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Browsing by Author "Ulanowski, Z."
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A 3D implementation of ray tracing combined with diffraction on facets: Verification and a potential application
Clarke, A.J.M.; Hesse, E.; Ulanowski, Z.; Kaye, Paul H. (2006)A 3D implementation of a new model of light scattering applicable to dielectric faceted objects is introduced. The model combines standard geometric optics with diffraction on individual facets. It can be applied to any ... -
The Ability of the Small Ice Detector (SID-2) to Characterize Cloud Particle and Aerosol Morphologies Obtained during Flights of the FAAM BAe-146 Research Aircraft
Cotton, R.; Osborne, S.; Ulanowski, Z.; Hirst, E.; Kaye, Paul H.; Greenaway, R. (2010)The Small Ice Detector mark 2 (SID-2), which was built by the University of Hertfordshire, has been operated by the Met Office on the Facility for Atmospheric Airborne Research (FAAM) BAe-146 aircraft during a large number ... -
Alignment of atmospheric mineral dust due to electric field
Ulanowski, Z.; Bailey, J. A.; Lucas, P.W.; Hough, J.; Hirst, E. (2007)Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction ... -
Application of RTDF to particles with curved surfaces
Hesse, E.; McCall, D.; Ulanowski, Z.; Stopford, C.; Kaye, Paul H. (2009)The applicability of the ray tracing with diffraction on facets model is extended to particles with curved surfaces. This allows tests against T-matrix calculations for larger size parameters and modelling of light scattering ... -
Application of RTDF to particles with curved surfaces
Hesse, E.; McCall, D.; Ulanowski, Z.; Stopford, C.; Kaye, Paul H. (University of Hertfordshire, 2008)The applicability of RTDF is extended to particles with curved surfaces. This allows tests against T-matrix calculations for larger size parameter and modeling of light scattering by more realistic particle shapes, such ... -
Astrobiological signatures: prospects for the detection of non-terrestrial biological material
Gledhill, T.; Sparks, W.; Ulanowski, Z.; Hough, J.; DasSarma, S. (2007)The possibilities for detecting non-terrestrial biological material are briefly reviewed in light of the flurry of extrasolar planet detections over the last ten years and the forthcoming space missions designed to search ... -
Beam tracing with diffraction
Taylor, Laurence; Hesse, Evelyn; Ulanowski, Z.; Kaye, Paul H.; Penttila, Antti; Nousiainen, Timo (2015-06-21) -
Calibration of the Cloud Particle Imager Probes Using Calibration Beads and Ice Crystal Analogs: The Depth of Field
Connolly, P.; Flynn, M.; Ulanowski, Z.; Choularton, T.W.; Gallagher, M.; Bower, K.N. (2007)This paper explains and develops a correction algorithm for measurement of cloud particle size distributions with the Stratton Park Engineering Company, Inc., Cloud Particle Imager (CPI). Cloud particle sizes, when inferred ... -
Compact optical trapping microscope using a diode laser
Ulanowski, Z.; Ludlow, I.K. (2000)Single beam gradient force optical trapping (laser tweezers) is increasing in importance as a technique for microparticle and cell manipulation and for the measurement of piconewton forces in aqueous media. An optical trap ... -
Dust layer profiling using an aerosol dropsonde
Ulanowski, Z.; Kaye, Paul H.; Hirst, Edwin; Wieser, Andreas; Stanley, Warren (2015-04-12)Routine meteorological data is obtained in the atmosphere using disposable radiosondes, giving temperature, pressure, humidity and wind speed. Additional measurements are obtained from dropsondes, released from research ... -
The effect of airborne dust on astronomical polarization measurements
Bailey, Jeremy; Ulanowski, Z.; Lucas, P.W.; Hough, J. H.; Hirst, E.; Tamura, M. (2008-05-11)In the past, it has generally been assumed that polarization observations made with ground-based telescopes are unaffected by the passage of light through the Earth's atmosphere. Here, we report observations with a new ... -
Fake ice and levitation
Ulanowski, Z.; Hesse, E. (2003) -
Ice analog halos
Ulanowski, Z. (2005) -
Influence of Alignment on the Scattering Properties Atmospheric Mineral Dust
Ulanowski, Z.; Kalashnikova, O.V.; Lucas, P.W.; Berçot, B. (2008)We carry out an investigation of the influence of particle alignment on the scattering properties of mineral dust layers. Our modelling indicates that in addition to modifying optical thickness, the alignment can significantly ... -
Initial investigation into using Fourier spectra as a means of classifying ice crystal shapes
Stopford, C.; Ulanowski, Z.; Hesse, E.; Kaye, Paul H.; Hirst, E.; Schnaiter, M.; McCall, D. (University of Hertfordshire, 2008)Fast Fourier Transforms of azimuthal light scattering patterns are investigated as a method for classifying cirrus cloud ice crystals. Small Ice Detector Mk. 2 data is compared to modelled reference data of various aspect ... -
Introducing phase tracing into a computational method which combines ray-tracing with diffraction on facets.
Hesse, E.; Ulanowski, Z.; Clarke, A.J.M.; Havemann, S.; Kaye, Paul H. (University of Bremen, 2005)The viability of introducing phase tracing into our ray tracing with diffraction on facets model is investigated. In order to prove the method, Monte Carlo ray-tracing results for a slit, based on our diffraction formula ... -
Investigation into Single Scattering Properties of Airborne Saharan Dust Particles
McCall, D.; Ulanowski, Z.; Hesse, E.; Stopford, C.; Kandler, K.; Kaye, Paul H. (2008)The phase functions of single mineral dust particles levitated in an electrodynamic balance have been measured. Normalized phase functions and the asymmetry parameter could be determined because nearly the full range of ... -
Investigation of growth kinetics and morphology of sodium fluorosilicate ice-analogue crystals in solutions and gels
Krasinski, M.J.; Krasinska, K.R.; Ulanowski, Z. (2007) -
A light scattering instrument for investigating cloud ice microcrystal morphology
Kaye, Paul H.; Hirst, E.; Ulanowski, Z.; Hesse, E.; Greenaway, R.; DeMott, P. (2008)We describe an optical scattering instrument designed to assess the shapes and sizes of microscopic atmospheric cloud particles, especially the smallest ice crystals that can profoundly affect cloud processes and radiative ... -
Measurement and modeling of light scattering by small particles.
Hesse, E.; Ulanowski, Z.; McCall, D.; Stopford, C.; Kaye, Paul H. (University of Bremen, 2008)At the University of Hertfordshire we measure and model light scattering by small particles, in particular by such relevant for climate research. The measurements comprise phase functions, linear polarization of single ...