Prof. Alexander M. J. van Eijk Profile

Prof. Alexander M. J. van Eijk

Principal Scientist at TNO

SPIE Involvement:

Publications (101)

Proceedings Article | 22 November 2024 Presentation

Comparative analysis of atmospheric aerosol models for quantifying aerosol loading and characterizing visibility in West Africa

Thomas Kociok, Carmen Ullwer, Karin Stein, Alexander M. van Eijk

Proceedings Volume 13194, 131940B (2024) https://doi.org/10.1117/12.3031852

KEYWORDS: Atmospheric modeling, Aerosols, Solar radiation models, Visibility, Atmospheric particles, Solar radiation, Optical properties, Data acquisition, Meteorology

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Proceedings Article | 19 November 2024 Paper

Exploration of length scales of the Kolmogorov turbulence spectrum in the atmospheric surface layer

Detlev Sprung, Erik Sucher, A. M. van Eijk

Proceedings Volume 13194, 1319407 (2024) https://doi.org/10.1117/12.3034012

KEYWORDS: Turbulence, Ultrasonics, Wind speed, Atmospheric turbulence, Wind measurement, Optical turbulence, Equipment, Atmospheric optics, Refractive index, Laser applications

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Proceedings Article | 19 November 2024 Paper

Comparison of mixing length scale parametrization for the investigation of turbulence relevant for ground to satellite communication

D. Sprung, C. Ullwer, A. M. van Eijk

Proceedings Volume 13194, 1319408 (2024) https://doi.org/10.1117/12.3034040

KEYWORDS: Turbulence, Satellite communications, Wind speed, Data modeling, Atmospheric modeling, Signal attenuation, Satellites, Meteorology, Laser frequency, Laser applications

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Proceedings Article | 1 November 2024 Presentation + Paper

High energy lasers as an anti-satellite capability

Roderik Overzier, Sven van Binsbergen, Alexander M. van Eijk, Eva Fernández Rodríguez, Alexander C. ter Haar, Loes C. Scheers, Ric Schleijpen

Proceedings Volume 13201, 132010G (2024) https://doi.org/10.1117/12.3031520

KEYWORDS: Satellites, Sensors, Adaptive optics, Pulsed laser operation, Atmospheric optics, Turbulence, Thermal blooming, Laser energy, Beam diameter, Laser damage threshold

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Proceedings Article | 1 November 2024 Presentation + Paper

Considerations on thermal blooming in relation to modern HEL systems

H. M. Schleijpen, L. C. Scheers, G. J. Vissers, R. Overzier, A. M. van Eijk, J. Tokaya

Proceedings Volume 13201, 132010D (2024) https://doi.org/10.1117/12.3031778

KEYWORDS: Thermal blooming, Distortion, Absorption, Turbulence, Aerosols, Atmospheric propagation, Wind speed, Atmospheric modeling, Simulations, Refractive index

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Research into thermal blooming effects in laser beam propagation has been initiated within ten years after the first demonstration of a laser. Results of these studies have been published in excellent review papers. Now several decades later, developments in laser technology are bringing High Energy Laser systems closer to actual operational application and to power levels where thermal blooming might affect the system performance. In support of understanding HEL performance and development of potential mitigation measures, it is of interest to be able to estimate the limits when a system will enter conditions where thermal blooming will affect performance. This will also support understanding of potential mitigation measures. This paper discusses which parameters influence thermal blooming in a High Energy Laser system in several realistic scenarios. The influence of these parameters on the laser beam are illustrated analytically for a collimated High Energy Laser beam. We provide a simplified derivation of the distortion parameter as presented in the review papers. This distortion parameter will be used to explore the effect of thermal blooming on three generic HEL systems: short range (I), medium range (II) and large range (III), with corresponding power levels for more complex beam shapes, thermal blooming effects on the power on target are analysed with wave optics simulations. Thermal blooming critically depends on the atmospheric conditions. More specifically: the molecular absorption, the wind speed component perpendicular to the beam and the atmospheric transmission losses due to scatter and absorption by aerosols and molecules in general. The averages of these parameters and their variability over location and time, have been analysed by exploring a data base over weather parameters collected over the whole of Europe in 2019. For a specific location in the Mediterranean their effect on thermal blooming in a generic large range HEL system are calculated. The combined effect of turbulence and thermal blooming has been investigated as well, to explore where one or the other effect might dominate and how the combined effect degrades HEL-system performance. Finally, some considerations on mitigation of thermal blooming effects by system design choices or change in wavelength are given.

Proceedings Article | 3 October 2024 Presentation + Paper

Turbulence strength experimental measurements for improved detection in free space optical communications

Carlos Pirela, Jaime Anguita, Jaime Cisternas, Alexander M. van Eijk, Ariadna Huerta-Viso

Proceedings Volume 13147, 131470J (2024) https://doi.org/10.1117/12.3028156

KEYWORDS: Turbulence, Scintillation, Receivers, Beam propagation method, Atmospheric turbulence, Atmospheric propagation, Sensors, Beam path, Reflection, Free space optical communications

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Proceedings Article | 23 October 2023 Paper

Design and implementation of a micrometeorological weather station for ground-based swarm environments

Thomas Kociok, Lars Ullmer, Christian Eisele, Alexander M. van Eijk, Karin Stein

Proceedings Volume 12736, 127360F (2023) https://doi.org/10.1117/12.2682300

KEYWORDS: Sensors, Environmental monitoring, Clouds, Internet of things, Design and modelling, Aerosols, Data transmission, Data processing, Data acquisition, Ultraviolet radiation

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Proceedings Article | 23 October 2023 Presentation

Numerical analysis of propagation conditions in which conventional adaptive optics can improve laser-directed energy weapons beam shaping

Loes Scheers, Gregal Vissers, Pieter Piscaer, Sven Van Binsbergen, Robert Nieuwenhuizen, Roderik Overzier, Lex Van Eijk, Ric Schleijpen

Proceedings Volume PC12739, PC1273902 (2023) https://doi.org/10.1117/12.2683965

KEYWORDS: Adaptive optics, Numerical analysis, Laser optics, Laser energy, Laser beam propagation, Improvised weapons, Energy based weapons, Beam shaping, Wave propagation, Optical aberrations

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Proceedings Article | 20 October 2023 Presentation

Evaluation of the performance and accuracy of a micrometeorological weather station for measuring weather parameters through point measurements

Thomas Kociok, Lars Ullmer, Eisele Christian, Alexander M.J. van Eijk, Karin Stein

Proceedings Volume 12727, 1272716 (2023) https://doi.org/10.1117/12.2682310

KEYWORDS: Ultraviolet radiation, Aerosols, Wind speed, Turbulence, Temperature metrology, Sensors, Reliability, Optical tracking, Infrared radiation, Meteorology

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Proceedings Article | 19 October 2023 Presentation + Paper

Laser beam propagation over the sea surface: experimental data and verification of simulations

L. C. Scheers, G. J. M. Vissers, S. van Binsbergen, A. Huerta Viso, R. Overzier, A. P. Oosterwijk, A. M. van Eijk, E. Sucher, K. Stein

Proceedings Volume 12731, 127310E (2023) https://doi.org/10.1117/12.2683975

KEYWORDS: Atmospheric propagation, Laser beam propagation, Beam wander, Scintillation, Beam propagation method, Atmospheric modeling

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Proceedings Article | 19 October 2023 Presentation + Paper

High-resolution modeling of the spatiotemporal variations in aerosol extinction in a complex coastal area

Alix Limoges, Christophe Yohia, Quentin Rodier, Alexander M. van Eijk, Jacques Piazzola

Proceedings Volume 12731, 127310C (2023) https://doi.org/10.1117/12.2680558

KEYWORDS: Atmospheric modeling, Aerosols, Wind speed, Atmospheric particles, Simulations, Coastal modeling, Modeling, Performance modeling

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Proceedings Article | 19 October 2023 Presentation + Paper

Sensitivity study on the number of height levels used in a numerical weather model to determine the vertical profile of Cn2

Carmen Ullwer, Detlev Sprung, Karin Stein, A. M. van Eijk

Proceedings Volume 12731, 127310M (2023) https://doi.org/10.1117/12.2684371

KEYWORDS: Simulations, Optical turbulence, Troposphere, Data modeling, Wind speed, Stratosphere, Atmospheric modeling, Modeling, Interpolation, Turbulence

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Proceedings Article | 3 October 2023 Presentation + Paper

Experimental measurements of atmospheric turbulence strength through scintillation and beam-wander analysis

Carlos Pirela, Jaime Anguita, Jaime Cisternas, Alexander M. van Eijk, Ariadna Huerta

Proceedings Volume 12691, 1269105 (2023) https://doi.org/10.1117/12.2677351

KEYWORDS: Turbulence, Scintillation, Receivers, Atmospheric turbulence, Beam propagation method, Atmospheric propagation, Beam wander, Reflection, Free space optics, Beam path

