1,770 research outputs found

    A Year in Space for the CubeSat Multispectral Observing System: CUMULOS

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    CUMULOS is a three-camera system flying as a secondary payload on the Integrated Solar Array and Reflectarray Antenna (ISARA) mission with the goals of researching the use of uncooled commercial infrared cameras for Earth remote sensing and demonstrating unique nighttime remote sensing capabilities. Three separate cameras comprise the CUMULOS payload: 1) a visible (VIS) Si CMOS camera, 2) a shortwave infrared (SWIR) InGaAs camera, and 3) a longwave infrared (LWIR) vanadium oxide microbolometer. This paper reviews on-orbit operations during the past year, in-space calibration observations and techniques, and Earth remote sensing highlights from the first year of space operations. CUMULOS operations commenced on 8 June 2018 following the successful completion of the primary ISARA mission. Some of the unique contributions from the CUMULOS payloads include: 1) demonstrating the use of bright stars for on-orbit radiometric calibration of CubeSat payloads, 2) acquisition of science-quality nighttime lights data at 130-m resolution, and 3) operating the first simple Earth observing infrared payloads successfully flown on a CubeSat. Sample remote sensing results include images of: cities at night, ship lights (including fishing vessels), oil industry gas flares, serious wildfires, volcanic activity, and daytime and nighttime clouds. The CUMULOS VIS camera has measured calibrated nightlights imagery of major cities such as Los Angeles, Singapore, Shanghai, Tokyo, Kuwait City, Abu Dhabi, Jeddah, Istanbul, and London at more than 5x the resolution of VIIRS. The utility of these data for measuring light pollution, and mapping urban growth and infrastructure development at higher resolution than VIIRS is being studied, with an emphasis placed on Los Angeles. The Carr , Camp and Woolsey fires from the 2018 California fire season were imaged with all three cameras and results highlight the excellent wildfire imaging performance that can be achieved by small sensors. The SWIR camera has exhibited extreme sensitivity to flare and fire hotspots, and was even capable of detecting airglow-illuminated nighttime cloud structures by taking advantage of the strong OH emissions within its 0.9-1.7 micron bandpass. The LWIR microbolometer has proven successful at providing cloud context imagery for our nightlights mapping experiments, can detect very large fires and the brightest flare hotspots, and can also image terrain temperature variation and urban heat islands at 300-m resolution. CUMULOS capabilities show the potential of CubeSats and small sensors to perform several VIIRS-like nighttime mission areas in which wide area coverage can be traded for greater resolution over a smaller field of view. The sensor has been used in collaboration with VIIRS researchers to explore these mission areas and side-by-side results will be presented illustrating the capabilities as well as the limitations of small aperture LEO CubeSat systems

    Isolated and Poor: the cost of remoteness from the capital city

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    This paper investigates whether areas isolated from the capital city are less de- veloped economically in Sub-Saharan Africa. We apply a boundary-discontinuity design using national borders that divide pre-colonial ethnic homelands to obtain quasi-experimental variation in distance to the national capital city. Based on night- lights and geocoded surveys, we find that a one percent increase in distance to the capital city causes a decrease in the probability of detecting nightlights by 3 percent- age points and a reduction in household wealth corresponding to 3.5 percentiles of the national wealth distribution. Our results suggest that a lower provision of public goods in isolated areas is a key link between remoteness and economic performance. Despite receiving worse services, people who are isolated exhibit a higher level of trust in their political leaders. We interpret this as pointing towards dysfunctional accountability mechanisms that reduce the incentives of state executives to invest into isolated areas

