"Fractenna" wrote in message
...
I believe you're about half-way to proving that Thermal Images are
impossible. What next? Santa Claus?


It has already been proven that Santa Claus is impossible. Too many
chimneys to
crawl down (let alone up: Claus is morbidy obses as I recall)) in one
night...


Perhaps the delta between our positions is that if the temperature
increases
are not significant, then I'm assuming that the information is not of
value

You miss the important issue. Heat is not dissipated at a point but over a
surface. If I take a soldering iron, for example, and distribute its 40
watts
of heat across a strip of 2 feet by 4 inches, for example, it won't get
very
warm in a differential way to ambient.

Hi,

Even if the difference is not important vs. ambient air, a good image
processing will improve it.
This is not the problem.
The first step if to find someone able to picture it...

Thierry, ON4SKY
http://www.astrosurf.com/lombry


That re-distribution of heat across a larger surface area is how heat
sinks
work.

Ergo, the increase in --temperature-- at a point of measurement--or even
across
an area or region-- can be small, even though the total amount of ohmic
loss
may be high.

Thermal cameras register differential thermal radiation losses, not
convective
losses (per se). And the heat is distributed across a surface, not a
point.

You can't take a picture of an antenna outside, and learn much about its
ohmic
loss, for example. (Too much convective cooling). Not unless its ohmic
loss is
confined to a small area, the air is rarefied and windless, and thus the
temperature differential is a few degrees or more and indicative of bona
fide
radiative thermal heating/loss.

Hope you learned something:-)!

Best,
Chip N1IR