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Proceedings Article | 15 March 2023 Presentation + Paper

Investigating the integrated optical turbulence over the sea by different measurement techniques and mesoscale model simulations

Erik Sucher, Sven van Binsbergen, Carmen Ullwer, Alexander M. van Eijk, Karin Stein, Detlev Sprung

Proceedings Volume 12266, 1226604 (2023) https://doi.org/10.1117/12.2638774

KEYWORDS: Simulations, Turbulence, Beam wander, Atmospheric propagation, Atmospheric modeling, Optical turbulence, Beam path, Equipment, Atmospheric optics, Transmitters

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Proceedings Article | 2 November 2022 Presentation + Paper

Reflection measurements in TNO’s 30 kW laser facility

D. Meuken, S. van Binsbergen, L. C. W. Scheers, P. van den Berg, A. M. van Eijk

Proceedings Volume 12273, 122730D (2022) https://doi.org/10.1117/12.2634047

KEYWORDS: Reflection, Nominal ocular hazard distance, Cameras, Specular reflections, Laser safety, High speed cameras, Data acquisition, Visible radiation, High power lasers

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Proceedings Article | 26 October 2022 Presentation + Paper

Laser propagation measurements over a multi-km path in a maritime environment

S. van Binsbergen, P. van den Berg, L. C. Scheers, J. Blom, E. Sucher, A. M. van Eijk, K. Stein

Proceedings Volume 12266, 1226603 (2022) https://doi.org/10.1117/12.2638663

KEYWORDS: Atmospheric propagation, Laser beam propagation, Cameras, Visibility, Environmental sensing, Short wave infrared radiation, Laser sources, Turbulence, Modulation, Laser safety

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Proceedings Article | 26 October 2022 Presentation

Characteristics of optical turbulence over the sea

Erik Sucher, Sven Binsbergen, Carmen Ullwer, Detlev Sprung, Alexander van Eijk, Karin Stein

Proceedings Volume 12266, 1226605 (2022) https://doi.org/10.1117/12.2636241

KEYWORDS: Turbulence, Optical turbulence, Wave propagation, Ultrasonics, Refraction, Data acquisition

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Proceedings Article | 30 September 2022 Presentation + Paper

Low-altitude laser propagation link over a marine surface

S. A. van Binsbergen, P. J. van den Berg, L. C. W. Scheers, J. Blom, E. Sucher, A. M. van Eijk

Proceedings Volume 12237, 122370C (2022) https://doi.org/10.1117/12.2632361

KEYWORDS: Visibility, Atmospheric propagation, Signal attenuation, Laser beam propagation, Cameras, Short wave infrared radiation, Turbulence, Atmospheric particles

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Proceedings Article | 12 September 2021 Presentation + Paper

Smoke as protection against high energy laser effects

Ric H. M. Schleijpen, Sven van Binsbergen, Amir Vosteen, Karin de Groot-Trouw, Denise Meuken, Alexander M. Van Eijk

Proceedings Volume 11867, 1186704 (2021) https://doi.org/10.1117/12.2598782

KEYWORDS: Particles, Refractive index, Spectroscopy, Cameras, Laser energy, Sensors, Signal attenuation

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Proceedings Article | 12 September 2021 Presentation + Paper

Investigation of vertical profiles of optical turbulence from mesoscale simulations runs and radiosonde data

Detlev Sprung, Carmen Ullwer, Alexander M. van Eijk, Karin Stein

Proceedings Volume 11860, 1186008 (2021) https://doi.org/10.1117/12.2600251

KEYWORDS: Atmospheric modeling, Meteorology, Optical turbulence, Refractive index, Humidity, Atmospheric optics, Turbulence, Data modeling, Troposphere

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Proceedings Article | 12 September 2021 Presentation + Paper

Investigation of the atmosphere above the sea regarding laser performance

Detlev Sprung, Carmen Ullwer, Erik Sucher, Peter Grossmann, Thomas Kociok, Alexander M. van Eijk, Karin Stein

Proceedings Volume 11860, 1186007 (2021) https://doi.org/10.1117/12.2600229

KEYWORDS: Turbulence, Visibility, Meteorology, Laser beam propagation, Atmospheric propagation, Signal attenuation, Optical turbulence, Ocean optics, Refractive index

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Proceedings Article | 12 September 2021 Presentation + Paper

System assessment capability for the laser effector

J. J. M. Paulissen, D. Meuken, A. M. van Eijk

Proceedings Volume 11867, 118670G (2021) https://doi.org/10.1117/12.2595483

KEYWORDS: Atmospheric propagation, Laser beam propagation, Atmospheric optics, Laser safety, Wave propagation, Turbulence

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Proceedings Article | 20 September 2020 Presentation + Paper

Investigation of optical turbulence over an urban area: comparison between experimental results and simulation

Detlev Sprung, Carmen Ullwer, Erik Sucher, Thomas Kociok, Alexander M. van Eijk, Karin Stein

Proceedings Volume 11532, 1153205 (2020) https://doi.org/10.1117/12.2572997

KEYWORDS: Optical turbulence, Atmospheric optics, Refractive index, Thermal effects, Wireless communications, Optical testing, Turbulence

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Proceedings Article | 20 September 2020 Presentation + Paper

Turbulence magnitude of West Africa: a virtual measuring campaign

Thomas Kociok, Carmen Ullwer, Detlev Sprung, Alexander M. J. van Eijk, Karin Stein

Proceedings Volume 11532, 1153204 (2020) https://doi.org/10.1117/12.2571061

KEYWORDS: Turbulence, Atmospheric modeling, Solar radiation models, Data modeling, Atmospheric monitoring, Atmospheric optics, Satellites, Humidity, Solar radiation, Aerosols

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SPIE Journal Paper | 24 July 2020 Open Access

Special Section Guest Editorial: Atmospheric Propagation

Steven Fiorino, Alexander M. van Eijk, Stephen Hammel, Alexander Berk

OE, Vol. 59, Issue 08, 081801, (July 2020) https://doi.org/10.1117/12.10.1117/1.OE.59.8.081801

KEYWORDS: Turbulence, Atmospheric propagation, Atmospheric particles, Atmospheric optics, Monte Carlo methods, Measurement devices, Free space optical communications, Geometrical optics, Atmospheric physics

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Proceedings Article | 18 October 2019 Paper

Turbulent kinetic energy estimates from profiling wind lidar and provisional derivation to calculate C2n

Thomas Kociok, Detlev Sprung, Erik Sucher, Alexander M. J. van Eijk, Karin Stein

Proceedings Volume 11153, 1115309 (2019) https://doi.org/10.1117/12.2533069

KEYWORDS: LIDAR, Turbulence, Wind energy, Optical turbulence, Atmospheric modeling, Refractive index, Clouds, Data modeling, Profiling, Atmospheric optics

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Proceedings Article | 17 October 2019 Presentation + Paper

Modelling sea clutter infrared synthetic images

B. Devecchi, K. Benoist, L. C. Scheers, H. E. Veerman, S. Binsbergen, A. M. van Eijk

Proceedings Volume 11158, 111580K (2019) https://doi.org/10.1117/12.2535820

KEYWORDS: Modeling, Atmospheric modeling, Infrared imaging, Infrared signatures, Cameras, Atmospheric monitoring, Remote sensing, Environmental monitoring, Surveillance, Thermal modeling

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Proceedings Article | 11 October 2019 Paper

Using ultrasonic anemometers for temperature measurements and implications on Cn2

Detlev Sprung, Erik Sucher, Peter Grossmann, Thomas Kociok, Alexander M. J. van Eijk, Karin Stein

Proceedings Volume 11153, 111530B (2019) https://doi.org/10.1117/12.2534023

KEYWORDS: Ultrasonics, Humidity, Turbulence, Optical turbulence, Refractive index, Temperature metrology, Atmospheric propagation, Wave propagation, Sensors, Atmospheric laser remote sensing

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Proceedings Article | 9 October 2019 Paper

The influence of atmospheric profile resolution on modelling propagation effects in high-elevation scenarios

L. C. W. Scheers, H. E. Veerman, B. A. Devecchi, A. M. M. Manders-Groot, J. S. Henzing, A. M. J. van Eijk

Proceedings Volume 11153, 1115306 (2019) https://doi.org/10.1117/12.2532798

KEYWORDS: Atmospheric propagation, Atmospheric modeling, Modeling, Atmospheric particles, Sensor performance, Atmospheric sensing, Meteorology, Radiative transfer, Thermal modeling, Spectral resolution

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Proceedings Article | 6 September 2019 Paper

Global simulations of Cn2 using the Weather Research and Forecast Model WRF and comparison to experimental results

Carmen Ullwer, Detlev Sprung, Erik Sucher, Thomas Kociok, Peter Grossmann, Alexander M. van Eijk, Karin Stein

