MISR Level 2 Surface parameters V002

MIL2ASLS_2 is the Multi-angle Imaging SpectroRadiometer (MISR) Level 2 Land Surface parameters version 2 data product. It contains a variety of information on the Earth's surface; such ashemispherical directional reflectance factor (HDRF), bihemispherical reflectance (BHR) (i.e., albedo), bidirectional reflectance factor (BRF), directional hemispherical reflectance (DHR), BRF model parameters, Fractional absorbed Photosysenthetically Active Radiation (FPAR), and terrain-referenced view and illumination angles. A surface retrieval is conducted on regions for which valid land aerosol retrieval exists. The retrieval is performed using the corrected equivalent reflectances, retrieved aerosol parameters, and auxiliary information from the Simulated MISR Ancillary Radiative Transfer (SMART) dataset. The spectral and Photosynthetically Active spectral Region (PAR)-integrated BHR and DHR are retrieved, along with the spectral land HDRF and BRF and BRF model parameters, for all valid land and inland water subregions. Subregion surface classification and leaf area index (LAI) and regional FPAR are also determined. Subregion variability is also calculated for land regions. Data collection for this product was completed in June 2017.

The MISR instrument consists of nine pushbroom cameras which 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 cameras pointing forward, and four cameras pointing 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 itself is an instrument 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 9 cameras, in each of 4 wavelengths (blue, green, red, and near-infrared). The goal of MISR is to improve our understanding of the affects of sunlight on Earth, as well as 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.