Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Baghdad Nights: Evaluating the US Military ‘Surge’ Using Nighttime Light Signatures John Agnew Thomas W. Gillespie Jorge Gonzalez Brian Min CCPR-064-08 December 2008 Latest Revised: December 2008 California Center for Population Research On-Line Working Paper Series <s> BIB001 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> We have produced annual estimates of national and global gas flaring and gas flaring efficiency from 1994 through 2008 using low light imaging data acquired by the Defense Meteorological Satellite Program (DMSP). Gas flaring is a widely used practice for the disposal of associated gas in oil production and processing facilities where there is insufficient infrastructure for utilization of the gas (primarily methane). Improved utilization of the gas is key to reducing global carbon emissions to the atmosphere. The DMSP estimates of flared gas volume are based on a calibration developed with a pooled set of reported national gas flaring volumes and data from individual flares. Flaring efficiency was calculated as the volume of flared gas per barrel of crude oil produced. Global gas flaring has remained largely stable over the past fifteen years, in the range of 140 to 170 billion cubic meters (BCM). Global flaring efficiency was in the seven to eight cubic meters per barrel from 1994 to 2005 and declined to 5.6 m 3 per barrel by 2008. The 2008 gas flaring estimate of 139 BCM represents 21% of the natural gas consumption of the USA with a potential retail market value of $68 billion. The 2008 flaring added more than 278 million metric tons of carbon dioxide equivalent (CO 2 e) into the atmosphere. The DMSP estimated gas flaring volumes indicate that global gas flaring has declined by 19% since 2005, led by gas flaring reductions in Russia and Nigeria, the two countries with the highest gas flaring levels. The flaring efficiency of both Russia and Nigeria improved from 2005 to 2008, suggesting that the reductions in gas flaring are likely the result of either improved utilization of the gas, reinjection, or direct venting of gas into the atmosphere, although the effect of uncertainties in the satellite data cannot be ruled out. It is anticipated that the capability to estimate gas flaring volumes based on satellite data will spur improved utilization of gas that was simply burnt as waste in previous years. <s> BIB002 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> The present study describes the night-time active forest fire detection capabilities of Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) satellite data over the forest region of Kerala State, India in 2004. Kerala State had a high incidence of forest fires during 2004 because of the extended dry season, with the unusual absence of intermittent rainfall from January to April. DMSP-OLS data were processed to detect active night-time forest fires over Kerala State and validated with ground data and fine-resolution Indian Remote Sensing (IRS)-P6 Advanced Wide Field Sensor (AWiFS) satellite imagery. DMSP-OLS-derived night-time fire products were compared with synchronous Moderate Resolution Imaging Spectroradiometer (MODIS)-derived daytime fire products to check for the spatial agreement and continuity of fires. To estimate the burnt areas, different atmospheric correction algorithms were applied to the IRS-P6 AWiFS dataset; these included the cosine approximation model (COST), ATCOR2 in ERDAS Imagine and the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) code. Atmospheric corrections to the satellite data indicated significant improvement in burnt area estimates. The results of the study suggest a good correlation between AWiFS data-derived burnt areas, DMSP-OLS-derived fire counts and MODIS-derived fire products. The fire occurrences derived from DMSP-OLS and MODIS data were validated with field records on fire occurrences over the study area. <s> BIB003 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Methods to map artificial night sky brightness and stellar visibility across large territories or their distribution over the entire sky at any site are based on the computation of the propagation of light pollution with Garstang models, a simplified solution of the radiative transfer problem in the atmosphere which allows a fast computation by reducing it to a ray-tracing approach. We present here up-to-date Extended Garstang Models (EGM) which provide a more general numerical solution for the radiative transfer problem applied to the propagation of light pollution in the atmosphere. We also present the LPTRAN software package, an application of EGM to high-resolution DMSP-OLS satellite measurements of artificial light emissions and to GTOPO30 digital elevation data, which provides an up-to-date method to predict the artificial brightness distribution of the night sky at any site in the World at any visible wavelength for a broad range of atmospheric situations and the artificial radiation density in the atmosphere across the territory. EGM account for (i) multiple scattering, (ii) wavelength from 250 nm to infrared, (iii) Earth curvature and its screening effects, (iv) sites and sources elevation, (v) many kinds of atmosphere with the possibility of custom setup (e.g. including thermal inversion layers), (vi) mix of different boundary layer aerosols and tropospheric aerosols, with the possibility of custom setup, (vii) up