Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Brightness temperature in remote sensing

  1. Jun 25, 2017 #1
    Hi all,

    I don't know if I'm on the right forum to ask this, but maybe somebody knows anything about brightness temperatures measured by remote sensing devices.

    In a paper that I read "Atmospheric corrections for retrieving ground brightness temperature at commonly-used passive microwave frequencies" by Han et al. (2017), I found the following formula:

    Tb = Tg.τ + Tba

    where: Tb is the brightness temperature at the TOA, Tg the brightness temperature at the ground, τ the atmospheric transmittance and Tba the brightness temperature of the atmospheric layers emitting into the direction of the TOA.

    This would mean that:
    Tg = (Tb - Tba) / τ

    Now: can anyone explain me why the brightness temperature at the TOA Tb is positively proportional to the atmospheric transmittance τ, whereas the ground brightness temperature is inversly proportional to it?

    Thanks already!
     
  2. jcsd
  3. Jun 25, 2017 #2

    olivermsun

    User Avatar
    Science Advisor

    One way to think about it is this:

    Tb is inversely proportional to ##\tau## because atmospheric transmittance decreases Tb for a given Tg.

    Tb is positively proportional to atmospheric transmittance because the observed brightness temperature increases if there is more transmittance, which allows more radiation from the surface to make it to the remote sensing device.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Brightness temperature in remote sensing
  1. Temperature Rising (Replies: 4)

  2. The global temperatures. (Replies: 26)

Loading...