Proceedings Volume 11133, 111330I (2019) https://doi.org/10.1117/12.2530280

KEYWORDS: Electro optical modeling, Systems modeling, Databases, Data modeling, Electro optical sensors, Electro optical systems, Laser systems engineering, Atmospheric optics, Atmospheric sensing, Optical turbulence

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Proceedings Article | 6 September 2019 Paper

Comparison of modelled atmospheric aerosol content and its influence on high-energy laser propagation

Aleid Oosterwijk, Stephanie Heikamp, Astrid Manders-Groot, A. M. (Lex) van Eijk

Proceedings Volume 11133, 111330C (2019) https://doi.org/10.1117/12.2529949

KEYWORDS: Aerosols, Laser beam propagation, Atmospheric optics, Atmospheric modeling, Meteorology, Atmospheric propagation, Wind energy, Thermal blooming, Atmospheric particles

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Proceedings Article | 16 November 2018 Paper

Investigation of aerosols in South Africa: Comparison of measurements and modeling

T. Kociok, F. February, P. Grossmann, D. Sprung, A. M. van Eijk, K. Stein

Proceedings Volume 10787, 1078704 (2018) https://doi.org/10.1117/12.2326526

KEYWORDS: Atmospheric modeling, Aerosols, MODIS, Data modeling, Atmospheric particles, Visibility, Satellites, Meteorology, Solids, Ocean optics

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Proceedings Article | 10 October 2018 Paper

Optical turbulence in the coastal area over False Bay, South Africa: comparison of measurements and modeling results

Detlev Sprung, Alexander M. van Eijk, Carmen Ullwer, Willi Gunter, Christian Eisele, Dirk Seiffer, Erik Sucher, Karin Stein

Proceedings Volume 10787, 1078703 (2018) https://doi.org/10.1117/12.2325609

KEYWORDS: Optical turbulence, Turbulence, Heat flux, Meteorology, Atmospheric propagation, Ultrasonics, Atmospheric modeling, Wave propagation, Atmospheric optics, Humidity

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Proceedings Article | 10 October 2018 Paper

Height dependence of characteristics of power spectra of temperature investigated in the surface layer of White Sands, US

Detlev Sprung, Erik Sucher, Alexander M. van Eijk, Christian Eisele, Dirk Seiffer, Karin Stein

Proceedings Volume 10787, 1078705 (2018) https://doi.org/10.1117/12.2325617

KEYWORDS: Turbulence, Ultrasonics, Optical turbulence, Temperature metrology, Wave propagation, Vegetation, Atmospheric propagation, Refractive index, Cameras, Data modeling

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Proceedings Article | 10 October 2018 Paper

Investigation of optical turbulence from an unmanned aerial system

Erik Sucher, Detlev Sprung, Michael Kremer, Thomas Kociok, Alexander M. van Eijk, Karin Stein

Proceedings Volume 10787, 1078706 (2018) https://doi.org/10.1117/12.2325626

KEYWORDS: Ultrasonics, Optical turbulence, Turbulence, Sensors, Atmospheric propagation, Refractive index, Electro optical systems, Wave propagation, Atmospheric optics, Temporal resolution

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Proceedings Article | 18 October 2017 Paper

Long-term experiment VERTURM (vertical turbulence measurements): comparison of measurements and modeling of the vertical distribution of optical turbulence Cn2 in the surface layer

Detlev Sprung, Peter Grossmann, Erik Sucher, Alexander M. van Eijk, Karin Stein

Proceedings Volume 10425, 1042508 (2017) https://doi.org/10.1117/12.2279427

KEYWORDS: Turbulence, Optical turbulence, Electro optical modeling, Atmospheric optics, Systems modeling, Atmospheric turbulence, Electro optical systems, Atmospheric modeling, Standards development, Meteorology

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Proceedings Article | 10 October 2017 Paper

Inhomogeneity of optical turbulence over False Bay (South Africa)

Carmen Ullwer, Detlev Sprung, Alexander M. van Eijk, Willi Gunter, Karin Stein

Proceedings Volume 10425, 1042509 (2017) https://doi.org/10.1117/12.2279381

KEYWORDS: Optical turbulence, Data modeling, Ultrasonics, Turbulence, Meteorology, Refractive index, Temperature metrology, Transmitters, Optical testing, Ocean optics

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Proceedings Article | 10 October 2017 Paper

Comparison of integrated optical turbulence over the sea in different coastal regions in the world

Detlev Sprung, Erik Sucher, Christian Eisele, Dirk Seiffer, Alexander M. van Eijk, Karin Stein

Proceedings Volume 10425, 1042502 (2017) https://doi.org/10.1117/12.2279425

KEYWORDS: Optical turbulence, Climatology, Integrated optics, Electro optics, Electro optical systems, Laser systems engineering, Atmospheric optics, Turbulence, High speed cameras, Halogens

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Proceedings Article | 5 October 2017 Paper

Simulation of an oil film at the sea surface and its radiometric properties in the SWIR

Frédéric Schwenger, Alexander M. Van Eijk

Proceedings Volume 10432, 104320D (2017) https://doi.org/10.1117/12.2278282

KEYWORDS: Computer simulations, Short wave infrared radiation, Bidirectional reflectance transmission function, Surface roughness, Modulation, Reflection, Ocean optics, Radio optics, 3D modeling, Capillaries

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Proceedings Article | 5 October 2017 Paper

Atmospheric and laser propagation

Alexander M. van Eijk, Karin Stein

Proceedings Volume 10435, 104350E (2017) https://doi.org/10.1117/12.2275865

KEYWORDS: Aerosols, Atmospheric particles, Refractive index, Atmospheric propagation, Electro optics, Turbulence

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Proceedings Article | 29 September 2017 Paper

Aerosol optical properties inferred from in-situ and path-averaged measurements

Sven van Binsbergen, Peter Grossmann, Leo Cohen, Alexander M. van Eijk, Karin Stein

Proceedings Volume 10425, 104250H (2017) https://doi.org/10.1117/12.2279424

KEYWORDS: Aerosols, Atmospheric particles, Visibility, Sensors, Optical properties

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Proceedings Article | 7 September 2017 Paper

In-situ and path-averaged measurements of aerosol optical properties

Sven van Binsbergen, Peter Grossmann, Faith February, Leo Cohen, Alexander M. van Eijk, Karin Stein

Proceedings Volume 10408, 104080V (2017) https://doi.org/10.1117/12.2275861

KEYWORDS: Aerosols, Atmospheric propagation, Atmospheric particles, Optical testing, Optical properties, Electro optics, Scattering, Absorption, Electro optical sensors, Electro optical systems

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Proceedings Article | 7 September 2017 Paper

Investigation of the height dependency of optical turbulence in the surface layer over False Bay (South Africa)

Detlev Sprung, Alexander M. van Eijk, Willie Günter, Derek Griffith, Christian Eisele, Erik Sucher, Dirk Seiffer, Karin Stein

Proceedings Volume 10408, 104080U (2017) https://doi.org/10.1117/12.2275859

KEYWORDS: Optical turbulence, Atmospheric propagation, Atmospheric turbulence, Electro optics, Scintillation, Laser systems engineering, Optical testing, Meteorology, Turbulence

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Proceedings Article | 20 October 2016 Presentation + Paper

Comparison of MODTRAN simulations and transmission measurements by path-integrated and in-situ techniques over a rural site in northwestern Germany

Silke Vogelbacher, Alexander M. van Eijk, Detlev Sprung, Leo Cohen, Erik Sucher, Karin Stein

Proceedings Volume 10002, 1000203 (2016) https://doi.org/10.1117/12.2240644

KEYWORDS: Atmospheric particles, Atmospheric modeling, Visibility, Aerosols, Electro optical modeling, Meteorology, Data modeling, Refractive index, Phase modulation, Sensors

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Proceedings Article | 19 October 2016 Paper

Vertical atmospheric variability measured above water during the FESTER experiment: first results

Benita Maritz, Mokete Koago, Carl Wainman, M. Gardener, Willie Gunter, Alexander M. van Eijk

Proceedings Volume 10002, 100020B (2016) https://doi.org/10.1117/12.2244532

KEYWORDS: Electro optical modeling, Atmospheric modeling, Temperature sensors, Sensors, Ray tracing, Humidity, Data modeling, Temperature metrology, Environmental sensing, Atmospheric sensing

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Proceedings Article | 19 October 2016 Presentation + Paper

First results on the Experiment FESTER on optical turbulence over False Bay South Africa: dependencies and consequences

Detlev Sprung, Alexander M. van Eijk, Erik Sucher, Christian Eisele, Dirk Seiffer, Karin Stein

Proceedings Volume 10002, 1000209 (2016) https://doi.org/10.1117/12.2240651

KEYWORDS: Optical turbulence, Atmospheric propagation, Electro optical systems, Turbulence, Heat flux, Ultrasonics, Kinematics, Refractive index, Temperature metrology, Receivers

