| 1. |
- Barup, Kerstin, et al.
(författare)
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Multi-disciplinary lidar applications
- 2010
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Ingår i: Laser Applications to Chemical, Security and Environmental Analysis, LACSEA 2010. - 2162-2701. - 9781557528803
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Konferensbidrag (refereegranskat)abstract
- Lidar is a powerful technique normally associated with atmospheric monitoring. However, lidar techniques, also of the laser-induced fluorescence and laser-induced breakdown spectroscopy varieties, provide many new possibilities in unconventional fields including cultural heritage and ecological applications.
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| 2. |
- Brydegaard, Mikkel
(författare)
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Advantages of shortwave infrared LIDAR entomology
- 2014
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Ingår i: Imaging and Applied Optics - Laser Applications to Chemical, Security and Environmental Analysis, LACSEA 2014. - Washington, D.C. : OSA. - 2162-2701. - 9781557523082 - 9781557523082
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Konferensbidrag (refereegranskat)abstract
- Challenges of insect monitoring is revised. I present our new lidar, and use remote dark-field monitoring as well as hyperspectral push-broom imaging to argue why lidar entomology is significantly improved when implemented at telecom wavelengths.
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| 3. |
- Brydegaard, Mikkel
(författare)
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Aspects of Optical Broad Band Spectroscopy and Information Extraction - Applications in Medicine and Ecology
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis describes a number of aspects of modern electro-optical measurement technology also known as bio-photonics; this includes instrumentation, applications, sample interaction and data interpretation. The methods employed operate over several domains, and light measurements are discretized both in intensity, space, angle, time, polarization and energy. Mainly the spectral domain is investigated over two orders of magnitude from deep ultraviolet to thermal infrared, and mainly broad spectral features in solid and liquid samples are studied. The intensity employed ranges from microwatts to megawatts, time processes are studied between hundred picoseconds to weeks and measurement are carried out from the micrometer scale and up to hundreds of meters. An important aspect of this thesis is the development of realistic instrumentation with the intention that research should benefit the supporting society; this is a key point for the success of academic research in the developing world but also goes hand-in-hand with innovation, commercialization and entrepreneurship in Scandinavia. For this reason the thesis also encompasses a number of patent applications filed during the thesis work. Most of these realistic setups are based on spectroscopy using inexpensive light emitting diodes. Their application for medical diagnosis has been demonstrated with fiber sensors in the context of oncology, and microscopy in relation to parasitology. The thesis also covers optical diagnostics of animal populations of different species on the habitat scale; these studies are pursued by the use of laser radar (lidar) or telescopes. In these areas novel approaches for remotely classifying marked or unmarked flying animals open for the investigation of a new type of questions in field entomology and ornithology. In optical applications for medicine as well as ecology the understanding of the light interaction with complex biological tissue types is essential. Several aspects of such interaction are treated in the thesis. The complex optical interrogation together with the broad and overlapping spectral features in solid samples implies that an empirical approach of data evaluation and computer learning is often more valuable than forward modeling of expected signals. An ongoing theme throughout this thesis is data reduction and chemometrical evaluation. Here discrete light measurements and linear algebra form the basis for advanced statistical evaluation. This applies to the spectral domain where redundancy can be removed, but also topics such as dynamical processes and texture analysis are approached in the temporal and spatial domains, respectively.
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| 4. |
- Brydegaard, Mikkel, et al.
(författare)
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Chemometric approach to chromatic spatial variance. Case study: patchiness of the Skyros wall lizard
- 2012
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Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383. ; 26:6, s. 246-255
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we demonstrate how to take advantage of the large number of spatial samples provided by commercial multispectral RGB imagers. We investigate the possibility to use various multidimensional histograms and probability distributions for decomposition and predictive models. We show how these methods can be used in an example using images of different Skyros wall lizards and demonstrate improved performance in prediction of color morph compared with traditional parameterization techniques of spatial variance. Copyright (c) 2012 John Wiley & Sons, Ltd.
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| 5. |
- Brydegaard, Mikkel, et al.
(författare)
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Feasibility study: fluorescence lidar for remote bird classification
- 2010
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Ingår i: Applied Optics. - 2155-3165. ; 49:24, s. 4531-4544
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Tidskriftsartikel (refereegranskat)abstract
- We present a method for remote classification of birds based on eye-safe fluorescence lidar techniques. Mechanisms of quenching are discussed. Plumage reflectance is related to plumage fluorescence. Laboratory measurements on reflectance and fluorescence are presented, as well as test-range measurements. Also we present examples of birds' in-flight lidar returns. The methods are suitable for studies of night migrating species and high-altitude classification with implications for the detailed understanding of bird migration and global virus spread. (C) 2010 Optical Society of America
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| 6. |
- Brydegaard, Mikkel, et al.
