As the sensor technology for polarimetric imaging is advancing into more robust commercial systems such sensors could soon be expected for, e.g., military surveillance and reconnaissance applications in addition to more conventional sensor systems. Thus, there might be an upcoming need to understand limitations on present camouflage systems to meet this new sensor threat. Some of the reasons why polarimetric imaging has drawn attention is the ability to achieve a higher contrast for artificial surfaces against natural backgrounds, by analyzing the degree of linear polarization, which in this work has been analyzed for different types of surfaces as a function of wavelength. We also compare with the polarimetric vision of horse-flies and other aquatic insects via the polarization properties of different colors of horse coat hair in order to give some further insight into polarimetric vision techniques developed by nature. In this work we have used different measurement techniques, such as angle dependent polarimetric spectral directional hemispherical reflectance and polarimetric imaging.
In order to characterize a target, the basic information that is of interest is spectral, polarization and distance. Imaging spectropolarimetry is a powerful tool for obtaining the polarization state of a scene and to discriminate manmade objects in a cluttered background. With respect to polarization, often the measurements are limited to the first three components of the Stokes vector, excluding circular polarization. The scene is therefore characterized in four directions of linear polarization, <i>I</i><sub>0</sub>, <i>I</i><sub>90</sub>, <i>I</i><sub>45</sub> and <i>I</i><sub>135</sub>. An efficient polarimetric BRDF model defined in a local coordinate system has recently been published. The model will now be extended to a global coordinate system for linear polarized radiation. This includes the first three elements of the Stokes vector. We will provide examples for surface of intrinsically different scattering materials, bulk scattering materials and clear coated surfaces.
In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and centralized processing is essential. There is a central role for sensor fusion of heterogeneous sensors in future processing. The changes that occur in the urban operations of the future due to the application of these new technologies will be the improved quality of information, with shorter reaction time, and with lower operator load.
The market demand for bright laser pointers has led to the development of readily available devices that can pose a threat
to road safety. Laser pointers can be involved in accidents caused by laser users who do not realise the dangers involved,
but laser pointers can also enable deliberate criminal activity. There are technologies available that can counter the threat
in different ways. A number of protective principles are outlined below. Some technologies built upon Liquid Crystal
Devices are described in greater detail.
Without any knowledge of what laser pointers a potential aggressor has access to, a frequency agile filter seems to be the
most promising way to avoid the most severe consequences of dazzle from laser pointers. Protective systems
incorporating suitable glasses or visors holding frequency agile filters of this kind however, are not commercially
We present a sol-gel derived photonic structure of beryllium oxide. A new low temperature synthesis route has been developed to produce beryllium oxide from beryllium alkoxide. The beryllium alkoxide was prepared from beryllium metal, methyl mercury and butyl alcohol as starting materials. The samples have been mathematically modelled and their IR reflectance characteristics in the 2-18 μm wavelengths rang has been measured.