Description
The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Night Version 1 product (VNP21A1N) is compiled daily from nighttime Level 2 Gridded (L2G) intermediate products.
The L2G process maps the daily (VNP21) (https://doi.org/10.5067/VIIRS/VNP21.001) swath granules onto a sinusoidal MODIS grid and stores all observations overlapping a gridded cell for a given night. The VNP21A1 algorithm sorts through all these observations for each cell and estimates the final LST value as an average from all cloud-free observations that have good LST accuracies. The nighttime average is weighted by the observation coverage for that cell. Only observations having observation coverage more than a certain threshold (15%) are considered for this averaging. The 1 kilometer dataset is derived through resampling the native 750 meter VIIRS resolution in the input product.
The VNP21A1N product is developed synergistically with the Moderate Resolution Imaging Spectroradiometer (MODIS) LST&E Version 6 product (MOD21A1N) (https://doi.org/10.5067/MODIS/MOD21A1N.006) using the same input atmospheric products and algorithmic approach. The overall objective for NASA VIIRS products is to ensure the algorithms and products are compatible with the MODIS Terra and Aqua algorithms to promote the continuity of the Earth Observation System (EOS) mission. Additional details regarding the method used to create this Level 3 (L3) product are available in the Algorithm Theoretical Basis Document (ATBD) (https://lpdaac.usgs.gov/documents/1332/VNP21_ATBD_V1.pdf). VIIRS LST&E products are available 2 months after acquisition due to latency of data inputs.
The VNP21A1N product contains seven Science Datasets (SDS): LST, quality control, emissivity for bands M14, M15, and M16, view zenith angle, and time of observation. A low-resolution browse image for LST is also available for each VNP21A1N granule.
Resources
| Name | Format | Description | Link |
|---|---|---|---|
| Download this dataset through APPEEARS | HTML | The Application for Extracting and Exploring Analysis Ready Samples (AρρEEARS) offers a simple and efficient way to perform data access and transformation processes. | 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 through a directory map | HDF | LP DAAC Data Pool provides direct access to available products via HTTPS. | Open resource |
| Get a related visualization | HTML | Browse image for Earthdata Search | Open resource |
| View this dataset's science data product validation documentation | HTML | Further details regarding VIIRS product validation and maturity status are available from VIIRS Land Product Quality Assessment site. | Open resource |
| View this dataset's product quality assessment | HTML | Quality Assessment provides information regarding the usability and usefulness of the data product. | 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 | |
| Use OPeNDAP to access the dataset's data | HTML | OPeNDAP provides direct access to data via HTTPS. | Open resource |
| Google Scholar search results | HTML | Search results for publications that cite this dataset by its DOI. | Open resource |
| Download this dataset through Earthdata Search | HDF | Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. | Open resource |
| View this dataset's science data product validation documentation | HTML | Validation at stage 1 has been achieved for the VIIRS land surface temperature product suite. | Open resource |
| View this dataset's science data product validation documentation | HTML | Validation at stage 1 has been achieved for the VIIRS land surface temperature product suite. | Open resource |
| View this dataset's science data product validation documentation | HTML | Further details regarding VIIRS product validation and maturity status are available from VIIRS Land Product Quality Assessment site. | Open resource |