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Proceedings Article | 19 October 2016 Paper

Path homogeneity along a horizontal line-of-sight path during the FESTER experiment: first results

W. Gunter, B. Maritz, M. Koago, C. Wainman, M. E. Gardener, F. February, A. M. J. van Eijk

Proceedings Volume 10002, 100020A (2016) https://doi.org/10.1117/12.2244531

KEYWORDS: Temperature metrology, Atmospheric propagation, Radio propagation, Water, Radiometry, Sensors, Long wavelength infrared, Skin, Electro optics, Black bodies

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Proceedings Article | 19 October 2016 Presentation + Paper

A world-wide comparison of aerosol data

Alexander M. van Eijk, Jacques Piazzola, Suzanne van Zuijlen, Leo Cohen, Marcel Moerman, Tathy Missamou, Gilles Tedeschi, Karin Stein

Proceedings Volume 10002, 1000202 (2016) https://doi.org/10.1117/12.2240843

KEYWORDS: Aerosols, Oceanography, Atmospheric modeling, Atmospheric particles, Data acquisition, Electro optical modeling, Refractive index, Particles, Electro optics, Atmospheric propagation

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Proceedings Article | 19 October 2016 Paper

FESTER: a propagation experiment, overview and first results

Christian Eisele, Dirk Peter Seiffer, Karin Stein, Erik Sucher, Willem Gunter, Faith February, George Vrahimis, Carl Wainman, Benita Maritz, Mokete Koago, Alexander M. van Eijk, Miranda van Iersel, Leo Cohen, Sven van Binsbergen, H. J. M. (Eric) Heemskerk, Armin Sternberg, Helmut Schulte, Arthur van Rheenen, Erik Brenthagen, Jan Thomassen, Derek Griffith

Proceedings Volume 10002, 1000208 (2016) https://doi.org/10.1117/12.2240771

KEYWORDS: Atmospheric propagation, Aerosols, Atmospheric particles, Sensors, Mid-IR, Long wavelength infrared, Environmental sensing, Turbulence, Halogens, Temperature metrology

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Proceedings Article | 19 September 2016 Presentation + Paper

The FESTER field trial

Alexander M. van Eijk, Willie Gunter, Faith February, Benita Maritz, George Vrahimis, Mokete Koago, Carl Wainman, Christian Eisele, Dirk Seiffer, Erik Sucher, Karin Stein, Miranda van Iersel, Leo Cohen, Sven Van Binsbergen, H. J. M. (Eric) Heemskerk, A. Sternberg, H. Schulte, Arthur van Rheenen, Erik Brenthagen, Jan Thomassen, D. Griffith

Proceedings Volume 9979, 99790Q (2016) https://doi.org/10.1117/12.2240642

KEYWORDS: Electro optics, Environmental sensing, Long wavelength infrared, Turbulence, Sensors, Mid-IR, Atmospheric propagation, Aerosols, Temperature metrology, Metals

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Proceedings Article | 19 September 2016 Presentation + Paper

The dependence of optical turbulence on thermal and mechanical forces over the sea

Alexander M. J. van Eijk, Detlev Sprung, Erik Sucher, Christian Eisele, Dirk Seiffer, Karin Stein

Proceedings Volume 9979, 99790R (2016) https://doi.org/10.1117/12.2239324

KEYWORDS: Optical turbulence, Turbulence, Refractive index, Heat flux, Humidity, Statistical analysis, Kinematics, Receivers, Meteorology, Wind measurement

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Proceedings Article | 8 October 2015 Paper

Influence of aerosols on atmospheric transmission at the Baltic Sea: comparison of experimental results with model simulations using MODTRAN

Silke Vogelbacher, Detlev Sprung, Alexander van Eijk, Karin Stein

Proceedings Volume 9641, 964106 (2015) https://doi.org/10.1117/12.2197090

KEYWORDS: Aerosols, Atmospheric modeling, Visibility, Atmospheric particles, Humidity, Meteorology, Electro optical modeling, Data modeling, Refractive index, Solar radiation models

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Proceedings Article | 4 September 2015 Paper

Infrared signature evolution of a CUBI

M. van Iersel, A. van Eijk, H. Veerman, K. Benoist, L. Cohen

Proceedings Volume 9614, 96140H (2015) https://doi.org/10.1117/12.2191262

KEYWORDS: Infrared signatures, Temperature metrology, Refractive index, Infrared cameras, Meteorology, Cameras, Long wavelength infrared, Sun, Mid-IR, Clouds

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Proceedings Article | 21 October 2014 Paper

Ship plume modelling in EOSTAR

M. van Iersel, A. Mack, M. A. Degache, A. M. van Eijk

Proceedings Volume 9242, 92421S (2014) https://doi.org/10.1117/12.2071821

KEYWORDS: Sensors, Atmospheric sensing, Electro optical sensors, Infrared signatures, Atmospheric propagation, 3D modeling, Atmospheric modeling, Gases, Molecules, Refractive index

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Proceedings Article | 20 October 2014 Open Access

Research topics on EO systems for maritime platforms

Judith Dijk, Piet Bijl, Sebastiaan van den Broek, Alenxander van Eijk

Proceedings Volume 9249, 92490M (2014) https://doi.org/10.1117/12.2070420

KEYWORDS: Sensors, Cameras, Environmental sensing, Image enhancement, Target detection, Visualization, Sensor performance, Electro optical sensors, Infrared cameras, Turbulence

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Proceedings Article | 7 October 2014 Paper

Propagation of light through ship exhaust plumes

M. van Iersel, A. Mack, A. M. van Eijk, H. M. Schleijpen

Proceedings Volume 9224, 92240T (2014) https://doi.org/10.1117/12.2063372

KEYWORDS: Sensors, Atmospheric modeling, Atmospheric sensing, 3D modeling, Atmospheric propagation, Cameras, Infrared signatures, Gases, Carbon dioxide, Scintillation

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Proceedings Article | 25 September 2013 Paper

Retrieval of structure functions of air temperature and refractive index from large eddy simulations of the atmospheric boundary layer

Chris Wilson, Alexander van Eijk, Evgeni Fedorovich

Proceedings Volume 8874, 887408 (2013) https://doi.org/10.1117/12.2023990

KEYWORDS: Humidity, Refractive index, Turbulence, Atmospheric modeling, Meteorology, Atmospheric propagation, Temperature metrology, Ions, Scintillation, Receivers

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SPIE Journal Paper | 1 April 2013

Validation of atmospheric propagation models in littoral waters

Arie de Jong, Piet B. Schwering, Alexander M. van Eijk, Willem Gunter

OE, Vol. 52, Issue 04, 046002, (April 2013) https://doi.org/10.1117/12.10.1117/1.OE.52.4.046002

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Proceedings Article | 11 October 2011 Paper

Marine boundary layer investigations in the False Bay, supported by optical refraction and scintillation measurements

Arie de Jong, Alexander M. van Eijk, Koen Benoist, Willem Gunter, George Vrahimis, Faith October

Proceedings Volume 8178, 817808 (2011) https://doi.org/10.1117/12.897461

KEYWORDS: Dysprosium, Refraction, Ocean optics, Scintillation, Data modeling, Humidity, Temperature metrology, Atmospheric modeling, Water, Turbulence

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Proceedings Article | 7 September 2011 Paper

Scintillation measurements over False Bay, South Africa

M. van Iersel, A. M. van Eijk

Proceedings Volume 8161, 81610B (2011) https://doi.org/10.1117/12.896179

KEYWORDS: Refractive index, Scintillation, Data modeling, Meteorology, Water, Turbulence, Humidity, Instrument modeling, Atmospheric propagation, Atmospheric turbulence

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Proceedings Article | 7 September 2011 Paper

The Advanced Navy Aerosol Model (ANAM): validation of small-particle modes

Alexander M. van Eijk, Jolanta Kusmierczyk-Michulec, Jacques Piazzola

Proceedings Volume 8161, 816108 (2011) https://doi.org/10.1117/12.896178

KEYWORDS: Aerosols, Atmospheric particles, Atmospheric modeling, Oceanography, Refractive index, Amplifiers, Electro optical modeling, Coastal modeling, Sun, Solar radiation models

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Proceedings Article | 7 September 2011 Paper

Application of year-round atmospheric transmission data, collected with the MSRT multiband transmissometer during the FATMOSE trial in the False Bay area

Arie de Jong, Alexander van Eijk, Leo Cohen, Peter Fritz, Willem Gunter, George Vrahimis, Faith October

Proceedings Volume 8161, 81610A (2011) https://doi.org/10.1117/12.892023

KEYWORDS: Humidity, Visibility, Aerosols, Atmospheric modeling, Atmospheric particles, Atmospheric propagation, Atmospheric optics, Particles, Atmospheric sensing, Sensors

