Retrieval of Air Quality information using image processing technique

摘要

This paper presents and describes an approach to retrieve concentration of particulate matter of size less than 10- micron (PM10) from Landsat TM data over Penang Island. The objective of this study is test the feasibility of using Landsat TM for PM10 mapping using our proposed developed algorithm. The development of the algorithm was developed base on the aerosol characteristics in the atmosphere. PM10 measurements were collected using a DustTrak Aerosol Monitor 8520 simultaneously with the image acquisition. The station locations of the PM10 measurements were detemined using a hand held GPS. The digital numbers were extracted corresponding to the ground-truth locations for each band and then converted into radiance and reflectance values. The reflectance measured from the satellite [reflectance at the top of atmospheric, ρ(TOA)] was subtracted by the amount given by the surface reflectance to obtain the atmospheric reflectance. Then the atmospheric reflectance was related to the PM10 using regression analysis. The surface reflectance values were created using ACTOR2 image correction software in the PCI Geomatica 9.1.8 image processing software. The proposed developed algorithm produced high accuracy and also showed a good agreement (R =0.8406) between the measured and estimated PM10. This study indicates that it is feasible to use Landsat TM data for mapping PM10 using the proposed algorithm.