Showing papers by "Pavan Kumar published in 2019"

Modeling the luminous intensity of Beijing, China using DMSP-OLS night-time lights series data for estimating population density

Abstract: Various scientific researches were conducted to monitor human activities and natural phenomena with the availability of various night time satellite data such as Defense Meteorological Satellite Program (DMPS). Population growth especially in a faster growing economy like China is an important indicator for assessing socio-economic development, urban planning and environmental management. Thus, spatial distribution of population is instrumental in assessing growth and developmental activities in Beijing city of China. The satellite observation data derived from Defense Meteorological Satellite Program (DMSP) was utilized to estimate population density through the measurement of light flux with radiometric recording. The data was calibrated using C0, C1, C2 parameters before processing. Population density of Beijing city was estimated using light volume of this calibrated data. Regression analysis between urban population and light volume revealed high correlation ( r 2 = 0.89 ) . Thus, population density can effectively be estimated using light intensity. The model used for estimating urban population density can effectively be utilized for other major cities of the world.

Analyzing trend in artificial light pollution pattern in India using NTL sensor's data

Abstract: Exponential growth of population and the resultant rapid rate of urbanization and industrialization in India have significantly transformed its nighttime light environment. The study makes an attempt to analyze the spatio-temporal pattern of light pollution and its causative actors in a fast-developing economy. We utilized nighttime light data from 1993 to 2013 and calibrated through linear regression. Ten patches of major changes from the whole study area were selected to assess the intensity of light pollution at regional scale. Spatial analysis of light pollution in selected patches revealed that New Delhi, Telangana, Maharashtra, Karnataka and Uttar Pradesh experienced increase in very high light pollution intensity. West Bengal, Gujarat and Tamil Nadu witnessed a remarkable change from low to high light pollution. Urban expansion, industrial development and air pollution are main drivers for increasing light pollution. Strong correlation was found between light pollution and digital numbers (DN) values at regional scale. The maps generated through Defense Meteorological Satellite Program Operational Line Scanner Night Time Light data not only helped in assessing the intensity of light pollution but also identified its causative actors.The results of study can effectively be utilized for setting priorities of environmental protection in different geographical regions at various scales.

Future Challenges and Perspective of Remote Sensing Technology

Abstract: During the last few decades, the world has experienced a remarkable and rapid advancement in the field of remote sensing, acquisition of geospatial information and mapping. The technology has gained momentum in its utilization and application in different fields. With increased demand of geospatial data, various space-borne, airborne and ground-based remote sensing technologies have been instigated and put into venture. Consequently, various research institutes, government agencies as well as private sectors are excessively utilizing this technology for getting timely data. This has resulted into easy accessibility and utilization of remote sensing data for finding solutions to more complicated problems. However, it experienced many challenges. Handling large volume of data and complex data formats with complex processing is a major issue to be tackled. Hence, real-time data processing and open GIS conversing data formats will go a long way for better utilization of spatial data. The technology has wide potential in analysing land, vegetation and water resources. Landsat, SPOT, Sentinel, IRS, IKONOS, QuickBird, etc. high-resolution data are in great use for making inventory and analysing various aspects of human interaction with land, water and vegetation. In this backdrop, the book presents an overview of the potential challenges and the perspective of the fast-growing geospatial technology.

Forest biomass estimation using remote sensing and field inventory: a case study of Tripura, India

Abstract: Forests are the potential source for managing carbon sequestration, regulating climate variations and balancing universal carbon equilibrium between sources and sinks. Further, assessment of biomass, carbon stock, and its spatial distribution is prerequisite for monitoring the health of forest ecosystem. Moreover, vegetation field inventories are valuable source of data for estimating aboveground biomass (AGB), density, and the carbon stored in biomass of forest vegetation. In view of the importance of biomass, the present study makes an attempt to estimate temporal AGB of Tripura State, India, using Moderate Resolution Imaging Spectroradiometer (MODIS), normalized difference vegetation index (NDVI), leaf area index (LAI) and the field inventory data through geospatial techniques. A model was developed for establishing the relationship between biomass, LAI, and NDVI in the selected study site. The study also aimed to improve method for quantifying and verifying inventory-based biomass stock estimation. The results demonstrate the correlation value obtained between LAI and NDVI were 0.87 and 0.53 for the years 2011 and 2014, respectively. The correlation value between estimated AGB with LAI were found as 0.66 and 0.69, while with NDVI, the values were obtained as 0.64 and 0.94 for the years 2011 and 2014, respectively. The regression model of measured biomass with MODIS NDVI and LAI was developed for the data obtained during the period 2011–2014. The developed model was used to estimate the spatial distribution of biomass and its relationship between LAI and NDVI. The R2 values obtained were 0.832 for estimated and the measured AGB during the training and 0.826 for the validation. The results indicate that the methodology adopted in this study can help in selecting best fit model for analyzing relationship between AGB and NDVI/LAI and for estimating biomass using allometric equation at various spatial scales. The developed output thematic map showed an average biomass distribution of 32–94 Mg ha−1. The highest biomass values (72–95 Mg ha −1) was confined to the dense region of the forest while the lowest biomass values (32–46 Mg ha−1) was identified in the outer regions of the study site.