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The FATMOSE trial (False Bay Atmospheric Experiment) is a continuation of the cooperative work between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment (South Africa). The atmospheric transmission, being of major importance for target detection, was measured with the MSRT multiband optical/IR transmissometer over a path of 15.7 km over sea. Simultaneously a set of instruments was installed on a midpath lighthouse for collection of local meteorological data, including turbulence, scintillation, sea surface temperature and visibility. The multiband transmission data allow the retrieval of the size distribution (PSD) of the particles (aerosols) in the transmission path. The retrieved PSD's can be correlated with the weather data such as windspeed, wind direction, relative humidity and visibility. This knowledge will lead to better atmospheric propagation models. The measurement period covered nearly a full year, starting in November 2009 and ending in October 2010. The False Bay site is ideal for studies on propagation effects over sea because of the large variety of weather conditions, including high windspeed, expected from the South East with maritime air masses, as well as Northerly winds, expected to bring warm and dry air from the continent. From an operational point of view the False Bay area is interesting, being representative for the scenery around the African coast with warships in an active protecting role in the battle against piracy. The yearround transmission data are an important input for range performance calculations of electro-optical sensors against maritime targets. The data support the choice of the proper spectral band and contain statistical information about the detection ranges to be expected. In this paper details on the instrumentation will be explained as well as the methods of calibration and PSD retrieval. Data are presented for various weather conditions, showing correlations between different parameters and including statistical behaviour over the year. Examples will be shown of special conditions such as refractive gain, gravity waves and showers.

Proceedings Article | 12 October 2010 Paper

EOSTAR Pro: a flexible extensive library to assess EO sensor performance

Alexander van Eijk, Marianne Degache, Dirk-Jan de Lange, Steve Hammel, Dimitris Tsintikidis

Proceedings Volume 7828, 782804 (2010) https://doi.org/10.1117/12.868184

KEYWORDS: Sensors, Electro optical modeling, Atmospheric modeling, Environmental sensing, Sensor performance, Data modeling, Image sensors, Atmospheric propagation, Coastal modeling, Human-machine interfaces

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Proceedings Article | 12 October 2010 Paper

Preliminary results of the FATMOSE atmospheric propagation trials in the False Bay, South Africa, November 2009-July 2010

Arie de Jong, Peter Fritz, Koen Benoist, Alexander van Eijk, Piet Schwering, Willem Gunter, George Vrahimis, Faith October

Proceedings Volume 7828, 782809 (2010) https://doi.org/10.1117/12.864067

KEYWORDS: Visibility, Scintillation, Atmospheric propagation, Data modeling, Cameras, Sensors, Atmospheric modeling, Refraction, Aerosols, Imaging systems

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The FATMOSE trial (FAlse-bay ATMOSpheric Experiment) running over a period from November 2009 to July 2010, was a continuation of the cooperation between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment. Instruments were installed for measuring scintillation, blurring- and refraction effects over a 15.7 km path over sea. Simultaneously, a set of instruments was installed on a mid-path lighthouse for collecting local meteorological data, including scintillation, sea surface temperature and visibility. The measurements covered summer and winter conditions with a prevailing high wind speed from the South East, bringing in maritime air masses. The weather conditions included variations in the Air-Sea Temperature Difference (ASTD), that may affect the vertical temperature gradient in the atmospheric boundary layer, causing refraction effects in the lightpath. This was measured with a theodolite camera, providing absolute Angles of Arrival (AOA). Blur data were collected with a high resolution camera system with 10 bits dynamic range. Specially designed image analysis software allows determination of the atmospheric blur, while simultaneously providing information on the Scintillation Index (S.I.). This S.I. was also measured by using the Multiband Spectral Radiometer Transmissometer (MSRT). The ratio of the transmission levels of this instrument contains information on the size distribution of the aerosols along the path. In the paper, experimental details on the set-up and the instrumentation are given as well as the methods of analysis. Preliminary results are shown, including a comparison of measured blur and scintillation data with Cn 2 data from the scintillometer, correlation between AOA and ASTD and comparison of transmission data with data from the visibility meter. Blur and scintillation data are compared with predictions from standard turbulence model predictions, using Cn 2. In future studies the data will be used for validation of propagation models such as EOSTAR.

Proceedings Article | 24 August 2010 Paper

Estimating turbulence in images

Miranda van Iersel, Alexander van Eijk

Proceedings Volume 7814, 78140Q (2010) https://doi.org/10.1117/12.861162

KEYWORDS: Point spread functions, Deconvolution, Atmospheric turbulence, Turbulence, Image filtering, Image enhancement, Meteorology, Scintillation, Image quality, Image analysis

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Proceedings Article | 12 August 2009 Paper

The Ångström coefficient as an indicator of non-marine particles in ANAM (Advanced Navy Aerosol Model)

Jolanta Kusmierczyk-Michulec, Alexander M. van Eijk

Proceedings Volume 7463, 74630G (2009) https://doi.org/10.1117/12.828394

KEYWORDS: Aerosols, Amplifiers, Oceanography, Atmospheric particles, Atmospheric modeling, Refractive index, Humidity, Carbon, Particles, Ocean optics

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Proceedings Article | 12 August 2009 Paper

Analysis and deconstruction of mirages to assess environmental features

Marianne A. Degache, Alexander M. van Eijk, Stephen Hammel, Dimitri Tsintikidis

Proceedings Volume 7463, 74630D (2009) https://doi.org/10.1117/12.828549

KEYWORDS: Sensors, Electro optical modeling, Atmospheric propagation, Atmospheric modeling, Refraction, Mirrors, Electro optical sensors, Image sensors, Infrared cameras, Atmospheric sensing

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Proceedings Article | 20 August 2008 Paper

Infrared background analysis of bay environments

Piet Schwering, Willem Gunter, Dirk Bezuidenhout, Alexander van Eijk

Proceedings Volume 7090, 709005 (2008) https://doi.org/10.1117/12.799628

KEYWORDS: Long wavelength infrared, Mid-IR, Target detection, Data modeling, Infrared backgrounds, Sensors, Sun, Atmospheric optics, Coastal modeling, Electro optical modeling

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Proceedings Article | 20 August 2008 Paper

Laser applications in the littoral: search lidar and ship identification

Johan van den Heuvel, Alexander van Eijk, Herman Bekman, Frank van Putten, Leo Cohen, Paul Pace

Proceedings Volume 7090, 709004 (2008) https://doi.org/10.1117/12.799744

KEYWORDS: LIDAR, Target detection, Receivers, Radar, Databases, Sensors, Signal to noise ratio, Profiling, Reflection, Photography

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Proceedings Article | 20 August 2008 Paper

Transmissometer versus sun photometer measurements of the aerosol optical properties

Jolanta Kusmierczyk-Michulec, Alexander Van Eijk, M. Moerman, L. Cohen, A. de Jong, P. Fritz

Proceedings Volume 7090, 70900L (2008) https://doi.org/10.1117/12.797837

KEYWORDS: Aerosols, Sun, Photometry, Atmospheric particles, Ocean optics, Calibration, Phase modulation, Atmospheric optics, Optical properties, Solar radiation

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Proceedings Article | 25 September 2007 Paper

The use of multi-band transmission data collected at Scripps pier in November 2006 for the investigation of aerosol characteristics

Arie de Jong, Alexander M. J. van Eijk, Peter Fritz, Leo Cohen, Marcel Moerman

Proceedings Volume 6708, 67080L (2007) https://doi.org/10.1117/12.730479

KEYWORDS: Aerosols, Phase modulation, Particles, Atmospheric particles, Clouds, Lanthanum, Humidity, Scattering, Signal attenuation, Sensors

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The knowledge of the atmospheric aerosol characteristics is of great importance for the range performance of Infrared and Electro-Optical sensor systems. The composition, the concentration and the size distribution of aerosols determine their scattering behavior as function of wavelength and thus their attenuation of light beams. When studies are made on this attenuation, it is considered to be very useful to incorporate the spatial variation of the aerosol characteristics along the measurement path, such as found during a previous campaign, carried out over the San Diego Bay (August 2005). In a more recent experiment (November 2006) a trial was set-up at Scripps pier of the Institute of Oceanography near La Jolla (US-West Coast). This place is known for the high frequency of occurrence of hazy conditions, not only variable with location, but also in time. TNO did participate in this experiment with two Particle Measurement Systems (PMS), one on the shore and one at the end of the pier, a weather station and the Multi Spectral Radiometer Transmissometer (MSRT), used in previous trials. It was shown before, that the use of multi-band transmission data allows a more detailed analysis of the aerosol characteristics in the measurement path. The advantage of the MSRT concerns a larger measurement volume, thus providing a higher signal to noise (S/N) ratio and a shorter response time, compared to the in-situ PMS systems. A similar method, based on the spectral dependence of the scattering coefficient, has been used during the analysis of the data, collected in November 2006. In this paper representative data samples are presented, showing the variability of the transmission in each of the spectral bands. By using the weather data, a separation has been made between extinction by molecules and aerosols. A brief description is given of the retrieval method, just mentioned. The retrieved particle characteristics are compared to the data from the PMS systems, taking into account the fact, that part of the measurement path, having a length of 6.68 km, was grazing the shore-line. In general the particle density, as found by the PMS systems was less than the retrieved value, especially when the wind was from off-shore directions. At certain occasions, sinusoidal variations in the transmission level, with a period of about 5 minutes, were found, probably due to oscillatory motions of the air mass in the measurement path. It was found, that the value of the Junge exponent of the Particle Size Distribution (PSD) was rather frequently of the order of -3, showing that the concentration of bigger particles (> 3 μm) compared to the smaller particles (< 0.5 μm), was greater than the value, found in experiments at other locations. It is investigated how accurate the transmission levels of the IR bands can be predicted by using the retrieved PSD's and the absolute humidity, obtained from the weather data. Due to the low wind speed during the trial (< 4 m/s), it was not possible to find any particular effect from aerosols, potentially created in the surf zone at higher wind speeds.

