Description
The MCD18C2 Version 6.1 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) (https://lpdaac.usgs.gov/documents/106/MCD18_ATBD.pdf)).
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.
Validation at stage 1 ( https://modis-land.gsfc.nasa.gov/MODLAND_val.html) has been achieved for the MODIS Surface Radiation products. Further details regarding MODIS land product validation for the MCD18 data products are available from the MODIS Land Team Validation site ( https://modis-land.gsfc.nasa.gov/ValStatus.php?ProductID=MCD18).
- The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.
- A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).
- The MCD18 suite has added CMG products (MCD18C1/MCD18C2).
Resources
| Name | Format | Description | Link |
|---|---|---|---|
| Get a related visualization | HTML | Browse image for Earthdata Search | Open resource |
| This dataset's landing page | HTML | The LP DAAC product page provides information on Science Data Set layers and links for user guides, ATBDs, data access, tools, customer support, etc. | Open resource |
| Download this dataset | HDF | LP DAAC Data Pool provides direct access to available products via HTTPS. | Open resource |
| The dataset's project home page | HTML | The LP DAAC website provides detailed information on discovery, distribution, access, and support of land data products. | Open resource |
| View this dataset's algorithm theoretical basis document | The ATBD provides physical theory and mathematical procedures for the calculations used to produce the data products. | Open resource | |
| View this dataset's user's guide | The technical information in the User's Guide enables users to interpret and use the data products. | Open resource | |
| View this dataset's science data product validation documentation | HTML | Validation at stage 1 has been achieved for the MODIS Surface Radiation products. | Open resource |
| View this dataset's science data product validation documentation | HTML | Further details regarding MODIS land product validation for the MCD18 data products are available from the MODIS Land Team Validation site. | Open resource |
| Google Scholar search results | HTML | Search results for publications that cite this dataset by its DOI. | Open resource |
| Download this dataset | HDF | Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. | Open resource |