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Author Pun, C.S.J.; So, C.W. url  doi
openurl 
  Title Night-sky brightness monitoring in Hong Kong: a city-wide light pollution assessment Type Journal Article
  Year 2012 Publication (up) Environmental Monitoring and Assessment Abbreviated Journal Environ Monit Assess  
  Volume 184 Issue 4 Pages 2537-2557  
  Keywords *Cities; Environmental Monitoring/instrumentation/*methods; *Environmental Pollution; Hong Kong; Humans; *Light  
  Abstract Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe-the urban night skies (sky brightness at 15.0 mag arcsec(- 2)) are on average ~ 100 times brighter than at the darkest rural sites (20.1 mag arcsec(- 2)), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag arcsec(- 2) can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by human factors such as land utilization and population density of the observation sites, together with meteorological and/or environmental factors. Moreover, earlier night skies (at 9:30 p.m. local time) are generally brighter than later time (at 11:30 p.m.), which can be attributed to some public and commercial lightings being turned off later at night. On the other hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong.  
  Address Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China. jcspun@hku.hk  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0167-6369 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21713499 Approved no  
  Call Number IDA @ john @ Serial 258  
Permanent link to this record
 

 
Author Windle, A. E., Hooley, D. S., & Johnston, D. W. url  doi
openurl 
  Title Robotic Vehicles Enable High-Resolution Light Pollution Sampling of Sea Turtle Nesting Beaches Type Journal Article
  Year 2018 Publication (up) Frontiers in Marine Science Abbreviated Journal  
  Volume 5 Issue 493 Pages  
  Keywords Instrumentation; Animals; Skyglow  
  Abstract Nesting sea turtles appear to avoid brightly lit beaches and often turn back to sea prematurely when exposed to artificial light. Observations and experiments have noted that nesting turtles prefer darker areas where buildings and high dunes act as light barriers. As a result, sea turtles often nest on darker beaches, creating spatial concentrations of nests. Artificial nighttime light, or light pollution, has been quantified using a variety of methods. However, it has proven challenging to make accurate measurements of ambient light at fine scales and on smaller nesting beaches. Additionally, light has traditionally been measured from stationary tripods perpendicular to beach vegetation, disregarding the point of view of a nesting sea turtle. In the present study, nighttime ambient light conditions were assessed on three beaches in central North Carolina: a developed coastline of a barrier island, a nearby State Park on the same barrier island comprised of protected and undeveloped land, and a completely uninhabited wilderness on an adjacent barrier island in the Cape Lookout National Seashore. Using an autonomous terrestrial rover, high resolution light measurements (mag/arcsec2) were collected every minute with two ambient light sensors along transects on each beach. Spatial comparisons between ambient light and nesting density at and between these locations reveal that highest densities of nests occur in regions with lowest light levels, supporting the hypothesis that light pollution from coastal development may influence turtle nesting distribution. These results can be used to support ongoing management strategies to mitigate this pressing conservation issue.  
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  Notes Approved no  
  Call Number IDA @ intern @ Serial 2315  
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Author Wang, G., Wang, S., Zhang, L., Sun, F., Yan, F., & Yang, X. url  doi
openurl 
  Title A New Light Control Method with Charge Induction of Moving Target Type Journal Article
  Year 2019 Publication (up) IEEE Sensors Journal Abbreviated Journal  
  Volume 19 Issue 16 Pages  
  Keywords Lighting; Instrumentation  
  Abstract Intelligent lamp control system has been widely studied all over the world because of its energy saving and social effect. In this paper, a new intelligent lamp control method based on charge induction for moving target is proposed. The detection model is established with the surface charge induction and verified by a luggage detection experiment. The intelligent lamp control system using the detection method is carried out. The performance of the system demonstrates that the proposed method can detect the moving target at any orientation whatever with or without occlusion and the detection distance can reach more than 3 m for the pedestrian.  
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  Notes Approved no  
  Call Number IDA @ intern @ Serial 2470  
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Author Schwarting, T., McIntire, J., Oudrari, H., & Xiong, X url  doi
openurl 
  Title JPSS-1/NOAA-20 VIIRS Day-Night Band Prelaunch Radiometric Calibration and Performance Type Journal Article
  Year 2019 Publication (up) IEEE Transactions on Geoscience and Remote Sensing Abbreviated Journal  
  Volume Issue Pages 1-13  
  Keywords Instrumentation  
  Abstract The Visible Infrared Imaging Radiometer Suite (VIIRS) on board the first Joint Polar-Orbiting Satellite System series 1 (JPSS-1) has a panchromatic, three gain stage, day-night band (DNB) capable of imaging the Earth under illumination conditions ranging from reflected moonlight to daytime scenes. The DNB has four charged-coupled devices (CCDs) with 32 different modes of time-delay integration and subpixel aggregation to achieve high SNR in low light conditions while maintaining roughly constant spatial resolution across scan. During the prelaunch testing phase, these 32 different aggregation modes are separately calibrated over a large dynamic range (covering seven orders of magnitude) through a series of radiometric tests designed to generate initial calibration coefficients for the sensor data record (SDR) operational algorithm, assess radiometric performance, and determine compliance with the sensor design requirements. Early in the environmental testing at the Raytheon El Segundo facility, nonlinear behavior was discovered in some DNB edge of scan aggregation modes at low signal levels. In response to this nonlinearity, the test program was altered to characterize the radiometric performance both in the baseline configuration and with a modified aggregation scheme that eliminates the modes used at the end of scan, replacing them with an unaffected adjacent mode and trading off spatial resolution for improved linearity. Presented in this paper is the radiometric performance under both sensor configurations including dynamic range, sensitivity, radiometric uncertainty, and nonlinearity along with a discussion of the potential impact to DNB on-orbit calibration and SDR performance.  
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  Notes Approved no  
  Call Number IDA @ intern @ Serial 2541  
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Author Wilson, T., & Xiong, X. url  doi
openurl 
  Title Intercomparison of the SNPP and NOAA-20 VIIRS DNB High-Gain Stage Using Observations of Bright Stars Type Journal Article
  Year 2020 Publication (up) IEEE Transactions on Geoscience and Remote Sensing Abbreviated Journal  
  Volume Issue Pages 1-8  
  Keywords Remote Sensing; Instrumentation  
  Abstract The Visible Infrared Imaging Radiometer Suite (VIIRS) on board the Suomi-NPP (SNPP) and NOAA-20 (N20) spacecrafts is a multispectral Earth-observing instrument with bands covering wavelengths from visible to long-wave infrared. Among these bands is a panchromatic day/night band (DNB) with a broad spectral response ranging from 500 to 900 nm, and a high dynamic range spanning over seven orders of magnitude, allowing for observations to take place during both daytime and nighttime. The DNB operates at three gain levels, with low- and mid-gain stages and two high-gain stages (HGSs). The HGS is capable of detecting dim city lights during Earth-view observations at night as well as bright stars through the instrument space-view port. Since SNPP and N20 are at opposite points of the same orbit, each VIIRS instrument is able to observe the same stars with the DNB in successive orbits. This will allow us to make a direct comparison of the relative calibration of each instrument using stars over a range of spectral classes. In this article, we develop methodology for accurately identifying target stars in order to make proper comparisons between the DNB HGS of each instrument. We then take observations from multiple stars in order to compute the ratio in the measured irradiance for each instrument as a function of spectral class. For K-type stars, which have the least spectral change over the DNB wavelength range, we measure a calibration bias between the SNPP and N20 DNB HGS of approximately 4%, which is stable over the duration of the N20 mission.  
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  Notes Approved no  
  Call Number IDA @ intern @ Serial 2959  
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