The target micro-motion features contain unique structural information and motion information, which can be utilized as an important basis for target recognition. At present, the main constraints of micro-motion featu...
ISBN:
(数字)9781728123455
ISBN:
(纸本)9781728123462
The target micro-motion features contain unique structural information and motion information, which can be utilized as an important basis for target recognition. At present, the main constraints of micro-motion feature extraction for high-speed targets include that the translational compensation is inaccurate, the scattering points are difficult to distinguish, the micro-motion amplitude is small, the data rate is not high enough, and so forth. The phase-derived velocity measurement (PDVM) method based on wideband radar has phase-magnitude velocity measurement precision, which can accurately reconstruct the target motion while ensuring high data rate, and meet the micro-motion measurement requirements of high-speed targets. In this paper, a PDVM method for high-speed targets based on wideband direct sampling LFM radar is proposed. The high-precision velocity measurement performance and micro-motion measurement capability of the proposed method are verified by simulation.
Three-dimensional high-resolution imaging is a new technology for long-range detection of underwater smalltargets, This technology enables three-dimensional mapping of targets in water, sinking and buried environment...
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ISBN:
(纸本)9781728117096
Three-dimensional high-resolution imaging is a new technology for long-range detection of underwater smalltargets, This technology enables three-dimensional mapping of targets in water, sinking and buried environments. The three-dimensional imaging sonar adopts the ultra-wideband low-frequency emission array with large glancing angle and the two-dimensional acoustic array with wide directivity reception, which effectively acquires underwater target depth dimension, navigation dimension and azimuth dimension information. The pulse compression processing, synthetic aperture tomography processing, and anti-reverberation high-resolution array processing are used to realize three-dimensional high-resolution imaging of underwater targets. However, since the underwater echoes come from different azimuths, depths, and media environments, the significant difference causes the reverberation of the target image area to be severely unbalanced, which directly affects the background brightness and feature contrast of the target image area, and ultimately increases the artificial identify the risk of errors. In this paper, A three-dimensional image processing method based on data layered two-dimensional normalization is studied. Firstly, by tracking the three-dimensional seabed interface, the distribution law of seafloor reflection echo energy in different azimuths is statistically obtained. Then, the acoustic energy attenuation loss of different geological strata is compensated. After that, the dynamic range of the three-dimensional acoustic image and the target feature contrast are improved by the two-dimensional normalization processing of the layered water and the stratum. The method has been processed and verified by experimental data, so as to achieve stable and efficient realization of 3D acoustic image background equalization and target enhancement, which has strong robustness, certain innovation and good engineering use value.
交通信号灯的检测在无人驾驶以及辅助驾驶中起着至关重要的作用,然而传统的图像处理方法因为速度和检测质量的原因,往往不能达到应用于无人驾驶系统的程度。同时交通信号灯属于小目标,因此检测难度大。所以本文提出了一种基于单阶段目标检测算法,该算法对YOLOv5(You only look once)算法进行了改进,保留了YOLOv5检测速度快以及搭建简单的优点,结合注意力模型将检测的重点放在交通信号灯检测上,使得对交通信号灯的检测更加的快速准确。该实验在LISA交通信号灯数据集上取得了显著的效果,进一步证明了我们算法的有效性。
The low, slow, and small (LSS) target detection has always been a problem for both ground-based and air-borne radar systems. The factors such as weak target reflection energy, ground clutter, and random Doppler compon...
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Detecting and tracking moving targets in synthetic aperture radar (SAR) data is a challenging task, demanding state-of-the-art processing methods and advanced SAR systems. Current approaches concentrate on the problem...
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Detecting and tracking moving targets in synthetic aperture radar (SAR) data is a challenging task, demanding state-of-the-art processing methods and advanced SAR systems. Current approaches concentrate on the problem of either endo-clutter moving target tracking or exo-clutter moving target tracking, neglecting the advantages of a joint tracking framework. We present an approach relying on a combined exo-and endo-clutter processing scheme using SAR data with a high pulse repetition frequency. The main processing chain is subdivided into four major steps: 1) focusing of temporal and spatial overlapping SAR images;2) extracting image statistics for each of these subaperture images in the endo-and exo-clutter domains;3) subsequent tracking of both endo-and exo-clutter observations using multitarget unscented Kalman filtering;and 4) calculating real-world speeds and positions from the SAR image space coordinates using a road network. The results of this approach are validated and compared with ground-based measurements, and it is found that 100% of the vehicles were detected correctly with an accuracy in speed of 0.02 +/- 0.31 m/s and an average tracking time of similar to 28 s.
