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Browsing by Author "Stopford, Chris"
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AIITS: Preliminary light scattering data from Tropical Tropopause Layer cirrus
Stopford, Chris; Kaye, Paul H.; Ulanowski, Joseph; Hirst, Edwin; Greenaway, Richard; Dorsey, James; Gallagher, Martin; Woods, Sarah; Lawson, Paul; Thornberry, Troy; Rollins, Drew; Harris, Neil (2015-07-22)The new optical particle spectrometer AIITS (Aerosol Ice Interface Transition Spectrometer) is the next instrument in the Small Ice Detector (SID) family. Like SID3, it acquires two-dimensional forward scattering patterns ... -
Applying machine learning methods for characterization of hexagonal prisms from their 2D scattering patterns – an investigation using modelled scattering data
Salawu, Emmanuel Oluwatobi; Hesse, Evelyn; Stopford, Chris; Davey, Neil; Sun, Yi (2017-11-01)Better understanding and characterization of cloud particles, whose properties and distributions affect climate and weather, are essential for the understanding of present climate and climate change. Since imaging cloud ... -
Characterization of small ice crystals using frequency analysis of azimuthal scattering patterns
Ulanowski, Zbigniew; Stopford, Chris; Hesse, Evelyn; Kaye, Paul H.; Hirst, Edwin; Schnaiter, M. (2007)Azimuthal scattering patterns obtained from ice crystals using the Small Ice Detector 2 are examined. They are converted to frequency spectra using Fast Fourier Transform. To classify the shape of the crystals, the spectra ... -
Design and field campaign validation of a multi-rotor unmanned aerial vehicle and optical particle counter
Girdwood, Joseph; Smith, Helen R.; Stanley, Warren; Ulanowski, Joseph; Stopford, Chris; Chemel, Charles; Doulgeris, Konstantinos-Matthaios; Brus, David; Campbell, David; Mackenzie, Robert (2020-12-07)Small unmanned aircraft (SUA) have the potential to be used as platforms for the measurement of atmospheric particulates. The use of an SUA platform for these measurements provides benefits such as high manoeuvrability, ... -
Design and field campaign validation of a multi-rotor unmanned aerial vehicle and optical particle counter
Girdwood, Joseph; Smith, Helen R.; Stanley, Warren; Ulanowski, Joseph; Stopford, Chris; Chemel, Charles; Doulgeris, Konstantinos-Matthaios; Brus, David; Campbell, David; Mackenzie, Robert (2020-12-07)Small unmanned aircraft (SUA) have the potential to be used as platforms for the measurement of atmospheric particulates. The use of an SUA platform for these measurements provides benefits such as high manoeuvrability, ... -
Detection of Airborne Biological Particles in Indoor Air Using a Real-Time Advanced Morphological Parameter UV-LIF Spectrometer and Gradient Boosting Ensemble Decision Tree Classifiers
Crawford, Ian; Topping, David; Gallagher, M.W.; Forde, Elizabeth; Lloyd , J R; Foot, Virginia; Stopford, Chris; Kaye, Paul H. (2020-09-29)We present results from a study evaluating the utility of supervised machine learning to classify single particle ultraviolet laser-induced fluorescence (UV-LIF) signatures to investigate airborne primary biological aerosol ... -
A High Speed Particle Phase Discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber
Mahrt, Fabian; Wieder, Jorg; Dietlicher, Remo; Smith, Helen R.; Stopford, Chris; Kanji, Zamin (2019-06-14)A new instrument, the High-speed Particle Phase Discriminator (PPD-HS), developed at the University of Hertfordshire, for sizing individual cloud hydrometeors and determining their phase is described herein. PPD-HS performs ... -
Measurement and modeling of light scattering by small particles
Hesse, Evelyn; Ulanowski, Zbigniew; McCall, D.; Stopford, Chris; 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 ... -
A Miniature Airborne Particle Classifier (APC)
Stopford, Chris; Kaye, Paul H.; Hirst, Edwin; Ulanowski, Zbigniew (2011-09-04)The single greatest source of uncertainty in the estimates of climate sensitivity to either natural or man-made changes continues to be clouds (IPCC 2001, 2007). Much of this uncertainty arises from the lack of information ... -
Real-time detection of airborne asbestos by light scattering from magnetically re-aligned fibers
Stopford, Chris; Kaye, Paul H.; Greenaway, Richard; Hirst, Edwin; Ulanowski, Zbigniew; Stanley, Warren (2013-05)Inadvertent inhalation of asbestos fibers and the subsequent development of incurable cancers is a leading cause of work-related deaths worldwide. Currently, there is no real-time in situ method for detecting airborne ... -
Simulation and Field Campaign Evaluation of an Optical Particle Counter on a Fixed-Wing UAV
Girdwood, Joseph; Stanley, Warren; Stopford, Chris (2022-04-05)Unmanned aerial vehicles (UAVs) have great potential to be utilised as an airborne platform for measurement of atmospheric particulates and droplets. In particular, the spatio-temporal resolution of UAV measurements could ... -
The Universal Cloud and Aerosol Sounding System (UCASS): a low-cost miniature optical particle counter for use in dropsonde or balloon-borne sounding systems
Smith, Helen R.; Ulanowski, Joseph; Kaye, Paul H.; Hirst, Edwin; Stanley, Warren; Kaye, Richard; Wieser, Andreas; Stopford, Chris; Kezoudi, Maria; Girdwood, Joseph; Greenaway, Richard; MacKenzie, A Robert (2019-12-13)A low-cost miniaturized particle counter has been developed by The University of Hertfordshire (UH) for the measurement of aerosol and droplet concentrations and size distributions. The Universal Cloud and Aerosol Sounding ... -
Using Machine Learning Techniques to Recover Prismatic Cirrus Ice Crystal Size from 2-Dimensional Light Scattering Patterns
Priori,, Daniel; de Sousa, Giseli; Roisenberg, Mauro; Stopford, Chris; Hesse, Evelyn; Davey, Neil; Sun, Yi (2016-08-13)In this paper, we present a prediction model developed to identify particles size of ice crystals in clouds. The proposed model combines a Feed Forward Multi-Layer Perceptron neural network withBayesian regularization ...