中国科学院机构知识库网格系统: 检索

Separating Scholte Wave and Body Wave in OBN Data Using Wave-Equation Migration 期刊论文 OAI收割
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 2022, 卷号: 60, 页码: 13
作者: Li, Chao; Wang, Yuan; Zhang, Jinhai; Geng, Jianhua; You, Qingyu

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收藏 | 浏览/下载：58/0 | 提交时间：2022/07/18

Surface waves Sea surface Filtering Imaging Cutoff frequency Background noise Underwater vehicles Body wave demigration migration ocean bottom node (OBN) Scholte wave wavefield separation

Effect of background parabolic current on characteristics and energetics of internal solitary waves by numerical simulation 期刊论文 OAI收割
ACTA OCEANOLOGICA SINICA, 2016, 卷号: 35, 期号: 1, 页码: 2016-01-10
作者: Lu Haibin; Xie Jieshuo; Yao Yuan; Xu Jiexin; Chen Zhiwu

收藏 | 浏览/下载：29/0 | 提交时间：2016/12/27

internal solitary waves background current baroclinic energy South China Sea

A new algorithm based on the background field for red tide monitoring in the East China Sea 期刊论文 OAI收割
ACTA OCEANOLOGICA SINICA, 2014, 卷号: 33, 期号: 5, 页码: 62-71
Xu, XH; Pan, DL; Mao, ZH; Tao, BY

收藏 | 浏览/下载：28/0 | 提交时间：2014/12/11

red tide remote sensing background field East China Sea

Research on infrared dim-point target detection and tracking under sea-sky-line complex background (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Dong Y.-X.; Zhang H.-B.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：111/0 | 提交时间：2013/03/25

Target detection and tracking technology in infrared image is an important part of modern military defense system. Infrared dim-point targets detection and recognition under complex background is a difficulty and important strategic value and challenging research topic. The main objects that carrier-borne infrared vigilance system detected are sea-skimming aircrafts and missiles. Due to the characteristics of wide field of view of vigilance system the target is usually under the sea clutter. Detection and recognition of the target will be taken great difficulties.There are some traditional point target detection algorithms such as adaptive background prediction detecting method. When background has dispersion-decreasing structure the traditional target detection algorithms would be more useful. But when the background has large gray gradient such as sea-sky-line sea waves etc.The bigger false-alarm rate will be taken in these local area.It could not obtain satisfactory results. Because dim-point target itself does not have obvious geometry or texture feature in our opinion from the perspective of mathematics the detection of dim-point targets in image is about singular function analysis.And from the perspective image processing analysis the judgment of isolated singularity in the image is key problem. The foregoing points for dim-point targets detection its essence is a separation of target and background of different singularity characteristics.The image from infrared sensor usually accompanied by different kinds of noise. These external noises could be caused by the complicated background or from the sensor itself. The noise might affect target detection and tracking. Therefore the purpose of the image preprocessing is to reduce the effects from noise also to raise the SNR of image and to increase the contrast of target and background. According to the low sea-skimming infrared flying small target characteristics the median filter is used to eliminate noise improve signal-to-noise ratio then the multi-point multi-storey vertical Sobel algorithm will be used to detect the sea-sky-line so that we can segment sea and sky in the image. Finally using centroid tracking method to capture and trace target. This method has been successfully used to trace target under the sea-sky complex background. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Paleosalinity in the Tianluoshan site and the correlation between the Hemudu culture and its environmental background 期刊论文 OAI收割
JOURNAL OF GEOGRAPHICAL SCIENCES, 2010, 卷号: 20, 期号: 3, 页码: 441-454
作者: Li Minglin; Mo Duowen; Mao Longjiang; Sun Guoping; Zhou Kunshu

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收藏 | 浏览/下载：38/0 | 提交时间：2018/09/26

The Tianluoshan Site The Hemudu Culture Paleosalinity Environmental Background Relative Sea Level

Paleosalinity in the Tianluoshan site and the correlation between the Hemudu culture and its environmental background 期刊论文 OAI收割
JOURNAL OF GEOGRAPHICAL SCIENCES, 2010, 卷号: 20, 期号: 3, 页码: 441-454
作者: Li Minglin; Mo Duowen; Mao Longjiang; Sun Guoping; Zhou Kunshu

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收藏 | 浏览/下载：21/0 | 提交时间：2018/09/26

The Tianluoshan Site The Hemudu Culture Paleosalinity Environmental Background Relative Sea Level

Extracting sea-sky-line based on improved local complexity (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: Zhang Y.-F.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

Sea-sky-line extraction under complicated sea-sky background is an important aspect of long-range target tracking research. An algorithm based on improved local complexity is proposed according to the feature that the sky and the sea usually show up at different gray levels in sea-sky background images. Median filter is applied first to remove peak noise and then the point set of sea-sky-line region which has the greatest change in image is obtained by calculating the local complexity of image and selecting a segmentation threshold. Finally Hough transform is used to extract the sea-sky-line. The experiment results indicate that this method can extract sea-sky-line under simple and complicated sea-sky backgrounds which is robust and can improve noise immunity of the algorithm. 2010 IEEE.

Research on tracking approach to low-flying weak small target near the sea (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者: Xue X.-C.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

Automatic target detection is very difficult in complicate background of sea and sky because of the clutter caused by waves and clouds nearby the sea-level line. In this paper in view of the low-flying target near the sea is always above the sea-level line we can first locate the sea-level line and neglect the image data beneath the sea-level line. Thus the noise under the sea-level line can be suppressed and the executive time of target segmentation is also much reduced. A new method is proposed which first uses neighborhood averaging method to suppress background and enhance targets so as to increase SNR and then uses the multi-point multi-layer vertical Sobel operator combined with linear least squares fitting to locate the sea-level line lastly uses the centroid tracking algorithm to detect and track the target. In the experiment high frame rate and high-resolution digital CCD camera and high performance DSP are applied. Experimental results show that this method can efficiently locate the sea-level line on various conditions of lower contrast and eliminate the negative impact of the clutter caused by waves and clouds and capture and track target real-timely and accurately.

Detecting of multi-target in sea or sky background based on wavelet energy (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications II, November 8, 2004 - November 12, 2004, Beijing, China
作者: Liu G.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

The technology of multi-target tracking is always detecting small targets in complex background. According to the frequency characteristic of nature background and small target a method of detecting targets based on wavelet energy is suggested. The energy of targets in horizontal and vertical direction outclass that of background or we can say the gray degree of targets outclass that of background. Then through selecting adaptive region-value targets and background can be divided. By the method of classifying the figure centers of every target can be calculated. According to the figure centers of every target in several neighboring frames the position and velocity of every target in next frame can be estimated by Kalman filter. Experiment results have shown that small targets in sea or sky nature background can be detected by this method and they can be tracking.

A method for automatic infrared point target detection in a sea background based on morphology and wavelet transform 会议论文 OAI收割
3rd International Symposium on Multispectral Image Processing and Pattern Recognition, BEIJING, China, October 20-22, 2003
作者: Wen PZ(温佩芝); Shi ZL(史泽林); Yu HB(于海斌); Wu XJ(吴晓军)

收藏 | 浏览/下载：13/0 | 提交时间：2012/06/06

infrared point-target wavelet transform morphology target detection and segmentation sea background