For the extremely small size and low signal-to-clutter ratio, target detection in infrared images is still a considerable challenge. Specifically, it is very difficult to detect the point targets because there is no t...
详细信息
For the extremely small size and low signal-to-clutter ratio, target detection in infrared images is still a considerable challenge. Specifically, it is very difficult to detect the point targets because there is no texture and shape information can be used. A target-oriented shallow-deep feature-based detection algorithm is proposed, opening up a promising direction for convolutional neural network-based infrared dim small target detection algorithms. To ensure that small target instances can be used correctly for networks, the effective small anchor is designed according to the shallow layer of ResNet50. To determine whether a detection result belongs to the target, the authors depend on whether the detection centre is included in the ground truth area, rather than on the Intersection Over Union overlap rate, which avoids misjudging the detection result. In this way, smalltargets can be trained and detected correctly through ResNet50. More importantly, the authors demonstrate that spatially finer shallow features are crucial for small target detection and that semantically stronger deep features are helpful for improving detection probability. Experimental results on simulation data sets and real data sets show that the proposed algorithm can detect the point target when the local signal-to-clutter ratio is approximately 1.3, displaying infinite advantage and great potentiality.
The assumption of Gaussian noise in the system and measurement model has been standard practice for target tracking algorithm development for many years. For problems involving manoeuvring targets this is known to be ...
详细信息
ISBN:
(纸本)081945351X
The assumption of Gaussian noise in the system and measurement model has been standard practice for target tracking algorithm development for many years. For problems involving manoeuvring targets this is known to be an over-simplification and a potentially poor approximation. In this paper the use of heavy-tailed distributions is suggested as a means of efficiently modelling the behaviour of manoeuvring targets with a single dynamic model. We exploit the fact that all heavy-tailed distributions can be written as scale mixture of Normals to propose a Rao-Blackwellised particle filter (SMNPF) where particles sample the history of the continuous scale parameter and a Kalman filter is used to conduct the associated filtering for each particle. Schemes are proposed for making the proposal of new particles efficient. Performance of a heavy-tailed system model implemented via the SMNPF filter is compared against an IMM for a sample trajectory taken from a benchmark problem.
In passive detection of small infrared targets in image data, we are faced with the difficult task of enhancing some characteristic of the target or signal while suppressing the clutter or background image noise. We r...
详细信息
ISBN:
(纸本)0819408638
In passive detection of small infrared targets in image data, we are faced with the difficult task of enhancing some characteristic of the target or signal while suppressing the clutter or background image noise. We reported that an effective means by which targets may be identified is to exploit characteristics which exist between scenes measured in different bands in the long wave infrared region of the electromagnetic spectrum. These methods are broadly termed multispectral techniques. In this paper we present a method by which a two- dimensional least-mean square adaptive filter is used to distinguish between target and clutter using multispectral techniques.
The measurements of the two closely-spaced targets will be merged when the target echoes are not resolved in angle, range, or radial velocity (i.e., Doppler processing). The modified Cramer Rao lower bound (CRLB) is g...
详细信息
ISBN:
(纸本)0819432954
The measurements of the two closely-spaced targets will be merged when the target echoes are not resolved in angle, range, or radial velocity (i.e., Doppler processing). The modified Cramer Rao lower bound (CRLB) is given for monopulse direction-of-arrival (DOA) estimation for two unresolved Rayleigh targets and used to give insight into the antenna boresight pointing. A monopulse processing technique is given for DOA estimation of two unresolved Rayleigh targets. The Nearest Neighbor Joint Probabilistic data Association Algorithm (NNJPDA) algorithm is extended to include the possibility of merged monopulse measurements of Rayleigh targets. The monopulse signals are incorporated into the data association as a feature to discriminate between merged and resolved measurements.
This paper proposes an algorithm for estimating the fractal dimension of real sea bistatic synthetic aperture radar data. The algorithm is based on the use of the fractal dimension estimated by the box counting method...
