Author: | Song, Siyang |
Title: | Research of Aerosol Optical Thickness retrieval using HJ-1 CCD data in the Pearl River Delta region |
Degree: | M.Sc. |
Year: | 2014 |
Subject: | Atmospheric aerosols -- China -- Pearl River Delta Aerosols -- Measurement Hong Kong Polytechnic University -- Dissertations |
Department: | Faculty of Construction and Environment |
Pages: | ix, 90 pages : color illustrations ; 30 cm |
Language: | English |
Abstract: | With the aggravation of the atmosphere pollution, the impact of aerosols on climate and environment has been realized by an increasing number of people. The Pearl River Delta (PRD) region, as the developed area in the southern of China, suffers the severe air pollution. HJ-1 satellites which are responsible for environmental monitoring and disaster alleviation have great application potential for aerosol retrieval due to the reasonable design of spectral bands and impressive high spatial and temporal resolution. However, as things stand, applying HJ-1 satellites to Aerosol Optical Thickness (AOT) retrieval still has a lot of development space. This study aims at using the modified Dense Dark Vegetation (DDV) algorithm to retrieve AOT value over PRD region. Original DDV algorithm is widely adopted by MODerate Resolution Imaging Spectroradiometer (MODIS) data. Compare with MODIS data, due to lack of 2.1μm shortwave infra-red band, HJ-1 Charge Coupled Device (CCD) data has to identify dark pixels by virtue of applying vegetation index. In this study, the Atmospherically Resistant Vegetation Index (ARVI) has been chosen in order to reduce the atmospheric influence. The Look Up Table (LUT) will be constructed by 6S radiation transfer model to simulate the relation between AOT and atmospheric parameters. Finally, taking advantages of the ratio existed between the reflectance of red band and that of blue band, the AOT could be retrieved. Through making comparisons with AErosol RObotic NETwork (AERONET) ground-based sunphotometer data and MODIS Level 2 product MOD04, the retrieval result of HJ-1 CCD data has an acceptable and satisfied quality and accuracy. The distribution and change tendency of AOT could be seen as identical with other two datasets. The correlation coefficient between AOT and AERONET data is 0.785, while that between AOT and MOD04 is 0.879, which proves that the accuracy of AOT retrieval by HJ-1 CCD data to a certain degree. |
Rights: | All rights reserved |
Access: | restricted access |
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File | Description | Size | Format | |
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b2759130x.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 7.32 MB | Adobe PDF | View/Open |
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