Currently, more and more attention is being paid to monitoring the state of road infrastructure, since it is the public domain of the country. As a result of the large flow of traffic and environmental influences, it leads to wear of the road surface. Timely detection of defects and damage to the pavement allows us to develop effective programs for maintenance and restoration of the pavement, which allows us to achieve significant costs and save time. Currently, fiber sensors are used as a more effective tool for monitoring the condition of the road surface. Since road surfaces are multilayer structures consisting of layers of granular and bituminous materials, the sensors must correspond to the heterogeneous nature and mechanical properties of the pavement materials. Fiber sensors based on the fiber Bragg grating (FBG) meet these requirements. Fiber sensors based on FBG are widely used due to advantages such as long-term stability and durability, good geometric shape, versatility, corrosion resistance, electromagnetic interference protection, low cost and high detection accuracy.
This work is the result of a study of the impact of photonic technologies on increasing productivity in agriculture. Mathematical models are presented that consider how external optical radiation affects the growth and productivity of crops. Analytical expressions are proposed for the distribution of the electromagnetic field inside a spherical grain. The model must take into account not only the characteristics of the incident field, but also the electrical and geometric characteristics of the cereal grains themselves. A model is considered when a light wave is incident on a spherical surface, the length of which is less than the size of the sphere by about three orders of magnitude. Also, based on the calculations, photonic matrices of the matrix for experiments were made. The main stages of system analysis of an automated control system for low-energy LED radiation are graphically presented.
In the article the combined reflectance model based on quadratic and cubic polynomials is discussed. The main characteristics of physically accurate Torrance-Sparrow, Löw models and empirical Blinn, Phong, Schlick models are analyzed. The advantages and disadvantages of the cubic and quadratic Blinn-Phong model approximations are explored. The need in the development of new Blinn-Phong model approximation through combining the quadratic and cubic functions is justified. The cubic model is improved in order to improve the accuracy of Blinn-Phong model approximation in the attenuation zone. The formulas of the improved cubic model coefficients are simplified. The precise and approximated formulas for the calculation of connection point between quadratic and cubic functions are obtained. The productivity gain from the replacing the cubic function by the quadratic function in the glare’s epicenter zone is calculated. The absolute and relative errors of Blinn-Phong model approximation by the quadratic, cubic and the proposed model are compared. Through the visualization of the test figures “Teapot” and “Robot” the advantages of the proposed function usage for increasing the realism of glares formation are shown.
KEYWORDS: Surveillance systems, Adaptive optics, Radar, Signal detection, Data processing, Control systems, Statistical analysis, Signal to noise ratio, Signal processing, Radar signal processing
The structure of information support for the airspace control system based on combined radar surveillance systems has been substantiated and investigated. This makes it possible to improve the quality of the detection of air objects, as well as to assess the accuracy of the location of the detected air objects. As a result, this improves the quality of information support for decision-makers in the airspace control system.
The theoretical analysis of the open electrodynamic system, which is a symbiosis of an open resonator and a segment of a rectangular waveguide, is carried out in the work. It is shown that the transverse dimensions of the waveguide made at the center of one of the mirrors of the open resonator are uniquely determined by the geometric parameters of the resonator and the working wavelength. In this case, the maximum efficiency of excitation of the main wave ТЕ10 in a rectangular waveguide with the help of the fundamental oscillation of the open resonator ТЕМ00q is 88%. As it turned out, in this case the normalized transverse dimensions of the waveguide are oversized, and the considered system can be used to measure the ultra-weak luminescence of seeds of grain crops.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.