Almukantar scans from AXIS camera @ JOYCE

The almukantar scan measures radiances over all azimtuhs at the same zenith angle as the sun is.
Every azimuth angle can be related to the scattering angle relative to the sun.
And all measured radiances of this scan are taken at the same relative airmass.
Plotting these radiances against the scattering angle provides a measure of the gross aerosol scattering phase function.
We use here the images at the shortest exposure time ('time_1') and lowest amplifier gain ('gain_1') taken evey 15minutes
to extract pixel values at positions of the current almukantar scan defined by the position of the sun.
As exposure parameters are fixed these pixel values relate to radiances in fixed arbitrary units.

Gross aerosol scattering phase functions of the atmosphere.
Colored lines: Pixelvalues (=Radiances in a.u.) of the cameras red, green and blue channel.
Black lines: Blue to red ratio ×100 of the radiances, i.e. an indicator for clouds (<~100) or sky (>~100)
Solid lines: eastern half of the sky.
Dashed lines: western half of the sky.
Vertical dashed lines mark major halo features.

See also the animation of these phase functions.

Phase functions as polar plots. Radiances are normalized.
Peanut shaped form around the center is the phase functions of molecular Rayleigh scattering.