What's measured

Each Sentinel-2 pass (every 2–5 days) is warped onto the same 10 m grid. Every pixel is sorted into water, vegetation, snow, ground or stockpile by colour, with a rule per cargo: wood is warm (red well above blue), container stacks are warmer than the grey pavement around them, and blades are bright, neutral white. Ground that turns green in spring is never counted (summer-dry grass is log-coloured). Specks under 300 m² are dropped and what's left becomes outlined piles. Active area leaves out ground that reads as stockpile on nearly every clear day, such as white roofs.

Clouds, smoke and snow

A scene is kept only if Sentinel's own scene classification finds under 10% cloud and shadow in a 3 km window around the yard, and almost none over it. Scenes where the whole yard is much brighter in blue than usual (cloud the mask missed, wildfire smoke) and scenes with a fifth of the yard under snow are set aside too. The counts are shown for each site; most losses are winter cloud.

Caveats

Ten-metre pixels see piles, not individual logs or blades; a pile under 300 m² is invisible. Area is not volume. Wet wood is darker than dry, so log yards read lower in winter: compare a date with the same weeks of other years (the norm and the year-over-year chart), not with last month. Treat the numbers as an index of activity, and the year-over-year shape as the story.