Searched for: contributor%3A%22Hammel%2C+S.M.+%28editor%29%22
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Sprung, D. (author), van Eijk, A.M.J. (author), Günter, W. (author), Griffith, D. (author), Eisele, C. (author), Sucher, E. (author), Seiffer, D. (author), Stein, K. (author)
Atmospheric turbulence impacts on the propagation of electro-optical radiation. Typical manifestations of optical turbulence are scintillation (intensity fluctuations), beam wander and (for laser systems) reduction of beam quality. For longer propagation channels, it is important to characterize the vertical and horizontal distribution ...
conference paper 2017
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van Binsbergen, S.A. (author), Grossmann, P. (author), February, F.J. (author), Cohen, L.H. (author), van Eijk, A.M.J. (author), Stein, K.U. (author)
This paper compares in-situ and path-averaged measurements of the electro-optical transmission, with emphasis on aerosol effects. The in-situ sensors consisted of optical particle counters (OPC), the path-averaged data was provided by a 7-wavelength transmissometer (MSRT) and scintillometers (BLS). Data were collected at two sites: a homogeneous...
conference paper 2017
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van Iersel, M. (author), Veerman, H.E.T. (author), Cohen, L.H. (author), Benoist, K.W. (author), van Binsbergen, S.A. (author), van Riggelen, F. (author), Peet, B.J.A. (author)
Most models that predict the infrared signature of an object are based on steady-state equilibrium conditions and do not model the dynamic nature of the real world. To gain more understanding of the dynamic infrared signatures of an object, several outdoor experiments were performed, using a CUBI and a small vessel as an object. Dynamic changes...
conference paper 2016
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van Eijk, A.M.J. (author), Gunter, W.H. (author), February, F.J. (author), Maritz, B. (author), Vrahimis, G. (author), Koago, M.S. (author), Wainman, C. (author), Eisele, C. (author), Seiffer, D. (author), Sucher, E. (author), Stein, K. (author), van Iersel, M. (author), Cohen, L.H. (author), van Binsbergen, S.A. (author), Heemskerk, H.J.M. (author), Sternberg, A. (author), Schulte, H. (author), van Rheenen, A.D. (author), Brenthagen, E. (author), Thomassen, J.B. (author), Griffith, D. (author)
An overview is given of the First European - South African Transmission ExpeRiment (FESTER), which took place in South Africa, over the False Bay area, centered around Simon's Town. The experiment lasted from April 2015 through February 2016 and involved continuous observations as well as periodic observations that took place during four...
conference paper 2016
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van Eijk, A.M.J. (author), Sprung, D. (author), Sucher, E. (author), Eisele, C. (author), Seiffer, D. (author), Stein, K. (author)
Optical turbulence for over-water conditions was investigated in a long-term experiment over False Bay near Cape Town, South Africa. A sonic anemometer and two boundary-layer scintillometers were deployed to access in-situ turbulence as well as the integrated turbulence over two 1.8 and 8.7 km paths. Statistical analysis reveals spatial temporal...
conference paper 2016
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van Iersel, M. (author), Mack, A. (author), van Eijk, A.M.J. (author), Schleijpen, H.M.A. (author)
Looking through the atmosphere, it is sometimes difficult to see the details of an object. Effects like scintillation and blur are the cause of these difficulties. Exhaust plumes of e.g. a ship can cause extreme scintillation and blur, making it even harder to see the details of what lies behind the plume. Exhaust plumes come in different shapes...
conference paper 2014
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Wilson, C. (author), van Eijk, A.M.J. (author), Fedorovich, E. (author)
A methodology is presented to infer the refractive-index structure function parameter and the structure parameters for temperature and humidity from numerical simulations of the turbulent atmospheric convective boundary layer (CBL). The method employs spatial and temporal averaging of multiple realizations of the CBL flow field reproduced by a...
conference paper 2013
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book 2012
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conference paper 2011
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de Jong, A.N. (author), van Eijk, A.M.J. (author), Cohen, L.H. (author), Fritz, P.J. (author), Gunter, W.H. (author), Vrahimisb, G. (author), Faith, J. (author)
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...