Proceedings Article | 25 September 2007 Paper

Angstrom coefficient as a tracer of the continental aerosols

Jolanta Kusmierczyk-Michulec, Alexander Van Eijk

Proceedings Volume 6708, 67080P (2007) https://doi.org/10.1117/12.732426

KEYWORDS: Aerosols, Atmospheric particles, Deposition processes, Optical testing, Oceanography, Mass attenuation coefficient, Atmospheric modeling, Ocean optics, Particles, Meteorology

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Proceedings Article | 28 September 2006 Paper

Aerosol size distributions retrieved from multiband transmissometer data in the southern Baltic Sea during the VAMPIRA trials

Arie de Jong, Alexander van Eijk, Marcel Moerman, Leo Cohen

Proceedings Volume 6364, 636406 (2006) https://doi.org/10.1117/12.688141

KEYWORDS: Particles, Refractive index, Phase modulation, Scattering, Atmospheric particles, Aerosols, Visibility, Visibility through fog, Fiber optic gyroscopes, Water

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In an earlier paper [1], data from our Multi-Band Radiometer Transmissometer (MSRT) were used to compare the ratio of extinction coefficients in different spectral bands during periods of changing visibility conditions. This ratio is an indication of the characteristics and origin (eg rural or maritime) of the haze- or fog particles, present in the measurement path. In this paper we will analyze the VAMPIRA transmission data in more detail by separating the contributions due to molecular extinction, scattering and (potentially) refraction. In our analysis we take the contribution due to scattering in order to obtain the characteristics of the Particle Size Distribution (PSD). For this purpose we take the average value and the slope of the measured transmission level in two neighboring spectral bands. Via a special simulation tool, developed for Junge-type PSD's, the slope of the PSD (defined: Junge exponent) and its value at a particle diameter of 1 μm (Junge coefficient) can be determined via a set of retrieval steps. Reference is made to a similar approach [2] where in stead of a Junge distribution, three contiguous lognormal distributions are taken. The associated procedure for the Junge-type PSD is explained in detail in this paper and applied to the VAMPIRA transmission data. The versatility of the new retrieval method is demonstrated, especially when wavelengths around lμm are chosen (a somewhat higher number than the diameter of the majority of the particles, so that most of the scattering is in the so-called Rayleigh regime). It is obvious, that the method fails in conditions of dense fog, when the transmission levels (average value and slope) over the 8.6 km path approach zero. The results are compared with in-situ PSD measurements, carried out simultaneously with a PMS (Particle Measurement System) probe at the pier near the Suerendorf shore station. In many conditions different results appear due to the fact that the MSRT system delivers path integrated data, while the PMS probe measures locally in a small volume. The MSRT data, collected over an overseas path, are more relevant to be used in the data analysis of the shore based sensor systems [3], measuring simultaneously signal values of distant point targets. The MSRT system has a higher signal to noise ratio and due to the shorter time constant, rapid fluctuations in particle characteristics are observed, not measured by the PMS probe. The availability of reliable aerosol characteristics (i.e. Junge exponent and -coefficient) allows a more precise interpretation of the data from the surveillance systems.

Proceedings Article | 1 September 2006 Paper

Investigation of aerosol particle size distributions in the San Diego Bay area by means of multiband transmissometry

Arie de Jong, Alexander van Eijk, Marcel Moerman, Leo Cohen

Proceedings Volume 6303, 63030L (2006) https://doi.org/10.1117/12.680288

KEYWORDS: Atmospheric particles, Phase modulation, Aerosols, Particles, Scattering, Atmospheric modeling, Visibility, Atmospheric sensing, Atmospheric optics, Light scattering

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The presence of atmospheric aerosols along the line of sight of infrared and electro-optical sensors greatly determines the range performance of these devices. On the one hand the aerosol particles scatter background (including sun) radiance into the field of view of the sensor, on the other hand they contribute to the atmospheric contrast reduction of the target. Proper knowledge of aerosol characteristics such as composition, concentration and size distribution is of vital importance for the prediction of their scattering and extinction characteristics. It is however found to be very difficult to collect accurate information on the particle size distribution (PSD) of aerosols. One of the reasons is the variation of the PSD along the path, which is likely to occur in a coastal area such as the San Diego Bay. One way to overcome these problems is the use of a multi-band transmissometer, as was done in previous measurement campaigns in the Baltic Sea [1] and in the Persian Gulf area [2]. The TNO seven-band optical/IR transmissometer system, providing path averaged transmission data for the intervening atmosphere, is operating at wavelengths between 0.4 and 14 μm,. In this spectral band, scattering in light hazy conditions is dominated by particles with a diameter of less than 4 μm. In order to simulate the transmission losses by scattering in various spectral bands a special calculation tool has been developed. This tool, described in this paper, allows detailed investigation of the possibilities of the retrieval of the PSD from multi-band transmission data. The slope in the plots of the transmission versus wavelength is directly related to the slope of the (log-normal) PSD plots (known as Junge exponent). The average transmission in a selected number of spectral bands is directly correlated to the average particle concentration (known as Junge coefficient). The principle of the methodology is illustrated with data collected during a measurement campaign, carried out over the San Diego Bay in August 2005. In this campaign we used six of the seven spectral bands, providing data over a 7.2 km over water path. It is shown that the retrieval method is very successful and the data correspond well with those, simultaneously collected with in-situ Particle Measurement Systems (PMS), located on both sides of the path. In addition to the path averaging, another advantage of the transmissometer PSD's, is the accuracy, being an order of magnitude higher than that of the PMS probes due to the fact that the measurement volume is more than a million times larger. A detailed analysis is given of the transmission data, showing peculiar effects were in the 2.3μm band around 19.00 UTC during most of the days. These effects are especially well illustrated in plots where the transmission in one spectral band is plotted against the transmission in another band for various times of the day.

Proceedings Article | 1 September 2006 Paper

Improvements in the Advanced Navy Aerosol Model (ANAM)

A. van Eijk, D. Merritt

Proceedings Volume 6303, 63030M (2006) https://doi.org/10.1117/12.680295

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Oceanography, Particles, Coastal modeling, Meteorology, Electro optical modeling, Amplifiers, Humidity

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Proceedings Article | 1 September 2006 Paper

Comparison of aerosol size distribution in coastal and oceanic environments

Jolanta Kusmierczyk-Michulec, Alexander van Eijk

Proceedings Volume 6303, 63030I (2006) https://doi.org/10.1117/12.678272

KEYWORDS: Aerosols, Atmospheric particles, Oceanography, Refractive index, Meteorology, Atmospheric modeling, Coastal modeling, Amplifiers, Superposition, Ocean optics

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Proceedings Article | 1 September 2006 Paper

The introduction of horizontal inhomogeneity of meteorological conditions in the EOSTAR propagation model

A. van Eijk, G. Kunz

Proceedings Volume 6303, 63030G (2006) https://doi.org/10.1117/12.680300

KEYWORDS: Sensors, Atmospheric modeling, Meteorology, Atmospheric propagation, Electro optical modeling, Refraction, Refractive index, Electro optics, Coastal modeling, Humidity

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Proceedings Article | 14 October 2005 Paper

Comparison of atmospheric refraction at radar and optical wavelengths

Gerard Kunz, Eric Heemskerk, Lex van Eijk

Proceedings Volume 5981, 59810B (2005) https://doi.org/10.1117/12.638613

KEYWORDS: Refraction, Humidity, Atmospheric propagation, Atmospheric modeling, Meteorology, Infrared radiation, Water, Refractive index, Atmospheric optics, Sensors

