toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Figura, J.; Haughwout, C.; Cahoy, K.; Welle, R.; Hardy, B.; Pack, D.; Bosh, A. url  openurl
  Title Initial Demonstration of an Uplink LED Beacon to a Low Earth Orbiting CubeSat Type Journal Article
  Year 2018 Publication Journal of Small Satellites Abbreviated Journal  
  Volume 7 Issue 2 Pages 719-732  
  Keywords Remote Sensing  
  Abstract In this study, an uplink light-emitting diode (LED) beacon that can enable a CubeSat to locate a laser communication ground station was designed, constructed, and tested, and detection of the beacon from low Earth orbit (LEO) with a CMOS camera on the AeroCube-5 CubeSat was demonstrated. The LED beacon described is an alternative to the near-infrared laser beacons commonly used in laser communication systems, and has the potential to be cheaper, easier to point, and to require less regulatory coordination than a laser beacon, while performing the same function. An optical design is detailed, consisting of an array of 80 green LEDs with a center wavelength of 528 nm, producing 15.9 watts of free-space optical power, focused to a beamwidth of 8.12 degrees full-widthhalf-max (FWHM). A link budget is presented that shows the beacon is detectable by a CubeSat-mounted camera with a 7.9 mm diameter aperture and a silicon CMOS detector. A prototype beacon comprised of an LED array, focusing optics, thermal control, and tracking mechanisms was designed and constructed, and laboratory measurements of the beam profile and optical power of the prototype beacon using an optical power meter are presented herein. A field test is also described, in which the beacon was deployed at Wallace Astrophysical Observatory in the early morning of May 15, 2017 and imaged with a camera on AeroCube-5. The array is successfully identified in a sequence of five images taken by the CubeSat, demonstrating the viability of LED uplink beacons with CubeSat imagers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) NC @ ehyde3 @ Serial 2108  
Permanent link to this record
 

 
Author Min, B.; O'Keeffe, Z.; Zhang, F. url  doi
openurl 
  Title Whose Power Gets Cut? Using High-Frequency Satellite Images to Measure Power Supply Irregularity Type Book Whole
  Year 2017 Publication Policy Research Working Papers Abbreviated Journal  
  Volume Issue Pages  
  Keywords Remote Sensing  
  Abstract In many parts of the developing world, access to electricity is uneven and inconsistent, characterized by frequent and long hours of power outages. Many countries now engage in systematic load shedding because of persistent power shortages. When and where electricity is provided can have important impacts on welfare and growth. But quantifying those impacts is difficult because utility-level data on power outages are rarely available and not always reliable. This paper introduces a new method of tracking power outages from outer space. This measure identifies outage-prone areas by detecting excess fluctuations in light outputs. To develop these measures, the study processed the complete historical archive of sub-orbital Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) nighttime imagery captured over South Asia on every night since 1993. The analysis computes annual estimates of the Power Supply Irregularity index for all 600,000 villages in India from 1993 to 2013. The Power Supply Irregularity index measures are consistent with ground-based measures of power supply reliability from the Indian Human Development Survey, and with feeder-level outage data from one of the largest utilities in India. The study's methods open new opportunities to study the determinants of power outages as well as their impacts on welfare.  
  Address  
  Corporate Author Thesis  
  Publisher The World Bank Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) NC @ ehyde3 @ Serial 2109  
Permanent link to this record
 

