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

7.2.1.2 Real Impact on L1B Measurement
The SZA science dataset in the L1A file usually has a 1 km spatial resolution. The
interpolation is necessary because on-orbit BBR shifts of all bands are less than one pixel
in both MODIS instruments. The simplest method, linear interpolation, is adopted. The
relative errors of L1B dataset caused by using uncorrected SZA for all Aqua MODIS
RSBs except band 1 are listed in Table 7.2, where the largest SZA is up to 68 0 . The third
and fourth columns provide the relative errors in scan or track direction individually, and
the last column presents the relative errors by combining errors in two directions together.
Since the relative error is proportional to the spatial BBR shift, those SMIR bands which
have larger BBR shifts also have larger relative errors. The relative errors of Terra
MODIS bands are less than those of Aqua MODIS bands due to their smaller BBR shifts.
The largest relative error of L1B dataset is less than 0.1%. The error is small enough to be
ignored, so far, in real applications for both MODIS instruments.
7.2.2 Impact analysis of mis-registration on science data products
The MODIS is of great importance in science research field, widely used for
applications in atmosphere, land, ocean, biosphere, and solid earth (Justice et al., 1998;
Esaias et al, 1998; King ea al., 2003; Parkinson et al., 2003). A series of data products
have been developed so far for various applications including a bunch of normalized
indices and products generated with the linear or non-linear combination of responses
from several spectral bands. The spatial mis-registration between different bands or FPAs
impacts obviously the precision of science data products when several bands combined
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