Determination of Haze from Satellite Remotely Sensed Data: Some Preliminary Results
Materials and Methods
a) Satellite Data
The NOAA 12 AVHRR satellite data dated 30 September 1995 (0657 UTC), which were obtained from the Malaysian Meteorological service were used in this study.
The data was subseted to area of interest - The Penisular Malaysia (see Figure 1).
Eight air pollution stations measurement of TSP at the day of satellite data acquisatin are shown as Table 1.
| Stations:
|
| 1 Bayan Lepas |
5 Kuala Terengganu |
| 2 Peteling Jaya |
6 Mersing |
| 3 Perai |
7 Kuantan |
| 4 Melaka |
8 Batu Embun |
Figure 1: The NOAA-12 AVHRR data (combination of channel 1, 2, 3, 4 and 5) of
Penisular Malaysia and the location of Air Pollution Stations. The air pollution
stations is demarcated by triangular points.
(b) Total Suspended Particulates (TSP)
The suspended particulates (generally known as aerosols) are minute non-aqueous matter (sizes ranging from 0.1 microns to 100 microns) floating in the atmosphere that will never settle to the ground because their higher buoyancy forces exceed the gravitational pull (Malaysian Meteorological Service, 1995).
The ground measured total suspended particulates (TSP) used in this study are collected from the Malaysian Meteorological Service. The corresponding TSP values at the selected eight air pollution stations are shown in Table 1.
Table 1 : Total Suspended Particulates (TSP) readings for 30 September 1995 (modified after Malaysian Meteorological Service, 1995)
| |
Air Pollution Station |
Geographic Coordinates |
Altitude (m) |
*Instrument Used |
TSP(mgm/m3) |
| Latitude |
Longitude |
| 1. |
Bayan Lepas |
05° 18'N |
100°16'E |
3.3 |
HVAS&AAPS |
29 |
| 2. |
Petaling Jaya |
03°06'N |
101°39'E |
45.7 |
HVAS & APS |
78 |
| 3. |
Perai |
05°21'N |
100°24'E |
1.0 |
HVAS &AAPS |
164 |
| 4. |
Melaka |
02°16'N |
102°15'E |
8.0 |
HVAS&ERNI |
43 |
| 5. |
Kuala Terengganu |
05°23'N |
103°06'E |
5.0 |
HVAS&AAPS |
36 |
| 6. |
Mersing |
02°27'N |
103°50'E |
44.0 |
HVPM10&APS |
24 |
| 7. |
Kuantan |
03°47'N |
103°13'E |
15.3 |
HVPM10&APS |
28 |
| 8. |
Batu Embun |
03°58'N |
102°21'E |
59.5 |
HVPM10&APS |
26 |
*Note
HVPM : High Volume PM10 Sampler
HVAS : High Volume Air Pollution Sampler
AAPS : Automatic Air Population Sampler
APS : Acid Precipitation Sampler
ERNI : Automatic Precipitation Sampler
c) Data Processing
All image processing tasks were carried out using PCI EASI/PACE digital image processing system at UTM Centre of Remote Sensing. Presumption was made in this study that each TSP measurement presented in Table 1 representing a locus of 2 km radius around each of the air pollution stations. In the geometrically corrected data location of the air pollution station were determined, hence the reflectance of the pixels within the 2 km-locus can also be determined. The relationship between the satellite data recorded by AVHRR (for all channels) and the TSP measured at all stations were analysed. The results of this study is shown in the following section.
