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Author Gu, Y., Uprety, S., Blonski, S., Zhang, B., & Cao, C. url  doi
openurl 
  Title Improved algorithm for determining the Visible Infrared Imaging Radiometer Suite Day/Night Band high-gain stage dark offset free from light contamination Type Journal Article
  Year 2019 Publication Applied Optics Abbreviated Journal  
  Volume 58 Issue 6 Pages 1400-1407  
  Keywords Remote Sensing; Instrumentation  
  Abstract Dark offset is one of the key parameters for Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) high-gain stage (HGS) radiometric calibration, whose accuracy strongly impacts applications of DNB low-light detection for Earth observation at nighttime. Currently, DNB observation of the VIIRS onboard calibrator blackbody (OBCBB) view, together with its observation of deep space during the spacecraft pitch maneuver performed early in the mission, has been used to compute the HGS dark offset continuously. However, the relationship between the DNB OBCBB data and the Earth view (EV) data is unclear due to electronic timing differences between these two views. It is questionable whether the DNB OBCBB data can monitor the EV HGS dark offset change. Through comprehensive analysis of the DNB OBCBB data and EV data acquired from the monthly special acquisitions known as the VIIRS recommended operating procedures (VROPs), we have shown that the OBCBB data can only track the dark current component of the DNB HGS EV dark offset, instead of the total dark offset. The DNB observation of deep space during the spacecraft pitch maneuver was also contaminated by starlight. With such background, in this paper we propose an improved algorithm for determining the DNB HGS dark offset. By combined use of the DNB OBCBB data and the DNB VROP data, the generated DNB HGS dark offset is both free from light contamination and capable of tracking continuous drift. The improved algorithm could potentially improve the DNB radiometric performance at low radiance level. Our results provide a solid theoretical basis for dark offset calibration of the VIIRS DNB onboard Suomi National Polar-Orbiting Partnership satellite and the following Joint Polar Satellite System satellites.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ intern @ Serial 2358  
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Author Tauc, M.J.; Fristrup, K.M.; Repasky, K.S.; Shaw, J.A. url  doi
openurl 
  Title Field demonstration of a wing-beat modulation lidar for the 3D mapping of flying insects Type Journal Article
  Year 2019 Publication OSA Continuum Abbreviated Journal OSA Continuum  
  Volume 2 Issue 2 Pages 332  
  Keywords Instrumentation; Animals  
  Abstract We describe a wing-beat modulation lidar system designed for the 3D mapping of flying insects in ecological or entomological studies. To better understand the signals from this instrument, we analyzed simulated signals to identify how they were affected by various imperfections, such as variations in the spacing and amplitude of each individual wing-beat reflection. In addition, a radiometric model was used to estimate signal-to-noise ratio to gain insight into the relationships between the optical system design and insect parameters (e.g., wing size, reflectivity, or diffusivity).  
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  Series Volume Series Issue Edition  
  ISSN 2578-7519 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2209  
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Author Babadi, S.; Ramirez-Inguiez, R.; Boutaleb, T.; Mallick, T. url  doi
openurl 
  Title Producing uniform illumination within a rectangular area by using a nonimaging optic Type Journal Article
  Year 2018 Publication Applied Optics Abbreviated Journal Appl. Opt.  
  Volume 57 Issue 31 Pages 9357  
  Keywords Lighting  
  Abstract This paper proposes a new design method to create a novel optical element to generate uniform illumination within a rectangular area. Based on this model, an illuminated area is irradiated by two sets of rays; the first one irradiates the target plane after refraction from the top section of the lens, and the second one irradiates from the reflection at the side profile of the lens and then from refraction at the top part of the lens. The results show that a uniformity of over 90% can be achieved.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1559-128X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2046  
Permanent link to this record
 

 
Author Barducci, A.; Marcoionni, P.; Pippi, I.; Poggesi, M. url  doi
openurl 
  Title Effects of light pollution revealed during a nocturnal aerial survey by two hyperspectral imagers Type Journal Article
  Year 2003 Publication Applied Optics Abbreviated Journal Appl. Opt.  
  Volume 42 Issue 21 Pages 4349  
  Keywords Remote Sensing  
  Abstract A remote-sensing campaign was performed in September 2001 at nighttime under clear-sky conditions before moonrise to assess the level of light pollution of urban and industrial origin. Two hyperspectral sensors, namely, the Multispectral Infrared and Visible Imaging Spectrometer and the Visible Infrared Scanner-200, which provide spectral coverage from the visible to the thermal infrared, were flown over the Tuscany coast (Italy) on board a Casa 212 airplane. The acquired images were processed to produce radiometrically calibrated data, which were then analyzed and compared with ground-based spectral measurements. Calibrated data acquired at high spectral resolution (∼2.5 nm) showed a maximum scene brightness almost of the same order of magnitude as that observed during similar daytime measurements, whereas their average luminosity was 3 orders of magnitude lower. The measurement analysis confirmed that artificial illumination hinders astronomical observations and produces noticeable effects even at great distances from the sources of the illumination.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6935 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2438  
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Author Malik, N.; Raj, A.; Dhasmana, R.; Bahadur, H. url  doi
openurl 
  Title Effect of Late Night Studying and Excessive Use of Video Display Terminals on the Ocular Health of Medical Undergraduate Students in A Tertiary Care Hospital Type Journal Article
  Year 2018 Publication Journal of Clinical & Experimental Ophthalmology Abbreviated Journal J Clin Exp Ophthalmol  
  Volume 09 Issue 06 Pages  
  Keywords Human Health  
  Abstract Purpose: To evaluate the effect of late night study and excessive use of smart phones on the ocular health of medical undergraduate students.

Design: An observational and cross-sectional study.

Participants: Two hundred and fifty nine normal and healthy M.B.B.S students of age 18-25 y were included in the study over a period of two months.

Methods: All the volunteers underwent an interview in form of a questionnaire. A complete ophthalmic examination was done including snellen visual acuity assessment, anterior segment examination with slit lamp, posterior segment with direct or indirect ophthalmoscopy; Schirmer’s test and tear film break up time.

Results: A total of 259 subjects were included in the study and maximum subjects 160 (61.8%) were females. According to age, the students were divided in two groups as I and II with age of 17-20 y and 21-23 y respectively. Maximum 195 (75.3%) students belonged to group I. Maximum subjects 245 (94.5%) were using only smartphones and 239 (92.27%) subjects were using smartphones for more than 2 y. The maximum 136 (52.51%) students studied at night with maximum using tube light 112 (43.24%). A significant association was seen between the digital device used and age of the subject (p value=0.01). Number of symptoms experienced by the students showed significant relationship with the number of hours of smartphone usage (p value=0.02). Source of light in which the students studied at night was significantly associated with the number of symptoms experienced (p value=0.03). An association between usage of smartphones (hours) showed significant relationship with slit lamp examination (tear debri) and Schirmer’s (less than 15 mm) with p value of 0.03, 0.05 respectively.

Conclusion: Source of light used to study at night and number of hours of use of devices shows relationship with symptoms. Smart phone users showed computer-related eye problems in more than half of the subjects.
 
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2155-9570 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2197  
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