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 ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
7.1.3.2 Date Source<br />
MODIS L1B data at three spatial resolutions are used to calculate the spatial<br />
deviation: 250 m for b<strong>and</strong> 2 (40 detectors / b<strong>and</strong>), 500 m for b<strong>and</strong> 3-7 (20 detectors /<br />
b<strong>and</strong>), <strong>and</strong> 1 km for other b<strong>and</strong>s (10 detectors / b<strong>and</strong>). The L1B data used is the version 5<br />
issued by NASA. Each MODIS L1B data set (referred to as a “granule”) collects<br />
consecutive measurements within five minutes, typically 203 scans. In each scan, 1,354<br />
data frames are recorded for each detector. For 500 m resolution b<strong>and</strong>, 2 sub-frames or<br />
samples per frame (1 km) are recorded for its 20 detectors, <strong>and</strong> 4 sub-frames for each 250<br />
m b<strong>and</strong> <strong>and</strong> its 40 detectors (Xiong et al., 2003). Thus, each granule typically contains<br />
2030 rows (along-track) × 1354 columns (along-scan) for 1 km resolution b<strong>and</strong>s, 8120<br />
rows × 5416 columns for 250 m resolution b<strong>and</strong>s, <strong>and</strong> 4060 rows ×2708 columns for 500<br />
m resolution b<strong>and</strong>s.<br />
102