地球信息科学学报 ›› 2020, Vol. 22 ›› Issue (8): 1714-1724.doi: 10.12082/dqxxkx.2020.200128

• 遥感科学与应用技术 • 上一篇    下一篇

基于2种夜间灯光影像亮度修正指数的城市建成区提取研究

闫庆武1,*(), 厉飞1, 李玲2   

  1. 1.中国矿业大学环境与测绘学院,徐州 221116
    2.徐州市规划设计院,徐州 221000
  • 收稿日期:2020-03-20 修回日期:2020-05-12 出版日期:2020-08-25 发布日期:2020-10-25
  • 通讯作者: 闫庆武 E-mail:yanqingwu@cumt.edu.cn
  • 作者简介:闫庆武(1975— ),男,山东邹城人,副教授,主要从事GIS应用、人口地理学、人口数据空间化研究。E-mail:yanqingwu@cumt.edu.cn
  • 基金资助:
    武汉大学测绘遥感信息工程国家重点实验室开放基金(18T03);内蒙古自治区科技计划项目(2060399-273)

Research on Built-up Area Extraction via Brightness Correction Indexes based on Two Kinds of Nighttime Light Images

YAN Qingwu1,*(), LI Fei1, LI Ling2   

  1. 1. School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
    2. Urban Planning and Design Institute of Xuzhou, Xuzhou 221000, China
  • Received:2020-03-20 Revised:2020-05-12 Online:2020-08-25 Published:2020-10-25
  • Contact: YAN Qingwu E-mail:yanqingwu@cumt.edu.cn
  • Supported by:
    Open Fund of State Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University(18T03);Science and technology project of Inner Mongolia Autonomous Region(2060399-273)

摘要:

夜间灯光影像容易受到道路灯光、水面散射等影响而产生背景噪声,这一定程度上影响了利用夜间灯光数据提取建成区的精度。本文基于夜间灯光影像的DN(Digital Number)值与路网密度正相关、与EVI指数(Enhanced Vegetation Index,增强型植被指数)呈负相关的规律,提出了2种可用于建成区提取的夜间灯光亮度修正指数:EVI夜间灯光亮度修正指数EANI (EVI Adjusted Nighttime Light(NTL) Index)和基于道路网密度与EVI指数的夜间灯光亮度修正指数REANI (Road Density & EVI Adjusted NTL Index),并利用珞珈1号卫星(LJ1-01,分辨率约130 m)影像和NPP-VIIRS影像(分辨率约 500 m) 2种不同空间分辨率夜间灯光遥感影像进行验证。以2018年徐州市建成区为研究对象,分区域(主城区、外围区)利用阈值法对2种原始夜间灯光影像、经EANI指数和REANI指数处理后的影像进行建成区提取,得到6种建成区提取的结果。研究表明: ① EANI指数和REANI指数能够有效抑制夜间灯光影像的背景噪声,建成区提取的结果均优于直接利用原始影像的结果,特别是对于城市化水平较低地区的建成区提取效果更佳;② 相较于NPP-VIIRS影像,利用LJ1-01影像提取建成区的效果提高6%左右,说明我国的LJ1-01夜间灯光影像在建成区提取方面有广阔的应用前景。EANI和REANI为建成区提取提供了有效工具,并可应用于城市规划和城市扩张等研究领域。

关键词: 夜间灯光影像, 珞珈01星影像, NPP-VIIRS影像, EANI, REANI, 去噪, 建成区提取, 徐州市

Abstract:

Nighttime light data are widely used to monitor human activities from space, such as urban development, population density simulation, energy gas emissions, power consumption, human activities and effects, economic development level, and ecological environment. However, due to road lights and light scattering from water surface, Nighttime Light (NTL) images always contain a lot of background noises. These background noises may greatly limit the application of nighttime light images in built-up area extraction. In our paper, based on high-resolution nighttime light images of Lujia1-01 from China and NPP-VIIRS from the United States in the second half of 2018, the Enhanced Vegetation Index (EVI) Adjusted NTL Index (EANI) and Road Density & EVI Adjusted NTL Index (REANI) were proposed to reduce background noises and applied to built-up area extraction. The EANI and REANI were developed based on the law that the Digital Number (DN) values of the nighttime light images are positively correlated with road density and negatively correlated with the EVI. In this paper, the Xuzhou city of China was selected as the research area. The threshold method was used to extract built-up areas in the main city and the peripheral area from the original LJ1-01 and NPP-VIIRS images, and the images processed by the EANI and the REANI, respectively. The results show that: (1) both EANI and REANI can effectively reduce background noises in nighttime light images. The results extracted from images processed by these two indexes were much better than that from the original NTL images, especially for the low urbanization areas; and (2) LJ1-01 performed better than NPP-VIIRS in built-up area extraction. Due to the higher spatial resolution of LJ1-01 data, the accuracy of extracted built-up areas from LJ1-01 was much higher than that from NPP-VIIRS in low-level urbanization areas, but was about the same with NPP-VIIRS in areas with high urbanization levels. Through error analysis, the relative error of extracted built-up areas from LJ1-01 decreased by about 6%, which indicates that LJ1-01 nighttime light image is promising for future built-up area extraction. Also, both EANI and REANI provide effective tools for the extraction of built-up areas and could be further applied to researches such as urban planning and urban expansion.

Key words: Nighttime Light Images, LJ1-01 Images, NPP-VIIRS Images, EANI, REANI, denoise, built-up area extraction, Xuzhou City