Prof. Roger M. Groves Profile

Prof. Roger M. Groves

Associate Professor at Technische Univ Delft

SPIE Involvement:

Conference Program Committee | Editor | Author

Area of Expertise:

shearography , optical fibre sensors , cultural heritage , aerospace

Websites:

Company Website

Publications (65)

Proceedings Article | 15 August 2023 Poster + Paper

Comparative performance of high and medium resolution cameras for defect detection in carbon-fiber reinforced composites by digital shearography

Kazi Monowar Abedin, Nan Tao, Andrei Anisimov, Roger Groves

Proceedings Volume 12618, 126181X (2023) https://doi.org/10.1117/12.2669718

KEYWORDS: Shearography, Composites, Digital cameras, Defect detection, Nondestructive evaluation, Spatial resolution, Shearing interferometers, Deformation

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Proceedings Article | 9 August 2023 Presentation + Paper

Four-flux model combined with optical coherence tomography technique for non-destructive testing of the colour ground layers of the paintings

Xiang Wang, Andrei Anisimov, Roger Groves

Proceedings Volume 12620, 1262009 (2023) https://doi.org/10.1117/12.2673457

KEYWORDS: Optical coherence tomography, Reflection, Pigments, Nondestructive evaluation, Hyperspectral imaging

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Proceedings Article | 9 August 2023 Presentation + Paper

Application of shearography with thermal loading for the structural inspection of Rembrandt’s Night Watch

Nan Tao, Andrei Anisimov, Esther van Duijn, Lisette Vos, Ilse Steeman, Katrien Keune, Petria Noble, Roger Groves

Proceedings Volume 12620, 126200A (2023) https://doi.org/10.1117/12.2673263

KEYWORDS: Inspection, Shearography, Cameras, Equipment, Deformation, 3D image processing, Cultural heritage, Optical metrology

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Proceedings Article | 17 May 2022 Presentation + Paper

Plasmon resonance spectral peak shift due to morphing of gold nanoparticles for strain sensing

Xiang Wang, Rinze Benedictus, Roger Groves

Proceedings Volume 12139, 121390S (2022) https://doi.org/10.1117/12.2619170

KEYWORDS: Gold, Neptunium, Nanoparticles, Plasmons, Spherical lenses, Light scattering, Refractive index, Structural health monitoring, Aerospace engineering, Visible radiation

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Proceedings Article | 19 April 2022 Presentation + Paper

Studying the effect of strain induced birefringence on the sensitivity of FBG sensors for guided wave measurements

Rohan Soman, Luigi Fazzi, Ali Nokhbatolfoghahai, Roger Groves, Wieslaw Ostachowicz

Proceedings Volume 12048, 1204807 (2022) https://doi.org/10.1117/12.2612487

KEYWORDS: Fiber Bragg gratings, Sensors, Birefringence, Actuators, Reflectivity, Optical filters, Waveguides, Structural health monitoring, Filtering (signal processing), Ferroelectric materials

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Proceedings Article | 8 July 2021 Presentation + Paper

Application of shearography and the percussion method for the structural inspection of wall paintings: a case study of St. Christopher in Maria Church, Nisse

Valentina Gatto, Andrei Anisimov, Wouter Lettinga, Nan Tao, Merel Lantman, Bernice Crijns, Roger Groves

Proceedings Volume 11784, 117840K (2021) https://doi.org/10.1117/12.2591911

KEYWORDS: Shearography, Inspection, Infrared cameras, Thermography, Temperature metrology, Lamps, Interferometry, Halogens, Defect detection, Data fusion

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Structural delamination in mural paintings is a complex phenomenon and is considered among the most frequent types of damage. In conservation practice, the most common technique to identify structural detachments in wall paintings is the percussion method, otherwise known as the ‘tap and listen’ approach. Full-field optical techniques based on interferometry, such as shearography, can potentially provide a more scientifically substantiated evaluation of the condition of heterogeneous structures of wall paintings. The empirical nature of the percussion method was observed during the condition assessment of two medieval wall paintings in Maria Church, Nisse, Netherlands. Consequently, the need to obtain more knowledge regarding the structural condition of these wall paintings was established. Furthermore, to allow the formulation of specific treatment needs for structural delamination in wall paintings, accurate defect mapping is needed. The application of shearography coupled with thermography was believed to provide an holistic representation of the structural condition of the wall painting depicting St. Christopher in Maria Church. A comparison of the practical execution and the interpretation of data between shearography and the percussion method was conducted to deliver a description of both techniques. Initial comparison of the two methods confirmed what was already hypothesised: I) the percussion method can provide an approximate indication of delaminated areas. Results, which are considered both non-qualitative and non-quantitative, are dependent on the experience of the conservator; II) shearography can produce qualitative and quantitative results regarding the presence of delamination in complex structures of wall paintings. Analysis of the shearography data together with the percussion method may result in a reliable way to map the defects for future conservation activities. The next steps include optimisation of the thermal excitation for shearography to maximise the defect detection and adapt the shearography output for onsite interpretation by conservators and professionals in the cultural heritage.

