ska-low-tmc-configure

Low TMC configure 2.0

Example JSON.
{
    "interface": "https://schema.skao.in/ska-low-tmc-configure/2.0",
    "transaction_id": "txn-....-00001",
    "mccs": {
        "stations": [{
            "station_id": 1
        }, {
            "station_id": 2
        }],
        "subarray_beams": [{
            "subarray_beam_id": 1,
            "station_ids": [1, 2],
            "update_rate": 0.0,
            "channels": [
                [0, 8, 1, 1],
                [8, 8, 2, 1],
                [24, 16, 2, 1]
            ],
            "antenna_weights": [1.0, 1.0, 1.0],
            "phase_centre": [0.0, 0.0],
            "target": {
                "reference_frame": "HORIZON",
                "target_name": "DriftScan",
                "az": 180.0,
                "el": 45.0
            }
        }]
    },
    "tmc": {
        "scan_duration": 10.0
    }
}
https://schema.skao.int/ska-low-tmc-configure/2.0
type object
properties
  • interface
URI of JSON schema applicable to this JSON payload.
type string
  • transaction_id
A transaction id specific to the command
type string
  • mccs
MCCS configuration specification.
type object
properties
  • stations

IDs of the MCCS stations to configure.

Maximum array size = 512, the maximum number of MCCS stations.

type array
items type object
properties
  • station_id

MCCS Station ID.

Each ID must be between 1 and 512.

type integer
additionalProperties False
  • subarray_beams
MCCS sub-array beam configuration.
type array
items type object
properties
  • subarray_beam_id

ID of MCCS sub-array beam to configure.

ID must be an integer between 1 and 48.

type integer
  • station_ids

IDs of MCCS stations within this sub-array beamto configure.

Array size must be less than 512, the maximum number of MCCS stations.

Each item in the list must be an integer between 1 and 512.

type array
items type integer
  • update_rate

Update rate for pointing information.

Value must be 0.0 or greater.

TODO: clarify whether this is specified as a frequency or as a cadence, plus units.

type number
  • channels

Channel block configurations.

Each item in the list is a channel block configuration, each specified as a list of 4 numbers as follows:

[start channel, number of channels, beam index, sub-station index]

Constraints are:

0 < start channel < 376

start channel must be a multiple of 8

8 < number of channels < 48

1 < beam index < 48

1 < sub-station index < 8

type array
items type array
items type integer
  • antenna_weights

Antenna weights.

Maximum array size = 512 (=256 antennas x2 pols per sub-array beam).

Antennas signals can be weighted to modify the station beam, varying from 0.0 for full exclusion to potentially 256.0 for an antenna contribution compensated for the number of antennas in the beam. This value is an amplitude multiplier added to that antenna signal before adding into the sum.

Weights apply to all channels assigned to a beam.

type array
items type number
  • phase_centre

Phase centre offset for the station beam, in metres.

The reference position for station phase must be modified to reflect antenna weighting and their contribution to the station beam. This offset can be can considered the desired centre of mass for the station.

Constraints: array size = 2 -20 < phase centre value < 20

type array
items type number
  • target

Target position for the sub-array beam.

Only drift scan targets are currently implemented by MCCS, hence only azimuth and elevation are specified.

type object
properties
  • reference_frame

Co-ordinate system.

Must be HORIZON for drift scan.

type string
  • target_name
Name of target.
type string
  • az
Pointing azimuth in degrees.
type number
  • el
Pointing elevation in degrees.
type number
additionalProperties False
additionalProperties False
additionalProperties False
  • tmc
TMC configuration specification.
type object
properties
  • scan_duration

Scan duration in seconds.

Value must be >= 0.0

type number
additionalProperties False
additionalProperties False

Low TMC configure 1.0

Example JSON.
{
    "interface": "https://schema.skatelescope.org/ska-low-tmc-configure/1.0",
    "mccs": {
        "stations": [{
            "station_id": 1
        }, {
            "station_id": 2
        }],
        "subarray_beams": [{
            "subarray_beam_id": 1,
            "station_ids": [1, 2],
            "update_rate": 0.0,
            "channels": [
                [0, 8, 1, 1],
                [8, 8, 2, 1],
                [24, 16, 2, 1]
            ],
            "antenna_weights": [1.0, 1.0, 1.0],
            "phase_centre": [0.0, 0.0],
            "target": {
                "system": "HORIZON",
                "name": "DriftScan",
                "az": 180.0,
                "el": 45.0
            }
        }]
    },
    "tmc": {
        "scan_duration": 10.0
    }
}
https://schema.skatelescope.org/ska-low-tmc-configure/1.0
type object
properties
  • interface
URI of JSON schema applicable to this JSON payload.
type string
  • transaction_id
A transaction id specific to the command
type string
  • mccs
MCCS configuration specification.
type object
properties
  • stations

IDs of the MCCS stations to configure.

Maximum array size = 512, the maximum number of MCCS stations.

type array
items type object
properties
  • station_id

MCCS Station ID.

Each ID must be between 1 and 512.

type integer
additionalProperties False
  • subarray_beams
MCCS sub-array beam configuration.
type array
items type object
properties
  • subarray_beam_id

ID of MCCS sub-array beam to configure.

ID must be an integer between 1 and 48.

type integer
  • station_ids

IDs of MCCS stations within this sub-array beamto configure.

Array size must be less than 512, the maximum number of MCCS stations.

Each item in the list must be an integer between 1 and 512.

type array
items type integer
  • update_rate

Update rate for pointing information.

Value must be 0.0 or greater.

TODO: clarify whether this is specified as a frequency or as a cadence, plus units.

type number
  • channels

Channel block configurations.

Each item in the list is a channel block configuration, each specified as a list of 4 numbers as follows:

[start channel, number of channels, beam index, sub-station index]

Constraints are:

0 < start channel < 376

start channel must be a multiple of 8

8 < number of channels < 48

1 < beam index < 48

1 < sub-station index < 8

type array
items type array
items type integer
  • antenna_weights

Antenna weights.

Maximum array size = 512 (=256 antennas x2 pols per sub-array beam).

Antennas signals can be weighted to modify the station beam, varying from 0.0 for full exclusion to potentially 256.0 for an antenna contribution compensated for the number of antennas in the beam. This value is an amplitude multiplier added to that antenna signal before adding into the sum.

Weights apply to all channels assigned to a beam.

type array
items type number
  • phase_centre

Phase centre offset for the station beam, in metres.

The reference position for station phase must be modified to reflect antenna weighting and their contribution to the station beam. This offset can be can considered the desired centre of mass for the station.

Constraints: array size = 2 -20 < phase centre value < 20

type array
items type number
  • target

Target position for the sub-array beam.

Only drift scan targets are currently implemented by MCCS, hence only azimuth and elevation are specified.

type object
properties
  • system

Co-ordinate system.

Must be HORIZON for drift scan.

type string
  • name
Name of target.
type string
  • az
Pointing azimuth in degrees.
type number
  • el
Pointing elevation in degrees.
type number
additionalProperties False
additionalProperties False
additionalProperties False
  • tmc
TMC configuration specification.
type object
properties
  • scan_duration

Scan duration in seconds.

Value must be >= 0.0

type number
additionalProperties False
additionalProperties False