Active modulation of laser coded systems using near infrared video projection system based on digital micromirror device (DMD)

2016 ◽  
Author(s):  
Aly A. Khalifa ◽  
Hussein A. Aly ◽  
Ashraf F. El-Sherif
Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 149 ◽  
Author(s):  
Zifeng Lu ◽  
Jinghang Zhang ◽  
Hua Liu ◽  
Jialin Xu ◽  
Jinhuan Li

In the Hadamard transform (HT) near-infrared (NIR) spectrometer, there are defects that can create a nonuniform distribution of spectral energy, significantly influencing the absorbance of the whole spectrum, generating stray light, and making the signal-to-noise ratio (SNR) of the spectrum inconsistent. To address this issue and improve the performance of the digital micromirror device (DMD) Hadamard transform near-infrared spectrometer, a split waveband scan mode is proposed to mitigate the impact of the stray light, and a new Hadamard mask of variable-width stripes is put forward to improve the SNR of the spectrometer. The results of the simulations and experiments indicate that by the new scan mode and Hadamard mask, the influence of stray light is restrained and reduced. In addition, the SNR of the spectrometer also is increased.


2021 ◽  
Vol 50 (2) ◽  
pp. 20200427-20200427
Author(s):  
刘宏明 Hongming Liu ◽  
刘玉娟 Yujuan Liu ◽  
宋莹 Ying Song ◽  
仲志成 Zhicheng Zhong ◽  
孔令胜 Lingsheng Kong ◽  
...  

1999 ◽  
Vol 50 (5) ◽  
pp. 684-688 ◽  
Author(s):  
Eric Borotto ◽  
Jacques Englender ◽  
Jean-Claude Pourny ◽  
Sylvie Naveau ◽  
Jean-Claude Chaput ◽  
...  

1998 ◽  
Vol 72 (2) ◽  
pp. 397-400 ◽  
Author(s):  
Michael J. Melchin ◽  
Alan J. Anderson

Organic-walled fossils, such as graptolites and Chitinozoa, show a high degree of transparency to near infrared radiation relative to visible light. Infrared video microscopy (IVM) provides real-time images of the three-dimensional form and internal structure of many specimens that are opaque to visible light. An infrared video camera can be mounted on a biological or petrographic, transmitted-light microscope, and with the addition of a monitor and video printer, images can be viewed and directly printed. With the use of a digital frame-capture system, the IVM images can be digitally stored for analysis, enhancement and printing. As compared with scanning electron microscopy, which only reveals the external form, IVM shows such features as fusellar growth bands and internal septa of graptolites and the prosome structure of Chitinozoa. This method eliminates the need for chemical clearing of specimens for study in visible light, which damages the surface texture and commonly renders specimens too brittle for further manipulation. Infrared video microscopy is potentially applicable to the study of any organic-walled fossils and to the petrographic study of sedimentary organic matter.


1992 ◽  
Vol 2 (2) ◽  
pp. 224-227
Author(s):  
G.W. Stutte ◽  
C.A. Stutte

Computer analysis of airborne, broad-band, near-infrared (NIR, 710 to 1100 nm) video imagery of peach tree canopies was used to determine spatial variability of cumulative stress in two peach orchards. A significant quadratic correlation was found between leaf-N content and the normalized mean pixel intensity (MPI) of the digital imagery of NIR canopy reflectance. This correlation was used to establish MPI estimates of N-stressed trees in the orchard. The relationship was used to localize site-specific spatial variability in a commercial peach orchard. The underlying soil type was found to be closely associated with the spatial variability in NIR imagery in the commercial peach orchard. Assessing spatial variability in the orchard with NIR video permits early localization of potentially low productivity regions within an orchard.


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