i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...

8.1 Conclusions
CHAPTER 8
CONCLUSIONS AND DISSCUSIONS
In this dissertation, the multi-spectral algorithm for observing and monitoring smoke
and dust aerosols over both bright and dark surfaces is developed by combining
measurements of MODIS solar and thermal bands. Since the algorithm uses its own cloud
module to separate the cloud, the algorithm can detect the smoke/dust at the areas close to
or mixed with clouds. In the algorithm, the spectral curves of several major scene types in
both solar and thermal spectrum, such as smoke, dust, cloud, and vegetated surface and
non-vegetated surface, are derived statistically from large quantity of training data.
According to spectral analysis, the algorithm is divided into land and ocean branches for
smoke detection, and into bright surface and dark surface branches for dust detection. In
the algorithm, the thermal bands are mainly used for filter out cloud, as well as a water
vapor band, while the RSBs are selected for separating smoke/dust from other scene
types. Some indices well developed in others previous studies are adopted directly. And
some tests are proposed first time, including the pseudo-NDVI, the reflectance of blue
band, and the normalized of two blue bands used for smoke detection; and the reflectance
of red band used for dust detection. The spatial resolution of smoke/dust detection results
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