to 5 aerosol layers in upper atmosphere including fresh and aged volcanic dust and meteoric dust, (viii) variations of the scattering phase function with elevation, (ix) continuum and line gas absorption from many species, ozone included, (x) up to 5 cloud layers, (xi) wavelength dependant bidirectional reflectance of the ground surface from NASA/MODIS satellites, main models or custom data (snow included), (xii) geographically variable upward light emission function. <s> BIB004 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> The primary focus of this research is to estimate light pollution in the urban and suburban regions of Pakistan with the help of satellite remote sensing (SRS) and geographic information system (GIS) techniques. Analog maps and multi-temporal nighttime images of the Defense Meteorological Satellite Program (DMSP) onboard Operational Linescan System (OLS) sensor were used in this study. A series of direct and indirect light pollution maps of the study area were generated and analyzed. The results of the study show that in the urban environment, light pollution is mainly due to artificial nightlight sources. <s> BIB005 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Historically, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) was the unique satellite sensor used to collect the nighttime light, which is an efficient means to map the global economic activities. Since it was launched in October 2011, the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (NPP) Satellite has become a new satellite used to monitor nighttime light. This study performed the first evaluation on the NPP-VIIRS nighttime light imagery in modeling economy, analyzing 31 provincial regions and 393 county regions in China. For each region, the total nighttime light (TNL) and gross regional product (GRP) around the year of 2010 were derived, and a linear regression model was applied on the data. Through the regression, the TNL from NPP-VIIRS were found to exhibit R2 values of 0.8699 and 0.8544 with the provincial GRP and county GRP, respectively, which are significantly stronger than the relationship between the TNL from DMSP-OLS (F16 and F18 satellites) and GRP. Using the regression models, the GRP was predicted from the TNL for each region, and we found that the NPP-VIIRS data is more predictable for the GRP than those of the DMSP-OLS data. This study demonstrates that the recently released NPP-VIIRS nighttime light imagery has a stronger capacity in modeling regional economy than those of the DMSP-OLS data. These findings provide a foundation to model the global and regional economy with the recently availability of the NPP-VIIRS data, especially in the regions where economic census data is difficult to access. <s> BIB006 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Daytime measurements of reflected sunlight in the visible spectrum have been a staple of Earth-viewing radiometers since the advent of the environmental satellite platform. At night, these same optical-spectrum sensors have traditionally been limited to thermal infrared emission, which contains relatively poor information content for many important weather and climate parameters. These deficiencies have limited our ability to characterize the full diurnal behavior and processes of parameters relevant to improved monitoring, understanding and modeling of weather and climate processes. Visible-spectrum light information does exist during the nighttime hours, originating from a wide variety of sources, but its detection requires specialized technology. Such measurements have existed, in a limited way, on USA Department of Defense satellites, but the Suomi National Polar-orbiting Partnership (NPP) satellite, which carries a new Day/Night Band (DNB) radiometer, offers the first quantitative measurements of nocturnal visible and near-infrared light. Here, we demonstrate the expanded potential for nocturnal low-light visible applications enabled by the DNB. Via a combination of terrestrial and extraterrestrial light sources, such observations are always available—expanding many current existing applications while enabling entirely new capabilities. These novel low-light measurements open doors to a wealth of new interdisciplinary research topics while lighting a pathway toward the optimized design of follow-on satellite based low light visible sensors. <s> BIB007 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> The objective of this research is to investigate the potential of nighttime light images, acquired with Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS), in evaluating global armed conflicts. To achieve this purpose, we assessed the relationship between armed conflicts and the satellite-observed nighttime light variation over 159 countries through annual composites of the nighttime light images. Firstly, a light ratio index was developed to reduce the data inconsistency of annual nighttime light images during 1992-2010. Then 12 countries were selected as examples for a primary investigation, and we found the outbreak of a war can reduce the light and the ceasefire can increase the light from the remote sensing images, which indicates armed conflict events always have significant impact on the nighttime light. Based on this assertion, a nighttime light variation index (NLVI) was developed to quantify the variation of the time series nighttime light. Then using conditional