QA Metric Exposure in MccsSubarray

Overview

This document describes the design for exposing Quality Assurance (QA) metrics from the MccsSubarray Tango device.

The interface is defined under:

MccsSubarray.qualityAssuranceMetrics

Purpose

The QA metrics interface is intended to:

Expose QA state for all beams within a subarray
Enable external systems to monitor beam QA in a single place via event-driven updates
Evolve with versioned SCHEMA.

Core Concept

The interface exposes a hierarchical view of QA metrics:

Subarray level - Aggregated metrics across all beams
Beam level - Aggregated metrics across apertures
Aperture level - Fine-grained QA metrics per aperture

The initial metric supported is:

is_beam_locked – indicates whether pointing delays are being updated in a timely and consistent manner

Data Model

Top-Level Structure

{
  "subarray_beams": {
    "<subarray_beam_id>": {
      "apertures": {
        "<aperture_id>": {
          "is_beam_locked": bool,
          "<metric_name>": value
        }
      },
      "is_beam_locked": bool
    }
  },
  "beam_locked_percent": float
}

Field Definitions

subarray_beams

A dictionary keyed by subarray_beam_id.

Each entry represents a beam within the subarray and contains:

A set of aperture-level QA metrics
A derived beam-level is_beam_locked state

subarray_beams.<beam_id>.apertures

Dictionary keyed by aperture_id (e.g. AP001.01).

This is aligned with the allocation and configuration SCHEMA.

subarray_beams.<beam_id>.is_beam_locked

A derived boolean metric representing the aggregated lock state of the beam.

This value is computed from aperture-level is_beam_locked states.

It provides a simplified view for higher-level consumers that do not require aperture-level granularity.

beam_locked_percent

A derived subarray-level metric representing the percentage of beams that are currently locked.

This is intended for:

Dashboard summarisation
Alerting thresholds
High-level system health monitoring

Example

{
  "subarray_beams": {
    "1": {
      "apertures": {
        "AP001.01": {
          "is_beam_locked": true
        },
        "AP002.01": {
          "is_beam_locked": false
        }
      },
      "is_beam_locked": false
    },
    "2": {
      "apertures": {
        "AP003.01": {
          "is_beam_locked": false
        }
      },
      "is_beam_locked": false
    }
  },
  "beam_locked_percent": 0.0
}