The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We consider the the detection problem of the polarimetric MIMO radar in the presence of the arbitrary correlated, possibly non-identically distributed target backscattered echoes, which is often appeared in both the transmit-receive (T-R) pairs and the different polarimetric channels. We obtain a fully adaptive detector employing two-step design strategy. Specifically, we first derive the Generalized...
This paper considers the target detection problem using the distributed polarimetric MIMO (P-MIMO) radar in the presence of spatially heterogeneous clutter. The polarimetric covariance matrices (PCMs) of the primary and the secondary data are assumed to be random with partial priori knowledge of the environment, sharing some appropriate joint distribution. Two-step strategy is employed to design adaptive...
Constant False Alarm Rate (CFAR) is commonly used in RADAR and SONAR to detect targets in different clutter situations. We aim to design a CFAR detector to be used in FMCW radar which is easily configurable and is best suited to its operational environment. Mathematical formulation and MATLAB simulation of six different CFAR detectors are presented in this paper. The performance of these detectors...
We endeavor to obtain the number of equivalent independent samples when the available samples are correlated in radar received system. Comparing the estimated matrix of independent secondary samples with that of correlated secondary samples, in several correlation coefficients, we obtain the equivalent independent number without an information loss.
According to the continuous time-frequency characteristic of linear frequency modulated (LFM) signals, a detection method based on Short-Time Fourier Transform (STFT) and a new Constant False Alarm Rate (CFAR) detector is proposed. The input signals are short-time Fourier transformed to achieve coherent integration of frequency-shift sample sequences with complex envelopes, modular square of which...
Ship detection is nowadays quite an important issue in tasks related to sea traffic control, fishery management and ship search and rescue. Although it has traditionally been carried out by patrol ships or aircrafts, coverage and weather conditions can become a problem. Synthetic aperture radars can surpass these coverage limitations and work under any climatological condition. Two ship detectors...
In this paper, the problem of the incoherent detection of targets with unknown parameters in K-distributed clutter is tackled. Multilayer Perceptron (MLP) based detectors are designed to approximate the Average Likelihood Ratio (ALR) based one, which implements the Neyman-Pearson optimum detector for the defined composite hypothesis test problem. Conventional solutions such as the linear law and Constant...
To robustly detect people in a video sequence is hard due to various challenges. One of the most successful discriminative features for finding people goes to the Histograms of Oriented Gradients (HOG). Although the major contour information is encoded in the HOG feature well, the background clutter disturbs the gradient information. Thus, an extension of HOG, called histograms of oriented gradient...
This paper tackles the detection of Swerling I targets with unknown Doppler shift in colored Gaussian interference. If the radar illuminated area is enough large, a Gaussian clutter model can be assumed. The average likelihood ratio has been formulated and sub optimum approaches based on the Constrained Generalized Likelihood Ratio (CGLR) analyzed. CGLR detectors have been considered as references...
This paper carries out a study of the suitability of Neural Networks (NN) as solutions for the problem of detecting Gaussian targets with unknown one-lag correlation coefficient (?s) in different radar clutter environments (Additive White Gaussian Noise (AWGN) and correlated Gaussian clutter plus AWGN). The optimum Neyman-Pearson detector is formulated assuming an uniform variation of ?s -- [0, 1]...
Multiple input multiple output (MIMO) radar systems employ multiple transmit and receive elements with transmit elements that have the ability to transmit arbitrary waveforms simultaneously and receive elements that have the ability to process all of the transmitted signals jointly. For ground moving target indication (GMTI) systems, MIMO offers the potential to improve angular resolution and illumination...
We design a parametric multicarrier phase-coded (MCPC) waveform that achieves the optimal performance in detecting an extended target in the presence of signal-dependent interference. Traditional waveform design techniques provide only the optimal energy spectral density of the transmit waveform and suffer a performance loss in the synthesis process of the time-domain signal. Therefore, we opt for...
We deal with the performance prediction of the conventional cell-averaging constant false alarm rate (CA-CFAR) detector in the presence of non-independent identically distributed (non-iid) target backscattered echoes. Accounting for the generalized Swerling-Chi fluctuation target model, we develop the analytical expressions for the target detection probability for CA-CFAR detector. Finally, we assess...
Traditionally, the land or sea clutter with unknown covariance matrix is generally modeled as compound-Gaussian distribution with completely correlated texture in high-resolution (HR) radar. However, the detailed study on the measured clutter data from the search radar exhibits that the clutter satisfies compound-Gaussian distribution with partially correlated texture. The paper mainly addresses adaptive...
In this paper, we focus on the performance improvement of constant false alarm rate (CFAR) detector in heterogeneous Compound-Gaussian background. This paper is motivated by the fact that the detectors' performance degradation when an unknown located clutter edge exists in the reference window that divide the data samples into two different independent and identically distributed (IID) Compound-Gaussian...
The illicit importation, development and deployment of nuclear or radiological dirty bombs poses a serious threat to the United States. Portal monitoring and inspection systems provide a major domestic layer of defense. Once radiological materials are inside the country, the detection, localization and identification of these threats becomes increasingly more difficult due to complex radiological...
We propose novel features, denoted as string features, which are represented by curves in the image plane. The string features take advantage of its locality at individual points of the curve and of its global aspect when considering the whole curve. The contributions of this paper are: (1) a feature detection procedure which produces a saliency measure by applying a novel technique, named geodesic...
The Probability Hypothesis Density (PHD) filter is a multi-object Bayes filter which has recently attracted a lot of interest in the tracking community mainly for its linear complexity and its ability to deal with high clutter especially in radar/sonar scenarios. In the computer vision community however, underlying constraints are different from radar scenarios and have to be taken into account when...
the problem of adaptive detection of spatially distributed targets or targets embedded in no homogeneous clutter with unknown covariance matrix is studied. At first, assume the clutter is complex circular zero-mean Gaussian clutter with an unknown positive definite covariance matrix, and it is independent of the covariance matrix vector under test, the secondary data are assumed to be random, then...
In this paper, we consider an adaptive subspace detector for partially homogeneous environments. In this environment, the clutter covariance matrix (CCM) of secondary data is equal to the CCM of the cell under test (CUT), except for a real constant factor. We also suppose that we have some prior knowledge of the CCM, and the prior knowledge is controlled by the parameters of the statistical distribution...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.