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A study is carried out to classify possible combinations of refractivity conditions for RF and IR over a wide range of meteorological conditions using different micrometeorological bulk models. The calculated refractivity profiles are analyzed for evaporation duct height (EDH), mainly relevant for RF propagation, and for gradients of the modified refractivity at different heights, relevant for both RF and IR propagation. These refractivity gradients are a direct indicator for the occurrence of sub- or super refraction at the height of interest. The present study reveals that under humid and unstable conditions evaporation ducts are found at approximately 3±2 m above cold (5°C) waters and at approximately 8±5 m over warm waters (25°C). Under dry conditions, these duct heights are approximately 9±5 m and 20±10 m, respectively. Duct heights decrease with increasing wind speed. Under humid and near-neutral conditions, duct heights range from 1 to 25 m, and decrease with increasing air temperature and/or wind speed. On the other hand, for dry and near-neutral conditions, and also for neutral conditions, the duct height is not well defined. Values between 1 m and 100 m are found, with an irregular dependence on air temperature and wind speed. Reliable modeling of duct height under these conditions remains questionable due to a lack of vertical mixing in the surface layer. The paper also shows that all four combinations of RF and IR sub- and super-refraction can occur in the atmosphere. The occurrence of a specific combination depends predominantly on temperature and humidity, and to a relatively minor part on wind speed. The magnitude of refraction effects in the two spectral bands is not necessarily coupled but varies with environmental conditions and height. Sub-sub refraction is generally weak and occurs under neutral conditions or at large heights. Super-super refraction occurs under warm and dry conditions and can reach medium strengths. RF-super refraction in combination with IR-sub refraction occurs under strong unstable conditions (e.g., surface temperature higher than air temperature) and can reach medium strengths. RF-sub refraction in combination with IR-super refraction occurs under stable and warm conditions. The magnitude of refraction can be very large, especially at low altitude.

Proceedings Article | 15 September 2005 Paper

Effects of atmospheric refraction and turbulence on long-range IR imaging in the marine surface layer: comparisons between experiment and simulation

G. Kunz, A. van Eijk, D. Tsintikidis, S. Hammel

Proceedings Volume 5891, 58910A (2005) https://doi.org/10.1117/12.614884

KEYWORDS: Atmospheric modeling, Electro optical modeling, Data modeling, Refraction, Sensors, Temperature metrology, Environmental sensing, Optical turbulence, Humidity, Refractive index

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Proceedings Article | 13 September 2005 Paper

Combining ANAM and satellite data to determine the EOSTAR aerosol component

R. Schoemaker, G. de Leeuw, A. van Eijk

Proceedings Volume 5891, 58910F (2005) https://doi.org/10.1117/12.617666

KEYWORDS: Aerosols, Atmospheric modeling, Satellites, Atmospheric particles, Electro optical modeling, Coastal modeling, Oceanography, Data modeling, Meteorology, Atmospheric propagation

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Proceedings Article | 18 August 2005 Paper

ANAM vs. NAM: Is the difference significant?

Steve Hammel, Alexander van Eijk, Dimitri Tsintikidis

Proceedings Volume 5891, 58910G (2005) https://doi.org/10.1117/12.618931

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Meteorology, Coastal modeling, Sensors, Data modeling, Humidity, Target detection, Atmospheric propagation

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Proceedings Article | 18 August 2005 Paper

Surface wave effects on long range IR imaging in the marine surface layer

M. Francius, G. Kunz, A. M. van Eijk

Proceedings Volume 5891, 58910J (2005) https://doi.org/10.1117/12.619953

KEYWORDS: Atmospheric modeling, Infrared imaging, Ocean optics, Coastal modeling, Sensors, Refraction, Cameras, Target detection, Long wavelength infrared, Wave propagation

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Proceedings Article | 11 November 2004 Paper

Status and developments in EOSTAR, a model to predict IR sensor performance in the marine environment

Gerard Kunz, Marianne Degache, Marcel Moerman, Alexander van Eijk, Filip Neele, Stephen Doss-Hammel, Dimitri Tsintikidis

Proceedings Volume 5572, (2004) https://doi.org/10.1117/12.563914

KEYWORDS: Sensors, Atmospheric modeling, Refraction, Refractive index, Humidity, Ocean optics, Atmospheric propagation, Atmospheric sensing, Meteorology, Electro optical modeling

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Proceedings Article | 11 November 2004 Paper

Aerosol extinction in coastal zones

Jacques Piazzola, Gennady Kaloshin, Gerrit De Leeuw, Alexander van Eijk

Proceedings Volume 5572, (2004) https://doi.org/10.1117/12.563299

KEYWORDS: Aerosols, Atmospheric particles, Atmospheric modeling, Refractive index, Coastal modeling, Data modeling, Oceanography, Electro optical modeling, Atmospheric propagation, Systems modeling

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Proceedings Article | 30 August 2004 Paper

Refractive effects, turbulence, and the EOSTAR model

Stephen Doss-Hammel, Dimitri Tsintikidis, Alexander van Eijk, Gerard Kunz

Proceedings Volume 5406, (2004) https://doi.org/10.1117/12.546625

KEYWORDS: Atmospheric propagation, Radio propagation, Atmospheric modeling, Electro optical modeling, Geometrical optics, Infrared radiation, Refractive index, Atmospheric optics, Receivers, Temperature metrology

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Proceedings Article | 6 February 2004 Paper

EOSTAR: an electro-optical sensor performance model for predicting atmospheric refraction, turbulence, and transmission in the marine surface layer

Gerard Kunz, Marcel Moerman, Alexander van Eijk, Stephen Doss-Hammel, Dimitri Tsintikidis

Proceedings Volume 5237, (2004) https://doi.org/10.1117/12.510708

KEYWORDS: Atmospheric modeling, Cameras, Meteorology, Data modeling, Refraction, Coastal modeling, Sensors, Humidity, Electro optical modeling, Aerosols

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SPIE Journal Paper | 1 April 2003

Development of the Mediterranean extinction code (MEDEX)

Jacques Piazzola, Frederic Bouchara, Gerrit de Leeuw, Alexander van Eijk

OE, Vol. 42, Issue 04, (April 2003) https://doi.org/10.1117/12.10.1117/1.1556765

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Coastal modeling, Particles, Data modeling, Refractive index, Oceanography, Electro optical modeling, Eye models

Proceedings Article | 20 March 2003 Paper

Near-surface aerosol transmission in the marine environment

Alexander van Eijk, Leo Cohen, Laurent Navarro, Gerrit de Leeuw

Proceedings Volume 4884, (2003) https://doi.org/10.1117/12.462497

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Statistical analysis, Coastal modeling, Oceanography, Meteorology, Data acquisition, Humidity, Data modeling

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Proceedings Article | 6 August 2002 Paper

ARTEAM: advanced ray tracing with earth atmospheric models

Gerard Kunz, Marcel Moerman, Alexander van Eijk

Proceedings Volume 4718, (2002) https://doi.org/10.1117/12.478827

KEYWORDS: Atmospheric modeling, Electro optical modeling, Aerosols, Atmospheric propagation, Refraction, Sensors, Refractive index, Coastal modeling, Meteorology, Atmospheric particles

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SPIE Journal Paper | 1 June 2000

Extension of the Navy aerosol model to coastal areas

Jacques Piazzola, Alexander van Eijk, Gerrit de Leeuw

OE, Vol. 39, Issue 06, (June 2000) https://doi.org/10.1117/12.10.1117/1.602538

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Coastal modeling, Data modeling, Oceanography, Performance modeling, Particles, Electro optical modeling, Eye models

Proceedings Article | 3 November 1998 Paper

Aerosol concentration and fetch

Jacques Piazzola, Alexander van Eijk, Gerrit de Leeuw

Proceedings Volume 3433, (1998) https://doi.org/10.1117/12.330230

KEYWORDS: Aerosols, Atmospheric modeling, Coastal modeling, Atmospheric particles, Data modeling, Eye models, Oceanography, Particles, Performance modeling, Electro optical modeling

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Proceedings Article | 3 November 1998 Paper

Characterizing large aerosols in the lowest level of the marine atmosphere

Stuart Gathman, Alexander van Eijk, Leo Cohen

Proceedings Volume 3433, (1998) https://doi.org/10.1117/12.330235

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Data modeling, Electro optical modeling, Coastal modeling, Ocean optics, Particles, Phase modulation, Atmospheric propagation

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Proceedings Article | 23 September 1997 Paper

Aerosol production in the surf zone and effects on IR extinction

Gerrit de Leeuw, Filip Neele, Alexander van Eijk, Elizabetta Vignati, Martin Hill, Michael Smith

Proceedings Volume 3125, (1997) https://doi.org/10.1117/12.279023

KEYWORDS: Aerosols, Atmospheric particles, Surf zone, Atmospheric modeling, Particles, Optical testing, Lanthanum, Humidity, Mineralogy, Oceanography

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Proceedings Article | 14 October 1996 Paper