Proceedings Article | 8 July 2021 Presentation + Paper

Three-dimensional spectral measurements of paint samples using optical coherence tomography

Michael Maria, Lieve d'Hont, Andrei Anisimov, Maartje Stols-Witlox, Roger Groves

Proceedings Volume 11784, 117840Q (2021) https://doi.org/10.1117/12.2592663

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Proceedings Article | 21 June 2021 Presentation

AIRTuB: towards automated inspection of leading-edge erosion of wind turbine blades by shape analysis

Andrei Anisimov, Ronald Beukema, Jason Hwang, Rogier Nijssen, Roger Groves

Proceedings Volume 11785, 117850W (2021) https://doi.org/10.1117/12.2592291

KEYWORDS: Inspection, Wind turbine technology, Shape analysis, Sensors, Manufacturing, Machine learning, Wind energy, Visualization, Laser scanners, Imaging systems

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Currently, wind turbine blades are designed following a safe-life paradigm where manufacturing defects and operational damages are not taken into account. However, industry competition steers innovation towards typical solutions to maximize the economical output. The harsh environment, especially for offshore wind turbines, significantly degrades the turbine structural integrity and its performance. One of the major factors that lowers energy production due to aerodynamic losses is the erosion of the leading edges. Nowadays this erosion is monitored visually, either directly or with drone-based camera systems. We expect a quantitative characterization of the current erosion state and long term degradation monitoring to provide crucial information for wind farm maintenance and possible recoating of wind turbine blades. In this project, a customized long-range laser line scanner is used to measure the profiles of the blades at distances of up to 2 m. Individual scans are assembled into a 3D point cloud which is processed and analysed for defects and erosion. Further in the project, a custom-developed heavy drone will be used to scan the blades offshore. Current results include the detection of eroded areas, impact damages and surface defects in laboratory conditions with the sensor positioned with a scanning frame. Two processing approaches, namely deterministic and machine learning are compared and benchmarked with an ambition to perform erosion detection at a submillimeter scale. The deterministic approach includes local analysis of the surface variation, thresholding and clustering of the defects. Present controlled conditions allow investigation of how predicted drone vibrations, possible water droplets and salt contamination affect the inspection in a real offshore environment. This development is done within the smart maintenance innovation project AIRTuB: Automatic Inspection and Repair of Turbine Blades where the inspection expertise is combined with drone and wind-turbine manufacturers to change the turbine design paradigm from safe life to damage-tolerant.

Proceedings Article | 20 June 2021 Presentation + Paper

Light scattering by gold nanoparticles cured in optical adhesive at optical fibre interfaces

Xiang Wang, Rinze Benedictus, Roger Groves

Proceedings Volume 11782, 1178212 (2021) https://doi.org/10.1117/12.2592308

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This study forms a part of the research in using nanoparticles (NPs) to increase the intensity of light scattering signal in the optical fibres. Increasing the intensity of the backscattered light signal in the optical fibres shows the potential to increase the signal-to-noise ratio in order to improve the sensitivity of the backscatter reflectometry. Doping NPs into the optical fibres can greatly increase the scattered light. However, it is not easy to manufacture NP-doped optical fibres to test different designs. To overcome this problem, in our former work we used the method of dropping refractive index matching liquid containing gold NPs at the optical fibres end tips to investigate the intensity change of the scattered light from the interfaces. In this paper, some new initial experimental results for the scattered light between the optical fibre end tips are shown. Gold NPs have been mixed into the optical adhesive (Norland) and is then dropped and cured at the optical fibre end tips. A backscatter reflectometer (LUNA ODiSI-B) was used in the experiment to measure the intensity of scattered light distribution between the optical fibre end tips. We investigated 4 cases of light scattering between the optical fibre end tips: (i) the backscattered light intensity distribution in the case of the air gap between the optical fibre end tips; (ii) the backscattered light intensity distribution with optical adhesive between the optical fibre end tips; (iii) the backscattered light intensity distribution with optical adhesive containing gold NPs (gold nanopowder (<100 nm), Sigma Aldrich) between the optical fibre end tips before curing process and (iv) the backscattered light intensity distribution with optical adhesive containing gold NPs between the optical fibre end tips after the curing process. Our initial findings are that the scattered light by gold NPs at the optical fibre interfaces can be detected by the backscatter reflectometer. By obtaining the differential signal between the distributed light scattering by cured optical adhesive containing gold NPs and only optical adhesive between the optical fibre end tips, the light scattered by the gold NPs has be determined.

Proceedings Article | 20 June 2021 Presentation + Paper

Spatially modulated thermal excitations for shearography non-destructive inspection of thick composites

Nan Tao, Andrei Anisimov, Roger Groves

Proceedings Volume 11782, 117820V (2021) https://doi.org/10.1117/12.2592293

KEYWORDS: Shearography, Modulation, Composites, Inspection, Nondestructive evaluation, Defect detection, Ocean optics, Wind energy, Signal to noise ratio, Signal detection

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Proceedings Article | 20 June 2021 Presentation + Paper

Explainability of deep learning classifier decisions for optical detection of manufacturing defects in the automated fiber placement process

Sebastian Meister, Mahdieu A. Wermes, Jan Stüve, Roger Groves

Proceedings Volume 11787, 1178705 (2021) https://doi.org/10.1117/12.2592584

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Proceedings Article | 23 April 2020 Presentation + Paper

Algorithm assessment for layup defect segmentation from laser line scan sensor based image data

