Saulius Rudys

Dr. Saulius Rudys

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
12 September 2022 in Drones
Verified
Journal Article
Open access
PDF file
SRSaulius Rudys
Saulius Rudys
ALAndrius Laučys
Andrius Laučys
PRPaulius Ragulis
Paulius Ragulis
RARimvydas Aleksiejūnas
Rimvydas Aleksiejūnas
KSKarolis Stankevičius
Karolis Stankevičius
RPRaimondas Pomarnacki
Raimondas Pomarnacki
The technologies of Unmanned Aerial Vehicles (UAVs) have seen extremely rapid development in recent years. UAV technologies are being developed much faster than the means of their legislation. There have been many means of UAV detection and neutralization proposed in recent research; nonetheless, all of them have serious disadvantages. The essential problems in the detection of UAVs is the small size of UAVs, weak radio wave reflection, weak radio signal, and sound emitting. The main problem of conventional UAV countermeasures is the short detection and neutralization range. The authors propose the concept of the airborne counter-UAV platform (consisting of several vehicles) with radar. We use a low-cost marine radar with a high resolution 2 m wide antenna, embedded into the wing. Radar scanning is implemented by changing the heading of the aircraft. For the countermeasures, the authors suggest using a small rotorcraft UAV carried by a bigger fixed-wing one. A mathematical model that allows the calculation of the coordinates of the detected drone while scanning the environment in a moving UAV with radar was created. Furthermore, the results of integrated radar performance with a detected drone and the results of successful neutralization experiments of different UAVs were achieved.

11 August 2022 in Electronics
Verified
Journal Article
Open access
PDF file
SRSaulius Rudys
Saulius Rudys
PRPaulius Ragulis
Paulius Ragulis
ALAndrius Laučys
Andrius Laučys
DBDomantas Bručas
Domantas Bručas
RPRaimondas Pomarnacki
Raimondas Pomarnacki
Darius PlonisDarius Plonis
Darius Plonis
The development of unmanned aerial vehicle (UAV) technologies provides not only benefits but also threats. UAV technologies are developing faster than means of detecting and neutralizing them. Radar technology is one of the means of UAV detection which provides the longest detection range. Today’s market provides low-cost solid-state marine radar working on FMCW and pulse-compression principles of operation. Despite such radars having attractive features, they were not designed for UAV detection. Although they are not optimal, they could be used for UAV detection. The detection possibility of UAVs by marine radars was investigated by using three types of radars and two types of small UAVs as targets. Radar cross-section measurements of the targets were made in laboratory conditions.

1 March 2020 in Review of Scientific Instruments
Verified
Journal Article
Open access
PDF file
ŠSŠarūnas Svirskas
Šarūnas Svirskas
DJDžiugas Jablonskas
Džiugas Jablonskas
SRSaulius Rudys
Saulius Rudys
SLSaulius Lapinskas
Saulius Lapinskas
RGRobertas Grigalaitis
Robertas Grigalaitis
Juras BanysJuras Banys
Juras Banys
The full-wave analysis was applied for a coaxial line (i.e., transmission line) that has a “short-circuited” discontinuity. The discontinuity has a radius less than or equal to the inner radius of the coaxial line. The “sample region” can be considered as a partially filled circular waveguide. Such a structure is very practical and is of particular interest for the dielectric spectroscopy applications. It takes into account the inhomogeneous field distribution, which is the limiting factor for the determination of high dielectric permittivity values at microwave frequencies. The direct problem was solved by using the mode-matching technique, and the relationship between the complex reflection coefficient and the dielectric permittivity of the cylindrical sample was obtained. By solving the inverse problem, it is possible to obtain the complex dielectric permittivity from the experimental values of the scattering matrix. The results were verified by the finite element modeling of the system and applied for particular materials. The correspondence between these approaches is excellent. This method is very suitable for the determination of permittivity, which exceeds several thousands (it is applicable for any type of material). It extends the frequency range where the permittivity can be determined reliably. There is no necessity to prepare samples with different geometries (i.e., surface area and thickness).

Verified
Journal Article
Open access
PDF file
SRSaulius Rudys
Saulius Rudys
ALAndrius Laučys
Andrius Laučys
DUDainius Udris
Dainius Udris
RPRaimondas Pomarnacki
Raimondas Pomarnacki
DBDomantas Bručas
Domantas Bručas
Some models of marine radars are light-weight enough and thus are attractive for potential applications when arranged on UAVs. Elevating a marine radar to high altitudes provides a much wider field of view, however, this could lead to a higher radio interference level. The practical estimation of the radio interferences affecting the solid-state FMCW marine radar at altitudes up to 120 m was the main objective of this contribution. A rotary-wing octocopter UAV was developed and built for the experiments. Two different kinds of interferences were observed at higher altitudes. Ray-like interferences were caused by signals, which are received by the radar’s antenna. Circle-like interferences appear due to the low frequency interfering signal directly penetrating the detector due to insufficient receiver screening.

19 October 2022 in Nonlinear Analysis Modelling and Control
Verified
Journal Article
Open access
PDF file
Ilona ZamaraiteIlona Zamaraite
Ilona Zamaraite
SRSaulius Rudys
Saulius Rudys
SLSaulius Lapinskas
Saulius Lapinskas
RARimvydas Aleksiejunas
Rimvydas Aleksiejunas
RGRobertas Grigalaitis
Robertas Grigalaitis
JBJuras Banys
Juras Banys
Journal provides a multidisciplinary forum for scientists, researchers and engineers involved in research and design of nonlinear processes and phenomena, including the nonlinear modelling of phenomena of the nature.