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We consider a conceptual approach for the applicability of airborne weather radar for the sea ice/water discrimination and estimation of the sea ice age. The sea ice/water discrimination method suited for the airborne weather radar utilization is based on finding the minimum statistical distance of the measured normalized radar cross sections within a wide azimuth sector to the geophysical model functions of the sea ice and water, respectively. The sea ice age classification is based on the comparison of the normalized radar cross section value at a given incidence angle to the lower normalized radar cross section boundaries for the first-, second-, and multi-year ice. Implementation of the proposed methodology is considered for the C-band airborne weather radar operated in the ground mapping mode as a scatterometer scanning in a wide azimuth sector up to ±100°. We show explicitly that the proposed approach provides the enhancement of the conventional airborne weather radar functionality for the sea ice/water discrimination and sea ice age estimation either using stand-alone or joint measurements.

This article presents a novel concept for a highly accurate and simple two-port vector signal analyzer. A current phase ratio measurement method is defined for one independent external signal with a restriction of the measuring range ±90 or ±180°. The article presents a new way of phase ratio evaluation of two independent external signals with precise phase determination in a wide range from 0° to 360°. The new functional blocks of the analyzer circuit element act as a four-position radio frequency (RF) switcher and an algorithm for phase determination is presented. Practical application and verification of the results achieved are demonstrated by measuring the phase directional radiation pattern of a complex object such as an aircraft fuselage.

Creation and operation of sensor systems is a complex challenge not only for industrial and military purposes but also for consumer services (“smart city”, “smart home”) and other applications such as agriculture (“smart farm”, “smart greenhouse”). The use of such systems gives a positive economic effect and provides additional benefits from various points of view. At the same time, due to a large number of threats and challenges to cyber security, it is necessary to detect attacks on sensor systems in a timely manner. Here we present an anomaly detection method in which sensor nodes observe their neighbors and detect obvious deviations in their behavior. In this way, the community of neighboring nodes works collectively to protect one another. The nodes record only those parameters and attributes that are inherent in any node. Regardless of the node’s functionality, such parameters include the amount of traffic passing through the node, its Central Processing Unit (CPU) load, as well as the presence and number of packets dropped by the node. Our method’s main goal is to implement protection against the active influence of an internal attacker on the whole sensor network. We present the anomaly detection method, a dataset collection strategy, and experimental results that show how different types of attacks can be distinguished in the data produced by the nodes.

In our laboratory, we developed a simple estimation of the wall thickness by the UWB (Ultra Wide-Band) radar system. The described technique measures the wall thickness in the two steps. The first step is a measurement of the wall relative permittivity. The second step is a reflections localisation and estimation of the wall thickness. The borders of the wall could be detected by the envelope of the received signals. The described technique calculates the signal envelope by the Hilbert transform. Moreover, the relative permittivity of the wall is estimated by the technique developed in our department as well. The effective relative permittivity is calculated from the frequency dependency of relative permittivity. This technique was developed for the impulse radar system. The aim of this article is compare the results from impulse radar system with M-sequence radar system which operates in the time domain as well measuring wall relative permittivity and wall thickness estimation.

The authors of this paper study the synthesis of new models and methods for signal detection in additive correlated non-Gaussian noise. A new moment quality criterion decision making is proposed based on a random process description using moments and a formation of polynomial decision rules. Taking into account parameters of non-Gaussian distribution of random variables (such as the moments of third and higher orders and joint cumulants), it is shown that nonlinear processing of samples can increase the signal processing efficiency. A synthesis of effective methods and algorithms of data processing in non-Gaussian noise is also presented in this work.

This article describes the design and implementation of a low-profile sinuous slot antenna, intended for ultra-wideband (UWB) sensor networks, which can be produced on one conductive layer. The article explains the design and optimization of the sinuous slot antenna and its modifications, including its sinusoidal curve shape. Other modifications were aimed at optimizing the antenna feeding. Desirable properties of the designed and implemented antenna modifications were verified both by simulation and empirically. Experimental measurements of the antenna&rsquo, s properties were carried out using a vector network analyzer in an anechoic chamber and also by a pulsed UWB radar in the frequency range from 0.1 to 6 GHz. The low-profile antennas were implemented on a Rogers RO3206 substrate.

In our laboratory, we developed a simple estimation of the wall thickness by the UWB (Ultra Wide-Band) radar system. The described technique measures the wall thickness in the two steps. The first step is a measurement of the wall relative permittivity. The second step is a reflections localization and estimation of the wall thickness. The borders of the wall could be detected by the envelope of the received signals. The described technique calculates the signal envelope by the Hilbert transform. Moreover, the relative permittivity of the wall is estimated by the technique developed in our department as well. The effective relative permittivity is calculated from the frequency dependency of relative permittivity.