Sebastian Meister, Mahdieu Amin Mahdieu Wermes, Jan Stüve, Roger Groves

Proceedings Volume 11379, 1137918 (2020) https://doi.org/10.1117/12.2558434

KEYWORDS: Image segmentation, Detection and tracking algorithms, Image processing algorithms and systems, Defect detection, Inspection, Manufacturing, Image sensors, Sensors, Line scan sensors, Aerospace engineering

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Proceedings Article | 1 April 2020 Presentation + Paper

Analysis of a SD-OCT-based hyperspectral system for spectral reflectance measurements

Michael Maria, Andrei Anisimov, Maartje Stols-Witlox, Roger Groves

Proceedings Volume 11354, 113541J (2020) https://doi.org/10.1117/12.2555435

KEYWORDS: Optical coherence tomography, Reflectivity, Cameras, Fourier transforms, Spectrometers, Hyperspectral systems, Visible radiation, Spectroscopy, Spectral resolution, Optical filters

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Proceedings Article | 1 April 2020 Presentation + Paper

Light scattering and rheological effects in an optical fibre coupled nanoparticle suspension

Xiang Wang, Rinze Benedictus, Roger Groves

Proceedings Volume 11354, 113540V (2020) https://doi.org/10.1117/12.2556799

KEYWORDS: Optical fibers, Liquids, Nanoparticles, Gold, Light scattering, Refractive index, Photodetectors, Microscopes, Geometrical optics, Collimation

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This study forms the first part of research into enhancing the forward and back scattering of light in an optical fibre using nanoparticles (NPs). This approach has the potential to enhance the sensitivity of optical fibre sensing by increasing the signal-to-noise ratio. The work described in this paper is focused on understanding the scattering of light by a suspension of NPs in refractive index matching liquid. It was noted early in the experimental work that rheological effects related to the viscosity and flow of the liquid affect the scattered light measured and therefore these effects are considered in the analysis. Gold nanoparticles in the tens to hundreds of micrometre size range were selected as the scattering particles based on their optical properties. These are suspended in a refractive index liquid with a similar refractive index to the optical fibre core. Effort was needed to transfer the NPs from their aqueous sodium citrate solution to the paraffin based solution. We investigated two types of interaction with the optical fibre: (i) dropping the NP suspension onto the end of a single-mode optical fibre and (ii) using the NP suspension as an interface between two single-mode optical fibres. It was noted that the surface tension of the liquid, the diameter of the fibre and the spacing between the fibres in case (ii) influence the reflected and transmitted light. In case of excess liquid, droplets flowed down the fibre and interestingly in case (ii) modified the reflected and forward transmitted light as it passed across the fibre interface. Our initial findings are that the influence of the gap between two optical fibres decreased after dropping refractive index liquid into the gap after fibre collimation, which is a beneficial result for understanding the influence of scattered light from a liquid containing NPs. Note, the position between the two fibres can also change due to the weight of the droplet and the fibre ends had to be re-collimated to investigate the influence of the moving droplets. These results will be expanded by additional experiments and modelling of the scattering from the nanoparticales and droplets.

Proceedings Article | 17 February 2020 Presentation + Paper

Spectra stitching for ultra-high resolution, low sensitivity decay and high-speed SD-OCT

Michael Maria, Andrei Anisimov, Maartje Stols-Witlox, Roger Groves

Proceedings Volume 11231, 1123104 (2020) https://doi.org/10.1117/12.2545157

KEYWORDS: Spectroscopy, Optical coherence tomography, Spectral resolution, Signal detection, Interferometers, Point spread functions, Imaging systems

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Proceedings Article | 28 August 2019 Paper

A method for determining the position of FBG sensors accurately

Aydin Rajabzadeh, Richard Hendriks, Richard Heusdens, Roger Groves

Proceedings Volume 11199, 111990U (2019) https://doi.org/10.1117/12.2545756

KEYWORDS: Fiber Bragg gratings, Sensors, Composites, Damage detection, Optical fibers, Fourier transforms, Aerospace engineering, Manufacturing, Thermal optics, Spatial resolution

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Proceedings Article | 27 July 2019 Presentation

Multimodal nondestructive inspection of impact damages in composite laminates: a case study to assess the damage volume (Conference Presentation)

Andrei Anisimov, Mariya Serikova, Nan Tao, Chirag Anand, Fardin Esrail, Christos Kassapoglou, Roger Groves

Proceedings Volume 11059, 110590W (2019) https://doi.org/10.1117/12.2525808

KEYWORDS: Inspection, Composites, Nondestructive evaluation, Ultrasonics, Data modeling, Numerical modeling, Phased arrays, Shearography, Algorithm development, Data analysis

