نتایج جستجو برای: doppler shift

تعداد نتایج: 180836  

Journal: :CoRR 2007
Ali Pezeshki A. Robert Calderbank William Moran Stephen D. Howard

We describe a method of constructing a sequence of phase coded waveforms with perfect autocorrelation in the presence of Doppler shift. The constituent waveforms are Golay complementary pairs which have perfect autocorrelation at zero Doppler but are sensitive to nonzero Doppler shifts. We extend this construction to multiple dimensions, in particular to radar polarimetry, where the two dimensi...

2010
Akos Ledeczi Janos Sallai

This paper introduces a novel method for bearing estimation based on a rotating antenna generating a Doppler shifted RF signal. The small frequency change can be measured even on low cost resource constrained nodes using a radio interferometric technique introduced previously. Measuring the Doppler shift at two known locations provides a bearing estimate to the rotating node. An alternative app...

2016
Antonios N Pouliopoulos James J Choi

The introduction of microbubbles in focused ultrasound therapies has enabled a diverse range of non-invasive technologies: sonoporation to deliver drugs into cells, sonothrombolysis to dissolve blood clots, and blood-brain barrier opening to deliver drugs into the brain. Current methods for passively monitoring the microbubble dynamics responsible for these therapeutic effects can identify the ...

1997
Trym Eggen

by Trym H. Eggen Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1997 This work is concerned with coherent communication by means of acoustic signals over underwater communication channels. The estimated scattering functions of real data ranging from the Arc...

2001
Ilir F. Progri

An innovative navigation algorithm, which utilizes a system of fixed pseudolites is derived, analyzed, discussed, and simulated in this paper. Although this algorithm uses the same Doppler measurements as a conventional least square algorithm LSA (which produces user velocity and ION NTM 2001, 22-24 January 2001, Long Beach, CA 61 user clock drift) or Kalman based filter (which obtains user pos...

Journal: :Applied optics 2015
O Jacquin E Lacot O Hugon H Guillet de Chatelus

This paper proposes what we believe is a new method to remove the contribution of parasitic reflections in the images of the laser optical feedback imaging (LOFI) technique. This simple method allows us to extend the LOFI technique to long-distance applications, as imaging through a fog or a smoke. The LOFI technique is an ultrasensitive imaging technique that is interesting for imaging objects...

2011
Swati Chowdhuri Arun Kumar Mondal

MIMO technologies are beneficial for Mobile ad-hoc networks by providing the diversity and capacity advantage as well as spatial degree of freedom in designing MAC protocol. The integration of MIMO technology in the area of mobile ad-hoc network has great attenuation in commercial and military application. Most important event in wireless communication is the advent of MIMO technologies which u...

Journal: :IET Communications 2013
Hassan A. Ahmed Ahmed Iyanda Sulyman Hossam S. Hassanein

The bit-error-rate (BER) performance of orthogonal frequency division multiplexing (OFDM) systems in mobile multihop relaying (MMR) system is severely degraded by the effect of Doppler shift and the severity of this degradation increases with the number of hops traversed by the OFDM signal. In this study, the authors propose a method to mitigate the effect of Doppler shift in MMR system (such a...

2009
T. J. Wang

Aims. We report the first observation of multiple-periodic propagating disturbances along a fan-like coronal structure simultaneously detected in both intensity and Doppler shift in the Fe xii 195 Å line with the EUV Imaging Spectrometer (EIS) onboard Hinode. A new application of coronal seismology is provided based on this observation. Methods. We analyzed the EIS sit-and-stare mode observatio...

Journal: :J. Electronic Imaging 1998
Steven Noel Harold Szu

In this paper we introduce wavelet video processing of proximity sensor signals. Proximity sensing is required for a wide range of military and commercial applications, including weapon fuzing, robotics, and automotive collision avoidance. While our proposed method temporarily increases signal dimension, it eventually performs data compression through the extraction of salient signal features. ...

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