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 configure 1.0

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

True

  • subarray_beams

MCCS sub-array beam configuration.

type

array

items

MCCS subarray beams 1.0

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

  • update_rate

Cadence in seconds of pointing correction updates.

If set, the value must be 0.0 or greater.

type

number

  • 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

default

null

items

type

integer

  • 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

default

null

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

default

null

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

default

null

items

type

number

  • target

MCCS target 1.0

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

default

null

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

True

additionalProperties

True

additionalProperties

True

  • tmc

TMC configuration specification.

type

object

properties

  • scan_duration

Scan duration in seconds.

Value must be >= 0.0

allOf

type

number

additionalProperties

True

additionalProperties

True