作者:
Gleich, DusanUniv Maribor
Lab Signal Proc & Remote Control Fac Elect Engn & Comp Sci Maribor 2000 Slovenia
Synthetic aperture radar (SAR) images are affected by a speckle noise, which is a consequence of random fluctuations in the return signal from an object that is no bigger than a single image processing element and it ...
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Synthetic aperture radar (SAR) images are affected by a speckle noise, which is a consequence of random fluctuations in the return signal from an object that is no bigger than a single image processing element and it is caused by coherent processing of backscattered signals from multiple distributed targets. Speckle within SAR images can be reduced using filtering methods. To preserve features within the SAR images, this paper proposes a noise removal based on scene and SAR data modeling. The proposed method is a model-based total variational optimization with the minimization of a cost function. The cost function consisted of enera and data fidelity terms. The energy term was modeled using optimal-dual-based l(1) analysis. The data fidelity term modeled the amplitude of the SAR data, which was approximated using a Nakagami distribution. The minimization of the cost function was solved using a quasi-Newton approach. The experimental results showed good results in SAR feature preservation. The proposed method was evaluated numerically using quality metrics for synthetic generated data and real amplitude SAR data.
Due to the non-stationary nature of sea clutter, traditional maritime radar detection schemes utilise non-coherent processing. To further enhance the detection performance, one alternative is to use sparse signal sepa...
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ISBN:
(纸本)9781538672174
Due to the non-stationary nature of sea clutter, traditional maritime radar detection schemes utilise non-coherent processing. To further enhance the detection performance, one alternative is to use sparse signal separation. This is an alternative paradigm, whereby the different spatio-temporal characteristics of the radar signal are exploited to separate targets from the background interference. In previous work, the sparse signal separation problem has been posed in a compressive sensing framework so as to improve detection of small maritime targets. This paper investigates the performance of three different algorithms for solving the signal separation problem. These include the Split Augmented Lagrangian Shrinkage Algorithm (SALSA), adaptive Complex Approximate Message Passing (CAMP) and the Fast Sparse Functional Iteration Algorithm (FSFIA). The first contribution is to reformulate the CAMP algorithm to the framework of sparse signal separation. The suitability of each algorithm is then assessed using real data from the Ingara radar, and is based on the quality of the solutions obtained, the computational speed and the robustness to the user's choice of 'tuning' parameters.
Aiming at improving the real-time performance of infrared weapon systems, a method based on block compressed sensing is proposed to detect infrared small target, which is also easy to be implemented with hardware. The...
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ISBN:
(纸本)9783319638560;9783319638553
Aiming at improving the real-time performance of infrared weapon systems, a method based on block compressed sensing is proposed to detect infrared small target, which is also easy to be implemented with hardware. The proposed method can detect and locate small infrared targets by classifying compressed results of blocks. In addition, in order to solve the low detection accuracy caused by using uniform block, the proposed method uses overlapping blocks to reduce the maximum distance between the center of the test sample block and that of the target. Experiments show that the proposed method can effectively improve the detection accuracy of infrared smalltargets.
small target detection is a problem common to a diverse number of fields such as radar, remote sensing, and infrared imaging. In this paper, we consider the application of feature extraction for detection of small haz...
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ISBN:
(数字)9781510618046
ISBN:
(纸本)9781510618046
small target detection is a problem common to a diverse number of fields such as radar, remote sensing, and infrared imaging. In this paper, we consider the application of feature extraction for detection of small hazardous materials in multiwavelength imaging. Since various materials may exist in the area of study each with varying degrees of reflectivity and absortion at different wavelengths of light, flexible, data-driven methods are needed for feature extraction of relevant sources. We propose the use of independent component analysis (ICA), a widely-used blind source separation method based on the statistical independence of the underlying sources. We compare 3 different prominent flavors of ICA on simulated data in a variety of environments. Then, we apply ICA to 2 multi-wavelength imaging datasets with results that suggest that features extracted are useful.
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