|
|
|
Retrieval of PM10 from ADOES Data
Sultan AlSultan
Al Sultan Environmental Research Center. Al Madina Rd., P.O.Box.
242 Riaydh Al Khabra, Al Qassim, Saudi Arabia.
Tel: +966504890977, Fax: +96663340366
E-mail: allssultan7@hotmail.com
H. S. Lim, M. Z. MatJafri and K. Abdullah
School of Physics, Universiti Sains Malaysia, Minden 11800 Penang, Malaysia.
Tel: +604-6577888, Fax: +604-6579150
E-mail: mjafri@usm.my, khirudd@usm.my
Abstract
AVNIR data captured by the ADOES earth observation satellite was used in this study for air quality mapping. A previously calibrated algorithm for measuring the concentration of atmospheric particles (size less than 10- micron, PM10) over Penang was used for PM10 mapping. Three visible wavelengths bands were used in this study. The surface reflectance values for these three visible wavelengths were determined based on the information given by the Landsat TM data. The atmospheric components were then estimated from the image. The main objective of this study is to evaluate the previously calibrated algorithm for its application with AVNIR satellite data. The retrieved PM10 values were then compared with the in situ PM10 measurements. High correlation was obtained between the measured and the estimated PM10 values. The developed algorithm has been tested successfully on AVNIR data in the urban areas of Penang, Island, Malaysia.
Introduction
The ADEOS primarily aims at observing, monitoring and analysing global-scale environmental changes, such as global warming, ozone depletion and extreme weather, in view of the future forecasting of these global phenomena. Data used in this study was captured by AVNIR sensor. Aerosols play a very important role in the radiation budget of the earth–atmosphere system and affect our climate. Hence the knowledge of their physical or chemical properties is very important. High concentration of aerosols in the atmosphere increases backscattering of solar radiation and atmospheric albedo, thereby reducing the solar energy reaching the ground (Kant, et al., 2000).
Several studies have shown the possible relationships between satellite data and air pollution [Weber, et al., (2001) and Ung, et al, (2001a)]. Other researchers used satellite data in their atmospheric studies, such as NOAA-14 AVHRR (Ahmad and Hashim, 1997) and TM Landsat (Ung, et al., 2001b). In fact, air quality can be measured using ground instruments such as air sample. But these instruments are quite expensive and are limited by the number of air pollutant stations in each area. So, they cannot provide a fine spatial distribution of the air pollutant over a city.
The acquired satellite image doesn’t have in situ PM10 data for algorithm calibration. So, a previously calibrated algorithm for Landsat TM at the same area was used to determine the PM10 from the AVNIR data. The objective of this study is to investigate the used of a calibrated algorithm for PM10 measurements using AVNIR satellite data.
|
|
|