Band 5 Down Conversion Support
==============================

The Subarray Node has been updated to support **Band 5 Down Conversion** by propagating the
`band5_downconversion_subband` parameter from the `dish` configuration block into the `csp.common` section.

AssignResources
---------------

No changes are required for Band 5 down conversion in AssignResources, but the subarray node
now supports standard assignment of receptors. Example AssignResources JSON:

.. code-block:: json

    {
      "interface": "https://schema.skao.int/ska-tmc-assignresources/2.2",
      "transaction_id": "txn-....-00001",
      "subarray_id": 1,
      "dish": {
        "receptor_ids": [
          "SKA001",
          "SKA036",
          "SKA063",
          "SKA100"
        ]
      },
      "sdp": {
        "interface": "https://schema.skao.int/ska-sdp-assignres/1.0",
        "execution_block": {
          "eb_id": "",
          "max_length": 100,
          "context": {},
          "beams": [
            {
              "beam_id": "vis0",
              "visibility_beam_id": 1,
              "function": "visibilities"
            }
          ],
          "scan_types": [
            {
              "scan_type_id": "my_scan",
              "beams": {
                "vis0": {
                  "field_ref": "my_field",
                  "channels_ref": "vis_channels",
                  "polarisations_ref": "all"
                }
              }
            }
          ],
          "channels": [
            {
              "channels_id": "vis_channels",
              "spectral_windows": [
                {
                  "spectral_window_id": "fsp_1_channels",
                  "count": 52080,
                  "start": 0,
                  "stride": 1,
                  "freq_min": 11450044800,
                  "freq_max": 12150000000
                }
              ]
            }
          ],
          "polarisations": [
            {
              "polarisations_id": "all",
              "corr_type": [
                "XX",
                "XY",
                "YX",
                "YY"
              ]
            }
          ],
          "fields": [
            {
              "field_id": "my_field",
              "phase_dir": {
                "target_name": "Polaris Australis",
                "reference_frame": "icrs",
                "attrs": {
                  "c1": 317.19966667,
                  "c2": -88.95636111
                }
              }
            }
          ]
        },
        "processing_blocks": [
          {
            "pb_id": "",
            "sbi_refs": [],
            "script": {
              "version": "5.1.1",
              "name": "vis_receive",
              "kind": "realtime"
            }
          }
        ],
        "resources": {
          "receptors": [
            "SKA001",
            "SKA036",
            "SKA063",
            "SKA100"
          ]
        }
      }
    }

Configure
---------

Users should provide `band5_downconversion_subband` inside the `dish` block in Configure.
The Subarray Node adds the same to the `csp.common` so CSP receives the correct
parameter for Band 5 down conversion.

**Example Configure JSON snippet:**

.. code-block:: json

    {
      "interface": "https://schema.skao.int/ska-tmc-configure/5.0",
      "dish": {
        "interface": "https://schema.skao.int/ska-dish-configure/1.0",
        "receiver_band": "5b",
        "band5_downconversion_subband": "1",
        "spfrx_processing_parameters": [
          {
            "dishes": ["SKA001"],
            "sync_pps": false,
            "attenuation_pol_x": 20.0,
            "attenuation_pol_y": 20.0,
            "saturation_threshold": 0.7,
            "noise_diode": {
              "pseudo_random": {
                "binary_polynomial": 2,
                "seed": 2,
                "dwell": 2
              }
            }
          }
        ]
      },
      "pointing": {
        "wrap_sector": 0,
        "ca_offset_arcsec": 0.0,
        "ie_offset_arcsec": 0.0,
        "groups": [
          {
            "receptors": ["SKA001", "SKA036", "SKA063", "SKA100"],
            "field": {
              "target_name": "Polaris Australis",
              "reference_frame": "icrs",
              "attrs": {"c1": 317.19966666666664, "c2": -88.95636111111111}
            },
            "trajectory": {"name": "fixed", "attrs": {"x": 1.23, "y": 4.56}},
            "projection": {"name": "SSN", "alignment": "ICRS"}
          }
        ]
      },
      "csp": {
        "interface": "https://schema.skao.int/ska-csp-configurescan/8.1",
        "common": {
          "config_id": "my_config",
          "frequency_band": "1",
          "band5_downconversion_subband": "1"
        },
        "midcbf": {
          "correlation": {
            "processing_regions": [
              {
                "fsp_ids": [1,2,3,4],
                "start_freq": 350006720,
                "channel_width": 13440,
                "channel_count": 52080,
                "sdp_start_channel_id": 0,
                "integration_factor": 1
              }
            ]
          }
        }
      },
      "sdp": {"interface": "https://schema.skao.int/ska-sdp-configure/1.0", "scan_type": "science_A"},
      "tmc": {"scan_duration": 10.0}
    }