VIIRS/JPSS2 Land Surface Temperature/Emissivity 8-Day L3 Global 1km SIN Grid V002

The NOAA-21 Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) 8-day product (VJ221A2) combines the daily ([VJ221A1D](http://doi.org/10.5067/VIIRS/VJ221A1D.002)) and ([VJ221A1N](http://doi.org/10.5067/VIIRS/VJ221A1N.002)) products over an 8-day compositing period into a single product.

The VJ221A2 dataset is an 8-day composite LST&E product at 1 kilometer resolution that uses an algorithm based on a simple-averaging method. The algorithm calculates the average from all the cloud-free VJ221A1D and VJ221A1N daily acquisitions from the 8-day period. Unlike the VJ221A1 datasets where the daytime and nighttime acquisitions are separate products, the VJ221A2 contains both daytime and nighttime acquisitions as separate science dataset (SDS) variables within a single Hierarchical Data Format (HDF) file.

The VJ221A2 product is developed synergistically with the Moderate Resolution Imaging Spectroradiometer (MODIS) LST&E Version 6.1 product ([MOD21A2](https://doi.org/10.5067/MODIS/MOD21A2.061)) 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).

The VJ221A2 product contains 11 variables: LST, quality control, view zenith angle, and time of observation for both day and night observations along with emissivity for bands M14, M15, and M16. Low-resolution browse images for day and night LST are also available for each VJ221A2 granule.

Known Issues
* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS&sat=J2&as=5200) and the User Guide.