Results 11 to 20 of about 16,290 (166)

Micro-Motion Parameter Extraction of Multi-Scattering-Point Target Based on Vortex Electromagnetic Wave Radar

open access: yesRemote Sensing, 2022
In addition to traditional linear Doppler shift, the angular Doppler shift in vortex electromagnetic wave (VEMW) radar systems carrying orbital angular momentum (OAM) can provide more accurate target identification micro-motion parameters, especially the
Lijun Bu   +5 more
doaj   +1 more source

Research on Calculation Method of Doppler Centroid Shift from Airborne Synthetic Aperture Radar for Ocean Feature Retrieval

open access: yesLeida xuebao, 2019
Doppler center shift is an important parameter for Synthetic Aperture Radar(SAR) to retrieve ocean surface wind field and ocean surface current field. We present a calculation method of Doppler centroid shift for airborne side-looking SAR.
ZHAO Xianbin   +4 more
doaj   +1 more source

A Novel Waveform Design Method for Shift-Frequency Jamming Confirmation

open access: yesInternational Journal of Antennas and Propagation, 2018
Shift-frequency jamming is generally used to form range false targets for ground-based early-warning radar systems; the frequency shift value of such interference is larger than the Doppler shift value of the moving target, and the key element to ...
Chang Zhou, Zhen-Bo Zhu, Zi-Yue Tang
doaj   +1 more source

Evaluating the effectiveness of Doppler frequency shift determination using pilots in broadband transmission [PDF]

open access: yesInternational Journal of Electronics and Telecommunications
In underwater communications, reciprocal motion between transmitter and receiver has a significant impact on reception quality. In orthogonal broadband systems that provide high bit rates, this problem becomes more important, especially in the higher ...
Agnieszka Czapiewska   +4 more
doaj   +1 more source

Robust Underwater Acoustic Communication Using the Overlapped Chirp Spread Carrier Technique in Doubly Spread Environments

open access: yesIEEE Access, 2023
The performance of underwater acoustic communication is significantly affected by multipath propagation and Doppler spread. In this paper, we propose a new communication technique called overlapped chirp spread carrier (OCSC) by modifying the existing ...
Chang-Hyun Youn   +3 more
doaj   +1 more source

Cell ID and Timing Estimation Techniques for Underwater Acoustic Cellular Systems in High-Doppler Environments

open access: yesSensors, 2020
In an underwater acoustic cellular (UAC) system, underwater equipment or sensor nodes need to detect the identity of an underwater base station (UBS) and synchronise it with a serving UBS. It is known that, in an underwater acoustic channel, the temporal
Muhammad Asim   +3 more
doaj   +1 more source

The Doppler effect induced by earthquakes: A case study of the Wenchuan MS8.0 earthquake

open access: yesGeodesy and Geodynamics, 2022
Seismologists have found that the first arrival frequencies of P waves at different seismic stations have different widths, that is, different periods or frequencies, and they think that this phenomenon can be used to identify whether a Doppler effect is
Qicheng Li   +3 more
doaj   +1 more source

Research of Mobile Underwater Acoustic Communication of M-Ary Combining FDM and Piecewise-LFM

open access: yesXibei Gongye Daxue Xuebao, 2019
Aiming at the countering doppler shift, a mobile underwater acoustic communication scheme of M-ary via FDM-PLFM is proposed. The cross-correlation between piecewise linear frequency modulation(PLFM) and traditional LFM signal is analyzed based on the ...

doaj   +1 more source

Doppler Stretch and Delay Statistical Performance Comparison for Wideband and Narrowband Signal Model

open access: yesИзвестия высших учебных заведений России: Радиоэлектроника, 2018
Narrowband approximation of Doppler effect by a frequency shift is inappropriate for some problems of radiolocation, hydro acoustics or passive location.
I. V. Gogolev
doaj   +1 more source

Folded Chirp-Rate Shift Keying Modulation for LEO Satellite IoT

open access: yesIEEE Access, 2019
In the low earth orbit (LEO) satellite Internet of Things (IoT), the IoT devices can be distributed in remote areas (e.g., desert, ocean, and forest) for some special applications, where they are unable to have direct terrestrial network accesses and can
Chao Yang   +3 more
doaj   +1 more source

Home - About - Disclaimer - Privacy