Trend Analysis
Explore historical half-hour and daily summary metrics. For underlying measurements, use Data Explorer.
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Summary time series
Triangles mark stored quality problems or incomplete record availability. Small fractional Coverage deficits alone do not trigger this marker. Values remain included.
About the CSV fields
Exports contain selected stored summary observations, including in Histogram view. The first row is the column header. Values retain full precision; missing/unavailable values are blank. Missing slots are enumerated only within available history. Each numeric summary counts once in a histogram, regardless of sample count or coverage.
Record availability counts expected one-second records. Coverage measures observed time. Analytical quality checks input continuity; neither Complete category establishes calibration or accuracy. Import integer microsecond columns as Text in Excel. Booleans use 1/0; text is protected against spreadsheet formulas.
| Field | Definition / units |
|---|---|
| selection_from, selection_to | Requested range, repeated per row: offset-bearing half-hour timestamps (End exclusive), or daily dates (both inclusive). |
| level | halfhour or daily; summary interval type. |
| metric | Selected configured metric key; determines value semantics. |
| unit | Display/export unit of value, supplied by metric metadata. |
| config_version | Trend metric/presentation configuration identifier; distinct from calculator method. |
| source_binding | explicit product-source binding or legacy_assumed; latter assumes A1 for an unbound legacy product. |
| source_station_id | Stable product monitor identity (currently guarded to A1), not display name or within-period composite lineage. |
| start_utc_us, end_utc_us | Exact interval boundaries as integer Unix microseconds; End exclusive. Import as Text in Excel. |
| start_aest, end_aest | Human-readable Brisbane interval timestamps derived from microseconds. |
| date | Queensland date at interval start. |
| state | value, null_value (stored row but selected value unavailable), or missing_summary (no stored row). |
| value | Full-precision selected stored metric after configured unit scaling; blank for missing/unavailable values. |
| sample_count | Count of accepted finite frequency endpoints in the summary interval; records, not duration or RoCoF-estimate count. |
| coverage_percent | Union duration of accepted measurement windows within the interval / interval duration ×100; %, overlaps counted once. |
| largest_gap_seconds | Longest uncovered duration in that union, including leading/trailing edges; seconds. |
| data_quality | Deprecated compatibility alias of record_availability. Retained for existing field readers; values now use Complete / Operational / Incomplete. |
| record_availability | Expected-record availability category: Complete ≥99%, Operational ≥95% and <99%, Incomplete <95%. Complete allows small gaps and does not establish accuracy. |
| record_availability_percent | Accepted record count / expected one-second record count ×100; %, distinct from time coverage. |
| quality_status | Stored analytical assessment: complete requires ≥99% observed-time coverage, no uncovered gap over 300 s, no invalid/duplicate input rows and no overlap over 0.5 s; otherwise incomplete. Distinct from expected-record availability and instrument accuracy. |
| quality_reasons | Comma-separated stored reason codes, quoted as one CSV cell; empty when no reasons. Codes: insufficient_coverage, excessive_gap, invalid_rows, duplicate_endpoints, overlapping_windows. |
| method_version | Stored core calculation method, currently core-v1: endpoint frequency statistics, measurement-window coverage/gaps, quality checks, deviation integrals and derived clock error. Not a software revision or calibration identifier; it does not guarantee every historical row has later-added fields. RoCoF has its own method field. |
| generated_at | Stored UTC generation timestamp; not observation time, download time or evidence of continuous recalculation. |
| typical_lower_hz, typical_upper_hz | Historical Typical Range bounds stored with the summary; Hz, nullable. |
| typical_mode | Stored Typical Range provenance mode (dynamic/fallback), nullable for unavailable historical context. |
| rocof_method | Stored RoCoF algorithm identifier, endpoint-linear-v1 for current generation; nullable for older rows. |
| zero_samples | 1 when a stored row has zero accepted frequency samples, otherwise 0; missing row leaves blank. |
| degraded | 1 if analytical status is not complete, coverage <100%, or record availability <99%; otherwise 0. Broader context flag than the chart marker. |
Metric values: Frequency in Hz; Mean Deviation signed mHz from 50 Hz; Standard Deviation population dispersion in mHz; Typical Range percentage of accepted records within stored inclusive limits; Max RoCoF maximum absolute eligible rate in mHz/s; Clock Error signed ms gained/lost; Absolute Deviation integrated magnitude in Hz·s. Coverage uses %, Samples records, Largest Gap seconds. Shared metric unit/scaling applies to exported value.
Observation values and quality details
Missing summaries and unavailable stored values remain gaps. The table provides keyboard-accessible details for every selected observation.
Complete record availability means ≥99% of expected one-second records were received; small gaps may remain. Analytical quality is a separate assessment.
On narrow screens, scroll the table sideways to see all fields. Keyboard users can focus the table region and use the arrow keys.
| Interval / Date | Value | Coverage | Samples | Largest gap | Record availability | Analytical quality / Notes |
|---|