Stellarium 0.12.2
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Extinction Class Reference

This class performs extinction computations, following literature from atmospheric optics and astronomy. More...

#include <RefractionExtinction.hpp>

Public Member Functions

void forward (const Vec3d *altAzPos, float *mag, const int num=1) const
 Compute extinction effect for arrays of size. More...
 
void forward (const Vec3f *altAzPos, float *mag, const int num=1) const
 
void forward (const double *sinAlt, float *mag, const int num) const
 
void forward (const float *sinAlt, float *mag, const int num) const
 
void forward (const double *sinAlt, float *mag) const
 
void forward (const float *sinAlt, float *mag) const
 
void backward (const Vec3d *altAzPos, float *mag, const int num=1) const
 Compute inverse extinction effect for arrays of size. More...
 
void backward (const Vec3f *altAzPos, float *mag, const int num=1) const
 
void backward (const double *sinAlt, float *mag, const int num=1) const
 
void backward (const float *sinAlt, float *mag, const int num=1) const
 
void setExtinctionCoefficient (float k)
 Set visual extinction coefficient (mag/airmass), influences extinction computation. More...
 
float getExtinctionCoefficient () const
 

Detailed Description

This class performs extinction computations, following literature from atmospheric optics and astronomy.

Airmass computations are limited to meaningful altitudes. The solution provided here will [hopefully!] result in a visible "zone of avoidance" near the horizon down to altitude -2, and may show stars in their full brightness below -2 degrees. Typical horizons do not go down below -1, so all natural sites should be covered. Note that forward/backward are no absolute reverse operations! All the computations should be in effect (1) only if atmosphere effects are true (2) only for terrestrial locations, not on Moon/Mars/Saturn etc config.ini:astro/flag_extinction_below_horizon=true|false controls if extinction kills objects below -2 degrees altitude by setting airmass to 42.

Definition at line 45 of file RefractionExtinction.hpp.

Member Function Documentation

void Extinction::backward ( const Vec3d altAzPos,
float *  mag,
const int  num = 1 
) const

Compute inverse extinction effect for arrays of size.

Parameters
numposition vectors and magnitudes.
altAzPosare the NORMALIZED (!!) (apparent) star position vectors, and their z components sin(apparent_altitude).
magthe magnitudes Note that forward/backward are no absolute reverse operations!
void Extinction::forward ( const Vec3d altAzPos,
float *  mag,
const int  num = 1 
) const

Compute extinction effect for arrays of size.

Parameters
numposition vectors and magnitudes.
altAzPosare the NORMALIZED (!!) (apparent) star position vectors, and their z components sin(apparent_altitude).
magthe magnitudes This call must therefore be done after application of Refraction, and only if atmospheric effects are on. Note that forward/backward are no absolute reverse operations!
void Extinction::setExtinctionCoefficient ( float  k)
inline

Set visual extinction coefficient (mag/airmass), influences extinction computation.

Parameters
k=0.1 for highest mountains, 0.2 for very good lowland locations, 0.35 for typical lowland, 0.5 in humid climates.

Definition at line 72 of file RefractionExtinction.hpp.


The documentation for this class was generated from the following file: