i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...
i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...
i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...
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7.3 Chapter Summary<br />
The mis-registration, or the BBR shift, has been observed between the b<strong>and</strong>s <strong>and</strong><br />
FPAs by the ground target approach <strong>and</strong> by the Spectro-Radiometric Calibration<br />
Assembly (SRCA). The impact analysis <strong>of</strong> MODIS BBR shift on MODIS L1B data <strong>and</strong><br />
science data products is performed based on the SRCA on-orbit spatial characterization<br />
results. The quality <strong>of</strong> L1B data could be lessened by executing the SZA correction using<br />
mismatch SZA due to mis-registration. The impacts are different between two directions<br />
due to the strong bow-tie effect in scan direction. The practically largest relative errors <strong>of</strong><br />
all RSBs for Aqua MODIS are less than 0.1% in the select case, which are negligible in<br />
actual applications. The spatial correction <strong>of</strong> L1B data is necessary if the BBR shift is too<br />
large to reduce the data quality significantly.<br />
The theoretical analysis shows that the influence <strong>of</strong> mis-registration on science data<br />
products is generally larger than that on L1B data. The NDDI, an index for dust aerosol<br />
identification, is selected to estimate the impact <strong>of</strong> mis-registration on science data<br />
product since. The influence on dust aerosol detection results is small at the homogenous<br />
or semi-homogenous areas but relative large at the mixed areas. The increase <strong>of</strong><br />
correlation coefficient demonstrates that the quality <strong>of</strong> science data product can be<br />
improved by shifting a pixel in track direction.<br />
This study provides valuable information for <strong>sensor</strong>s without spatial characterization<br />
capability <strong>and</strong> also for the specification design <strong>of</strong> future <strong>sensor</strong>s.<br />
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