conference paper 2011
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van Eijk, A.M.J. (author), Kusmierczyk-Michulec, J.T. (author), Piazzola, J.P. (author)
The image quality of electro-optical sensors in the (lower-altitude marine) atmosphere is limited by aerosols, which cause contrast reduction due to transmission losses and impact on the thermal signature of objects by scattering solar radiation. The Advanced Navy Aerosol Model (ANAM) aims at providing a quantitative estimate of the aerosol...
conference paper 2011
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Iersel, M.van (author), van Eijk, A.M.J. (author)
A commercial long-range scintillometer was deployed over a 2-km path in False Bay, South Africa, for a timeframe of one year. The turbulence data retrieved from the instrument are compared to turbulence parameters inferred from micrometeorological data and models, and the relation between experimental and model-data is explored.
conference paper 2011
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Kusmierczyk-Michulec, J.T. (author), Schleijpen, H.M.A. (author), TNO Defensie en Veiligheid (author)
The radiation coming from a laser which operates in the coastal zone can be detected not only when a detector is placed in front of the laser beam but also when it is located outside the main beam direction. The reason is that in a real detection scheme the power collected by a detector not only comes from direct radiation but also from other...
conference paper 2009
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TNO Defensie en Veiligheid (author), Kusmierczyk-Michulec, J.T. (author), van Eijk, A.M.J. (author)
The Advanced Navy Aerosol model (ANAM), being a modified version of the Navy Aerosol Model (NAM), is a wellknown engineering tool providing a quick and reasonable estimate of the aerosol extinction in the marine near-surface environment on the basis of simple meteorological input data. The original NAM consists of 3 lognormal distributions,...
conference paper 2009
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van den Heuvel, J.C. (author), van Eijk, A.M.J. (author), Bekman, H.H.P.T. (author), van Putten, F.J.M. (author), Cohen, L.A. (author), Pace, P.W. (author), TNO Defensie en Veiligheid (author)
conference paper 2008
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Schwering, P.B.W. (author), Gunter, W.H. (author), Bezuidenhout, D.F. (author), van Eijk, A.M.J. (author), TNO Defensie en Veiligheid (author)
Present-day naval operations take place in coastal environments as well as narrow straits all over the world. Coastal environments around the world are exhibiting a number of threats to naval forces. In particular a large number of asymmetric threats can be present in environments with cluttered backgrounds as well as rapidly varying atmospheric...
conference paper 2008
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de Jong, A.N. (author), van Eijk, A.M.J. (author), Fritz, P.J. (author), Cohen, L.H. (author), Moerman, M.M. (author), TNO Defensie en Veiligheid (author)
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...
conference paper 2007
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TNO Defensie en Veiligheid (author), Degache, M.A.C. (author), Hammel, S. (author)
Within the marine atmospheric surface layer it is possible for a single camera to deduce passively the range to a point target. Although this range determination would appear impossible at first glance, such a measurement exploits the common occurrence of sub-refractive propagation conditions in the marine environment. A calculation of the range...
conference paper 2007
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TNO Defensie en Veiligheid (author), Kuśmierczyk-Michulec, J.T. (author), van Eijk, A.M.J. (author)
The variation of the extinction coefficient with wavelength can be presented as a power law function with a constant (related to the power factor) known as the Ångström coefficient. When the particle size distribution is dominated by small particles, usually associated with pollution, the Ångström coefficients are high; in clear conditions they...
conference paper 2007
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TNO Defensie en Veiligheid (author), Francius, M.J. (author), Piazzola, J. (author), Forget, P. (author), le Calve, O. (author), Kusmierczyk-Michulec, J. (author)
Results from a quantitative model for the prediction of the sea-salt mass flux produced in the surf zone are presented in this paper. The model relates the surf zone sea salt mass flux to the amount of wave energy dissipated in the surf zone. In order to apply this aerosol emission model, a wave numerical model is required to obtain estimates...
conference paper 2007
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