Aladdin's Magic Lamp: Developing Methods for Calibration and Geolocation Accuracy Assessment of the DMSP OLS

Nighttime satellite imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has a unique capability to observe nocturnal light emissions from sources including cities, wild fires, and gas flares. Data from the DMSP OLS is used in a wide range of studies including mapping urban areas, estimating informal economies, and estimating urban populations. Given the extensive and increasing list of applications a repeatable method for assessing geolocation accuracy, performing inter-calibration, and defining the minimum detectable brightness would be beneficial. An array of portable lights was designed and taken to multiple field sites known to have no other light sources. The lights were operated during nighttime overpasses by the DMSP OLS and observed in the imagery. A first estimate of the minimum detectable brightness is presented based on the field experiments conducted. An assessment of the geolocation accuracy was performed by measuring the distance between the GPS measured location of the lights and the observed location in the imagery. A systematic shift was observed and the mean distance was measured at 2.9km. A method for in situ radiance calibration of the DMSP OLS using a ground based light source as an active target is presented. The wattage of light used by the active target strongly correlates with the signal measured by the DMSP OLS. This approach can be used to enhance our ability to make inter-temporal and inter-satellite comparisons of DMSP OLS imagery. Exploring the possibility of establishing a permanent active target for the calibration of nocturnal imaging systems is recommended. The methods used to assess the minimum detectable brightness, assess the geolocation accuracy, and build inter-calibration models lay the ground work for assessing the energy expended on light emitted into the sky at night. An estimate of the total energy consumed to light the night sky globally is presented.

What We Are Learning About the Diverse Backgrounds of Academic Library Users: An Overview of Research Designs and Methods in Information Behaviour Studies

Academic libraries increasingly serve a more diverse population of users not only in regard to race and ethnicity, but also to age, gender, language, sexual orientation, and national and cultural backgrounds. This papers reports the findings of the study that explored information behaviour research as a potential source of information about diversity of academic library users and examined the relationship between the use of different research designs and data collection methods and the information gathered about users’ diverse backgrounds. The study found that information behaviour research offers limited insight into the diversity of academic library users. The choice of a research design was not critical but the use of multiple data collection played a role in gathering information about culturally diverse users.

A Watershed Approach to Managing the Natural Resources in South Carolina

Environmental degradation from point and non-point source pollution in the past ten years has made it increasingly clear that threats to aquatic resources cannot adequately be addressed without a more integrated watershed approach to the management. Through comprehensive, qualitative interviews of experts in the watershed approach in South Carolina, recommendations will be made to improve this holistic process. Conducting interviews to compile institutional knowledge on the incentives and barriers from professionals working within the watershed approach will show how managing the natural resources in South Carolina could be more effective and efficient. By gathering experiences of lessons learned, best approach techniques, and suggestions for future watershed planning, several recommendations were made to further the use of the watershed approach in South Carolina.