Polarization Cloud Detection with Imaging Polarimetry

Chapter
Part of the Springer Series in Vision Research book series (SSVR, volume 2)

Abstract

In this chapter we show some practical applications of 180° field-of-view (full-sky) imaging polarimetry. The concept and structure of some full-sky imagers (Total Sky Imager, Whole Sky Imager, All Sky Imager) widely used in environmental optics are presented. Some algorithms dealing with photometric cloud detection, a hot topic in meteorology, are described. A brief summary of the satellite-borne PARASOL/POLDER imaging polarimeter is given. Two versions of full-sky imaging polarimetry are described. Both use the measured extra polarization information of skylight. Their advantageous features are (1) enhancement of accuracy and reliability of cloud detection, (2) estimation of the relative cloud-base distance distribution in the sky and (3) applicability in solar forecasting, a very special current topic.

Supplementary material

71484_2_En_24_MOESM1_ESM.zip (1.1 mb)
Colour Version of Fig. 24.1 A TSI-880 instrument at the Baseline Measurement System site of the National Renewable Energy Laboratory. The TSI-880 and its predecessor, the TSI-440, consists of a CCD camera pointing downward to the centre of a spherical mirror dome. The latter is responsible to form the image of the whole sky dome. Underneath the mirror the controlling unit is placed inside a rectangular housing. The mirror has a radial dark band on it, and the mirror itself is rotatable by an embedded motor, so the dark band can be placed in a way that it occludes the image of the Sun from the detector (source of the photograph: http://www.nrel.gov/midc/srrl_bms/pictures.html) (CDR 1170 kb)
71484_2_En_24_MOESM2_ESM.zip (134 kb)
Colour Version of Fig. 24.2 A Whole Sky Imager with the solar occulter trolley and arc system (source of the photograph: http://www.arm.gov/instruments/wsi) (CDR 138 kb)
71484_2_En_24_MOESM3_ESM.zip (528 kb)
Colour Version of Fig. 24.4 An All Sky Imager (ASI) installed on a rooftop at Grupo de Física de la Atmósfera, Granada, Spain. The black arms with three black spheres compose the Sun tracker. The biggest central sphere shades the fisheye lens of the ASI, while the two smaller ones on the sides shade two other optical instruments placed nearby the ASI on the same platform (source of the photograph: http://atmosfera.ugr.es/inv/index.php/es/instrumentacion/76-all-sky-imager.html) (CDR 533 kb)
71484_2_En_24_MOESM4_ESM.zip (13.6 mb)
Colour Version of Fig. 24.6 Full-Sky Imaging Polarimetric Cloud Detector (FSIPCD) developed by Estrato Ltd tested in expedition ANT-XXVII-1-2010 from Bremerhaven (Germany) through the Atlantic Ocean to Capetown (South Africa) onboard the research vessel Polarstern organized by the German Alfred Wegener Institute for Polar and Marine Research (Barta et al. 2014). Underneath the transparent dome the fisheye lens and the arbitrarily adjustable solar occultor are visible (CDR 13920 kb)

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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Estrato Research and Development LtdBudapestHungary
  2. 2.Environmental Optics Laboratory, Department of Biological Physics, Physical InstituteEötvös UniversityBudapestHungary

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