Reference

`air.quality`

domain: air

Interpolated air quality over an H3 CELL — a derived cell measure. Cell-ness is carried by the `space` block ({h3,res}); the schema is named by domain.subject (air.quality), never 'cell.*'. Produced hourly by an interpolation engine from air.sensor_reading points; carries method + confidence + a prov.derivation link to its inputs. Valid-time is `observed_at`.

Field	Type	Required	Description
`schema`	`—`	✓
`id`	`string`	✓
`space`	`object`	✓	{h3, res, centroid} — the H3 cell this value is for
`pm25`	`number`
`no2`	`number`
`o3`	`number`
`observed_at`	`string`	✓	ISO8601 observation time (valid-time)
`method`	`string`		interpolation method, e.g. idw \| kriging
`confidence`	`number`