180° Fish-Eye Camera

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  A Canon EOS 1D Mark III is used in combination with a 180° fish-eye lense to measure the angular distribution of solar radiance in the lower hemisphere below the aircraft. The fish-eye camera is calubrated similar to SMART-Albedometer and provides images with high spatial resolution up to a frequency of 4 s. In combination with the SMART-Albedometer downward irradiance, the hemispherical-directional reflectivity distribution function (HDRF comparable to BRDF) can be derived. The measurements will be analyzed for sea ice surfaces as well as for clouds.
  The sea ice, snow HDRF will be characterized in dependence of sea ice fraction, snow cover and surface roughness. Measurements above clouds provide cloud thermodynamic phase and for liquid clouds, particle diameter by analyzing the backscatter directions with cloud bow and glory.

  
  

Name	Spectral Modular Airborne Radiation measurement sysTem
Measured species	Atmospheric Radiation
Method	Grating Spectrometry
Quantity primary	Spectral irradiance and radiance, upwelling and downwelling
Quantity secondary	Cloud reflectivity
Spectral range	0.3–2.2 μm
Location	Top and bottom openings of aircraft fuselage
Radiance Viewing Angle	2.1°
Temporal resolution	0.3 seconds

References

Ehrlich, A., Bierwirth, E., Wendisch, M., Herber, A., and Gayet, J.-F. (2012): Airborne hyperspectral observations of surface and cloud directional reflectivity using a commercial digital camera, Atmos. Chem. Phys. 12, 3493-3510