Re: Asphalt and Concrete surfaces

[Jan Hollan <jhollan@amper....muni.cz>]

(... Asphalt concrete would be more accurate... Non-dusty roads are always
concrete, if not paved, the concrete is either asphalt or cement one.)

I did not reply to DK's first Re on this forum, just on OLF. That old
reply is available within
  http://amper.ped.muni.cz/jenik/letters/public/msg00117.html

Now I've measured albeda myself, by a digital camera and a sheet of white
paper. The results are the same as said previously. Typical albedo 12 per
cent, no albedos below 10 per cent apart from pure asphalt seams between
surface parts of different age, 15 per cent being commmon. If the
luminance is a criterion (as it is common for roads in Europe), the
installed power can be easily 1.5 times less then usual now.

The results and comments are within
  http://amper.ped.muni.cz/light/luminance/albeda

As said in the last sentence of the comments, similar measurement can be
done by any camera when the linearity of the image is sure (when it has
been stored this way by demanding gamma=1).

jenik