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The objective of this case study is to characterise and to numerically assess the volume of impact damages in composite laminates with multiple non-destructive testing techniques. Reliable and robust assessments of the damage volume will be used as input and validation data for the existing and developing numerical models of composite materials. In everyday work, researchers in the area of composite materials mostly use 2D assessment of the damaged area acquired with conventional inspection methods as ultrasonic c-scan. This practice is supported by the relative simplicity of the data analysis carried in 2D. It is proposed to assess the damage volume in 3D which may serve as a more reliable criterion to improve coupling with the numerical modelling. In this paper micro X-ray computed tomography (CT) was used as the reference technique for the damage volume assessment and comparison with an industrial ultrasonic c-scan. In addition, for this case study, ultrasonic phased array technique with the full matrix capture algorithms was used for the inspection together with shearography (speckle pattern shearing interferometry). A comparison of all techniques referenced to the CT data formed the guidance for their applicability. In addition, an attempt to fuse the multiple assessments was made to support the comparison of 2D and 3D inspection techniques. For the experimental part, carbon fiber reinforced polymer (CFRP) specimens of three layups were manufactured and damaged with 4 different impact energies in the range of 18-45 J. The layups were orthotropic, quasi-isotropic and a novel one adapted for the impact events. In total 12 specimens were inspected with multiple non-destructive testing techniques to numerically assess the volume of the impact damages. 3 additional specimens were used to assess the repeatability of the damage in the specimens with the same layup and impact energy. 3D CT reconstructions were made by a rotation of specimens using a cone-beam system with the voxel side size of 50 μm. A developed automatic segmentation algorithm was used for the damage volume estimation in all specimens. The phased array inspection was made with a full-matrix capture technique with the frequencies of 2.25 and 5 MHz. An available 3D shape shearography setup was used to characterise the damages both with the in- and out-of-plane surface strains with a thermal loading of the specimen. Future developments include the comparison of the inspection results together with the numerical modelling predictions and with residual strength after the impact.

Proceedings Article | 21 June 2019 Presentation + Paper

EXTREME shearography: high-speed shearography instrument for in-plane surface strain measurements during an impact event

Andrei Anisimov, Roger Groves

Proceedings Volume 11056, 110560J (2019) https://doi.org/10.1117/12.2525801

KEYWORDS: Shearography, Cameras, Composites, Sensors, Interferometers, Mach-Zehnder interferometers, Speckle, Aluminum, Data modeling, Phase shifts

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Proceedings Article | 1 April 2019 Paper

Image analysis for classification of damaged and undamaged areas on composite structures

Pratik Shrestha, Roger Groves

Proceedings Volume 10971, 109711C (2019) https://doi.org/10.1117/12.2513430

KEYWORDS: Image analysis, Inspection, Composites, Thermography, Nondestructive evaluation, Algorithm development, Damage detection, Infrared imaging, Feature extraction

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Proceedings Article | 27 March 2019 Presentation + Paper

DeepSHM: a deep learning approach for structural health monitoring based on guided Lamb wave technique

Vincentius Ewald, Roger Groves, Rinze Benedictus

Proceedings Volume 10970, 109700H (2019) https://doi.org/10.1117/12.2506794

KEYWORDS: Structural health monitoring, Diagnostics, Nondestructive evaluation, Waveguides, Data modeling, Machine learning, Wavelets, Signal processing, Neural networks

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Proceedings Article | 27 March 2019 Presentation + Paper

Analysis of FBG reflection spectra under uniform and non-uniform transverse loads

Luigi Fazzi, Aydin Rajabzadeh, Alberto Milazzo, Roger Groves

Proceedings Volume 10970, 109701X (2019) https://doi.org/10.1117/12.2513795

KEYWORDS: Fiber Bragg gratings, Sensors, Polarization, Birefringence, Optical fibers, Bragg gratings, Reflection, Fiber optics, Computer simulations

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Proceedings Article | 27 March 2019 Presentation + Paper

Simultaneous position and displacement sensing using two fibre Bragg grating sensors

Nakash Nazeer, Roger Groves, Rinze Benedictus

Proceedings Volume 10970, 109701Z (2019) https://doi.org/10.1117/12.2513415

KEYWORDS: Sensors, Fiber Bragg gratings, Optical fibers, Calibration, Aerospace engineering, Beam shaping, Optical testing, Fabry–Perot interferometry, Optical interferometry, Shape analysis, Structural health monitoring

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Proceedings Article | 7 September 2018 Paper

EXTREME shearography: development of a high-speed shearography instrument for measurements of the surface strain components during an impact event

Andrei Anisimov, Roger Groves

Proceedings Volume 10834, 108340X (2018) https://doi.org/10.1117/12.2318692

KEYWORDS: Damage detection, Experimental mechanics, Shearography, Cameras, Composites, Sensors, Acoustic emission, Wave propagation, Speckle, Interferometry

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Proceedings Article | 9 May 2018 Presentation + Paper

Analysis of FBG reflection spectra under anti-symmetrical strain distributions using the approximated transfer matrix model

Aydin Rajabzadeh, Richard Hendriks, Richard Heusdens, Roger Groves

Proceedings Volume 10680, 106800O (2018) https://doi.org/10.1117/12.2306381

KEYWORDS: Fiber Bragg gratings, Sensors, Matrices, Systems modeling, Computer simulations, Light wave propagation, Refractive index, Fourier transforms

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Proceedings Article | 11 July 2017 Paper

Mapping the opacity of paint layers in paintings with coloured grounds using optical coherence tomography

Ping Liu, Moorea Hall-Aquitania, Erma Hermens, Roger Groves

Proceedings Volume 10331, 103310C (2017) https://doi.org/10.1117/12.2270273

KEYWORDS: Optical coherence tomography, Opacity, Inspection, Visualization, Optical diagnostics, Nondestructive evaluation, Light scattering, Signal attenuation, 3D image processing, 3D microstructuring

