MI3MAEF_002 is the Multi-angle Imaging SpectroRadiometer (MISR) Level 3 FIRSTLOOK Component Global Aerosol Product covering a month version 2 data product. It contains a statistical summary of column aerosol 555-nanometer optical depth and a monthly aerosol compositional type frequency histogram. This data product is a global summary of the Level 2 aerosol parameters of interest averaged over a month and reported on a geographic grid with a resolution of 0.5 degrees by 0.5 degrees. Data collection for this product was completed in October 2017.
FIRSTLOOK processing uses the new time dependence of the Atmospheric and Surface Climatology (TASC) from the same month/previous year. The TASC data set now contains snow-ice and ocean surface wind speed values that are updated on a monthly basis. Therefore, these data sets cannot be generated until the end of the month. Products generated are distinguished by the presence of FIRSTLOOK in the file names. The MISR instrument consists of nine push-broom cameras that measure radiance in four spectral bands. Global coverage is achieved in nine days. The cameras are arranged with one camera pointing toward the nadir, four forward, and four aftward. It takes seven minutes for all nine cameras to view the same surface location. The view angles relative to the surface reference ellipsoid are 0, 26.1, 45.6, 60.0, and 70.5 degrees. The spectral band shapes are nominally Gaussian, centered at 443, 555, 670, and 865 nm.
MISR is designed to view Earth with cameras in 9 different directions. As the instrument flies overhead, each piece of Earth's surface below is successfully imaged by all nine cameras in 4 wavelengths (blue, green, red, and near-infrared). The goal of MISR is to improve our understanding of the effects of sunlight on Earth and distinguish different types of clouds, particles, and surfaces. Specifically, MISR monitors the monthly, seasonal, and long-term trends in three areas: 1) amount and type of atmospheric particles (aerosols), including those formed by natural sources and by human activities; 2) amounts, types, and heights of clouds, and 3) distribution of land surface cover, including vegetation canopy structure.