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Description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) monthly Climate Modeling Grid Version 2 product (VJ121C3) 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 VJ121C3 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 VJ121A1D and VJ121A1N daily acquisitions from the monthly period. Unlike the VJ121A1 data sets where the daytime and nighttime acquisitions are separate products, the VJ121C3 contains both daytime and nighttime acquisitions as separate Science Dataset (SDS) layers 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 VJ121C3 product contains 25 Science Datasets (SDS): 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 VJ121C3 granule.

Known Issues

Version Description

NOAA-20 (JPSS-1) VIIRS data products, designated as "VJ1", were introduced in VIIRS Version 2.

Product Summary

Platforms
NOAA-20
Instruments
VIIRS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
5600 Meters x 5600 Meters
Spatial Reference System(s)
VIIRS Climate Modeling Grid (CMG)
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2018-01-01 to Present
Temporal Resolution
1 Month
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC) ,
Land Science Investigator-led Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Sciences and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/LandSIPS)
Concept ID
C2545310909-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
97
Processing Level
3
Published
Updated
Science Keywords
Emissivity ,
Land Surface Temperature

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Hulley, G., & Hook, S. (2023). VIIRS/JPSS1 Land Surface Temperature/Emissivity Monthly L3 Global 0.05Deg CMG V002 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VJ121C3.002 Date Accessed: 2026-02-15

File Naming Convention

VJ121C3.A2025182.002.2025213220945.h5

The file name begins with the Product Short Name (VJ121C3) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025182), the Version of the data collection (002), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025213220945), and the Data Format (h5).

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
Emis_14 M14 emissivity N/A uint8 0 1 to 255 0.002
Emis_15 M15 emissivity N/A uint8 0 1 to 255 0.002
Emis_16 M16 emissivity N/A uint8 0 1 to 255 0.002
LST_Day_1KM Day Land Surface Temperature Kelvin uint16 0 7500 to 65535 0.02
LST_Night_1KM Night 1 km Land Surface Temperature Kelvin uint16 0 7500 to 65535 0.02
QC_Day Day Quality control for LST and emissivity N/A uint8 0 1 to 255 N/A
QC_Night Night Quality control for LST and emissivity N/A uint8 0 1 to 255 N/A
View_Angle_Day Day View zenith angle of LST Degree uint8 255 0 to 130 N/A
View_Angle_Night Night View zenith angle of LST Degree uint8 255 0 to 130 N/A
View_Time_Day Day Time of LST observation Hours uint8 255 0 to 240 0.1
View_Time_Night Night Time of LST observation Hours uint8 255 0 to 240 0.1
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