scholarly journals Extremely Robust Remote-Target Detection Based on Carbon Dioxide-Double Spikes in Midwave Spectral Imaging

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2896 ◽  
Author(s):  
Sungho Kim ◽  
Jungsub Shin ◽  
Joonmo Ahn ◽  
Sunho Kim
Keyword(s):  
Carbon Dioxide ◽  
Fourier Transform ◽  
Target Detection ◽  
Emission Band ◽  
Co2 Emission ◽  
Spectral Feature ◽  
Spectral Imaging ◽  
Joint Analysis ◽  
Spectral Bands ◽  
Background Clutter

Infrared ship-target detection for sea surveillance from the coast is very challenging because of strong background clutter, such as cloud and sea glint. Conventional approaches utilize either spatial or temporal information to reduce false positives. This paper proposes a completely different approach, called carbon dioxide-double spike (CO2-DS) detection in midwave spectral imaging. The proposed CO2-DS is based on the spectral feature where a hot CO2 emission band is broader than that which is absorbed by normal atmospheric CO2, which generates CO2-double spikes. A directional-mean subtraction filter (D-MSF) detects each CO2 spike, and final targets are detected by joint analysis of both types of detection. The most important property of CO2-DS detection is that it generates an extremely low number of false positive caused by background clutter. Only the hot CO2 spike of a ship plume can penetrate atmosphere, and furthermore, there are only ship CO2 plume signatures in the double spikes of different spectral bands. Experimental results using midwave Fourier transform infrared (FTIR) in a remote sea environment validate the extreme robustness of the proposed ship-target detection.

scholarly journals Hierarchical Suppression Based Matched Filter for Hyperspertral Imagery Target Detection

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 144
Author(s):  
Ce Gao ◽  
Yiquan Wu ◽  
Xiaohui Hao
Keyword(s):  
Target Detection ◽  
Matched Filter ◽  
Single Layer ◽  
Vital Role ◽  
Separation Performance ◽  
Average Output ◽  
Spectral Bands ◽  
Target Spectrum ◽  
Background Clutter ◽  
The Given

Target detection in hyperspectral imagery (HSI) aims at extracting target components of interest from hundreds of narrow contiguous spectral bands, where the prior target information plays a vital role. However, the limitation of the previous methods is that only single-layer detection is carried out, which is not sufficient to discriminate the target parts from complex background spectra accurately. In this paper, we introduce a hierarchical structure to the traditional algorithm matched filter (MF). Because of the advantages of MF in target separation performance, that is, the background components are suppressed while preserving the targets, the detection result of MF is used to further suppress the background components in a cyclic iterative manner. In each iteration, the average output of the previous iteration is used as a suppression criterion to distinguish these pixels judged as backgrounds in the current iteration. To better stand out the target spectra from the background clutter, HSI spectral input and the given target spectrum are whitened and then used to construct the MF in the current iteration. Finally, we provide the corresponding proofs for the convergence of the output and suppression criterion. Experimental results on three classical hyperspectral datasets confirm that the proposed method performs better than some traditional and recently proposed methods.

Wideband Time-space Radon-Fourier Transform for High-speed and Weak Target Detection

2014 ◽  
Vol 35 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Li-chang Qian ◽  
Jia Xu ◽  
Wen-feng Sun ◽  
Ying-ning Peng
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
High Speed ◽  
Time Space ◽  
Weak Target

scholarly journals Clutter Cancellation and Long Time Integration for GNSS-Based Passive Bistatic Radar

2021 ◽  
Vol 13 (4) ◽  
pp. 701 ◽  
Author(s):  
Binbin Wang ◽  
Hao Cha ◽  
Zibo Zhou ◽  
Bin Tian
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
Time Integration ◽  
Detection Performance ◽  
Bistatic Radar ◽  
Detection Range ◽  
Robust Detection ◽  
Coherent Integration ◽  
Long Time ◽  
Long Time Integration

Clutter cancellation and long time integration are two vital steps for global navigation satellite system (GNSS)-based bistatic radar target detection. The former eliminates the influence of direct and multipath signals on the target detection performance, and the latter improves the radar detection range. In this paper, the extensive cancellation algorithm (ECA), which projects the surveillance channel signal in the subspace orthogonal to the clutter subspace, is first applied in GNSS-based bistatic radar. As a result, the clutter has been removed from the surveillance channel effectively. For long time integration, a modified version of the Fourier transform (FT), called long-time integration Fourier transform (LIFT), is proposed to obtain a high coherent processing gain. Relative acceleration (RA) is defined to describe the Doppler variation results from the motion of the target and long integration time. With the estimated RA, the Doppler frequency shift compensation is carried out in the LIFT. This method achieves a better and robust detection performance when comparing with the traditional coherent integration method. The simulation results demonstrate the effectiveness and advantages of the proposed processing method.

scholarly journals High-Speed Target Detection Algorithm Based on Sparse Fourier Transform

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 37828-37836 ◽  
Author(s):  
Cunsuo Pang ◽  
Shengheng Liu ◽  
Yan Han
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
High Speed ◽  
Detection Algorithm

Repair of Porous Methylsilsesquioxane Films using Supercritical Carbon Dioxide

2004 ◽  
Vol 812 ◽  
Author(s):  
Bo Xie ◽  
Anthony J. Muscat
Keyword(s):  
Carbon Dioxide ◽  
Dielectric Constant ◽  
Fourier Transform ◽  
Supercritical Carbon Dioxide ◽  
Ftir Spectroscopy ◽  
Oxygen Plasma ◽  
Contact Angles ◽  
Silanol Groups ◽  
Chain Lengths ◽  
Supercritical Carbon

AbstractPorous methylsilsesquioxane (p-MSQ) films (JSR LKD 5109) were treated with alkyldimethylmonochlorosilanes having chain lengths of one, four, and eight carbon atoms dissolved in supercritical carbon dioxide at 150-300 atm and 50-60°C to repair oxygen ashing damage. Fourier transform infrared (FTIR) spectroscopy showed that trimethylchlorosilane (TMCS), butyldimethylchlorosilane (BDMCS), and octyldimethylchlorosilane (ODMCS) reacted with silanol groups on the surfaces of the pores producing covalent Si-O-Si bonds. Selfcondensation between alkylsilanols produced a residue on the surface, which was partially removed using a pure scCO2 rinse. The hydrophobicity of the blanket p-MSQ surface was recovered after silylation treatment as shown by contact angles >85°. The initial dielectric constant of 2.4 ± 0.1 increased to 3.5 ± 0.1 after oxygen plasma ashing and was reduced to 2.6 ± 0.1 by TMCS, 2.8 ± 0.1 by BDMCS, and 3.2 by ODMCS.

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