this paper describes the Fast Discrete Curvelet Transform (FDCT) which is integrated into an automated object detection framework capable of fast image processing for the purpose of tracking multiple objects of intere...
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ISBN:
(纸本)9780819497079
this paper describes the Fast Discrete Curvelet Transform (FDCT) which is integrated into an automated object detection framework capable of fast image processing for the purpose of tracking multiple objects of interest. the distinguishing difference between FDCT and other transforms is that the Curvelet coefficients have three beneficial parameters, which define scale, orientation, and spatial locations. We utilize these parameters to efficiently detect relatively small objects in a variety of image and video data sets. We have implemented the FDCT in a multi-stage automatic target recognition (ATR) architecture. the results of the current algorithm yield a highly sensitive detection of smalltargets in noisy backgrounds.
An examination of the application of Space Time Adaptive processing (STAP) techniques to real, multi-channel, medium grazing angle, radar sea clutter data is undertaken and the detection performance is quantified agai...
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ISBN:
(纸本)9780819497079
An examination of the application of Space Time Adaptive processing (STAP) techniques to real, multi-channel, medium grazing angle, radar sea clutter data is undertaken and the detection performance is quantified against simulated moving maritime surface targets. the application of sub-optimal STAP approaches to the maritime radar detection problem is shown to be complicated by non-stationarity of sea clutter and rapid variations of the sea clutter spectrum due to transient wave activity. Observed performance gains from maritime STAP are much more limited than those observed for Ground Moving Target Indication (GMTI) due to the inherent spectral width of sea clutter and the slow Doppler velocities of maritime targets. three sub-optimal STAP processing architectures are examined and PRI-Staggered Post-Doppler is shown to provide consistently superior detection performance for the data set in question.
Tracking moving vehicles has received less attention than its its aerial counterpart. the smooth velocity transitions common to aircraft are replaced with abrupt turns and and speed changes. though the kinematic evolu...
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ISBN:
(纸本)0819459186
Tracking moving vehicles has received less attention than its its aerial counterpart. the smooth velocity transitions common to aircraft are replaced with abrupt turns and and speed changes. though the kinematic evolution of a ground vehicle is more complex, the path is more restricted. For example, if target motion is constrained by a terrain map, the topography should be integrated into the tracking algorithm. this paper shows by means of an example that the Gaussian wavelet estimator is particularly suited to map-enhanced estimation.
In this paper a new method is presented to deal with multiple model filtering. the method is the so called Multiple Model Multiple Hypothesis Filter (MMMH filter). For each hypothesis a Kalman filter is running. this ...
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ISBN:
(纸本)0819441872
In this paper a new method is presented to deal with multiple model filtering. the method is the so called Multiple Model Multiple Hypothesis Filter (MMMH filter). For each hypothesis a Kalman filter is running. this hypothesis represents a specific model mode sequence history. the proposed method has a high level of genericity and is highly flexible. the main feature is that the number of hypotheses that are maintained varies withthe 'difficulty' of a scenario. It is shown that the MMMH performs better than the widely used Interacting Multiple Model (IMM) filter.
Without range measurements, a sensor platform must execute a nontrivial motion if good target location estimates are to be generated with conventional tracking algorithms. this paper shows that even a stationary image...
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ISBN:
(纸本)0819441872
Without range measurements, a sensor platform must execute a nontrivial motion if good target location estimates are to be generated with conventional tracking algorithms. this paper shows that even a stationary image-based tracker can provide good location estimates when the target maneuvers. A tight cover region is generated withthe proposed algorithm, and is compared with a more general bound.
this paper presents the results of a study of tracking algorithms for maneuvering targets. the design focuses on alternative algorithms to track two-dimensional targets during maneuvers. the algorithms explored includ...
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ISBN:
(纸本)0819444782
this paper presents the results of a study of tracking algorithms for maneuvering targets. the design focuses on alternative algorithms to track two-dimensional targets during maneuvers. the algorithms explored include a standard Kalman algorithm, an extended Kalman algorithm in which the target turn rate is an additional state variable, an interactive multiple model (IMM) algorithm consisting of two models with varying plant noise, a three-model IMM specifying three distinct target turn rates, and a constant gain alpha-beta filter. the IMM trackers tended to work the best in this study, withthe three-model IMM performing the best overall.
In the past there was a rapid development of new components for matched filtering of signals with large time-bandwidth-product on the basis of surface acoustic waves (SAW). Such components, as the SAW convolver, allow...
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In the past there was a rapid development of new components for matched filtering of signals with large time-bandwidth-product on the basis of surface acoustic waves (SAW). Such components, as the SAW convolver, allow the realization of fast and precise operating distance measurement systems with a minimum of components in the signalprocessing circuitry. In addition continous wave (CW) radar systems employ a minimum of radiation power. A microcomputer-controlled distance measurement system using a SAW convolver is presented. For data acquisition a special interface circuitry has been realized that allows real-time distance measurement of up to sixteen targets within the observed range. For an improvement of the range accuracy a combination of time-delay and phase measurement is employed.
Cetin(1-2) has applied non-quadratic optimization methods to produce feature-enhanced high-range resolution (ERR) radar profiles. this work concerned ground-based targets and was carried-out in the temporal domain. In...
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ISBN:
(纸本)081945351X
Cetin(1-2) has applied non-quadratic optimization methods to produce feature-enhanced high-range resolution (ERR) radar profiles. this work concerned ground-based targets and was carried-out in the temporal domain. In this paper, we propose a wavelet-based-half-quadratic technique(3) for ground-to-air target identification. the method is tested on simulated data generated by standard techniques(4). this analysis shows the ability of the proposed method to recover high-resolution features such as the locations and amplitudes of the dominant scatterers in the HRR profile. this suggests that the technique potentially may help improve the performance of HRR target recognition systems.
In this paper, two modifications are made to the derivation of the PDAF: one replaces the Poisson distributed false alarms with a binomial distribution, the other involves the assumed distribution of the angular measu...
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ISBN:
(纸本)0819441872
In this paper, two modifications are made to the derivation of the PDAF: one replaces the Poisson distributed false alarms with a binomial distribution, the other involves the assumed distribution of the angular measurements associated with false alarms. the Binomial distribution better fits the kind of data typically seen in radar because the track gate typically, involves a small number of candidate range cells. the second modification is founded on the assumption that the angle-of-arrival estimates are produced with monopulse techniques. Previous work has modeled the false measurements as being uniformly distributed in the uncertainty volume of the track gate, while a more accurate approach recognizes that the angle components of the false alarms are better modeled as Gaussian perturbations about beam center.
data containing the radar signature of amoving person on the ground were collected at ranges of up to 30 km from a moving airborne platform using the DRDC Ottawa X-band Wideband Experimental Airborne Radar (XWEAR). th...
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ISBN:
(纸本)9780819497079
data containing the radar signature of amoving person on the ground were collected at ranges of up to 30 km from a moving airborne platform using the DRDC Ottawa X-band Wideband Experimental Airborne Radar (XWEAR). the human target radar echo returns were found to possess a characteristic amplitude modulated (AM) and frequency modulated (FM) signature which could be usefully characterized in terms of conventional AM and FM modulation parameters. Human detection performance after space time adaptive processing is frequently limited by false alarms arising from incomplete cancellation of large radar cross-section discretes during the whitening step. However, the clutter discretes possess different modulation characteristics from the human targets discussed above. the ability of pattern classification techniques to use this parameter measurement space to distinguish between human targets and clutter discretes is explored and preliminary results presented.
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