If you inspect scrap yards for a living, you already know the permit doesn't just cap tonnage. It usually specifies form: how much can sit as loose pile versus how much is baled and staged for shipment. A yard licensed for 2,000 tons of loose ferrous and a separate baled-inventory allowance isn't in violation just because the total tonnage looks fine from the road. It's the mix that matters, and the mix is exactly what's hard to verify without walking every row.
Satellite imagery won't replace a walk-through for everything, but it's good enough at sub-meter resolution to tell you which rows are bales and which are loose material, and that's often the one data point you need before you decide whether a site visit is worth the drive.
What bales look like from above
A bale stack reads as a grid. Car-body bales and shredded-scrap bales both get stacked in rows, and because balers compress material into roughly uniform cubes, the shadows between units fall in straight, repeating lines. From directly overhead at 0.5 m resolution or finer, you can't make out individual wires or dents. You can make out the geometry: sharp rectangular edges, consistent unit spacing, and stack heights that step down in even increments as rows get pulled for shipment.
Loose piles don't do any of that. A loose ferrous pile or a mixed non-ferrous pile slumps into a cone or ridge with no internal edges. The shadow pattern is soft and continuous rather than gridded. Turnings and borings piles are the clearest case: they photograph as a smooth, low mound with almost no texture, because there's nothing rigid inside to cast a hard shadow.
The tell that trips people up is color. New baled auto scrap and a loose pile of the same mixed steel can look nearly identical in tone, especially in RGB imagery with no thermal band to separate material density. Rely on edges and shadow geometry instead. If the imagery is a few meters off, coarse enough that the grid lines blur, you're looking at a pixel-smearing problem, not an ambiguous pile.
Reading the yard layout, not just the pile
Form factor also shows up in where material sits on the lot. Baled inventory tends to stage near the scale house or the rail spur, in rows sized to a flatbed or a container, because it's waiting on a pickup. Loose material tends to sit closer to the shear or the baler itself, in irregular footprints that grow and shrink as the processing line eats into it. If you're cross-checking a permit that caps loose storage at a certain footprint near the processing equipment, zoom in on that area first, not the whole yard.
Stack height matters too. Bale stacks have a hard physical ceiling, usually two to four units high depending on the baler output and the forklift reach, and that ceiling shows up as a flat-topped shadow line. A loose pile has no such ceiling; it tapers off at the edges instead. If a permit limits stockpile height and you see a flat-topped rectangular stack well above what a front-end loader could reasonably build as a loose heap, that tells you you're looking at a bale stack. Measure the actual height against the permit limit before you cite anything.
One more practical note: seasonal moisture changes the look of loose piles (wet material darkens and the pile edge gets a sharper waterline) but doesn't change bale geometry at all, since the material inside a bale is already compressed and shedding water off the top. If a pile's outline is shifting month to month with no rain event to explain it, that's worth a second look regardless of form factor.
None of this replaces walking the scale tickets against the inventory log. What it does is narrow down, before you leave the office, which rows are worth measuring in person and which ones are clearly within the baled or loose allowance the permit already accounts for. Recycling Facility Map runs a monthly read of stored material at a site and separates the count by what's piled loose and what's staged in bales, so you can line it up against the licence before you schedule the visit.
If you're tired of guessing pile type from a windshield survey, see what a monthly imagery read turns up for your next site on the list.