Estimating the effective spatial resolution of the operational BRDF, albedo, and nadir reflectance products from MODIS and VIIRS

Satellite derived surface albedo and view-angle corrected surface reflectance products serve as the key inputs for an array of climate, biogeochemical, and hydrologic modeling efforts. This research effort is particularly focused on establishing the effective spatial resolution of the global MODIS and VIIRS Nadir BRDF-Adjusted Reflectance (NBAR) and Albedo products. The standard MODIS Products (MCD43) are created by fitting a kernel-driven, semi-empirical BRDF model to multi-date, multi-angular surface reflectance data to establish the surface reflectance anisotropy of a location. Emphasis on a particular date within the rolling multi-date period has resulted in a daily product reported on a 500m Sinusoidal grid tiling system. While anecdotal and theoretical experiences have suggested that this product would be representative of a larger surface area than the 500m grid, this research both quantifies that effect, and verifies that the spatial effective resolution is consistently less than 1km for MODIS. Results for 500m VIIRS NBAR product show an improvement of approximately 250m in spatial effective resolution along the scan direction. In addition to their use in modeling, the MODIS BRDF/Albedo/NBAR products (and into the future with the analogous VIIRS products) are increasingly being relied upon to monitor vegetation phenology, identify land cover and land cover disturbance, track snow fall and melt, and establish surface energy balance variability. Thus, this research provides the quantification both for MODIS and VIIRS necessary for the effective use of these products by the global modeling and monitoring communities. [Display omitted] •500m MODIS high quality BRDF/Albedo/NBAR resolution is consistently under 1km.•500m VIIRS gridded products exhibit median resolutions under 600m.•1km MCD43 and VIIRS products both have median effective resolution close to 1km.•Noise and resolution estimates reduce when full inversion proportion increases.