(författare)
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On the Exploitation of Mid-infrared Iridescence of Plumage for Remote Classification of Nocturnal Migrating Birds
- 2013
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Ingår i: Applied Spectroscopy. - : SAGE Publications. - 1943-3530 .- 0003-7028. ; 67:5, s. 477-490
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Tidskriftsartikel (refereegranskat)abstract
- A challenging task in ornithology lies in identifying high-altitude nocturnal migrating bird species and genders. While the current approaches including radar, lunar obscuration, and single-band thermal imaging provide means of detection, a more detailed spectral or polarimetric analysis of light has the potential for retrieval of additional information whereby the species and sex could be determined. In this paper, we explore remote classification opportunities provided by iridescent features within feathers in the mid-infrared region. Our approach first involves characterizing the microstructural features of the feather by using rotation and straining, and a scheme for their remote detection is proposed by correlating these microstructural changes to spectral and polarimetric effects. Furthermore, we simulate the spectral signature of the entire bird by using a model that demonstrates how classification would be achieved. Finally, we apply infrared hyperspectral polarization imaging, showing that the net iridescent effect persists for the bird as a whole.
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| 7. |
- Brydegaard, Mikkel, et al.
(författare)
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Photobleaching-Insensitive Fluorescence Diagnostics in Skin and Brain Tissue
- 2011
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Ingår i: IEEE Photonics Journal. - : Institute of Electrical and Electronics Engineers. - 1943-0655. ; 3:3, s. 407-421
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we investigate the possibility of using accurate prediction models for the prediction of protoporphyrin bleaching dynamics to achieve photobleaching-insensitive methods to improve the evaluation of data in an existing clinical fluorescence-guided resection technique. To simulate the scenario, measurements were carried out in vivo on skin of healthy volunteers using a compact fiber-based fluorescence spectroscopy system. We have developed an effective method for the parameterization of sequences of bleaching spectra. We analyze convergence and decay rates with respect to initial conditions and excitation irradiance. We also discuss the consequences and the potential for bleaching-insensitive measurements and their applicability in a few examples from in vivo open brain surgery.
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| 8. |
- Brydegaard, Mikkel, et al.
(författare)
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Simulation of multispectral x-ray imaging scenarios by Wien shift optical spectroscopy
- 2010
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Ingår i: American Journal of Physics. - : American Association of Physics Teachers (AAPT). - 0002-9505 .- 1943-2909. ; 78:2, s. 170-175
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Tidskriftsartikel (refereegranskat)abstract
- The acquisition of multispectral x-ray images and the treatment of such data are essential for understanding many devices that we encounter in everyday life. Examples include computerized tomography in hospitals and scanners at airports. X-ray devices remain impractical for undergraduate laboratories because of their considerable cost and the risk of exposure to ionizing radiation. One way to acquire spectral information and thus constituent-discriminating data in x-ray imaging is to alter the spectral contents of the illuminating x-ray source, which can be achieved by changing the x-ray tube voltage and thus energetically displacing the bremsstrahlung. A similar effect occurs in the emission from a black-body radiator in the optical and infrared regions when altering the temperature. We illustrate how to simulate the x-ray scenario with a webcam and an ordinary light bulb. Insight into how chemical and physical information regarding objects can be obtained in multispectral imaging supported by multivariate analysis is gained.
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| 9. |
- Brydegaard, Mikkel, et al.
(författare)
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Super Resolution Laser Radar with Blinking Atmospheric Particles - Application to Interacting Flying Insects
- 2014
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Ingår i: Progress in Electromagnetics Research-Pier. - 1070-4698. ; 147, s. 141-151
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of biodiversity of pollinators on the landscape scale or estimation of fluxes of disease-transmitting biting midges constitutes a major technical challenge today. We have developed a laser-radar system for field entomology based on the so called Scheimpflug principle and a continuouswave laser. The sample-rate of this method is unconstrained by the round-trip time of the light, and the method allows assessment of the fast oscillatory insect wing-beats and harmonics over kilometers range, e.g., for species identification and relating abundances to the topography. Whereas range resolution in conventional lidars is limited by the pulse duration, systems of the Scheimpflug type are limited by the diffraction of the telescopes. However, in the case of sparse occurrence of the atmospheric insects, where the optical cross-section oscillates, estimation of the range and spacing between individuals with a precision beyond the diffraction limit is now demonstrated. This enables studies of insect interaction processes in-situ.
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| 10. |
- Brydegaard, Mikkel, et al.
(författare)
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Versatile multispectral microscope based on light emitting diodes.
- 2011
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 82:12
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Tidskriftsartikel (refereegranskat)abstract
- We describe the development of a novel multispectral microscope, based on light-emitting diodes, capable of acquiring megapixel images in thirteen spectral bands from the ultraviolet to the near infrared. The system captures images and spectra in transmittance, reflectance, and scattering modes. We present as examples of applications ground truth measurements for remote sensing and parasitology diagnostics. The system is a general purpose scientific instrument that could be used to develop dedicated simplified instruments with optimal bands and mode selection.
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