Anyone know what these rows of pits are in my LiDAR scan of the Eifel?

I have scanned quite a bit of forest in that part of Germany and what you are describing sounds alot like wartime remains rather than charcoal platforms. I have come across both, and they look pretty diferent once you know what to check. Charcoal kiln sites are usally flat-bottomed, shallow platforms with a slight raised edge where the pile was stacked, and they sit scattered across a slope wherever wood was handy, not in neat rows. If your depressions are deeper than wide-ish and lined up in rows, I whould look at shell or bomb craters instead. Carpet bombing and artillery fire tend to leave craters in loose patterns or strings, especially near a defensive position.

The straight bank angled across the slope is the giveaway for me. Dug earth gets thrown up on one side, so on a scan you often see the filled-in trench as a soft bank with maybe a shallow dip next to it. Try rendering your elevation model with hillshading from several different light angles. If the bank has a parallel shallow ditch on the upslope side, that is almost certainly a man-made trench or a communication trench rather than a field boundary. The rows of pits in front of or behind such a line would fit foxholes or impact craters from fire aimed at the position. The Eifel saw heavy fighting in late 44 and early 45, and forests there are full of this stuff that was never cleared.

One more check: old afforestation sometimes shows as evenly spaced small pits where saplings were planted, but those are usually shallower and perfectly regular in a grid. If yours wander a bit and cluster near the bank, go with the military explanation.

I'm pretty new here too, only done a couple of scans so far, but I had somethig similar on a patch of woodland behind my in-laws' place. Turned out my mystery rows were just old drainage channels, way softer and longer than what you're describing though. One thing I found handy was overlaying my scan on old survey maps and wartime aerial photos, some of that stuff is online for that region and it settled the arguement pretty fast. Did you try that yet? Also curious what drone and processing setup you used, mine struggles a bit under dense canopy.

That matches what I ran into a few years back when I surveyed a block near Hürtgenwald. I counted something like 60 depressions across 40 hectares and they lined up in loose strings just like yours, all clustered around a sunken track. One thing that helped me was pulling a cross section through a few of the pits. Bomb and shell craters have an uneven, sloshy profile with the throw pile pushed to one side, while tree throw pits and planting holes look symmetric. If your drone data has good vertical accuracy, even half a metre of depth difference tells you a lot. Post the elevation grid, the shape of that bank will settle it fast.

Been doing this since we were lugging a total station up hills and logging everthing in a wet notebook, so trust me when I say LiDAR spoiled us. That said, one trick from the old days still works: dig out the 1930s Prussian survey sheets for that spot. If the bank is on those, it is agricultural or a boundary. If it only shows up post-war, you have your answer right there.

Worth asking too wheather the rows run downhill or across it. Old terracing and vineyard strips follow the contour, while foxholes and craters coud care less about slope.