Hannover 2010 – wissenschaftliches Programm
UP 2.6: Poster
Dienstag, 9. März 2010, 16:30–18:30, Lichthof
The SO2 camera Theoretical basis of measurement and data evaluation — •Peter Lübcke, Christoph Kern, Leif Vogel, Felix Kick, Markus Wöhrbach, and Ulrich Platt — Institute of Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
The SO2 camera is a novel technique for the remote sensing of volcanic emissions based on measuring the ultra-violet absorption of SO2 in a narrow wavelength window around 310 nm by employing a band-pass interference filter and a 2D UV-sensitive CCD detector. Solar radiation scattered in the atmosphere is used as a light source for the measurements. The effect of aerosol scattering can be eliminated by additionally measuring the incident radiation around 325 nm where the absorption of SO2 is no longer significant, thus rendering the method applicable to optically opaque plumes. The ability to deliver spatially resolved images of volcanic SO2 distributions at a frame rate on the order of 1 Hz makes the SO2 camera a very promising technique for volcanic monitoring. However, we show here that the relationship between SO2 column density and measured signal is non-trivial. Due to the finite filter transmission window, the camera's sensitivity to SO2 depends on parameters such as the solar zenith angle, the total ozone column, the filter illumination angle, and even on the SO2 column itself.