Geospatial Nightlight Dataset for Sub-districts of India

Geospatial data have become a valuable asset in the 21st century with its applications in almost everyday life and an overriding scope in the field of research. One such growing spatial data is the remotely sensed nighttime lights (NTL) imagery, which simply is a depiction of human activities around the globe at night. It may be a stunning visual to many yet the valuable insights it provides in measuring a number of parameters like population, poverty, electrification, migration, disaster, health, fishing, fires, GDP, pollution, urbanization, settlement, etc. have made researchers and scientists look up to this data to validate and evaluate socio-economic and other indicators independently and concurrently. Apart from using as a proxy in many researches, NTL allows to track statistics of region where data is often not collected or is not reliable. It has potential applications for policy makers and government in the decision making processes. Nighttime lights were in used since the mid 1990's and are publicly made available from 1992 onwards through the Defense Meteorological Satellite Program (DMSP) provided by National Ocean and Atmospheric Administration (NOAA). A more advance system called Visible Infrared Imaging Radiometer Suite (VIIRS) Day Night band (DNB) replaces DMSP system. The extraction provided uses VIIRS monthly aggregates with spatial polygon units of India at sub-districts level. The monthly raw dataset is available from April 2012 onwards. This extraction cover 141 months till December 2023. The primary intent is to disseminate the dataset to a larger audience, be it researcher or policy analyst and planners. The broader objective is to keep on updating the data continuously.

地理空间数据已成为21世纪的宝贵资产，其应用覆盖日常生活的诸多场景，在科研领域亦拥有举足轻重的地位。其中一类日益受到关注的空间数据是遥感夜间灯光（Remotely Sensed Nighttime Lights, NTL）影像，其本质是全球夜间人类活动的可视化记录。对多数人而言，它或许只是一幅颇具视觉冲击力的画面，但其可用于测算人口、贫困、通电率、人口迁移、灾害、健康、渔业、火情、国内生产总值（GDP）、污染、城市化、人居聚落等诸多参数，所提供的宝贵价值使得科研人员与科学家纷纷依托该数据，独立且同步地验证、评估社会经济及其他各类指标。除作为诸多研究的替代指标之外，NTL还可用于统计那些通常难以获取数据或数据可靠性不足的地区的相关信息。该数据可为政策制定者与政府部门的决策流程提供潜在应用价值。夜间灯光数据自20世纪90年代中期开始投入使用，并自1992年起通过美国国防气象卫星计划（Defense Meteorological Satellite Program, DMSP）由美国国家海洋和大气管理局（National Ocean and Atmospheric Administration, NOAA）对外公开提供。更为先进的可见光红外成像辐射仪套件（Visible Infrared Imaging Radiometer Suite, VIIRS）日夜波段（Day Night Band, DNB）系统取代了此前的DMSP系统。本次提供的数据集提取产物采用VIIRS月度聚合数据，空间单元为印度乡级（分区级）行政多边形。原始月度数据集自2012年4月起对外公开。本次数据集覆盖至2023年12月，共计141个月份。本次发布的核心目的是面向更广泛的受众——包括科研人员、政策分析师与规划者——共享该数据集。其长期目标则是持续对该数据集进行更新维护。