Skip to main content

Description

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) 8-day Climate Modeling Grid Version 2 product (VJ121C2) combines the daily VJ121A1D and VJ121A1N products over an 8-day compositing period into a single product. The VJ121C2 dataset is an 8-day composite LST&E product at 0.05 degree (~5,600 meter) resolution 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 8-day period. Unlike the VJ121A1 datasets where the daytime and nighttime acquisitions are separate products, the VJ121C2 contains both daytime and nighttime acquisitions as separate science dataset (SDS) layers within a single Hierarchical Data Format (HDF) file.

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 VJ121C2 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 VJ121C2 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
8 Day
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
C2545310905-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
372
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 8-Day L3 Global 0.05Deg CMG V002 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VJ121C2.002 Date Accessed: 2026-02-19

File Naming Convention

VJ121C2.A2025209.002.2025217142839.h5

The file name begins with the Product Short Name (VJ121C2) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025209), the Version of the data collection (002), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025217142839), 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
Clear_sky_days Bitmap of Clear Sky Days (1 = clear, LSB = 1st day) N/A uint8 0 0 to 255 N/A
Clear_sky_nights Bitmap of Clear Sky Nights (1 = clear, LSB = 1st day) N/A uint8 0 0 to 255 N/A
Count_Day Count of Daytime Input Values N/A uint16 0 1 to 65535 N/A
Count_Night Count of Nighttime Input Values N/A uint16 0 1 to 65535 N/A
Day_view_angle Average Daytime View Zenith Angle Degree uint8 255 0 to 130 N/A
Day_view_time Average Daytime View Time Hours uint8 255 0 to 240 0.2
Emis_14_Day Average Daytime Band 14 Emissivity N/A uint8 0 1 to 255 0.002
Emis_14_Day_err Root-mean-square-error Daytime Band 14 Emissivity N/A uint16 0 1 to 65535 0.0001
Emis_14_Night Average Nighttime Band 14 Emissivity N/A uint8 0 1 to 255 0.002
Emis_14_Night_err Root-mean-square-error Nighttime Band 14 Emissivity N/A uint16 0 1 to 65535 0.0001
Emis_15_Day Average Daytime Band 15 Emissivity N/A uint8 0 1 to 255 0.002
Emis_15_Day_err Root-mean-square-error Daytime Band 15 Emissivity N/A uint16 0 1 to 65535 0.0001
Emis_15_Night Average Nighttime Band 15 Emissivity N/A uint8 0 1 to 255 0.002
Emis_15_Night_err Root-mean-square-error Nighttime Band 15 Emissivity N/A uint16 0 1 to 65535 0.0001
Emis_16_Day Average Daytime Band 16 Emissivity N/A uint8 0 1 to 255 0.002
Emis_16_Day_err Root-mean-square-error Daytime Band 16 Emissivity N/A uint16 0 1 to 65535 0.0001
Emis_16_Night Average Nighttime Band 16 Emissivity N/A uint8 0 1 to 255 0.002
Emis_16_Night_err Root-mean-square-error Nighttime Band 16 Emissivity N/A uint16 0 1 to 65535 0.0001
LST_Day Average Daytime Land Surface Temperature Kelvin uint16 0 7500 to 65535 0.02
LST_Day_err Root-mean-square-error Daytime Land Surface Temperature Kelvin uint8 0 1 to 255 0.04
LST_Night Average Nighttime Land Surface Temperature Kelvin uint16 0 7500 to 65535 0.02
LST_Night_err Root-mean-square-error Nighttime Land Surface Temperature Kelvin uint8 0 1 to 255 0.04
Night_view_angle Average Nighttime View Zenith Angle Degree uint8 255 0 to 130 N/A
Night_view_time Average Nighttime View Time Hours uint8 255 0 to 240 0.2
Percent_land_in_grid Percent of Land Detections in Grid Cell Percent uint8 255 0 to 100 N/A
QC_Day Quality Control for Daytime LST and Emissivity N/A uint8 0 0 to 255 N/A
QC_Night Quality Control for Nighttime LST and Emissivity N/A uint8 0 0 to 255 N/A
You're viewing 27 of 27