Part 05
Reference
What "above the quiet range" and "within the quiet range" mean, and how confidence is read.
The statuses, in plain words
| The record says | It means |
|---|---|
| above the estate's quiet range | This stand changed more, between the before and after windows, than it or the estate's other stands change in a year with no event. It is the rank 1 to look at first. |
| within their quiet range | This stand changed no more than it, or the estate as a whole, changes without the event. |
| no clear look | Cloud took every look in the windows this read used, on both archives, so the stand has no reading for this event yet. |
| after window not yet reached | The event is recent enough that the after window has not yet closed; read the event again once it has. |
The quiet range, in plain words
Every stand has its own history: the same weeks of the same months, three years running up to the event. In most years a stand's canopy and its radar signature move a little on their own, from a thinning, a path of shade, or simple noise in the read. The largest of those three years, and the way the rest of the estate moved in its own quiet years, together set the stand's quiet range: how much movement is ordinary for ground like this, read this way, with no event at all.
A stand is ranked above the quiet range only when this event moved it further than that. The comparison is the stand's own, not a figure carried over from another estate or another region, which is why the record needs no local calibration before it reads an estate for the first time.
Above the quiet range says a stand moved more than it does in a quiet year, on the dates stated. It does not name what moved it. A storm, a beetle attack, a salvage cut and an ordinary harvest can all take a stand above its own quiet range; the record dates the change and ranks it, and the visit establishes the cause.
Confidence
High confidence means the two archives agree on a stand, or the optical reading alone cleared its own bar with room to spare. Moderate confidence means only one archive answered, or the optical reading cleared its bar narrowly. Confidence is about how sure the call is, not about how far above the quiet range a stand sits.
Which archive decides
Sentinel-2 decides a stand's status whenever it had a clear look in both windows. Where cloud kept Sentinel-2 from a clear look, Sentinel-1's radar reading decides instead. The ranked list's By column names which one did, for every stand.