7
$\begingroup$

My answer to Could UV-A imaging sensor reasonably see a total eclipse in progress through clouds? suggests that while clouds blocking visible light observation of the (partially) eclipsed solar disk would also likely block near UV viewing, there's a chance that there might be some transmission in the 10 micron "window" in the thermal infrared.

My original hypothesis that the water droplets of clouds were sub-wavelength even for visible light (and so Rayleigh's $1/\lambda^4$ would help for 10 micron transparency) was nicely shot down by another answer but I'm still wondering if terrestrial thermal IR viewing observatories can sometimes see through clouds, or at least haze, that would obscure visible light (the way these wavelengths can see through galactic dust). So I'd like to ask:

Question: Can terrestrial infrared telescopes see through clouds or haze, sometimes at least?

Related:


https://commons.wikimedia.org/wiki/File:Atmospheric_Transmission.png

Source and detailed explanation

$\endgroup$
9
  • 2
    $\begingroup$ good question, I support $\endgroup$
    – dtn
    Jan 11 at 7:53
  • $\begingroup$ I don't have an answer, but when doing a google search for "thermal camera cloud" I get a lot of thermal images where you see clouds. So clouds will be transmitted better than in the Vis, but it doesn't seem to be a magic trick making all clouds invisible. Plus, water absorbs Infrared, so there will be attenuation by absorption (in addition to scattering) as well. $\endgroup$ Jan 11 at 8:24
  • 1
    $\begingroup$ Probably limited. See en.wikipedia.org/wiki/List_of_largest_infrared_telescopes which contains ground-based facilities $\endgroup$ Jan 11 at 8:49
  • 1
    $\begingroup$ @uhoh That's a good point. I wonder if that could improve vision through fog on Earth as well. Would help autonomous cars for example... $\endgroup$ Jan 11 at 9:45
  • 1
    $\begingroup$ This page by FLIR seems to sum up as 'it depends' flir.com.au/discover/rd-science/… and matches my observations with them that some environments IR cameras drastically improve the seeing and others are somewhat worse. Do not have the optics chops to convert those graphs into an answer so you are welcome to do so if it makes sense to you. $\endgroup$ Jan 13 at 4:34

0

You must log in to answer this question.