VIIRS/JPSS2 Land Surface Temperature/Emissivity Monthly L3 Global 0.05Deg CMG V002

The NOAA-21 Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) monthly Climate Modeling Grid Version 2 product (VJ221C3) provides LST&E by a process of selecting the best available pixel over a monthly acquisition period at 0.05 degree (~5,600 meter) resolution. The VJ221C3 dataset is a monthly composite LST&E product that uses an algorithm based on a simple averaging method and is formatted as a CMG for use in climate simulation models. The algorithm calculates the average from all the cloud free [VJ221A1D](https://doi.org/10.5067/VIIRS/VJ221A1D.002) and [VJ221A1N](https://doi.org/10.5067/VIIRS/VJ221A1N.002) daily acquisitions from the monthly period. Unlike the VJ221A1 data sets where the daytime and nighttime acquisitions are separate products, the VJ221C3 contains both daytime and nighttime acquisitions as separate Science Dataset (SDS) variables within a single Hierarchical Data Format (HDF) file.

Additional details regarding the method used to create this Level 3 (L3) product are available in the Algorithm Theoretical Basis Document (ATBD).

The VJ221C3 product contains 27 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 VJ221C3 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).

NOAA-21可见光红外成像辐射仪套件（Visible Infrared Imaging Radiometer Suite, VIIRS）地表温度与发射率（Land Surface Temperature and Emissivity, LST&E）月度气候建模网格第2版产品（VJ221C3），通过在月度采集周期内选取最优可用像素的方式，生成分辨率为0.05度（约5600米）的LST&E数据。VJ221C3数据集属于月度合成LST&E产品，采用基于简单平均法的算法构建，格式为气候建模网格（Climate Modeling Grid, CMG），适配气候模拟模型使用。该算法从月度周期内的所有无云[VJ221A1D](https://doi.org/10.5067/VIIRS/VJ221A1D.002)和[VJ221A1N](https://doi.org/10.5067/VIIRS/VJ221A1N.002)日采集数据中计算平均值。与昼、夜采集数据分别作为独立产品的VJ221A1系列数据集不同，VJ221C3将昼、夜采集数据作为独立的科学数据集（Science Dataset, SDS）图层整合至单个分层数据格式（Hierarchical Data Format, HDF）文件中。

有关此三级（Level 3, L3）产品的构建方法的更多细节，可查阅《算法理论基础文档》（Algorithm Theoretical Basis Document, ATBD）。

VJ221C3产品包含27个变量：涵盖昼、夜观测的地表温度（LST）、质量控制信息、观测天顶角以及观测时间，同时包含M14、M15和M16波段的发射率数据。此外，每个VJ221C3数据粒均配有昼、夜地表温度的低分辨率浏览图像。

已知问题
* 有关已知问题的完整信息，请参阅[中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）/VIIRS陆地质量评估网站](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS&sat=J2&as=5200)。