Effect of solar stray light on imaging quality of infrared detection system

Author(s):  
Jianhua Li ◽  
Qian Zhao ◽  
Lian Xue ◽  
Zhenghong Liu ◽  
Lu Gao ◽  
...  
2010 ◽  
Vol 30 (8) ◽  
pp. 2267-2271 ◽  
Author(s):  
牛金星 Niu Jinxing ◽  
周仁魁 Zhou Renkui ◽  
刘朝晖 Liu Zhaohui ◽  
杨建国 Yang Jianguo ◽  
蔡占恩 Cai Zhan′en ◽  
...  

2011 ◽  
Vol 138-139 ◽  
pp. 387-390
Author(s):  
Jin Xing Niu ◽  
Heng Can Li

Analysis and calculation of stray light is important to improve the performance of infrared detection system. In this article, we mainly discussed two sources: earth and atmosphere emission and thermal stray radiation. A method based on Monte Carlo ray-tracing in TracePro is proposed to calculate the irradiance of detector arisen from earth and atmosphere emission. The thermal stray light irradiance on detector can also be obtained by simulation in TracePro.


2003 ◽  
Vol 18 (6) ◽  
pp. 1471-1473 ◽  
Author(s):  
Yukio Takahashi ◽  
Kouichi Hayashi ◽  
Kimio Wakoh ◽  
Naomi Nishiki ◽  
Eiichiro Matsubara

Laboratory x-ray fluorescence holography equipment was developed. A single-bent graphite monochromator with a large curvature and a high-count-rate x-ray detection system were applied in this equipment. To evaluate the performance of this equipment, a hologram pattern of a gold single crystal was measured. It took two days, which was about one-third the time required for the previous measurements using the conventional x-ray source and several times that using the synchrotron source. The quality of the hologram pattern is as good as that obtained using the synchrotrons. Clear atomic images on (002) are reconstructed.


2020 ◽  
Vol 26 (4) ◽  
pp. 496-507
Author(s):  
Kheir Daouadi ◽  
Rim Rebaï ◽  
Ikram Amous

Nowadays, bot detection from Twitter attracts the attention of several researchers around the world. Different bot detection approaches have been proposed as a result of these research efforts. Four of the main challenges faced in this context are the diversity of types of content propagated throughout Twitter, the problem inherent to the text, the lack of sufficient labeled datasets and the fact that the current bot detection approaches are not sufficient to detect bot activities accurately. We propose, Twitterbot+, a bot detection system that leveraged a minimal number of language-independent features extracted from one single tweet with temporal enrichment of a previously labeled datasets. We conducted experiments on three benchmark datasets with standard evaluation scenarios, and the achieved results demonstrate the efficiency of Twitterbot+ against the state-of-the-art. This yielded a promising accuracy results (>95%). Our proposition is suitable for accurate and real-time use in a Twitter data collection step as an initial filtering technique to improve the quality of research data.


Author(s):  
Johannes Felix Simon Brachmann ◽  
Andreas Baumgartner ◽  
Peter Gege

The Calibration Home Base (CHB) is an optical laboratory designed for the calibration of imaging spectrometers for the VNIR/SWIR wavelength range. Radiometric, spectral and geometric calibration as well as the characterization of sensor signal dependency on polarization are realized in a precise and highly automated fashion. This allows to carry out a wide range of time consuming measurements in an ecient way. The implementation of ISO 9001 standards in all procedures ensures a traceable quality of results. Spectral measurements in the wavelength range 380–1000 nm are performed to a wavelength uncertainty of +- 0.1 nm, while an uncertainty of +-0.2 nm is reached in the wavelength range 1000 – 2500 nm. Geometric measurements are performed at increments of 1.7 µrad across track and 7.6 µrad along track. Radiometric measurements reach an absolute uncertainty of +-3% (k=1). Sensor artifacts, such as caused by stray light will be characterizable and correctable in the near future. For now, the CHB is suitable for the characterization of pushbroom sensors, spectrometers and cameras. However, it is planned to extend the CHBs capabilities in the near future such that snapshot hyperspectral imagers can be characterized as well. The calibration services of the CHB are open to third party customers from research institutes as well as industry.


Author(s):  
Tomasz Rymarczyk ◽  
Krzysztof Polakowski ◽  
Jan Sikora

In this paper a new version of discretization model for Ultrasonic Transmission Tomography is presented. The algorithm has been extensively tested for synthetic noisy data on various configurations of internal objects. In order to improve the imaging quality, the pixels/voxels have been enlarged compared to the figures inscribed in pixels/voxels however no more than figures described on the standard square pixels or cubic voxels. The proposed algorithm provides better quality of imaging.


Optik ◽  
2018 ◽  
Vol 157 ◽  
pp. 298-305
Author(s):  
Liang Guo ◽  
Wei Li ◽  
Xiaozhen Li ◽  
Guanglie Hong ◽  
Jiangfeng Zhu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document