MIL3MJTA_2 is the Multi-angle Imaging SpectroRadiometer (MISR) Level 3 Global Joint Aerosol monthly version 2 data product. It contains global statistical summaries of MISR Level 2 aerosol optical depth on a 5-degree geographic grid. Within each grid cell, optical depth is summarized by a set of representative vectors, each representing a cluster of similar Level 2 aerosol optical depth retrievals. Data is summarized monthly. Data collection for this product is ongoing.

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 pointed in 9 different directions. As the instrument flies overhead, each piece of Earth's surface below is successively 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.