Retrieval of subpixel snow covered area, grain size, and albedo from MODIS
Painter, Thomas H.
Davis, Robert E.
MetadataShow full item record
We describe and validate a model that retrieves fractional snow-covered area and the grain size and albedo of that snow from surface reflectance data (product MOD09GA) acquired by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). The model analyzes the MODIS visible, near infrared, and shortwave infrared bands with multiple endmember spectral mixtures from a library of snow, vegetation, rock, and soil. We derive snow spectral endmembers of varying grain size from a radiative transfer model specific to a scene's illumination geometry; spectra for vegetation, rock, and soil were collected in the field and laboratory. We validate the model with fractional snow cover estimates from Landsat Thematic Mapper data, at 30 m resolution, for the Sierra Nevada, Rocky Mountains, high plains of Colorado, and Himalaya. Grain size measurements are validated with field measurements during the Cold Land Processes Experiment, and albedo retrievals are validated with in situ measurements in the San Juan Mountains of Colorado. The pixel-weighted average RMS error for snow-covered area across 31 scenes is 5%, ranging from 1% to 13%. The mean absolute error for grain size was 51 μm and the mean absolute error for albedo was 4.2%. Fractional snow cover errors are relatively insensitive to solar zenith angle. Because MODSCAG is a physically based algorithm that accounts for the spatial and temporal variation in surface reflectances of snow and other surfaces, it is capable of global snow cover mapping in its more computationally efficient, operational mode.
The article of record as published may be found at http://dx.doi.org/10.1016/j.rse.2009.01.001
Showing items related by title, author, creator and subject.
Camacho, Mark A. (Monterey California. Naval Postgraduate School, 2006-09);Shallow water bathymetry is important for both safe navigation and natural resource management purposes. Extracting depth information from spectral imagery allows identification of benthic features and characterization of ...
Assessing the cannabis legalization debate: lessons learned from the Colorado and Washington experiment Neener, Michael C. (Monterey, California: Naval Postgraduate School, 2016-03);Cannabis is illegal as far as federal law is concerned; yet recent trends in the United States indicate it is moving toward more widespread legalization. While both sides of the legalization debate pose valid arguments, ...
Brown, Andrew. (Monterey, California. Naval Postgraduate School, 1995-03);The physical and optical characteristics of 27 shiptracks are analyzed using AVHRR satellite data. Channel 1 (.63um), and channel 3 (3.7um), are utilized to determine the temporal variations in shiptrack albedo and track ...