Ján Gamec

Imaging method: A strong tool for moving target tracking by a multistatic UWB radar system

In this paper, imaging method for moving target tracking by a multistatic ultra-wideband radar system is described. The task of moving target tracking consists in estimation of a target trajectory based on processing of raw radar data obtained from all receiving channels of a radar system. Then, the imaging method applied for target tracking consists of such signal processing phases as raw radar data pre-processing, background subtraction, fusion of the data obtained by receiving antennas of a radar, detection, localization and tracking itself. The performance of the imaging method described in this paper is demonstrated by signal processing obtained by M-sequence UWB radar for a scenario represented by through wall tracking of a single moving target. The obtained results confirm the excellent performance of the discussed method.

Design of narrow-band 2.4 – 2.5 GHz notch filter using various materials

This paper deals with design, simulation and measurement of narrow-band notch filter from 2.4 GHz to 2.5 GHz using five dielectric materials with various dielectric constants (glass microfiber, ceramic reinforced PTFE, hydrocarbon or epoxy based material). This paper presents filters based on microstrip line structure with half wavelength L - resonators and bandstop characteristic. Various dimensions of each structure were designed due to characteristic of used dielectrics, characterised by dielectric constant εr. The scattering parameters at various frequencies are investigating by modelling this structure with linear network analyses and electromagnetic simulation provides by Ansoft Designer simulating tool from ANSYS and measurement was done by VNA (Vector Network Analyzer). This article presents results of simulation and real measurement of scattering parameters of designed microstrip line structure. This paper refers how used dielectric materials (Rogers RO3003C, Rogers RO4003C, RT/duroid 5880, RT/duroid 6010LM and FR4) influence quality of designed notch filter and which of used material is the most suitable for purpose of high frequency filter using microstrip transmission lines.

Algorithm of traffic signs recognition based on the rapid transform

This paper presents a model of a system for invariant object recognition, which consists of five stages. The first stage shifts the object so that the centroid of the object coincides with the center of the image plane. The second stage is an application of the polar-coordinate transforms used to obtain N-dimensional vectors-representations of the input object. In this stage, any rotation of the input object becomes a cyclic shift of the output value of this stage. The third stage employs CT (Certain Transform), a class of shift-invariant transformations to provide invariant representations for cyclically shifted inputs. The next stage normalizes the outputs of the previous stage to obtain scale invariance. The final stage realizes a classification.

Alternative antenna measuring methods with use of impulse UWB radar

This paper presents alternative methods of measuring the electric properties of antennas. In this case, the UWB impulse radar system is used. Also, the paper describes a relatively low cost measuring system, its calibration, verification and calculation methods of the required parameters - return loss and radiation pattern. All experimental results obtained by UWB radar are compared with the results obtained by measurements in an anechoic chamber. Experimental results of the measurements using UWB impulse radar system show good agreement with the simulated performance and with the measurements in the anechoic chamber.

Simple estimation of relative permittivity of wall by UWB radar system

This paper describes a simple method for the relative permittivity estimation of the wall by an UWB (ultra wideband) impulse radar system. It is non-invasive reflected free space method for data gathering just from the single side of the wall. There is just one condition also by which we can achieve the best possible accuracy. It is a short time window of monitored signal, while there is an undesired reflection from the other side of the wall. Frequency dependence of the relative permittivity is then obtained from the reflection coefficient of the transmitted TEM (transverse electromagnetic) wave. The paper describes two demonstrative measurements and verification of the measured data by the transmission method.

Theoretical Analysis of Recent Changes and Expectations in Intelligent Robotics

This paper deals with the current trend towards moving from industrial robots to the service or social robotics era. The time when robots populated the environment ‘alone’ is over and networked robotics and the acquisition and understanding of crowd-sourcing is fully supported by the trends in Computer technology.