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Proceedings Article | 23 April 2017 Paper

Modelling non-uniform strain distributions in aerospace composites using fibre Bragg gratings

Aydin Rajabzadeh, Roger Groves, Richard Hendriks, Richard Heusdens

Proceedings Volume 10323, 103237T (2017) https://doi.org/10.1117/12.2265376

KEYWORDS: Adhesives, Reflection, Optical fibers, Fiber Bragg gratings, Sensors, Structural health monitoring, Composites, Modeling, Aerospace engineering, Finite element methods

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Proceedings Article | 12 April 2017 Paper

Classification of composite damage from FBG load monitoring signals

Aydin Rajabzadeh, Richard Hendriks, Richard Heusdens, Roger Groves

Proceedings Volume 10168, 1016831 (2017) https://doi.org/10.1117/12.2257660

KEYWORDS: Composites, Fiber Bragg gratings, Discrete wavelet transforms, Structural health monitoring, Sensors, Wavelets, Damage detection, Manufacturing, Databases, Optical fibers, Feature extraction, Modulation, Refractive index, Glasses

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Proceedings Article | 8 April 2016 Paper

Monitoring chemical degradation of thermally cycled glass-fibre composites using hyperspectral imaging

V. Papadakis, B. Müller, M. Hagenbeek, J. Sinke, R. Groves

Proceedings Volume 9804, 98040S (2016) https://doi.org/10.1117/12.2221919

KEYWORDS: Thermal effects, Hyperspectral systems, Imaging spectroscopy, Composites, Hyperspectral imaging, Glasses, Fiber reinforced polymers, Polymers, Chemical analysis, Nondestructive evaluation, Epoxies, Temperature metrology, Industrial chemicals, Aerospace engineering, Spectroscopy

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Proceedings Article | 30 June 2015 Paper

Optical coherence tomography complemented by hyperspectral imaging for the study of protective wood coatings

L. Dingemans, V. Papadakis, P. Liu, A. Adam, R. Groves

Proceedings Volume 9527, 952708 (2015) https://doi.org/10.1117/12.2184716

KEYWORDS: Optical coherence tomography, Optical coatings, Mass attenuation coefficient, Reflection, Light scattering, Nondestructive evaluation, Scattering, Hyperspectral imaging, Algorithm development, Sensors

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Proceedings Article | 22 June 2015 Paper

3D shape shearography with integrated structured light projection for strain inspection of curved objects

Andrei Anisimov, Roger Groves

Proceedings Volume 9525, 952517 (2015) https://doi.org/10.1117/12.2184058

KEYWORDS: Shearography, Cameras, Clouds, Projection systems, Imaging systems, Calibration, Inspection, Speckle pattern, Prototyping, Structured light

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Proceedings Article | 3 April 2015 Paper

Strain characterization of embedded aerospace smart materials using shearography

Andrei Anisimov, Bernhard Müller, Jos Sinke, Roger Groves

Proceedings Volume 9435, 943524 (2015) https://doi.org/10.1117/12.2082636

KEYWORDS: Cameras, Shearography, Aerospace engineering, Manufacturing, Smart materials, Composites, Aluminum, Copper, Defect detection, Glasses

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Proceedings Article | 15 May 2014 Paper

Damage and deterioration monitoring of artwork by data fusion of 3D surface and hyperspectral measurements

Roger Groves, José Caballero, Ianisse Quinzan, Emilio Ribes-Gómez

Proceedings Volume 9141, 91411E (2014) https://doi.org/10.1117/12.2051898

KEYWORDS: 3D metrology, Calibration, Cameras, Data fusion, Image fusion, Visible radiation, Infrared imaging, Infrared radiation, Fringe analysis, 3D image processing

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Proceedings Article | 9 March 2014 Paper

Non-destructive evaluation of delamination growth in glass fiber composites using optical coherence tomography

Ping Liu, Roger Groves, Rinze Benedictus

Proceedings Volume 9063, 90631M (2014) https://doi.org/10.1117/12.2044758

KEYWORDS: Optical coherence tomography, Composites, Glasses, Signal processing, Nondestructive evaluation, Algorithm development, Coherence (optics), Interferometry, Data processing, Wind turbine technology

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Proceedings Article | 30 May 2013 Paper

SYDDARTA: new methodology for digitization of deterioration estimation in paintings

Luís Granero-Montagud, Cristina Portalés, Begoña Pastor-Carbonell, Emilio Ribes-Gómez, Antonio Gutiérrez-Lucas, Vivi Tornari, Vassilis Papadakis, Roger Groves, Beril Sirmacek, Alessandra Bonazza, Izabela Ozga, Jan Vermeiren, Koen van der Zanden, Matthias Föster, Petra Aswendt, Albert Borreman, Jon Ward, António Cardoso, Luís Aguiar, Filipa Alves, Polonca Ropret, José María Luzón-Nogué, Christian Dietz

Proceedings Volume 8790, 879011 (2013) https://doi.org/10.1117/12.2020333

KEYWORDS: Prototyping, 3D image processing, Chemical analysis, Data acquisition, Hyperspectral imaging, Raman spectroscopy, Short wave infrared radiation, Databases, Infrared imaging, Infrared radiation