Lateral variations of aerosols and meteorological properties in off-shore winds

Alexander van Eijk, Gerrit de Leeuw, Marcel Moerman

Proceedings Volume 2828, (1996) https://doi.org/10.1117/12.254175

KEYWORDS: Aerosols, Meteorology, Atmospheric particles, Humidity, Particles, Oceanography, Temperature metrology, Sensors, Data centers, Wind measurement

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Proceedings Article | 14 October 1996 Paper

Transmission of 10 micron radiation over coastal waters: comparison of point-source image intensities with aerosol extinction and MODTRAN calculations

Piet Schwering, Gerrit de Leeuw, Alexander van Eijk

Proceedings Volume 2828, (1996) https://doi.org/10.1117/12.254201

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Infrared radiation, Scintillation, Mass attenuation coefficient, Meteorology, Ocean optics, Coastal modeling, Thermography

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Proceedings Article | 14 October 1996 Paper

Marine aerosol properties and thermal imager performance (MAPTIP): an overview

Gerrit de Leeuw, Alexander van Eijk, Douglas Jensen

Proceedings Volume 2828, (1996) https://doi.org/10.1117/12.254157

KEYWORDS: Aerosols, Atmospheric modeling, Electro optical modeling, Coastal modeling, Atmospheric particles, Thermography, Atmospheric propagation, Thermal modeling, Data modeling, Ocean optics

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Proceedings Article | 6 June 1995 Paper

MAPTIP--Marine Aerosol Properties and Thermal Imager Performance: summary and initial results

Alexander van Eijk, Gerrit de Leeuw, Douglas Jensen

Proceedings Volume 2426, (1995) https://doi.org/10.1117/12.211177

KEYWORDS: Aerosols, Atmospheric modeling, Thermography, Thermal modeling, Data modeling, Atmospheric particles, Coastal modeling, Electro optical modeling, Ocean optics, Systems modeling

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Proceedings Article | 29 June 1994 Paper

MAPTIP experiment, marine aerosol properties and thermal imager performance

Alexander van Eijk, Douglas Jensen, Gerrit de Leeuw

Proceedings Volume 2222, (1994) https://doi.org/10.1117/12.177997

KEYWORDS: Aerosols, Atmospheric modeling, Thermography, Thermal modeling, Data modeling, Electro optical modeling, Atmospheric particles, Coastal modeling, Ocean optics, Meteorology

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Proceedings Article | 1 November 1993 Paper

Atmospheric effects on IR propagation

Alexander van Eijk, Gerrit de Leeuw

Proceedings Volume 2020, (1993) https://doi.org/10.1117/12.160542

KEYWORDS: Aerosols, Atmospheric modeling, Coastal modeling, Atmospheric particles, Atmospheric propagation, Electro optical modeling, Data modeling, Meteorology, Oceanography, Humidity

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Proceedings Article | 15 September 1993 Paper

Modeling aerosols and extinction in the marine atmospheric boundary layer

Gerrit de Leeuw, Alexander van Eijk, G. Noordhuis

Proceedings Volume 1968, (1993) https://doi.org/10.1117/12.154879

KEYWORDS: Aerosols, Atmospheric modeling, Atmospheric particles, Coastal modeling, Particles, Performance modeling, Meteorology, Visibility, Humidity, Oceanography

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Proceedings Article | 1 August 1992 Paper

Modeling aerosol extinction in a coastal environment

Alexander van Eijk, Gerrit de Leeuw

Proceedings Volume 1688, (1992) https://doi.org/10.1117/12.137894

KEYWORDS: Aerosols, Atmospheric modeling, Coastal modeling, Atmospheric particles, Electro optical modeling, Performance modeling, Meteorology, Oceanography, Data modeling, Remote sensing

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Showing 5 of 101 publications

Proceedings Volume Editor (12)

SPIE Conference Volume | 1 November 2019

Laser Communication and Propagation through the Atmosphere and Oceans VIII

SPIE Conference Volume | 30 November 2018

Laser Communication and Propagation through the Atmosphere and Oceans VII

SPIE Conference Volume | 21 November 2017

Laser Communication and Propagation through the Atmosphere and Oceans VI

SPIE Conference Volume | 17 November 2016

Laser Communication and Propagation through the Atmosphere and Oceans V

SPIE Conference Volume | 20 October 2015

Laser Communication and Propagation through the Atmosphere and Oceans IV

Showing 5 of 12 publications

Conference Committee Involvement (46)

Environmental Effects on Light Propagation and Adaptive Systems VIII

15 September 2025 | Madrid, Spain

High-Power Lasers and Technologies for Optical Countermeasures III

15 September 2025 | Madrid, Spain

Laser Communication and Propagation through the Atmosphere and Oceans XIV

3 August 2025 | San Diego, California, United States

Optical Engineering + Applications

3 August 2025 | San Diego, United States

Environmental Effects on Light Propagation and Adaptive Systems VII

18 September 2024 | Edinburgh, United Kingdom

High-Power Lasers and Technologies for Optical Countermeasures II

16 September 2024 | Edinburgh, United Kingdom

Laser Communication and Propagation through the Atmosphere and Oceans XIII

20 August 2024 | San Diego, California, United States

Environmental Effects on Light Propagation and Adaptive Systems VI

5 September 2023 | Amsterdam, Netherlands

Technologies for Optical Countermeasures XIX

5 September 2023 | Amsterdam, Netherlands

Laser Communication and Propagation through the Atmosphere and Oceans XII

22 August 2023 | San Diego, California, United States

High-Power Lasers and Technologies for Optical Countermeasures

6 September 2022 | Berlin, Germany

Environmental Effects on Light Propagation and Adaptive Systems V

6 September 2022 | Berlin, Germany

Laser Communication and Propagation through the Atmosphere and Oceans XI

22 August 2022 | San Diego, California, United States

Technologies for Optical Countermeasures XVIII and High Power Lasers: Technology and Systems, Platforms, Effects V

13 September 2021 | Online Only, Spain

Environmental Effects on Light Propagation and Adaptive Systems IV

13 September 2021 | Online Only, Spain

Laser Communication and Propagation through the Atmosphere and Oceans X

3 August 2021 | San Diego, California, United States

Environmental Effects on Light Propagation and Adaptive Systems III

23 September 2020 | Online Only, United Kingdom

Technologies for Optical Countermeasures XVII; and High-Power Lasers: Technology and Systems, Platforms, Effects IV

22 September 2020 | Online Only, United Kingdom

Laser Communication and Propagation through the Atmosphere and Oceans IX

24 August 2020 | Online Only, California, United States

Environmental Effects on Light Propagation and Adaptive Systems II

11 September 2019 | Strasbourg, France

Technologies for Optical Countermeasures XVI

10 September 2019 | Strasbourg, France

Laser Communication and Propagation through the Atmosphere and Oceans VIII

13 August 2019 | San Diego, California, United States

Environmental Effects on Light Propagation and Adaptive Systems

12 September 2018 | Berlin, Germany

Technologies for Optical Countermeasures

10 September 2018 | Berlin, Germany

Laser Communication and Propagation through the Atmosphere and Oceans VII

20 August 2018 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

13 September 2017 | Warsaw, Poland

Technologies for Optical Countermeasures

12 September 2017 | Warsaw, Poland

Laser Communication and Propagation through the Atmosphere and Oceans VI

8 August 2017 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

28 September 2016 | Edinburgh, United Kingdom

Laser Communication and Propagation through the Atmosphere and Oceans V

30 August 2016 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

22 September 2015 | Toulouse, France

Laser Communication and Propagation through the Atmosphere and Oceans IV

10 August 2015 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

22 September 2014 | Amsterdam, Netherlands

Laser Communication and Propagation through the Atmosphere and Oceans III

17 August 2014 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems XVI

23 September 2013 | Dresden, Germany

Laser Communication and Propagation through the Atmosphere and Oceans II

26 August 2013 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

25 September 2012 | Edinburgh, United Kingdom

Laser Communication and Propagation through the Atmosphere and Oceans

13 August 2012 | San Diego, California, United States

Optics in Atmospheric Propagation and Adaptive Systems

20 September 2011 | Prague, Czech Republic

Atmospheric Optics: Turbulence and Propagation

23 August 2011 | San Diego, California, United States

Free-Space Laser Communications X

2 August 2010 | San Diego, California, United States

Atmospheric Optics: Models, Measurements, and Target-in-the-Loop Propagation III

3 August 2009 | San Diego, California, United States

Atmospheric Optics: Models, Measurements, and Target-in-the-Loop Propagation II

12 August 2008 | San Diego, California, United States

Atmospheric Optics: Models, Measurements, and Target-in-the-Loop Propagation

27 August 2007 | San Diego, California, United States

Atmospheric Optical Modeling, Measurement, and Simulation II

15 August 2006 | San Diego, California, United States

Atmospheric Optical Modeling, Measurement, and Simulation

2 August 2005 | San Diego, California, United States

Showing 5 of 46 Conference Committees

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