MODIS/Terra+Aqua Downward Shortwave Radiation Daily/3-Hour L3 Global 0.05Deg CMG V062

The MCD18A1 Version 6.2 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Downward Shortwave Radiation (DSR) gridded Level 3 product produced daily at 1 kilometer pixel resolution with estimates of DSR every 3 hours. DSR is incident solar radiation over land surfaces in the shortwave spectrum (300-4,000 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident DSR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global DSR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD). Provided in the MOD18A1 product are layers for instantaneous DSR array for each individual MODIS overpass and 3-hour DSR array along with a View Zenith Angle layer. Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

The MCD18C2 Version 6.2 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Photosynthetically Active Radiation (PAR) gridded Level 3 product produced daily at 0.05 degree (5,600 meters at the equator) resolution with estimates of PAR every 3 hours. PAR is incident solar radiation in the visible spectrum (400-700 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident PAR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global PAR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD). Provided in the MOD18C2 product are layers for instantaneous PAR array for each individual MODIS overpass and 3-hour PAR array along with a View Zenith Angle layer. Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

The MCD18A2 Version 6.2 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Photosynthetically Active Radiation (PAR) gridded Level 3 product produced daily at 1 kilometer pixel resolution with estimates of PAR every 3 hours. PAR is incident solar radiation in the visible spectrum (400-700 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident PAR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global PAR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD). Provided in the MOD18A2 product are layers for instantaneous PAR array for each individual MODIS overpass and 3-hour PAR array along with a View Zenith Angle layer. Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

The NOAA-21 Visible Infrared Imaging Radiometer Suite (VIIRS) Downward Shortwave Radiation (DSR) Level 3 Climate Modeling Grid (CMG) product produced at 0.05 degree pixel resolution at daily intervals. DSR is the incident solar radiation over land surfaces in the shortwave spectrum (300-4,000 nanometers) and is a significant variable in land surface models (LSMs), receiving increased attention due to its importance for the management and operation of solar energy systems. The VJ218 algorithm adapts the narrowband look-up table (LUT) approach to estimate DSR. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. The Algorithm Theoretical Basis Document (ATBD) is forthcoming and will provide additional details regarding the methodology used to create the data. The VJ218C1 product is aggregated from VJ218A1 files and includes one set of global 3-hour DSR variables and one set of daily mean DSR. Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Downward Shortwave Radiation (DSR) Level 3 Climate Modeling Grid (CMG) product produced at 0.05 degree pixel resolution at daily intervals. DSR is the incident solar radiation over land surfaces in the shortwave spectrum (300-4,000 nanometers) and is a significant variable in land surface models (LSMs), receiving increased attention due to its importance for the management and operation of solar energy systems. The VJ118 algorithm adapts the narrowband look-up table (LUT) approach to estimate DSR. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. The Algorithm Theoretical Basis Document (ATBD) is forthcoming and will provide additional details regarding the methodology used to create the data. The VJ118C1 product is aggregated from VJ118A1 files and includes one set of global 3-hour DSR variables and one set of daily mean DSR.

The MCD43D28 Version 6.1 Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Model Parameter dataset is produced daily using 16 days of Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data at 30 arc second (1,000 meter) resolution. Data are temporally weighted to the ninth day which is reflected in the Julian date in the file name. This Climate Modeling Grid (CMG) product covers the entire globe for use in climate simulation models. Due to the large file size, each MCD43D product contains just one data layer. Each of the three model parameters (isotropic, volumetric, and geometric) for each of the MODIS bands 1 through 7 and the visible, near-infrared (NIR), and shortwave bands included in MCD43C1 are stored in a separate file as MCD43D01 through MCD43D30. Users are urged to use the band specific quality flags to isolate the highest quality full inversion results for their own science applications as described in the User Guide. MCD43D28 is the BRDF isotropic parameter for the MODIS shortwave broadband. The isotropic parameter, in conjunction with the volumetric and geometric parameters, is used to derive the BRDF/Albedo values for the MODIS shortwave broadband. Known Issues * For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.