The paper describes the original results of a comparative study of the standard seismic station vs. a novel interferometric sensor for civil engineering needs. The presented results showed that to implement seismic measurements using standard seismic stations, a method using a fiber optic interferometer may serve as an alternative. We presented time records and the frequency spectra obtained from experimental measurements of the dynamic response of the upper rock mass beneath passing tram vehicles (a total of 769 passes) over a period of five months of practical measurements under various climatic conditions. The fiber-optic sensor detected all phenomena at a 100% rate, and the recorded results were compared to the results from a standard seismic station. Both sets of results were recorded simultaneously and agreed significantly, especially in terms of frequency. With regard to time, all tram vehicle axles were detected in individual time records. With regard to frequency, the results detected in the bandwidth generally correlated to rail transport for individual types of tram vehicles.

In this paper, basic information about use of the RGBY (Red Green Blue Yellow) model for mobile visible light communication systems is presented. This document contains information about differences between the traditional RGB model and the RGBY model with respect to the area coverage and white light creation, since the adding of the yellow significantly affects system properties in many ways. There are also mentioned some modulations suitable for this type of communication, because it is important to keep the mean value of the output signal stable and undetectable by the human eye.

This article deals with the design of construction of new type of transmitter for indoor Free Space Optic (FSO) networks. This transmitter will be able to provide the lighting and communication at the same time. Thanks to special solution in spectral characteristic of transmitted light it is necessary to use two LED diodes radiation sources. The light beams of these LED diodes have to be spatially overlapped in crisscross direction, then the transmitter can realize both functions. In this article it is described how to set the LED diodes and which optical elements should be used for correct function of the transmitter.

Purposeful Suppression and Reconstruction of White Light from LED for Improvement of Communication Properties

The article follows on from the article presented at the LS17 conference entitled “Case study – Modelling of Visible Light Communication (VLC) on Luminous Intensity Distribution Curve (LIDC) of LED Low Beam Car Headlamps”. This post dealt with the possibility of using VLC on roads with road lighting systems. In particular, it addressed the minimum light levels at which VLC can still be operated in the outdoor traffic area. These have been compared to the illuminance levels that can be achieved using LED low beam cars headlamps. It was mainly about the distance in front of the car at which it is able to distribute a useful VLC signal. The post addressed whether this technology is even possible to implement in relation to the distances that cars need to stop safely [1]. Since road lighting is also part of the night-time traffic space in cities and towns, this article will deal with its possibilities for implementing VLC in relation to the car communication with this infrastructure. This is made possible by the fundamental expansion of LED technologies, which have already penetrated not only light sources in automotive, but also road lighting [1]. The existing lighting systems of road lighting did not allow the application of VLC, because they were dominantly fitted with high-pressure sodium discharge lamps, which did not allow even slow regulation of the luminous flux, let alone fast switching (modulation) of the luminous flux at kHz levels and above. To demonstrate the possibilities of road lighting, a standard LED lighting system of road lighting with low levels of requirements according to European road lighting standards [EN 13201-2 Road lighting - Part 2: Performance requirements] and classification M5 was chosen for modelling.

This paper presents the construction of an innovative high-temperature sensor based on the optical principle. The sensor is designed especially for the measurement of exhaust gases with a temperature range of up to +850 °C. The methodology is based on two principles-luminescence and dark body radiation. The core of this study is the description of sensing element construction together with electronics and the system of photodiode dark current compensation. An advantage of this optical-based system is its immunity to strong magnetic fields. This study also discusses results achieved and further steps. The solution is covered by a European Patent.