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Proceedings Article | 30 May 2013 Paper

Deterioration estimation of paintings by means of combined 3D and hyperspectral data analysis

Proceedings Volume 8790, 879008 (2013) https://doi.org/10.1117/12.2020336

KEYWORDS: 3D modeling, Clouds, Cameras, Chemical analysis, 3D image processing, 3D image reconstruction, 3D acquisition, Fringe analysis, Calibration, Statistical analysis

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SPIE Journal Paper | 9 May 2013

Statistically guided improvements in speckle phase discontinuity predictions by machine learning systems

Firas Sawaf, Roger Groves

OE, Vol. 52, Issue 10, 101907, (May 2013) https://doi.org/10.1117/12.10.1117/1.OE.52.10.101907

KEYWORDS: Neural networks, Machine learning, Speckle, Phase shift keying, Optical engineering, Computing systems, Image analysis, Absorption, Silver, Nondestructive evaluation

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Proceedings Article | 19 April 2013 Paper

Laser displacement sensor to monitor the layup process of composite laminate production

Nick Miesen, Roger Groves, Jos Sinke, Rinze Benedictus

Proceedings Volume 8692, 86922T (2013) https://doi.org/10.1117/12.2009177

KEYWORDS: Composites, Sensors, Carbon, Nondestructive evaluation, Distance measurement, Computer aided design, Sensing systems, MATLAB, Aerospace engineering, Lasers

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SPIE Journal Paper | 4 March 2013

Signal processing in optical coherence tomography for aerospace material characterization

Ping Liu, Roger Groves, Rinze Benedictus

OE, Vol. 52, Issue 03, 033201, (March 2013) https://doi.org/10.1117/12.10.1117/1.OE.52.3.033201

KEYWORDS: Optical coherence tomography, Filtering (signal processing), Demodulation, Signal processing, Digital filtering, Sensors, Bandpass filters, Electronic filtering, Image quality, Interference (communication)

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Proceedings Article | 5 May 2012 Paper

Quality assessment of aerospace materials with optical coherence tomography

Ping Liu, Roger Groves, Rinze Benedictus

Proceedings Volume 8430, 84300I (2012) https://doi.org/10.1117/12.922511

KEYWORDS: Optical coherence tomography, Aerospace engineering, Nondestructive evaluation, Epoxies, Optical coatings, Composites, Demodulation, Biomedical optics, Inspection, Polymers

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Proceedings Article | 23 May 2011 Paper

Opto-mechanical modelling and experimental approach to the measurement of aerospace materials using shearography and thermal loading

Eduardo Corso Krutul, Roger Groves

Proceedings Volume 8083, 80831C (2011) https://doi.org/10.1117/12.889457

KEYWORDS: Shearography, Phase measurement, Temperature metrology, Thermal modeling, Lamps, Finite element methods, Surface plasmons, Aerospace engineering, Aluminum, Cameras

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Proceedings Article | 14 April 2011 Paper

Lamb wave detection in prepreg composite materials with fibre Bragg grating sensors

Nick Miesen, Yoshihiro Mizutani, Roger Groves, Jos Sinke, Rinze Benedictus

Proceedings Volume 7981, 79812J (2011) https://doi.org/10.1117/12.880215

KEYWORDS: Sensors, Fiber Bragg gratings, Composites, Ferroelectric materials, Structural health monitoring, Wave propagation, Transducers, Process control, Carbon, Nondestructive evaluation

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Proceedings Article | 14 September 2010 Paper

A combined experiment with simulation approach to calibrated 3D strain measurement using shearography

Dênis Goto, Roger Groves

Proceedings Volume 7387, 73871J (2010) https://doi.org/10.1117/12.870572

KEYWORDS: Cameras, Shearography, 3D metrology, Content addressable memory, Calibration, Sensors, 3D modeling, Imaging systems, Distortion, Finite element methods

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Proceedings Article | 14 May 2010 Paper

Error analysis of 3D shearography using finite-element modelling

D. Goto, R. Groves

Proceedings Volume 7718, 771816 (2010) https://doi.org/10.1117/12.853602

KEYWORDS: Cameras, Shearography, Content addressable memory, Error analysis, 3D modeling, Device simulation, Optical simulations, 3D metrology, Finite element methods, Laser sources

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Proceedings Article | 11 July 2009 Paper

Multi-sensor evaluation of a wooden panel painting using terahertz imaging and shearography

Roger Groves, Boris Pradarutti, Eleni Kouloumpi, Wolfgang Osten, Gunther Notni

Proceedings Volume 7391, 73910E (2009) https://doi.org/10.1117/12.827528

KEYWORDS: Shearography, Millimeter wave imaging, Sensors, Terahertz radiation, Diagnostics, Crystals, Cultural heritage, Shearing interferometers, Mirrors, Beam splitters

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Proceedings Article | 7 July 2009 Paper

2.5D virtual reality visualisation of shearography strain data from a canvas painting

R. Groves, A. Li, X. Liu, S. Hackney, X. Peng, W. Osten

Proceedings Volume 7391, 739109 (2009) https://doi.org/10.1117/12.827519

KEYWORDS: Shearography, Virtual reality, Volume rendering, Visualization, Interferometers, Image processing, Diagnostics, Photography, Mirrors, CCD cameras

