY  (antenna_name, receptor_label) float64 224B dask.array<chunksize=(14, 2), meta=np.ndarray>
    Attributes:
        measured_date:  2018-05-26T15:33:49.500000000
        type:           gain_curve

xarray.DataTree

'gain_curve_xds'

• Dimensions:
  • time: 480
  • baseline_id: 57
  • frequency: 32
  • polarization: 4
  • uvw_label: 3
  • antenna_name: 14
  • poly_term: 3
  • receptor_label: 2
• Coordinates: (8)
  • antenna_name
    (antenna_name)
    <U2
    'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

    array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP',
           'BR', 'MK'], dtype='<U2')

  • antenna_id
    (antenna_name)
    int32
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 56 B 56 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type int32 numpy.ndarray

  • gain_curve_type
    (antenna_name)
    <U9
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 504 B 504 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • mount
    (antenna_name)
    <U16
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • station_name
    (antenna_name)
    <U2
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • telescope_name
    (antenna_name)
    <U3
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 168 B 168 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • 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=(14, 2), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

• Inherited coordinates: (5)
  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 5 6 ... 51 52 53 54 55 56

    array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
           18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
           36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
           54, 55, 56])

  • frequency
    (frequency)
    float64
    4.9e+09 4.901e+09 ... 4.916e+09

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 500000.0, 'dims': []}

    observer :

    gcrs

    reference_frequency :

    {'attrs': {'observer': 'gcrs', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 4900500000.0, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    spw_0

    type :

    spectral_coord

    units :

    Hz

    array([4.9005e+09, 4.9010e+09, 4.9015e+09, 4.9020e+09, 4.9025e+09, 4.9030e+09,
           4.9035e+09, 4.9040e+09, 4.9045e+09, 4.9050e+09, 4.9055e+09, 4.9060e+09,
           4.9065e+09, 4.9070e+09, 4.9075e+09, 4.9080e+09, 4.9085e+09, 4.9090e+09,
           4.9095e+09, 4.9100e+09, 4.9105e+09, 4.9110e+09, 4.9115e+09, 4.9120e+09,
           4.9125e+09, 4.9130e+09, 4.9135e+09, 4.9140e+09, 4.9145e+09, 4.9150e+09,
           4.9155e+09, 4.9160e+09])

  • polarization
    (polarization)
    <U2
    'RR' 'RL' 'LR' 'LL'

    array(['RR', 'RL', 'LR', 'LL'], dtype='<U2')

  • time
    (time)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 1.0, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527341e+09, 1.527341e+09, 1.527341e+09, ..., 1.527405e+09,
           1.527405e+09, 1.527405e+09], shape=(480,))

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

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

• Data variables: (3)
  • GAIN_CURVE
    (antenna_name, poly_term, receptor_label)
    float64
    dask.array<chunksize=(14, 3, 2), meta=np.ndarray>

    Array Chunk Bytes 672 B 672 B Shape (14, 3, 2) (14, 3, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • GAIN_CURVE_INTERVAL
    (antenna_name)
    float64
    dask.array<chunksize=(14,), meta=np.ndarray>

    type :

    quantity

    units :

    s

    Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

  • GAIN_CURVE_SENSITIVITY
    (antenna_name, receptor_label)
    float64
    dask.array<chunksize=(14, 2), meta=np.ndarray>

    type :

    quantity

    units :

    K/Jy

    Array Chunk Bytes 224 B 224 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (2)

  measured_date :

  2018-05-26T15:33:49.500000000

  type :

  gain_curve

ms_xdt.system_calibration_xds   # or ms_xdt["system_calibration_xds"]

<xarray.DataTree 'system_calibration_xds'>
Group: /global_vlbi_gg084b_reduced_0/system_calibration_xds
    Dimensions:            (time: 480, baseline_id: 57, frequency: 32,
                            polarization: 4, uvw_label: 3, antenna_name: 14,
                            time_system_cal: 10357, receptor_label: 2)
    Coordinates:
      * antenna_name       (antenna_name) <U2 112B 'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'
        antenna_id         (antenna_name) int32 56B dask.array<chunksize=(14,), meta=np.ndarray>
        mount              (antenna_name) <U16 896B dask.array<chunksize=(14,), meta=np.ndarray>
        station_name       (antenna_name) <U2 112B dask.array<chunksize=(14,), meta=np.ndarray>
        telescope_name     (antenna_name) <U3 168B dask.array<chunksize=(14,), meta=np.ndarray>
      * time_system_cal    (time_system_cal) float64 83kB 1.527e+09 ... 1.527e+09
      * receptor_label     (receptor_label) <U5 40B 'pol_0' 'pol_1'
        polarization_type  (antenna_name, receptor_label) <U1 112B dask.array<chunksize=(14, 2), meta=np.ndarray>
    Inherited coordinates:
      * baseline_id        (baseline_id) int64 456B 0 1 2 3 4 5 ... 52 53 54 55 56
      * frequency          (frequency) float64 256B 4.9e+09 4.901e+09 ... 4.916e+09
      * polarization       (polarization) <U2 32B 'RR' 'RL' 'LR' 'LL'
      * time               (time) float64 4kB 1.527e+09 1.527e+09 ... 1.527e+09
      * uvw_label          (uvw_label) <U1 12B 'u' 'v' 'w'
    Data variables:
        TSYS               (antenna_name, time_system_cal, receptor_label) float64 2MB dask.array<chunksize=(7, 5179, 1), meta=np.ndarray>
    Attributes:
        type:     system_calibration

xarray.DataTree

'system_calibration_xds'