probability analysis, the probability of a country suffering from armed conflicts increases with increase of NLVI. Particularly, when the NLVI value is in a very high level as defined, 80% of the countries have experienced armed conflicts. Furthermore, using correlation analysis, the number of global armed conflicts is highly correlated with the global NLVI in temporal dimension, with a correlation coefficient larger than 0.77. In summary, the potential of nighttime light images in armed conflict evaluation is extended from a regional scale to a global scale by this study. <s> BIB008 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Abstract Previous studies demonstrated that DMSP-OLS stable nighttime light data are useful data source for delineating urban areas. However, the nighttime light data acquired in different years are not directly comparable, due to the variations in atmospheric condition from year to year and the periodic change in satellite sensor. This makes it difficult to use the time series nighttime light data for urban growth analysis. This paper presents a novel technique for normalizing time series DMSP/OLS nighttime light data and deriving urban detection threshold using Pseudo Invariant Features (PIFs). Our technique consists of three steps: (1) estimate an optimal threshold value for urban area detection for a reference year, when high resolution image data are available for some local areas. (2) Based on the irreversible nature of urbanization process, determine a set of PIFs, which are deemed as urban areas and did not exhibit significant change in nighttime light condition during the study period. (3) Normalize the time series DMSP-OLS data sets based on the PIFs and linear regression, determine optimal threshold values for urban area detection for all years based on the reference year threshold value, and extract urban areas accordingly. This technique was successfully applied to time series DMSP-OLS nighttime light images of the Central Liaoning region in China. Patterns of this urban agglomeration's spatial–temporal evolution from 2000 to 2010 were mapped and analyzed. The reliability and spatial accuracy of this technique were evaluated with multitemporal Landsat TM images. The technique was proved accurate and effective. <s> BIB009 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> The nighttime light data records artificial light on the Earth’s surface and can be used to estimate the spatial distribution of the gross domestic product (GDP) and the electric power consumption (EPC). In early 2013, the first global NPP-VIIRS nighttime light data were released by the Earth Observation Group of National Oceanic and Atmospheric Administration’s National Geophysical Data Center (NOAA/NGDC). As new-generation data, NPP-VIIRS data have a higher spatial resolution and a wider radiometric detection range than the traditional DMSP-OLS nighttime light data. This study aims to investigate the potential of NPP-VIIRS data in modeling GDP and EPC at multiple scales through a case study of China. A series of preprocessing procedures are proposed to reduce the background noise of original data and to generate corrected NPP-VIIRS nighttime light images. Subsequently, linear regression is used to fit the correlation between the total nighttime light (TNL) (which is extracted from corrected NPP-VIIRS data and DMSP-OLS data) and the GDP and EPC (which is from the country’s statistical data) at provincial- and prefectural-level divisions of mainland China. The result of the linear regression shows that R2 values of TNL from NPP-VIIRS with GDP and EPC at multiple scales are all higher than those from DMSP-OLS data. This study reveals that the NPP-VIIRS data can be a powerful tool for modeling socioeconomic indicators; such as GDP and EPC. <s> BIB010 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> The first global night-time light composite data from the Visible Infrared Imaging Radiometer Suite (VIIRS) day–night band carried by the Suomi National Polar-orbiting Partnership (NPP) satellite were released recently. So far, few studies have been conducted to assess the ability of NPP-VIIRS night-time light composite data to extract built-up urban areas. This letter aims to evaluate the potential of this new-generation night-time light data for extracting urban areas and compares the results with Defense Meteorological Satellite Program–Operational Linescan System (DMSP-OLS) data through a case study of 12 cities in China. The built-up urban areas of 12 cities are extracted from NPP-VIIRS and DMSP-OLS data by using statistical data from government as reference. The urban areas classified from Landsat 8 data are used as ground truth to evaluate the spatial accuracy. The results show the built-up urban areas extracted from NPP-VIIRS data have higher spatial accuracies than those from DMSP-OLS data for al... <s> BIB011 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> China’s rapid urbanization has led to increasing steel consumption for buildings and civil engineering infrastructure. The in-use steel stock in the same is considered to be closely related to social welfare and urban metabolism. Traditional approaches for determining the in-use steel stock are labor-intensive and time-consuming processes and always hindered by the availability of statistical data. To address this issue, this study proposed the use of long-term nighttime lights as a proxy