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Proceedings Article | 25 April 2008 Paper

Extended dynamic range imaging in shearography

Roger Groves, Giancarlo Pedrini, Wolfgang Osten

Proceedings Volume 7000, 700010 (2008) https://doi.org/10.1117/12.781949

KEYWORDS: Cameras, Shearography, Camera shutters, Image processing, Range imaging, Reflectivity, Sensors, Image fusion, Speckle interferometry, Gold

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Proceedings Article | 19 July 2007 Paper

Multifunctional encoding system for assessment of movable cultural heritage

V. Tornari, E. Bernikola, W. Osten, R. Groves, G. Marc, G. Hustinx, E. Kouloumpi, S. Hackney

Proceedings Volume 6618, 66180W (2007) https://doi.org/10.1117/12.726170

KEYWORDS: Holography, Fringe analysis, Cultural heritage, Crystals, Sensors, Holograms, Digital holography, Laser crystals, Diffraction, Computer programming

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Proceedings Article | 19 July 2007 Paper

Shearography as part of a multi-functional sensor for the detection of signature features in movable cultural heritage

Roger Groves, Wolfgang Osten, Michael Doulgeridis, Eleni Kouloumpi, Tim Green, Stephen Hackney, Vivi Tornari

Proceedings Volume 6618, 661810 (2007) https://doi.org/10.1117/12.727497

KEYWORDS: Sensors, Shearography, Cultural heritage, Cameras, Algorithm development, Lamps, Head, Interferometry, Databases, Photography

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Proceedings Article | 18 June 2007 Paper

Fresnel wavefront propagation model for shearography shape measurement

Arun Anand, Roger Groves, Xavier Schwab, Giancarlo Pedrini, Wolfgang Osten

Proceedings Volume 6617, 66170Q (2007) https://doi.org/10.1117/12.725985

KEYWORDS: Wavefronts, Shearography, Sensors, Wave propagation, Optical components, Light wave propagation, Shearing interferometers, Mathematical modeling, Interferometers, Speckle

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Proceedings Article | 15 September 2006 Paper

Temporal phase measurement methods in shearography

Roger Groves, Wolfgang Osten

Proceedings Volume 6341, 63411L (2006) https://doi.org/10.1117/12.695377

KEYWORDS: Shearography, Phase shift keying, Mirrors, Phase shifts, Fourier transforms, Interferometers, Modulation, Image processing, Cameras, Phase measurement

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Proceedings Article | 7 March 2006 Paper

Surface strain characterization using time-division-multiplexed 3D shearography

Stephen James, Roger Groves, Ralph Tatam

Proceedings Volume 4101, (2006) https://doi.org/10.1117/12.498404

KEYWORDS: Shearography, CCD cameras, 3D metrology, Cameras, Semiconductor lasers, Optical fibers, Time division multiplexing, Speckle, Mirrors, Shearing interferometers

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Proceedings Article | 7 March 2006 Paper

Shadow moire method for the measurement of the source position in three-dimensional shearography

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 4101, (2006) https://doi.org/10.1117/12.498429

KEYWORDS: Moire patterns, Fringe analysis, Shearography, Cameras, Mirrors, Imaging systems, CCD cameras, Image segmentation, Reflection, Optical testing

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Proceedings Article | 7 March 2006 Paper

Shape measurement by source displacement in three-dimensional shearography

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 4101, (2006) https://doi.org/10.1117/12.498430

KEYWORDS: Mathematical modeling, Shearography, Interferometry, Speckle pattern, Cameras, Imaging systems, Distortion, Speckle, Mirrors, Optical spheres

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Proceedings Article | 13 June 2005 Paper

Comparison of shearography and optical fibre Bragg grating strain sensors with resistance foil strain gauge measurements

Roger Groves, Edmon Chehura, Weilai Li, Stephen Staines, Stephen James, Ralph Tatam

Proceedings Volume 5856, (2005) https://doi.org/10.1117/12.611887

KEYWORDS: Fiber Bragg gratings, Shearography, Sensors, Optical fibers, Resistance, Refractive index, Optical testing, Demodulation, Speckle, Cameras

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Proceedings Article | 23 May 2005 Paper

Comparison of optical fibre Bragg grating strain sensors with shearography and resistance foil strain gauge measurements

Edmon Chehura, Roger Groves, Weilai Li, Stephen Staines, Stephen James, Ralph Tatam

Proceedings Volume 5855, (2005) https://doi.org/10.1117/12.624218

KEYWORDS: Fiber Bragg gratings, Sensors, Shearography, Optical fibers, Resistance, Demodulation, Interferometers, Mirrors, Cameras, Fiber optics sensors

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SPIE Journal Paper | 1 February 2005

Single-axis combined shearography and digital speckle photography instrument for full surface strain characterization

Roger Groves, Shan Fu, Stephen James, Ralph Tatam

OE, Vol. 44, Issue 02, 025602, (February 2005) https://doi.org/10.1117/12.10.1117/1.1842779

KEYWORDS: Shearography, Digital photography, Speckle, Digital signal processing, Photography, Speckle pattern, Image processing, Mirrors, Optical engineering, Error analysis

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Proceedings Article | 10 September 2004 Paper

Multicomponent laser shearography for the investigation of defects in rotating machinery