• Dimensions:
  • time: 480
  • baseline_id: 57
  • frequency: 32
  • polarization: 4
  • uvw_label: 3
  • antenna_name: 14
  • time_system_cal: 10357
  • receptor_label: 2
• Coordinates: (8)
  • antenna_name
    (antenna_name)
    <U2
    'BD' 'HH' 'YS' ... 'KP' 'BR' 'MK'

    array(['BD', 'HH', 'YS', 'SC', 'HN', 'GB', 'NL', 'FD', 'YY', 'LA', 'PT', 'KP',
           'BR', 'MK'], dtype='<U2')

  • antenna_id
    (antenna_name)
    int32
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 56 B 56 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type int32 numpy.ndarray

  • mount
    (antenna_name)
    <U16
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 896 B 896 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • station_name
    (antenna_name)
    <U2
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • telescope_name
    (antenna_name)
    <U3
    dask.array<chunksize=(14,), meta=np.ndarray>

    Array Chunk Bytes 168 B 168 B Shape (14,) (14,) Dask graph 1 chunks in 2 graph layers Data type

  • time_system_cal
    (time_system_cal)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527340e+09, 1.527340e+09, 1.527340e+09, ..., 1.527406e+09,
           1.527406e+09, 1.527406e+09], shape=(10357,))

  • 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=(14, 2), meta=np.ndarray>

    Array Chunk Bytes 112 B 112 B Shape (14, 2) (14, 2) Dask graph 1 chunks in 2 graph layers Data type

• Inherited coordinates: (5)
  • baseline_id
    (baseline_id)
    int64
    0 1 2 3 4 5 6 ... 51 52 53 54 55 56

    array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
           18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
           36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
           54, 55, 56])

  • frequency
    (frequency)
    float64
    4.9e+09 4.901e+09 ... 4.916e+09

    channel_width :

    {'attrs': {'type': 'quantity', 'units': 'Hz'}, 'data': 500000.0, 'dims': []}

    observer :

    gcrs

    reference_frequency :

    {'attrs': {'observer': 'gcrs', 'type': 'spectral_coord', 'units': 'Hz'}, 'data': 4900500000.0, 'dims': []}

    spectral_window_intents :

    ['UNSPECIFIED']

    spectral_window_name :

    spw_0

    type :

    spectral_coord

    units :

    Hz

    array([4.9005e+09, 4.9010e+09, 4.9015e+09, 4.9020e+09, 4.9025e+09, 4.9030e+09,
           4.9035e+09, 4.9040e+09, 4.9045e+09, 4.9050e+09, 4.9055e+09, 4.9060e+09,
           4.9065e+09, 4.9070e+09, 4.9075e+09, 4.9080e+09, 4.9085e+09, 4.9090e+09,
           4.9095e+09, 4.9100e+09, 4.9105e+09, 4.9110e+09, 4.9115e+09, 4.9120e+09,
           4.9125e+09, 4.9130e+09, 4.9135e+09, 4.9140e+09, 4.9145e+09, 4.9150e+09,
           4.9155e+09, 4.9160e+09])

  • polarization
    (polarization)
    <U2
    'RR' 'RL' 'LR' 'LL'

    array(['RR', 'RL', 'LR', 'LL'], dtype='<U2')

  • time
    (time)
    float64
    1.527e+09 1.527e+09 ... 1.527e+09

    format :

    unix

    integration_time :

    {'attrs': {'type': 'quantity', 'units': 's'}, 'data': 1.0, 'dims': []}

    scale :

    utc

    type :

    time

    units :

    s

    array([1.527341e+09, 1.527341e+09, 1.527341e+09, ..., 1.527405e+09,
           1.527405e+09, 1.527405e+09], shape=(480,))

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

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

• Data variables: (1)
  • TSYS
    (antenna_name, time_system_cal, receptor_label)
    float64
    dask.array<chunksize=(7, 5179, 1), meta=np.ndarray>

    type :

    quantity

    units :

    K

    Array Chunk Bytes 2.21 MiB 283.23 kiB Shape (14, 10357, 2) (7, 5179, 1) Dask graph 8 chunks in 2 graph layers Data type float64 numpy.ndarray

• Attributes: (1)

  type :

  system_calibration

ps_xdt.xr_ps.plot_antenna_positions_2d()

ps_xdt.xr_ps.plot_phase_centers()