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Poster Session
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Using TM data to quantify the contribution of
chlorophyll, phytoplankton and fish productivity
Huang Qi-Quan
Remote Sensing Center of Chinese Academy
of
Fishery Sciences, Beijing 100039, China
Abstract
In this article, data sampling, spectral measurement, TM image band selection, mosaic, image processing and computer auto classify will be described. An active economic, accurate, and quick method to quantify chlorophyll (CHL) and phytoplankton biomass (PPB) had been designed out by using TM data with computer image processing system.
Methods
- Spectrum Measurement and Data Sampling
The in situ measurement and investigation were carried out during August 24 to 26, 1989. 12 sampling stations were selected by experts who is familiar with lake Taihu. These 12 sampling datas were used as the control data to calculate the CHL and PPB over the whole lake.
12 spectral reflection and CHL curves were depicted using the in situ data. The spectral band ranges from 400nm to 900nm corresponding to the TM data from bandl to band4.
- TM Image acquirement
Landsat TM data was got from Remote Sensing Ground Station of Chinese Academy of Sciences in may 30, 1989. Two scenes of TM image (path=119, row=38 39) were combined into one scene (6) (Including water body, land, urban and island). By means of task "DF' of image process system the working region of Taihu scene can copy out.
- Correlation Analysis and Image Processing
The 12 groups of sampling data are listed in table 1.
| Station no. |
CHL (ug/1) |
PPB (mg/1) |
Depth (m) |
Weather |
| 1 |
7.5 |
22.61 |
1.85 |
fine |
| 2 |
13.8 |
43.85 |
3.00 |
fine |
| 11 |
9.9 |
31.90 |
2.90 |
cloudy |
| 5 |
2.2 |
7.42 |
2.50 |
fine |
| 7 |
2.5 |
7.70 |
1.90 |
fine |
| 4 |
3.8 |
11.97 |
2.70 |
fine |
| 3 |
3.5 |
9.09 |
2.50 |
fine |
| 10 |
3.9 |
9.15 |
3.4 |
cloudy |
| 9 |
2.7 |
6.81 |
3.00 |
fine |
| 8 |
3.4 |
11.25 |
2.70 |
fine |
| 6 |
2.7 |
6.86 |
2.20 |
fine |
| 12 |
4.5 |
19.94 |
2.60 |
cloudy |
A.The TM data characters were listed in table 2.
| TM band |
Band range |
Colour |
Spectrum characters |
| band 1 |
0.45-052 |
blue |
water quality,depth |
| band2 |
0.52-0.60 |
green |
distinguish water and wat.weed |
| band3 |
0.63-0.69 |
red |
enhance vegetible, non-vegetible CHL absorbed band |
| band4 |
0.76-0.90 |
near
infrared |
great contrast between plant and water. obvious reflection for water weeds. |
| band 5 |
1.55-1.75 |
near
infrared |
distinguish vegetibles,obvious for soil moisture |
| band 6 |
10.4-12.5 |
thermal
infrared |
calculate the surface tem. and eatimate the plant production |
| band7 |
2.08-2.35 |
mid
infrared |
to map geological structure |
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