We consider how to protect Unmanned Aerial Vehicles (UAVs) from Global Positioning System (GPS) spoofing attacks to provide safe navigation. The Global Navigation Satellite System (GNSS) is widely used for locating drones and is by far the most popular navigation solution. This is because of the simplicity and relatively low cost of this technology, as well as the accuracy of the transmitted coordinates. Nevertheless, there are many security threats to GPS navigation. These are primarily related to the nature of the GPS signal, as an intruder can jam and spoof the GPS signal. We discuss methods of protection against this type of attack and have developed an experimental stand and conducted scenarios of attacks on a drone&rsquo, s GPS system. Data from the UAV&rsquo, s flight log were collected and analyzed in order to see the attack&rsquo, s impact on sensor readings. From this we identify a new method for detecting UAV anomalies by analyzing changes in internal parameters of the UAV. This self-diagnosis method allows a UAV to independently assess the presence of changes in its own subsystems indicative of cyber attacks.

Energy harvesting is a future technology for capturing ambient energy from the environment to be recycled to feed low-power devices. A planar antipodal Vivaldi antenna is presented for gathering energy from GSM, WLAN, UMTS and related applications. The designed antenna has the potential to be used in energy harvesting systems. Moreover, the antenna is suitable for UWB applications, because it operates according to FCC regulations (3.1 – 10.6 GHz). The designed antenna is printed on ARLON 600 substrate and operates in frequency band from 0.810 GHz up to more than 12 GHz. Experimental results show good conformity with simulated performance.

The article is dealing with the theory of Crossed Field Antenna -CFA. This type was patented recently and sees its practical application particularly in area of long and medium waves. A brief theoretical analysis of the principle of radiation of this new type of antenna, which is not wave dependent to its physical dimensions, is present in this article. The independence on waves of the current CFA s enables substantial reduction of mechanical dimensions for medium wave (MW) antennas. Thereby, the dimensions of MW antennas reduces from hundreds of meters to structures measuring only several meters without affecting their electrical parameters -like power, impedance and radiation. The article is presenting a proposal and an analysis regarding the potentials in using CFA in high frequency (HF) and very high frequency (VHF) frequency bands. From this point of view, reducing the size of the airborne communication antennas is among the long-term goals of the authors research conducted at the educational institute.

In our laboratory, we developed a new technique for measurement of the relative permittivity of the wall by the UWB (Ultra-wideband) radar system. The primary use of the radar is the localization of moving objects behind the wall. Developed method will be used in a process of the localization ofpersons for increasing the accuracy of the measurement process. The method was developed for the impulse radar system. This paper describes the behaviour of this method in M-sequence radar system and comparison of results with the impulse radar system.

This paper describes a simple method of the wall permittivity estimation by the UWB radar system in the free space. The method is developed and dedicated for a localisation of objects behind a obstacle for example the wall. The paper also describes a influence of the transversal of incident wave and a proper windowing of signals.

Historical overview of evolution wideband antennas and some practical realizations of UWB antennas are presented. Practical realization of antennas are made by LTCC technology mostly, PCB technology or their combinations. Main features of antennas such as wide frequency bandwidth, high gain and the smallest dimensions as possible are described. The features should be helpful for future research of described antennas suitable for UWB radar applications.

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.

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.

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.

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 er. 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.

The subject of this article is to bring the problem analysis of vehicle communication through diagnostic interface OBDII with diagnostic tools used in automotive diagnostics with an emphasis on Bluetooth communication. Based on the analysis, this paper deals with the description of software design and its implementation to mobile devices on purpose of communication with CAN OBDII interface. For this type of communication is usually used diagnostically-oriented communication processor ELM 327. Aim of this solution is to bring an application provided for mobile devices with Android operating system, which can obtain real time data from engine control unit through ELM 327.

This paper presents an in-vehicle monocular road detection system. The system acquires color images in the input and uses image processing techniques to boost robustness of this algorithm that it is possible to improve it's autonomy and "intelligence" in segmentation of driving space in different road scenes. The road detection algorithm consists of two main steps: Vanishing point estimation and Road detection. The main idea of driving space detection is based on successful Vanishing point estimation. This algorithm was tested under different traffic scenarios (e.g., simply structured highway, complex urban street, varying illumination conditions).

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.

The Block matching algorithms suffers from limitation concerning the fidelity of the predicted image: blocking effect is introduced for the lack of coherence of the estimated motion to the actual motion. It is possible to partially overcome this drawback by smoothing the estimated vector field in a further stage. Smoothing can be accomplished, for example, by using various filtering methods. In this paper, it is main purpose to present the motion estimation and filtering techniques that give consideration to both estimation performance and computational efficiency.