• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1647
  • 298
  • 260
  • 185
  • 58
  • 54
  • 51
  • 37
  • 37
  • 37
  • 37
  • 37
  • 37
  • 32
  • 29
  • Tagged with
  • 3230
  • 609
  • 344
  • 320
  • 315
  • 288
  • 283
  • 277
  • 276
  • 273
  • 254
  • 237
  • 231
  • 223
  • 222
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Bi-spectral method for radar target recognition

Yeo, Jiunn Wah. 12 1900 (has links)
Target recognition and identification in battlefields has been a crucial determinant to the ultimate success or failure of modern military campaigns. Since World War II, the Identification of Friend or Foe (IFF) systems installed in radar systems have served as the primary cooperative target identification techniques based on the "question and answer" interrogation loop of unidentified aircraft. However, the IFF system has a number of limitations that pose significant challenges in the positive identification of hostile and neutral aircrafts, which can lead to a catastrophic outcome of fratricide and the possible elimination of a friendly or commercial aircraft. To reduce the probability of fratricide and enhance the effectiveness and robustness of target identification, this research will examine the radar Non-Cooperative Target Recognition (NCTR) technique of using the bi-spectral signatures of backscattered radar signals. The basic idea is that the geometry of the target scatterers and their mutual interactions impose features in the reflected radar signal that are typical and unique to the target of interests. The bi-spectrum can be used to detect these multiple interactions features which then may be used to match against a reference database that contains signatures of different target types for recognition and identification.

Wirelessly networked opportunistic digital phased array system analysis and development of a 2.4 GHz demonstrator

Yeo, Eng Choon. 12 1900 (has links)
The concept of a wirelessly networked opportunistic digital phased array radar brings about the added advantages of stealth, enhanced survivability, and maximum maneuverablity. The array elements are spread over a wide range of locations on the ship's hull and superstructure, and the Local Oscillator (LO) and data/control signals are wirelessly transmitted to and from a central computer processor, which also performs as the digital beamformer. As part of the ongoing research effort, this thesis focused on the hardware and software development of a 2.4 GHz two-element array demonstrator. A system analysis of a generic distributed array radar was done and some key parameters pertaining to the Transmit/Recieve (T/R) module and an eight-element array radar were calculated. In addition, the research analyzed the radar waveform properties, sampling and data rates, the digital beamformer concept and requirements, and assessed their impacts on the radar performoance. Two Transmit/Recieve (T/R) modules were built and a two-element array test bench developed using the various National Instruments Compact Reconfigurable Input and Output (cRIO) and Field Programmable Gate Array (FPGA) modules. The main software, written in LabVIEW, allowed the test bench to demonstrate proper functionalities of transmission and reception of the T/R modules. The hardware and software code could be extended easily for an eight-element array radar. Lastly, a number of measurements to characterize the T/R module were done. No significant interference between the modulator and demodulator boards inside of the compact T/R module chassis were observed.

Synthesis of shaped-beam radiation patterns /

Stutzman, Warren L. January 1969 (has links)
Thesis (Ph. D.)--Ohio State University, 1969. / Includes bibliographical references (leaves 282-299). Available online via OhioLINK's ETD Center.

Properties, limitations, and applications of the radar ambiguity function

Brown, William M. (William Milton) 05 1900 (has links)
No description available.

Ein Beitrag zum Verbessern der azimutalen Auflösung vorwärtsschauender Radarsysteme mit synthetischer Apertur /

Löhner, Andreas. January 1999 (has links) (PDF)
Univ., Diss.--Kaiserlautern. / Nebent.: Vorwärtsschauende SAR-Systeme. Literaturverz. S. 144 - 155.

Development of a Distributed Digital Array Radar (DDAR)

Djerf, Pontus R. Tornazakis, Ioannis. January 2008 (has links) (PDF)
Thesis (M.S. in Electronic Warfare Systems Engineering)--Naval Postgraduate School, September 2008. / Thesis Advisor(s): Jenn, David. "September 2008." Description based on title screen as viewed on November 3, 2008. Includes bibliographical references (p. 153-155). Also available in print.

Hochauflösende Verarbeitung von Radardaten mit synthetischer Apertur : 17 Tabellen, 81 Literaturstellen /

Mittermayer, Josef. January 2000 (has links) (PDF)
Universiẗat-Gesamthochsch., Diss.--Siegen, 2000.

Development of the phase synchronization circuit for wirelessly distributed digital phased array

Tsai, Yen-Chang. January 2009 (has links) (PDF)
Thesis (M.S. in Electronic Warfare Systems Engineering)--Naval Postgraduate School, September 2009. / Thesis Advisor(s): Jenn, David C. "September 2009." Description based on title screen as viewed on Novermber 5, 2009. Author(s) subject terms: Radar, Distributed array, Phased Array, Phase Synchronization, Digital Radar, Digital Beamforming (DBF), Wireless Beamforming, Wireless Network Sensor, Aperstructure, Opportunistic Array, LabVIEW, Ballistic Missile Defense (BMD), CG(X), DDG-1000, Network-Centric Warfare (NCW), UAV, Modulator, Demodulator, Filter, Transmit/ Receive (T/R) Module, Leakage Cancellation. Includes bibliographical references (p. 105-108). Also available in print.

Sidelobe canceller jamming using hot-clutter /

Goktun, Sargun. Oruc, Ercan. January 2004 (has links) (PDF)
Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): D. Curtis Schleher. Includes bibliographical references (p. 107-109). Also available online.

Analysis of low probability of intercept (LPI) radar signals using the Wigner Distribution /

Gau, Jen-Yu. January 2002 (has links) (PDF)
Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, September 2002. / Thesis advisor(s): Phillip E. Pace, Herschel H. Loomis, Jr. Includes bibliographical references (p. 145-146). Also available online.

Page generated in 0.3728 seconds