Cloud Discrimination from Sky Images Using a Clear-Sky Index

Cloud characterization and clear-sky correction from Landsat-7

Landsat, with its wide swath and high resolution, fills an important mesoscale gap between atmospheric variations seen on a few kilometer scale by local surface instrumentation and the global view of coarser resolution satellites such as MODIS. In this important scale range, Landsat reveals radiative effects on the few hundred-meter scale of common photon mean-free-paths, typical of scattering ...

Automatic cloud classification of whole sky images

Automatic cloud classification of whole sky images A. Heinle, A. Macke, and A. Srivastav Excellence Cluster “The Future Ocean”, Department of Computer Science, Kiel University, Kiel, Germany Leibniz Institute of Marine Sciences at Kiel University (IFM-GEOMAR), Kiel, Germany Received: 21 October 2009 – Accepted: 22 December 2009 – Published: 27 January 2010 Correspondence to: A. Heinle (ahe@info...

A clear-sky radiance archive from Meteosat ”water vapor” observations

An assessment of microwave absorption models and retrievals of cloud liquid water using clear-sky data

[1] Passive microwave radiometers have a long history in the remote sensing of atmospheric liquid and water vapor. Retrievals of these quantities are sensitive to variations in pressure and temperature of the liquid and water vapor. Rather than use a statistical or climatological approach to account for the natural variability in atmospheric pressure and temperature, additional information on t...

Digital imaging of clear-sky polarization.

If digital images of clear daytime or twilight skies are acquired through a linear polarizing filter, they can be combined to produce high-resolution maps of skylight polarization. Here polarization P and normalized Stokes parameter Q are measured near sunset at one inland and two coastal sites. Maps that include the principal plane consistently show that the familiar Arago and Babinet neutral ...