 
Author Boyce, P.R. url  doi
openurl 
  Title The Present and Future of Lighting Research Type Journal Article
  Year 2018 Publication SDAR* Journal of Sustainable Design & Applied Research Abbreviated Journal  
  Volume 6 Issue 1 Pages  
  Keywords Commentary; Lighting; Vision; Human Health  
  Abstract The aim of this paper is to consider where lighting research is today and what its future might be. There is little doubt that, today, lighting research is an active field. A brief review of the topics being studied reveals that they range from residual studies on visibility and visual discomfort, through attempts to identify the influence of lighting on factors beyond visibility such as mood and behaviour, to the whole new field of light and health. But activity alone is not enough to justify a future. For lighting research to have a future it is necessary for it to

be influential. To become influential, research needs to focus its attention on outcomes that matter to people and the elements of those outcomes on which lighting is known to have a major influence. Further, researchers will have to be determined to overcome the barriers to changing lighting practice. By doing this, lighting research may change the world for the better, to be an important topic, not an irrelevance.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) NC @ ehyde3 @ Serial 2113  
Permanent link to this record
 

 
Author McGlashan, E.M.; Poudel, G.R.; Vidafar, P.; Drummond, S.P.A.; Cain, S.W. url  doi
openurl 
  Title Imaging Individual Differences in the Response of the Human Suprachiasmatic Area to Light Type Journal Article
  Year 2018 Publication Frontiers in Neurology Abbreviated Journal Front. Neurol.  
  Volume 9 Issue Pages  
  Keywords Human Health  
  Abstract Circadian disruption is associated with poor health outcomes, including sleep and mood disorders. The suprachiasmatic nucleus (SCN) of the anterior hypothalamus acts as the master biological clock in mammals, regulating circadian rhythms throughout the body. The clock is synchronized to the day/night cycle via retinal light exposure. The BOLD-fMRI response of the human suprachiasmatic area to light has been shown to be greater in the night than in the day, consistent with the known sensitivity of the clock to light at night. Whether the BOLD-fMRI response of the human suprachiasmatic area to light is related to a functional outcome has not been demonstrated. In a pilot study (n = 10), we investigated suprachiasmatic area activation in response to light in a 30 s block-paradigm of lights on (100 lux) and lights off (< 1 lux) using the BOLD-fMRI response, compared to each participant's melatonin suppression response to moderate indoor light (100 lux). We found a significant correlation between activation in the suprachiasmatic area in response to light in the scanner and melatonin suppression, with increased melatonin suppression being associated with increased suprachiasmatic area activation in response to the same light level. These preliminary findings are a first step toward using imaging techniques to measure individual differences in circadian light sensitivity, a measure that may have clinical relevance in understanding vulnerability in disorders that are influenced by circadian disruption.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1664-2295 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) NC @ ehyde3 @ Serial 2114  
Permanent link to this record
 

 
Author Kerstel, E.; Gardelein, A.; Barthelemy, M.; Fink, M.; Joshi, S.K.; Ursin, R. url  doi
openurl 
  Title Nanobob: a CubeSat mission concept for quantum communication experiments in an uplink configuration Type Journal Article
  Year 2018 Publication European physical journal quantum technology Abbreviated Journal EPJ Quantum Technol.  
  Volume 5 Issue 6 Pages 1-30  
  Keywords Remote Sensing  
  Abstract We present a ground-to-space quantum key distribution (QKD) mission concept and the accompanying feasibility study for the development of the associated low earth orbit nanosatellite payload. The quantum information is carried by single photons with the binary codes represented by polarization states of the photons. Distribution of entangled photons between the ground and the satellite can be used to certify the quantum nature of the link: a guarantee that no eavesdropping can take place. By placing the entangled photon source on the ground, the space segments contains “only” the less complex detection system, enabling its implementation in a compact enclosure, compatible with the 12U CubeSat standard (∼12 dm3). This reduces the overall cost of the project, making it an ideal choice as a pathfinder for future European quantum communication satellite missions. The space segment is also more versatile than one that contains the source since it is compatible with a multiple of QKD protocols (not restricted to entangled photon schemes) and can be used in quantum physics experiments, such as the investigation of entanglement decoherence. Other possible experiments include atmospheric transmission/turbulence characterization, dark area mapping, fine pointing and tracking, and accurate clock synchronization; all crucial for future global scale quantum communication efforts.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2196-0763 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (down) NC @ ehyde3 @ Serial 2115  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: