Authors:
Mikio Ikeda,
Kazuya Takeda,
Fumitada Itakura,
Page (NA) Paper number 1820
Abstract:
This paper proposes the use of band-limited random sequences to introduce
further flexibility in the spread spectrum based audio data hiding.
To realize the sub-band data hiding, a systematic method is developed
in order to generate band-limited and orthonormal random sequences
of any length. In experiments, we evaluated the selective use of frequency
channels to be used for information embedding, and the robustness against
the MPEG1 layer 3 encoding and decoding. From the results, it is clarified
that the proposed method is robust against more than 160 kbps MPEG1
coding and decoding when the center frequency of the sub-band is lower
than 11 kHz.
Authors:
Michael A Koets,
Randolph L Moses,
Page (NA) Paper number 2438
Abstract:
We consider the problem of estimating a parametric model that describes
radar backscattering from synthetic aperture radar imagery. We adopt
a scattering center model that incorporates both frequency and aspect
dependence of scattering. We develop an approximate maximum likelihood
algorithm for parameter estimation directly on regions of the SAR image.
The algorithm autonomously selects model order and structure. Results
are presented for both synthetic and measured SAR imagery, and algorithm
accuracy is compared with the Cramer-Rao bound.
Authors:
Stephen M Kogon,
Daniel J Rabideau,
Richard M Barnes,
Page (NA) Paper number 2116
Abstract:
The mission of a ground moving target indication (GMTI) radar, as its
name implies, is to detect and classify ground-based vehicles, even
ones with very low velocities. This type of radar can provide a wide
area of coverage and frequent updates of a specific area of interest
if the radar is placed in a low earth orbit. However, because of the
large footprint of the radar on the ground and the high satellite velocity,
target signals must compete with very strong, nearby clutter. This
paper describes how space-time adaptive processing (STAP) can be used
for the purposes of clutter rejection in order to perform the GMTI
function. In addition, we confront several important issues for a space-based
radar such as pulse repetition frequency (PRF) selection, the choice
of a STAP algorithm, and the number of spatial channels. These results
are quantified in terms of clutter cancellation and angle accuracy.
Authors:
Ping Gao, Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708-0291 (U.K.)
Leslie M Collins, Department of Electrical and Computer Engineering, Duke University, Durham NC 27708-0291 (U.K.)
Norbert Geng, Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708-0291 (U.K.)
Lawrence Carin, Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708-0291 (U.K.)
Dean A Keiswetter,
I. J Won,
Page (NA) Paper number 1783
Abstract:
Our previous work has indicated that the careful application of signal
detection theory can dramatically improve detectability of landmines
using time-domain electromagnetic induction (EMI) data [L. Collins,
P. Gao, and L. Carin, IEEE Trans. Geosc. Remote Sens., in press]. In
this paper, classification of various metal targets via signal detection
theory is investigated using a prototype wideband frequency-domain
EMI sensor [I.J. Won, D.A. Keiswetter, and D.R. Hansen, J. Envir. Engin.
Geophysics, 2:53-64 (1997)]. An algorithm that incorporates both the
uncertainties regarding the target-sensor orientation and a theoretical
model of the response of such a sensor is developed. The performance
of this approach is evaluated using both simulated and experimental
data. The results show that this approach affords substantial classification
performance gains over the traditional matched filter approach, on
the average by 60%.
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