Inter-calibration and Urban Light Index of DMSP-OLS Night-Time Data for Evaluating the Urbanization Process in Australian Capital Territory

Abstract: The magnification mechanism of human settlement is called urbanization, involving various other activities such as population transition, resource consumption, etc. leading to various growing patterns of urban augmentation. The assessment of such spatial pattern is crucial in developing a sustainable urban agglomeration. Night-time light (NTL) data is an important machination for such assessment and detailed monitoring. In this paper, DMSP-OLS (the Defence Meteorological Satellite Program/Operational Linescan Program) datasets have been used to assess the urban straggle of Australian Capital Territory (ACT) and to delineate the urban extent from 1992 to 2012, at an interval of 3 years. DMSP-OLS has the unique capability to detect synthetic lights from cities, towns, industrial sites, ports, etc. Moreover, using ARC GIS calligraphies, 20 random points were selected from the extracted area of interest (AOI). Pixels values of those 20 random points are derived from the given time series dataset (1992–2012). A regression value was extracted from each year by using a second-order polynomial equation. A polynomial regression model is also constructed by taking the regression values and the time series as the two variables, respectively. Urban light index (ULI) is also constructed for analysing the progression of urbanization in ACT from 1992 to 2012 with the help of a derived formula. Furthermore, a unit circle buffer zone having a radius of 20 km is established by taking the centre of each built-up zone as the focal point of the constructed buffer, to compare easily the rate of expansion of urbanization. The present paper indicates the growing potential of the DMSP-OLS night-time satellite data to define the urban light space information, which truly describes the attributes of urban sprawl, and to delineate the evolution of urban morphology and urban extension.

Exploring Geomorphic Processes and Martian Gale Crater Topography on Mars using CTX and HiRISE Express Image Dataset

Abstract: . Exploration of Martian surface and the crater deposition has recently attracted scientific community. We hypothesized the existence of momentous topographic features of different origin on the Martian surface. It was observed that Gale Crater has a thick sediment deposition mainly of fluvial and aeolian origin. This study has utilized spatially referenced topographic dataset Context Camera images acquired from Mars reconnaissance orbiter for exploring the geomorphic processes and topography of Gale Crater. A base map was prepared by mosaicking all imagesfor preparing geomorphologic map of the crater. Surface map of the topography of the Crater was prepared using Mars Orbiter Laser Altimeter (MOLA) data. HiRISE images were used to examine the identified geomorphic features. Results revealed that the presence of both fluvial and aeolian processes and their respective associated landforms in the Crater. Depositional landforms such as alluvial fan, inverted channel and mound and erosional landform namely canyons were distinctly identified on the image. Yardangs produced by erosional and ripple and dunes formed by the depositional work of wind were also identified in the Crater. The fluvial channel, inverted channels and fan shaped deposits further signifies ongoing aqueous activity on the Gale Crater. Sinuous ridges are the common features present on the floor of Crater. Rock particles, sand and silt in the crater were found to have been transported and deposited by flowing water on its floor. Presence of different sedimentary structures and valley revealed ancient sedimentary deposition due to water action. Significant ejecta morphologies were also identified on Martian surface. Our study confirms the previous studies that presence of H2O sub surface volatiles. Concentrations of volatiles have produced double layer ejecta morphology. The concept and findings of this study will escalate knowledge about the surface features on Gale Crater. However, more coherent investigation is needed for modelling and understanding the processes and landforms of the crater. Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE) images have proved useful for geomorphic and topographic mapping of the Mars planet. The dataset used in this study can be accessed on Mars Orbital Data Explorer ( https://ode.rsl.wustl.edu/mars/indexproductsearch.aspx ).

Assessment of Forest Species Diversity in Sariska Tiger Reserve, Rajasthan, India

Abstract: This study makes an attempt to assess tree species diversity in Sariska Tiger Reserve (STR), Rajasthan, India, using Sentinel-2A data. We collected tree samples from ten plots in STR through random variable probability selection method. A total of 62 different species and 584 individual trees were selected from the plots using a principal coordinates of neighborhood matrices (PCNM). Four ecological indicator indices, namely, Margalef index (SR), Simpson’s diversity (D) index, Shannon-Wiener index (H′), and Pielou’s index (J), were utilized for measuring species diversity. Results revealed that Simpson’s diversity (D) index was more suited for determining species diversity, while Shannon-Wiener index (H/) was found to be the best index for assessing species richness. The methodology used in this study can help forest managers, environmentalist, and conservationist for formulating policies for management of forest ecosystem at various scales. This approach will be instructive in examining varied tree species and their richness with Simpson’s diversity (D) index and Shannon-Wiener index (H/).