to effectively estimate in-use steel stock for buildings (IUSSB) and civil engineering infrastructure (IUSSCE) at the provincial level in China. Significant relationships between nighttime lights versus IUSSB and IUSSCE were observed for provincial variables in a single year, as well as for time series variables of a single province. However, these relationships were found to differ among provinces (referred to as “inter-individual differences”) and with time (referred to as “temporal differences”). Panel regression models were therefore proposed to estimate IUSSB and IUSSCE in consideration of the temporal and inter-individual differences based on a dataset covering 1992–2007. These models were validated using data for 2008, and the results showed good estimation for both IUSSB and IUSSCE. The proposed approach can be used to easily monitor the dynamic of IUSSB and IUSSCE in China. This should be critical in providing valuable information for policy making regarding regional development of buildings and infrastructure, sustainable urban resource management, and cross-boundary material recycling. <s> BIB012 </s> Application of DMSP/OLS Nighttime Light Images: A Meta-Analysis and a Systematic Literature Review <s> Major Challenges <s> Contrasting trends in light pollution across Europe based on satellite observed night time lights <s> BIB013
Although enhanced nighttime images are currently collected by the new VIIRS sensor along with the OLS nighttime images, OLS nighttime images will still be a dominant data source for a large number of empirical applications as they provide a relatively consistent dataset on nighttime light over the past two decades. Based on how these data have been applied and considering the new data source from the VIIRS sensor, we argue that several challenges should be tackled. First, ensuring the comparability and consistency of data will be a major obstacle. In our review, we found that the release of different datasets derived from the DMSP/OLS database increased the extent and depth of studies. However, even the latest Version 4 dataset has apparent limitations in terms of data comparability and consistency BIB002 BIB009 . Thus, a new rigorous and robust dataset of long-term nighttime images after systematic inter-annual and inter-satellite calibrations could stimulate relevant studies. The tradeoff between loss of information after calibration and comparability before calibration is a noteworthy consideration. In addition, novel methods that can integrate OLS images with VIIRS images and guarantee their comparability will encourage the use of OLS images and VIIRS images simultaneously; this has the potential to prolong the availability of data for VIIRS images as well as enhance the spatial and spectral resolution of OLS images. Second, new methods that improve data quality and performance need to be developed. While radiance-calibration and the reduction of blooming and saturation effects are two main ways to enhance the meaning and performance of these data, improving current methods for extracting expected information automatically and intelligently is also a potential research direction. Third, comparative studies between OLS and VIIRS images will attract considerable attention. Although nighttime images collected from the VIIRS sensor have been released, empirical research based on these datasets is rare. Comparing results of studies on the same research topic between the old OLS images and the new VIIRS images will allow us to further understand the advancement and intrinsic limitations of the new database BIB006  BIB007 BIB010 BIB011 . Therefore, it can answer a series of research questions, such as how does the VIIRS images perform in overcoming the saturation and blooming phenomena in OLS images; does the improved quality of VIIRS images contribute to better estimations of social-economic parameters, and how to fuse the data from the two sensors? Fourth, fully exploring the potential of DMSP/OLS nighttime images from the perspective of multidisciplinary or interdisciplinary research will be a key research area. Interesting results and applications can be discovered by combining DMSP/OLS nighttime images with research from a broader range of disciplines. For example, a recent study has found a positive association between regional nighttime light intensity and the birth region of current political leaders worldwide  . The results supported the hypothesis of regional favoritism that some political leaders may make political decisions beneficial to their birth regions. Other examples can be found in modeling in-use steel stock in buildings and civil engineering infrastructure BIB012 , monitoring trend of light pollution BIB004 BIB005  BIB013 and evaluating global armed conflicts BIB001 BIB003 BIB008 . Finally, we suggest that a transparent platform will be important for communicating and discussing application areas. This platform can collect different versions of processed nighttime images, open-source algorithm codes for different applications, and results under the same research target at different locations and scales. This will be beneficial for validating research results, improving existing extracting methods, and discovering and examining academic assumptions at different scales. Furthermore, this will improve the communication of research results within academia, and among scientists, the public, and political stakeholders.