How GeoLira decides whether a value is current, stale, degraded or unavailable. Missing data is never silently converted to zero, and each provider has its own freshness and failure policy.
Freshness belongs to the specific product
Each source has its own publication cadence. For NOAA RTSW and GOES, observed operational latency led GeoLira to use a 600 second warning threshold and 1200 second hard stale age in critical current-data paths. Kp has a longer cadence and separate limits. HTTP success by itself never proves that the payload is current.
STALE never means zero
An old record may be shown as the last known value only where the contract allows it and the interface clearly labels STALE. Features that require current evidence, including selected alerts and authored indices, reject hard-expired records. A missing observation is not a zero observation and is never substituted as one.
Quality flags, contaminated samples and event revisions
SOURCE_WARNING cannot enter the verified current cache. OUT_OF_RANGE and BAD_STATION_STATE remain fail-closed. Source-marked contaminated GOES X-ray samples are excluded from current values and history. USGS may revise the same earthquake repeatedly, so canonical history preserves revisions while user-facing views show the newest accepted revision of one logical event.