| 1. |
- Malmqvist, E., et al.
(författare)
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CW-laser radar for combustion diagnostics
- 2016
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Ingår i: Laser Applications to Chemical, Security and Environmental Analysis, LACSEA 2016. - 2162-2701. - 9781943580156 ; Part F10-LACSEA 2016
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Konferensbidrag (refereegranskat)abstract
- A CW-laser radar system developed for combustion diagnostics is described. It is based on triangulation to attain range information. Some initial results from measurements in sooting flames are shown and some future perspectives are discussed.
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| 2. |
- Brydegaard, M., et al.
(författare)
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Lidar profiling biological targets : - Detection limits and dynamic range.
- 2020
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Ingår i: Proceedings - International Conference Laser Optics 2020, ICLO 2020. - 9781728152332
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Konferensbidrag (refereegranskat)abstract
- Here we present recent advances and applications of profiling biological targets with Scheimpflug lidar. In particular we demonstrate applications for profiling the aerofauna and classifying various groups of species. Based on lidar data over the Ivorian countryside we investigate range dependent detection limits by comparing data with distinct sample rates and pulse energies.
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| 3. |
- Brydegaard, Mikkel, et al.
(författare)
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Short-Wave infrared atmospheric scheimpflug lidar
- 2018
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. ; 176
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Konferensbidrag (refereegranskat)abstract
- Atmospheric dual-band Scheimpflug lidar is demonstrated at 980 and 1550 nm. Signals are compared during three weather conditions, and the spatio-temporal resolution of the atmospheric structure is considered. The potential for aerosol classification is evaluated, and future directions are discussed.
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| 4. |
- Kirkeby, Carsten, et al.
(författare)
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Advances in automatic identification of flying insects using optical sensors and machine learning
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Worldwide, farmers use insecticides to prevent crop damage caused by insect pests, while they also rely on insect pollinators to enhance crop yield and other insect as natural enemies of pests. In order to target pesticides to pests only, farmers must know exactly where and when pests and beneficial insects are present in the field. A promising solution to this problem could be optical sensors combined with machine learning. We obtained around 10,000 records of flying insects found in oilseed rape (Brassica napus) crops, using an optical remote sensor and evaluated three different classification methods for the obtained signals, reaching over 80% accuracy. We demonstrate that it is possible to classify insects in flight, making it possible to optimize the application of insecticides in space and time. This will enable a technological leap in precision agriculture, where focus on prudent and environmentally-sensitive use of pesticides is a top priority.
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| 5. |
- Nielsen, J. H., et al.
(författare)
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Dual-band fluorosensor for discriminating non-eating from algae-eating zooplankton in aquatic environments
- 2020
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Ingår i: OSA Continuum. - 2578-7519. ; 3:7, s. 1730-1738
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Tidskriftsartikel (refereegranskat)abstract
- We present a fluorosensor for the detection of laser-induced autofluorescence of zooplankton in marine environments. The sensor uses an inexpensive 410 nm laser diode as excitation source and simultaneously measures two fluorescence bands, 500-550 nm and 675-725 nm, using two identical 16-bit linear array detectors. We show continuous measurements at 200 Hz of zooplankton swimming through a water volume illuminated by the 410 nm laser. The sensor can distinguish salmon lice (Lepeophtheirus salmonis) larvae from an algae-eating reference species (Acartia tonsa) with a sensitivity of up to 99%. The system successfully differentiates the two species using mixed-species cultures at different ratios. This work shows the potential of fluorescent pest monitoring in the salmon farming industry and paves the way for single-ended aquatic lidars.
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| 6. |
- Nielsen, J. H., et al.
(författare)
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Investigation of autofluorescence in zooplankton for use in classification of larval salmon lice
- 2019
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Ingår i: Applied Optics. - 1559-128X. ; 58:26, s. 7022-7027
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Tidskriftsartikel (refereegranskat)abstract
- We present autofluorescence of six zooplankton species, including salmon lice (Lepeophtheirus salmonis), for the purpose of classification in marine environments. Using a 410 nm excitation wavelength, we find that all measured zooplankton species exhibit broad cyan fluorescence centered around 510–520 nm. Furthermore, salmon lice show an absence of red fluorescence from undigested chlorophyll, which is measured from the gut of the herbivorous zooplankton species. We show the capability to distinguish noneating species, including salmon lice, from algae-eating species using a dual-band analysis of the fluorescence spectra. This shows the potential of autofluorescence as an important signature in real-time monitoring and classification of salmon lice.
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| 7. |
- Thompson, Alex, et al.
(författare)
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Hyperspectral fluorescence lifetime fibre probe spectroscopy for use in the study and diagnosis of osteoarthritis and skin cancer
- 2011
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Ingår i: Optical Biopsy IX. - : SPIE. - 1605-7422. - 9780819484321 ; 7895
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Konferensbidrag (refereegranskat)abstract
- We present the application of two fibre-optic-coupled time-resolved spectrofluorometers and a compact steady-state diffuse reflected light/fluorescence spectrometer to in vivo and ex vivo studies of skin cancer and osteoarthritis. In a clinical study of skin cancer, 27 lesions on 25 patients were investigated in vivo before surgical excision of the region measured. Preliminary analysis reveals a statistically significant decrease in the autofluorescence lifetime of basal cell carcinomas compared to neighbouring healthy tissue. A study of autofluorescence signals associated with the onset of osteoarthritis indicates autofluorescence lifetime changes associated with collagen degradation.
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| 8. |
- Thompson, Alex J., et al.
(författare)
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In vivo measurements of diffuse reflectance and time-resolved autofluorescence emission spectra of basal cell carcinomas
- 2012
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Ingår i: Journal of Biophotonics. - : Wiley. - 1864-063X. ; 5:3, s. 240-254
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present a clinical investigation of diffuse reflectance and time-resolved autofluorescence spectra of skin cancer with an emphasis on basal cell carcinoma. A total of 25 patients were measured using a compact steady-state diffuse reflectance/fluorescence spectrometer and a fibre-optic-coupled multispectral time-resolved spectrofluorometer. Measurements were performed in vivo prior to surgical excision of the investigated region. Singular value decomposition was used to reduce the dimensionality of steady state diffuse reflectance and fluorescence spectra. Linear discriminant analysis was then applied to the measurements of basal cell carcinomas (BCCs) and used to predict the tissue disease state with a leave-one-out methodology. This approach was able to correctly diagnose 87% of the BCCs. With 445 nm excitation a decrease in the spectrally averaged fluorescence lifetime was observed between normal tissue and BCC lesions with a mean value of 886 ps. Furthermore, the fluorescence lifetime for BCCs was lower than that of the surrounding healthy tissue in all cases and statistical analysis of the data revealed that this decrease was significant (p = 0.002). (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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