- UHRA Home
- Browsing by Author
Browsing by Author "Hirst, E."
Now showing items 1-20 of 27
-
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 ... -
Airborne particle shape and size classification from spatial light scattering profiles
Kaye, Paul H.; Hirst, E.; Clark, J.M.; Micheli, F. (1992)A new instrument for the study of airborne particles is described. The instrument incorporates a laminar flow sample delivery system which constrains airborne particles to traverse a focussed laser beam in single file. ... -
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 ... -
Characterisation of atmospheric cloud particles using a light scattering probe
Hirst, E.; Kaye, Paul H.; Greenaway, R.; Field, P.R. (2000)When investigating the composition and dynamics of the atmosphere's particulate matter, particle shape is an important parameter by which classification and possibly identification of particles may be achieved. Spherical ... -
Complementary techniques for the analysis of the shape of airborne particles
Clark, J.M.; Kaye, Paul H.; Hirst, E. (1993-03-26) -
Discrimination of micrometre-sized ice and super-cooled droplets in mixed-phase cloud
Hirst, E.; Kaye, Paul H.; Greenaway, R.; Field, P.R.; Johnson, D.W. (2001)Preliminary experimental results are presented from an aircraft-mounted probe designed to provide in situ data on cloud particle shape, size, and number concentration. In particular, the probe has been designed to facilitate ... -
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 ... -
Experimental and theoretical light scattering profiles from spherical and non-spherical particles
Hirst, E.; Kaye, Paul H. (1996)A laser light scattering instrument has been designed to allow an investigation of the wide angle spatial intensity distribution, or scattering profile, of light scattered by individual airborne particles constrained within ... -
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 ... -
An instrument for the simultaneous acquisition of size, shape, and spectral fluorescence data from single aerosol particles
Hirst, E.; Kaye, Paul H.; Foot, V.E.; Clark, J.M.; Withers, P.B. (2004) -
Light scattering from deformed droplets and droplets with inclusions 1 : experimental results
Secker, D.R.; Kaye, Paul H.; Greenaway, R.; Hirst, E.; Bartley, D.L.; Videen, G. (2000) -
Light scattering from deformed droplets and droplets with inclusions II : theoretical treatment
Videen, G.; Sun, W.; Fu, Q.; Secker, D.R.; Greenaway, R.; Kaye, Paul H.; Hirst, E.; Bartley, D.L. (2000)We provide theoretical results from the scattering of light by deformed liquid droplets and droplets with inclusions. With improved instrumentation and computer technologies available, researchers are able to employ ... -
Light scattering from non-spherical airborne particles : experimental and theoretical comparisons
Hirst, E.; Kaye, Paul H.; Guppy, J.R. (1994)A laser light-scattering instrument has been designed to permit an investigation of the spatial intensity distribution of light scattered by individual airborne particles constrained within a laminar flow, with a view to ... -
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 ... -
A low-cost multi-channel aerosol fluorescence sensor for networked deployment
Kaye, Paul H.; Hirst, E.; Foot, V.E.; Clark, J.M.; Baxter, K. (2004) -
A low-cost multi-channel aerosol fluorescence sensor for networked deployment.
Kaye, Paul H.; Hirst, E.; Foot, V.E.; Clark, J.M.; Baxter, K. (2004)We describe a low-cost prototype bio-aerosol fluorescence sensor designed for unattended deployment in medium to large area networks. The sensor uses two compact xenon flash units to excite fluorescence in an aerosol sample ... -
Measurements of deformed droplets and droplets with inclusions in an aerodynamic particle sizer
Secker, D.R.; Hirst, E.; Kaye, Paul H. (2000)This paper describes the progress on a project aimed at quantifying the degree of deformation experienced by liquid droplets in the TSI Aerodynamic Particle Sizer with a view to providing automatic correction for errors ... -
A method of investigating the orientational behaviour of fibrous particles in gaseous flow
Hirst, E.; Kaye, Paul H. (1995) -
A neural network based spatial light scattering instrument for hazardous airborne fiber detection
Hirst, E.; Kaye, Paul H.; Wang, Z. (1997)A laser light scattering instrument has been designed to facilitate the real-time detection of potentially hazardous respirable fibers, such as asbestos, within an ambient environment. The instrument captures data relating ... -
PlanetPol : A very high sensitivity polarimeter
Hough, J.H.; Lucas, P.W.; Bailey, J.A.; Tamura, M.; Hirst, E.; Harrison, D.; Bartholomew-Biggs, M. (2006-09-01)We have built and used on several occasions an optical broadband stellar polarimeter, PlanetPol, which employs photoelastic modulators and avalanche photodiodes and achieves a photon-noise-limited sensitivity of at least ...