scholarly journals Aperture Filter and Adaptive Filter Response for Reconstruction of Sea Surface Image Based on LIDAR Observation

2015 ◽  
Vol 5 (5) ◽  
pp. 317-324
Author(s):  
Muhammad Sameer Sheikh ◽  
◽  
Cao QunSheng ◽  
Wang Caiyun
Keyword(s):  
Adaptive Filter ◽  
Sea Surface ◽  
Lidar Observation ◽  
Surface Image ◽  
Aperture Filter ◽  
Filter Response

scholarly journals Sea Surface Imaging with a Shortened Delayed-Dechirp Process of Airborne FMCW SAR for Ocean Monitoring on Emergency

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7310
Author(s):  
Ji-hwan Hwang ◽  
Duk-jin Kim
Keyword(s):  
Emergency Response ◽  
Continuous Wave ◽  
Incidence Angle ◽  
Incident Angle ◽  
Measurement Data ◽  
Sea Surface ◽  
Surface Imaging ◽  
Dual Channel ◽  
Surface Image ◽  
Ocean Monitoring

A sea surface imaging technique for an emergency response using a ready-made frequency modulated continuous wave–synthetic aperture radar (FMCW SAR) system and its experimental results are described in this paper. The optimal range of radiowave incidence angle for sea surface imaging was analyzed by a theoretical scattering model and measurement data, and it was properly applied to the FMCW SAR system by readjusting the delayed-dechirp process. Raw data acquired through flight experiments were reconstructed to SAR image by the range-doppler algorithm. To verify the performance of the reconstructed sea surface image, dual-channel images collected by the configuration of the along-track interferometry were used, and then performance indicators such as signal attenuation, coherence, and phase difference were analyzed. Through this experimental study, it was confirmed that the ready-made FMCW SAR system without a function of the incident angle control can also conduct limited missions for maritime observation. It is possible to be an alternative resource for emergency response, in which the cases are requiring urgent maritime disaster detection and analysis.

Lidar observation of the bubble trace in the sea surface layer

2010 ◽  
Vol 18 (3) ◽  
pp. 230-235
Author(s):  
A. F. Bunkin ◽  
V. K. Klinkov ◽  
V. A. Luk’yanenko ◽  
S. M. Pershin
Keyword(s):  
Surface Layer ◽  
Sea Surface ◽  
Lidar Observation

scholarly journals Multi-Visual Feature Saliency Detection for Sea-Surface Targets through Improved Sea-Sky-Line Detection

2020 ◽  
Vol 8 (10) ◽  
pp. 799
Author(s):  
Chang Lin ◽  
Wu Chen ◽  
Haifeng Zhou
Keyword(s):  
Saliency Detection ◽  
Obstacle Detection ◽  
Sea Surface ◽  
Line Detection ◽  
Target Area ◽  
Visual Feature ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Surface Image ◽  
Surface Images

To visually detect sea-surface targets, the objects of interest must be effectively and rapidly isolated from the background of sea-surface images. In contrast to traditional image detection methods, which employ a single visual feature, this paper proposes a significance detection algorithm based on the fusion of multi-visual features after detecting the sea-sky-lines. The gradient edges of the sea-surface images are enhanced using a Gaussian low-pass filter to eliminate the effect of the image gradients pertaining to the clouds, wave points, and illumination. The potential region and points of the sea-sky-line are identified. The sea-sky-line is fitted through polynomial iterations to obtain a sea-surface image containing the target object. The saliency subgraphs of the high and low frequency, gradient texture, luminance, and color antagonism features are fused to obtain an integrated saliency map of the sea-surface image. The saliency target area of the sea surface is segmented. The effectiveness of the proposed method was verified. The average detection rate and time for the sea-sky-line detection were 96.3% and 1.05 fps, respectively. The proposed method outperformed the existing saliency models on the marine obstacle detection dataset and Singapore maritime dataset, with mean absolute errors of 0.075 and 0.051, respectively.

scholarly journals Single Sea Surface Image Dehazing via Multi-scale Concatenated Attention Network

2021 ◽  
Vol 1972 (1) ◽  
pp. 012025
Author(s):  
Xin He ◽  
Wanfeng Ji ◽  
Zheng Wang ◽  
Yaoqing Zhang
Keyword(s):  
Sea Surface ◽  
Image Dehazing ◽  
Attention Network ◽  
Multi Scale ◽  
Surface Image
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