详细信息
This paper proposes an algorithm for estimating the fractal dimension of real sea bistatic synthetic aperture radar data. The algorithm is based on the use of the fractal dimension estimated by the box counting method to detect the sub-data which contain the targets. Based on this approach, the performance of the fractal detector proposed in this paper was demonstrated by the evaluation of the probability of detection by means of Monte Carlo simulation and was verified that we can use the fractal dimension to distinguish between targets and clutter, even for a smallsignal-to-noise ratio.
The effect of the crosscovariance in track-to-track fusion has been studied in [2] [3] [4] [5]. Ignoring the crosscovariance of the local track estimation errors leads to optimistic covariance for the fused state esti...
详细信息
ISBN:
(纸本)081945351X
The effect of the crosscovariance in track-to-track fusion has been studied in [2] [3] [4] [5]. Ignoring the crosscovariance of the local track estimation errors leads to optimistic covariance for the fused state estimates. However, evaluation of this crosscovariance is too demanding. Consequently, we approximate the crosscovariances between two sensors' track estimation errors in a manner similar to one of the procedures presented in [2], namely, with constant crosscorrelation coefficients. The results of using this in a practical naval surveillance system are discussed by comparing the exact covariances;of the fused tracks, the covariances obtained with the approximation and the covariances obtained by completely ignoring the crosscorrelations.
In this paper, we apply higher ordered statistics filters to hyperspectral data to enable the detection of anomalous targets whose signatures are known. Each frame has subtracted from it an estimate based on an ordere...
详细信息
In this paper, we apply higher ordered statistics filters to hyperspectral data to enable the detection of anomalous targets whose signatures are known. Each frame has subtracted from it an estimate based on an ordered statistics filter;the resulting frames are then combined optimally based on the covariance data of the cube and the spectral signature of the target. We show that the effect of the ordered statistic filter is to eliminate false alarms at edge points.
Sea clutter in marine surveillance radar makes the task of detecting smalltargets a very challenging problem. In this paper, a set of three signalprocessing techniques designed to suppress unwanted sea clutter radar...
详细信息
Sea clutter in marine surveillance radar makes the task of detecting smalltargets a very challenging problem. In this paper, a set of three signalprocessing techniques designed to suppress unwanted sea clutter radar echo and achieve target detection with no prior knowledge of the ocean and environmental conditions is presented. These include signal averaging, time-frequency representation, and morphological filtering. datasets from real marine radar operating in staring mode are used to illustrate the performance of the new approaches.
A use of automatic acquisition and tracking for electro-optic fire control is described. The techniques used for detection of targets and rounds are described. Additionally test results obtained during Navy testing ar...
详细信息
ISBN:
(纸本)0819408638
A use of automatic acquisition and tracking for electro-optic fire control is described. The techniques used for detection of targets and rounds are described. Additionally test results obtained during Navy testing are described.
Radar signalprocessing is a key part in tracking closely spaced targets and targets in the presence of sea-surface-induced multipath. These issues are the salient features of the benchmark problem for tracking unreso...
详细信息
ISBN:
(纸本)0819450774
Radar signalprocessing is a key part in tracking closely spaced targets and targets in the presence of sea-surface-induced multipath. These issues are the salient features of the benchmark problem for tracking unresolved targets combined with radar management, for which this paper presents the only complete solution to date. In this paper a modified version of a recently developed "superresolution" maximum likelihood (ML) angle estimator for closely spaced targets as well as targets in the presence of multipath are presented. Efficient radar resource allocation algorithms for two closely spaced targets and targets flying close to the sea surface are also presented. Finally, the IMMPDAF (interacting multiple model estimator with probabilistic data association filter modules) is used to track these targets. It is found that a two-model IMMPDAF performs better than the three model version used in the previous benchmark. Also, the IMMPDAF with a coordinated turn model works better than the one using a Wiener process acceleration model. The signalprocessing and tracking algorithms presented here, operating in a feedback manner, form a comprehensive solution to the most realistic tracking and radar management problem to date.
暂无评论