14th September 2012, 01:23 PM
Dinosaur Wrote:err, as I think I've already pointed out, try actually READING my original post and maybe you'll realise how stupid that post is in this context, I specifically exempted earthworks !!
- on stripped archaeology snow seems to last longer on better draining stuff like gravel for some reason, maybe the snow on those bits isn't having warmth circulated to it from the meltwater it's sitting in? If you think of snow melting on a hard surface it's often melting from underneath with an overhang around the edges, which is perhaps part of a similar process?
@John - good earthwork/snow pics, but I'd been thinking more of semi-melted. Years back after a light snow shower the flattened part of the Rudston A cursus showed up beautifully as two white stripes (over the ditches, drainage again?) running across an otherwise melted landscape - only lasted for 10 mins and of course I didn't have a camera with me, but bl**dy brilliant!
Now now old man (:face-stir
Interesting about differential melting rates on stripped archaeology...............like differential drying rates on a recently wetted surface meaning features staying as damp blobs for a bit as it drys out. Maybe linked?
Also I'm guessing wet deposits have differing thermal properties than dryer ones? Doesn't water stay warmer for longer than a solid? Guess it depends on the thermal conductivity of the substance. Or is it to do with latent heat of whatsits face.....can't really remember my thermodynamics
I know from my gliding days that tarmac heats up and keeps its heat better than the surrounding fields, and creates mini thermals.
But to get back to the photography stuff...........John, where do you see your experiments leading to is my burning question?
A greater understanding of aerial images?
Prospecting for sites before excavation?
Or the identification of individual unexcavated features on an already stripped area from the ground?
Or as an aid to show already excavated features more vividly?
Or all of the above?
I think there may have been an initial misunderstanding of your questions
'Have any readers photographed areas of an excavation outside the visible spectrum (near UV and near IR), with a normal digital camera on a tripod and appropriate filters?
Has anyone used a thermal imaging camera with any success? '