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Piotr Samczynski

Bio: Piotr Samczynski is an academic researcher from Warsaw University of Technology. The author has contributed to research in topics: Radar & Synthetic aperture radar. The author has an hindex of 22, co-authored 158 publications receiving 1561 citations.


Papers
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Journal ArticleDOI
TL;DR: The presented technique allows flight parameters to be estimated with accuracy that is independent of the initial velocity error, and can be used for real-time processing for both Earth imaging and moving-target indication.
Abstract: A new parametric autofocus technique with a high accuracy of flight-parameter estimation dedicated to strip-mode synthetic aperture radar (SAR) systems is presented. Most of the known autofocus techniques require high-reflectivity targets (man-made targets) to obtain a properly focused SAR image. The technique proposed in this paper allows flight parameters to be estimated effectively, even for a low-contrast scene (e.g., forests, fields, small paths, etc.). The autofocus technique is based on well-known MapDrift (MD) principles. The presented technique is a coherent one, which allows flight parameters to be estimated more precisely than in the other well-known parametric technique referred to as classical MD. The presented technique allows flight parameters to be estimated with accuracy that is independent of the initial velocity error. It can be used for real-time processing for both Earth imaging and moving-target indication.

110 citations

Proceedings ArticleDOI
10 May 2016
TL;DR: This paper presents an experimental system dedicated for the detection and tracking of small aerial targets such as Unmanned Aerial Vehicles (UAVs) in particular small drones (multirotors).
Abstract: This paper presents an experimental system dedicated for the detection and tracking of small aerial targets such as Unmanned Aerial Vehicles (UAVs) in particular small drones (multirotors). The system was proposed in response to increasing drone popularity and the related threats. The hardware and software parts of the system are covered, including the analogue front-end, FPGA based pre-processing and PC based processing, detection and tracking. Real life trials are described with promising results provided. Further research on the subject is proposed.

93 citations

Journal ArticleDOI
TL;DR: In this article, the authors present an analysis of the detection range of a passive bistatic radar (PBR) by using FM radio transmitters as the illuminators of opportunity and the analysis of a required analogue-front-end dynamic range.
Abstract: This study presents an analysis of the detection range of a passive bistatic radar (PBR) by using FM radio transmitters as the illuminators of opportunity and the analysis of a required analogue-front-end dynamic range. Firstly, the theoretical considerations are presented in which the power budget is analysed, by taking into account the specific features of the PBR such as instantaneous reception of the direct illumination signal and weak target echoes and direct path interference removal. In the second part of this study, measurements performed by using an FM-based PBR demonstrator PaRaDe (passive radar demonstrator) are presented. The PaRaDe is a deployable system operating in real time, developed at the Warsaw University of Technology, Poland. The measurements include a scan of a typical spectrum in the range of 88-108 MHz, and the analysis of the long range detection of the air targets.

89 citations

Journal ArticleDOI
TL;DR: The main goal of the presented experiment was to verify the possibility of ground imaging using passive SAR technology and validate previously presented theoretical results.
Abstract: In this letter, pioneering experimental results of passive synthetic aperture radar (SAR) imaging are presented. The classical active SAR radar operates in monostatic geometry. The SAR sensor presented in this letter is a passive radar utilizing commercial Digital Video Broadcasting—Terrestrial transmitters as illuminators of opportunity. It works in a bistatic configuration, where the receiver is placed on a moving platform and the transmitter is placed on the ground and is stationary. The imaged scenes are stationary surfaces on Earth such as agriculture or urban areas, buildings, etc. In this letter, pioneering results of signal processing verified by a measurement campaign are presented. In the experiment, two synchronized passive radar receivers were mounted on a small airborne platform. The main goal of the presented experiment was to verify the possibility of ground imaging using passive SAR technology and validate previously presented theoretical results.

78 citations

Journal ArticleDOI
TL;DR: The main goal of the research conducted was to present different aspects of an efficient space-time ground moving target indication (GMTI) algorithm for PCL radar mounted to airborne platforms.
Abstract: A new approach to the passive coherent location (PCL) signal processing technique dedicated for use on mobile radar platforms is presented. The main goal of the research conducted was to present different aspects of an efficient space-time ground moving target indication (GMTI) algorithm for PCL radar mounted to airborne platforms. The algorithm described, based on displacement phase center antenna (DPCA), has been successfully tested with simulated and real-life data collected with an airborne passive radar demonstrator (PaRaDe).

77 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 Jan 2016
TL;DR: Thank you very much for downloading spotlight synthetic aperture radar signal processing algorithms, maybe you have knowledge that, people have search numerous times for their favorite books, but end up in malicious downloads.
Abstract: Thank you very much for downloading spotlight synthetic aperture radar signal processing algorithms. Maybe you have knowledge that, people have search numerous times for their favorite books like this spotlight synthetic aperture radar signal processing algorithms, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they juggled with some harmful virus inside their laptop.

455 citations

Journal ArticleDOI
TL;DR: In this paper, the authors considered both the downlink and uplink UAV communications with a ground node, namely, UAV-to-ground (U2G) and groundto-UAV (G2U) communications, respectively, subject to a potential eavesdropper on the ground.
Abstract: Unmanned aerial vehicle (UAV) communication is anticipated to be widely applied in the forthcoming fifth-generation wireless networks, due to its many advantages such as low cost, high mobility, and on-demand deployment. However, the broadcast and line-of-sight nature of air-to-ground wireless channels give rise to a new challenge on how to realize secure UAV communications with the destined nodes on the ground. This paper aims to tackle this challenge by applying the physical layer security technique. We consider both the downlink and uplink UAV communications with a ground node, namely, UAV-to-ground (U2G) and ground-to-UAV (G2U) communications, respectively, subject to a potential eavesdropper on the ground. In contrast to the existing literature on the wireless physical layer security only with the ground nodes at fixed or quasi-static locations, we exploit the high mobility of the UAV to proactively establish favorable and degraded channels for the legitimate and eavesdropping links, through its trajectory design. We formulate new problems to maximize the average secrecy rates of the U2G and G2U transmissions, by jointly optimizing the UAV’s trajectory, and the transmit power of the legitimate transmitter over a given flight period of the UAV. Although the formulated problems are non-convex, we propose iterative algorithms to solve them efficiently by applying the block coordinate descent and successive convex optimization methods. Specifically, both the transmit power and UAV trajectory are optimized, with the other being fixed in an alternating manner, until the algorithms converge. The simulation results show that the proposed algorithms can improve the secrecy rates for both U2G and G2U communications, as compared to other benchmark schemes without power control and/or trajectory optimization.

436 citations