    Multisource Remote Sensing based Impervious Surface Mapping

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    Impervious surface (IS) not only serves as a key indicator of urbanization, but also affects the micro-ecosystem. Therefore, it is essential to monitor IS distribution timely and accurately. Remote sensing is an effective approach as it can provide straightforward and consistent information over large area with low cost. This thesis integrates multi-source remote sensing data to interpretate urban patterns and provide more reliable IS mapping results. Registration of optical daytime and nighttime lights (NTL) data is developed in the first contribution. An impervious surface based optical-to-NTL image registration algorithm with iterative blooming effect reduction (IS_iBER) algorithm is proposed. This coarse-to-fine procedure investigates the correlation between optical and NTL features. The iterative registration and blooming effect reduction method obtains precise matching results and reduce the spatial extension of NTL. Considering the spatial transitional nature of urban-rural fringes (URF) areas, the second study proposed approach for URF delineation, namely optical and nighttime lights (NTL) data based multi-scale URF (msON_URF).The landscape heterogeneity and development vitality derived from optical and NTL features are analyzed at a series of scales to illustrate the urban-URF-rural pattern. Results illustrate that msON_URF is effective and practical for not only concentric, but also polycentric urban patterns. The third study proposes a nighttime light adjusted impervious surface index (NAISI) to detect IS area. Parallel to baseline subtraction approaches, NAISI takes advantage of features, rather than spectral band information to map IS. NAISI makes the most of independence between NTL-ISS and pervious surface to address the high spectral similarity between IS and bare soil in optical image. An optical and NTL based spectral mixture analysis (ON_SMA) is proposed to achieve sub-pixel IS mapping result in the fourth study. It integrates characteristics of optical and NTL imagery to adaptively select local endmembers. Results illustrate the proposed method yields effective improvement and highlight the potential of NTL data in IS mapping. In the fifth study, GA-SVM IS mapping algorithm is investigated with introduction of the achieved urban-URF-rural spatial structure. The combination of optical, NTL and SAR imagery is discussed. GA is implemented for feature selection and parameter optimization in each urban scenario

    Remote Sensing Monitoring of Land Surface Temperature (LST)

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    This book is a collection of recent developments, methodologies, calibration and validation techniques, and applications of thermal remote sensing data and derived products from UAV-based, aerial, and satellite remote sensing. A set of 15 papers written by a total of 70 authors was selected for this book. The published papers cover a wide range of topics, which can be classified in five groups: algorithms, calibration and validation techniques, improvements in long-term consistency in satellite LST, downscaling of LST, and LST applications and land surface emissivity research

    Geo-Information Technology and Its Applications

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    Geo-information technology has been playing an ever more important role in environmental monitoring, land resource quantification and mapping, geo-disaster damage and risk assessment, urban planning and smart city development. This book focuses on the fundamental and applied research in these domains, aiming to promote exchanges and communications, share the research outcomes of scientists worldwide and to put these achievements better social use. This Special Issue collects fourteen high-quality research papers and is expected to provide a useful reference and technical support for graduate students, scientists, civil engineers and experts of governments to valorize scientific research

    Nighttime Lights as a Proxy for Economic Performance of Regions

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    Studying and managing regional economic development in the current globalization era demands prompt, reliable, and comparable estimates for a region’s economic performance. Night-time lights (NTL) emitted from residential areas, entertainment places, industrial facilities, etc., and captured by satellites have become an increasingly recognized proxy for on-ground human activities. Compared to traditional indicators supplied by statistical offices, NTLs may have several advantages. First, NTL data are available all over the world, providing researchers and official bodies with the opportunity to obtain estimates even for regions with extremely poor reporting practices. Second, in contrast to non-standardized traditional reporting procedures, the unified NTL data remove the problem of inter-regional comparability. Finally, NTL data are currently globally available on a daily basis, which makes it possible to obtain these estimates promptly. In this book, we provide the reader with the contributions demonstrating the potential and efficiency of using NTL data as a proxy for the performance of regions

    Liberated pixels : alternative narratives for lighting future cities

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 165-171).Lighting and illuminated displays shape our relations to urban environments and to one another at night and increasingly during the day by transforming what Kevin Lynch referred to as the "image of the city" (1964). Today, the wide-spread availability of LEDs (light-emitting diodes) in combination with embedded, miniaturized computation offers different ways of designing ambient infrastructures. In this dissertation, I explore these alternatives by exploiting the programmable and responsive capabilities of LED-based, low-resolution systems. In short, I examine the alternative aesthetic and communications opportunities afforded by a new generation of lighting and display technologies in the city. I investigate the origins of lighting and displays to illustrate how they have evolved through a complex interleaving of the social and the material. This grounding leads me to develop three design explorations that focus on programmability, addressability, responsiveness, mobility and ad-hoc control. The first of these explorations, Urban Pixels, presents a wireless network of individual, autonomous physical pixels that can be deployed on any surface in the city. The second, Light Bodies, reconnects with the history of lights-on-people like lanterns that travel through the city with their users. The third, Augmented-reality (AR) Street Light, provides a layer of programmability for existing infrastructural networks. Together the historical perspective and design interventions lead to a framework of what I call "liberated pixels", a new generation of lighting and display technologies. Liberated pixels can be placed flexibly within any context and recruited in different situations for aesthetic and ambient information purposes. This vision captures the contingent and emergent nature of "sociomaterial assemblages" (Suchman 2007) to chart holistic technical, aesthetic, and social directions for future infrastructures of "imageability" (Lynch 1964) in the city.by Susanne SeitingerPh.D
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