Roger Groves, Stephen James, Stuart Barnes, Shan Fu, Domenico Furfari, Philip Irving, Ralph Tatam

Proceedings Volume 5457, (2004) https://doi.org/10.1117/12.545125

KEYWORDS: Shearography, Optical fibers, Cameras, Head, Pulsed laser operation, Semiconductor lasers, Fourier transforms, Lenses, Optical imaging, Mirrors

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Proceedings Article | 10 November 2003 Paper

Multi-component pulsed-laser shearography using optical fiber imaging-bundles

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 5191, (2003) https://doi.org/10.1117/12.503738

KEYWORDS: Shearography, Optical fibers, Cameras, Head, Interferometers, Pulsed laser operation, Optical imaging, Nd:YAG lasers, Speckle, Mirrors

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Proceedings Article | 30 May 2003 Paper

Multicomponent shearography using optical fiber imaging-bundles

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 5144, (2003) https://doi.org/10.1117/12.499784

KEYWORDS: Shearography, Optical fibers, Cameras, Head, Interferometers, Lenses, Speckle pattern, Speckle, Laser sources, Optical imaging

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Proceedings Article | 27 May 2003 Paper

Multi component shearography employing four measurements channels

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 4933, (2003) https://doi.org/10.1117/12.516623

KEYWORDS: Shearography, Speckle, Channel projecting optics, Speckle pattern, 3D metrology, Optical sensors, Photonics, Optical engineering, Interferometry, Interferometers

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Proceedings Article | 29 April 2003 Paper

Combined shearography and speckle pattern photography for single-access multi-component surface strain measurement

Roger Groves, Shan Fu, Stephen James, Ralph Tatam

Proceedings Volume 5058, (2003) https://doi.org/10.1117/12.509780

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Proceedings Article | 26 November 2001 Paper

Full surface strain measurement using shearography

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 4448, (2001) https://doi.org/10.1117/12.449371

KEYWORDS: Shearography, Cameras, Speckle pattern, Mirrors, Head, Speckle, Semiconductor lasers, Interferometry, Interferometers, Image processing

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Proceedings Article | 23 October 2001 Paper

Strain measurement in curved industrial components using multicomponent shearography

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 4398, (2001) https://doi.org/10.1117/12.445554

KEYWORDS: Shearography, Speckle pattern, Cameras, Interferometry, Mirrors, Head, Semiconductor lasers, CCD cameras, Imaging systems, Beam delivery

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Proceedings Article | 9 November 2000 Paper

Polarisation-multiplexed and phase-stepped fibre optic shearography using laser diode wavelength tuning

Roger Groves

Proceedings Volume 4185, 41852O (2000) https://doi.org/10.1117/12.2302239

KEYWORDS: Polarization, Phase shift keying, Semiconductor lasers, Interferometers, Shearography, Wavelength tuning, Optical fibers, Mirrors, Switching, Speckle

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Proceedings Article | 17 August 1999 Paper

Polarization-multiplexed and phase-stepped fiber optic shearography using laser wavelength modulation

Roger Groves, Stephen James, Ralph Tatam

Proceedings Volume 3745, (1999) https://doi.org/10.1117/12.357773

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Showing 5 of 65 publications

Proceedings Volume Editor (3)

SPIE Conference Volume | 7 September 2023

Optics for Arts, Architecture, and Archaeology (O3A) IX

SPIE Conference Volume | 16 July 2021

Optics for Arts, Architecture, and Archaeology VIII

SPIE Conference Volume | 22 August 2019

Optics for Arts, Architecture, and Archaeology VII

Conference Committee Involvement (17)

Optical Sensing and Detection VIII

7 April 2024 | Strasbourg, France

Optics for Arts, Architecture, and Archaeology (O3A) IX

26 June 2023 | Munich, Germany

Optical Sensing and Detection VII

3 April 2022 | Strasbourg, France

Optics for Arts, Architecture, and Archaeology (O3A) VIII

21 June 2021 | Online Only, Germany

Optical Methods for Inspection, Characterization, and Imaging of Biomaterials V

21 June 2021 | Online Only, Germany

Optical Sensing and Detection VI

6 April 2020 | Online Only, France

Optics for Arts, Architecture, and Archaeology VII

24 June 2019 | Munich, Germany

Optical Methods for Inspection, Characterization, and Imaging of Biomaterials IV

24 June 2019 | Munich, Germany

Optical Sensing and Detection

23 April 2018 | Strasbourg, France

O3A: Optics for Art, Architecture, and Archaeology

28 June 2017 | Munich, Germany

Optical Methods for Inspection, Characterization, and Imaging of Biomaterials

26 June 2017 | Munich, Germany

Optical Sensing and Detection

3 April 2016 | Brussels, Belgium

Optics for Arts, Architecture, and Archaeology V

24 June 2015 | Munich, Germany

Optical Methods for Inspection, Characterization, and Imaging of Biomaterials II

22 June 2015 | Munich, Germany

Optics for Arts, Architecture, and Archaeology IV

15 May 2013 | Munich, Germany

Optical Measurement Systems for Industrial Inspection

23 May 2011 | Munich, Germany

Optical Measurement Systems for Industrial Inspection

16 June 2009 | Munich, Germany

Showing 5 of 17 Conference Committees

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