Thermal imageing

[deadstick]

Hi All,

 

can anyone point me to a reference on the differing thermal properties of aluminium and earth, I am interested to know if an aluminium aircraft would show up against a background of earth with a thermal imaging device? Any help appreciated

 

 

[Guest Andys@coffs]

Deadstick, we covered that in a round about way some time ago when I was talking about those remote temperature measurement guns for measuring CHT etc the more expensive have an emissivity constant that you need to specify before measuring and its different for different materials, I believe the specific word to look for is emissivity and it relates to the characteristics of specific elements to emit heat....polished aluminium is one of the worst..... but anyway google emissivity and remote sensing and I reckon you'll be well on your way

 

Andy

 

 

[djpacro]

Check out www.flir.com for specs. Been many years since I flew an aeroplane around at night (and day) with one of their devices but I expect it to be able to do the job. It can play tricks - I recall a posse creeping up on a crook in the bush at night-time - turns out the FLIR had picked out a rock of the appropriate size and shape.

 

You can also find a needle in a haystack.

 

Also worth looking at the system fitted to the Aviat Husky - aviataircraft.com/evs.html

 

 

[djpacro]

I should've qualified my earlier statement, now that I know your objective. In a heavily wooded area the aluminium won't heat up much and it is not X-ray vision so if obscured by foliage it will indeed be like looking for a needle in a haystack.

 

 

[av8vfr]

A thermal camera relies on a difference of temperature.

 

That is, if the earth and the aluminium are at the same temperature, minimum thermal difference will appear.

 

As aluminium is a very good heat sink, it will stabilise to the surrounding temperature relatively quickly. Things like engines, exhaust, etc will be highly visible though if operating.

 

Hope that makes sense

 

 

[rankamateur]

Things like engines, exhaust, etc will be highly visible though if operating. Hope that makes sense

Unless Malcolm has a mate who has been tinkering it won't help much then, it's been frosty lately.

 

 

[deadstick]

LOL,

 

I was at the place where they captured him today, H really must be a great bushman to survive up there.