ARTS 2.5.9 (git: 825fa5f2)
Raw::Correction Namespace Reference

Functions

Numeric naive_tropospheric_singletau_median (const ConstVectorView &bt, const Numeric trop_bt, const Numeric target_bt)
 Naive tropospheric correction parameterization. More...
 
VectorView naive_tropospheric (VectorView bt, const Numeric tau, const Numeric trop_bt)
 Apply tropospheric correction. More...
 

Function Documentation

◆ naive_tropospheric()

VectorView Raw::Correction::naive_tropospheric ( VectorView  bt,
const Numeric  tau,
const Numeric  trop_bt 
)

Apply tropospheric correction.

Tropospheric correction comes here from

\[ T_{b, 1}(f) = \frac{T_{b, 0}(f) - \overline{T_{b, trop}(f)}(1 - e^{-\overline{\tau(f)}})}{e^{-\overline{\tau(f)}}}, \]

where \( T_{b, 1}(f) \) is the corrected radiation to some higher altitude, \( T_{b, 0}(f) \) is the measured brightness temperature at surface altitude, \( \overline{T_{b, trop}(f)} \) is the averaged brightness temperature emission of the troposphere and \( \overline{\tau(f)} \) is the averaged finite opacity of the troposphere. Here \( f \) is the frequency dimension of bt

This method assumes \( \overline{T_{b, trop}(f)} \) and \( \overline{\tau(f)} \) are constant for all frequencies. They have a frequency dependency, but we naively ignore it, thus giving the method its name

Note that \( \overline{\tau(f)} \) so large that \( e^{-\overline{\tau(f)}} := 0 \) are ignored and the original input is retained for such an input

Parameters
[in,out]bt\( T_{b, 0}(f) \)
[in]tau\( \overline{\tau(f)} \)
[in]trop_bt\( \overline{T_{b, trop}(f)} \)
Returns
\( T_{b, 1}(f) \)

Definition at line 423 of file raw.cc.

◆ naive_tropospheric_singletau_median()

Numeric Raw::Correction::naive_tropospheric_singletau_median ( const ConstVectorView bt,
const Numeric  trop_bt,
const Numeric  target_bt 
)

Naive tropospheric correction parameterization.

Tropospheric correction comes from the idea seen in Raw::Correction::naive_tropospheric

The "naive" part of this implementation comes from assuming

\[ \overline{\tau(f)} := - \ln\left(\frac{\overline{T_{b, trop}(f)} - \overline{T_{b, 0}(f)}}{\overline{T_{b, trop}(f)} - \overline{T_{b, target}(f)}} \right), \]

where \( \overline{T_{b, 0}(f)} \) is the nan-median of input brightness temperature at the surface, \( \overline{T_{b, trop}(f)} \) is infinite brightness temperature of the troposphere, and \( \overline{T_{b, target}(f)} \) is brightness temperature of the tropopause. Here \( f \) is the frequency dimension of bt, from which only the nan-median is extracted

Parameters
[in]btThe measurement vector \( T_{b, 0}(f) \)
[in]trop_bt\( \overline{T_{b, trop}(f)} \)
[in]target_bt\( \overline{T_{b, target}(f)} \)
Returns
\( \overline{\tau(f)} \) as equations above

Definition at line 419 of file raw.cc.

References Raw::Average::nanmedian().