VNP21A1D.002: Day Land Surface Temperature and Emissivity Daily 1km

AI-generated Key Takeaways

• The VNP21A1D dataset provides daily Land Surface Temperature and Emissivity data from the NASA Suomi NPP VIIRS instrument.

• This dataset is available from 2012-01-19 to 2025-10-15 and is updated daily.

• The product is compiled from daytime Level 2 Gridded data, with LST values estimated by averaging cloud-free observations with good accuracy.

• Key bands include daily 1 km Land Surface Temperature, Quality Control information, and emissivities.

• The data is freely accessible, and users are requested to cite the datasets when publishing.

Dataset Availability

2012-01-19T00:00:00Z–2025-10-15T00:00:00Z

Dataset Provider

NASA LP DAAC at the USGS EROS Center

Earth Engine Snippet

ee.ImageCollection("NASA/VIIRS/002/VNP21A1D")

Cadence

1 Day

Tags

climate daily day land nasa noaa surface temperature viirs

Description

The NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Day Version 1 product (VNP21A1D) is compiled daily from daytime Level 2 Gridded (L2G) intermediate products.

The L2G process maps the daily VNP21 swath granules onto a sinusoidal MODIS grid and stores all observations overlapping a gridded cell for a given day. 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. Only observations having observation coverage more than a certain threshold (15%) are considered for this averaging.

Documentation:

• User's Guide

• Algorithm Theoretical Basis Document (ATBD)

• General Documentation

• Land Product Quality Assessment website

Bands

Pixel Size
1000 meters

Bands

Name	Units	Pixel Size	Description
LST_1KM	K	meters	Daily 1 km Land Surface Temperature.
QC		meters	Daily Quality control for LST and emissivity
Bitmask for QC Bits 0-1: Mandatory QA flags 0: Pixel produced, good quality, no further QA info necessary 1: Pixel produced but unreliable quality 2: Pixel not produced due to cloud 3: Pixel not produced due to reasons other than cloud Bits 2-3: Data quality flag 0: Good data quality of L1B bands 14, 15, 16 1: Missing pixel 2: Fairly calibrated 3: Poorly calibrated, TES processing skipped Bits 4-5: Cloud Flag 0: Cloud-free 1: Thin cirrus 2: Pixel within 2 pixels of nearest cloud 3: Cloudy pixels Bits 6-7: Iterations 0: Slow convergence 1: Nominal 2: Nominal 3: Fast Bits 8-9: Atmospheric Opacity 0: ≥3 (Warm, humid air; or cold land) 1: 0.2 - 0.3 (Nominal value) 2: 0.1 - 0.2 (Nominal value) 3: <0.1 (Dry, or high altitude pixel) Bits 10-11: MMD 0: >0.15 (Most silicate rocks) 1: 0.1 - 0.15 (Rocks, sand, some soils) 2: 0.03 - 0.1 (Mostly soils, mixed pixel) 3: <0.03 (Vegetation, snow, water, ice, some soils) Bits 12-13: Emissivity accuracy 0: >0.02 (Poor performance) 1: 0.015 - 0.02 (Marginal performance) 2: 0.01 - 0.015 (Good performance) 3: <0.01 (Excellent performance) Bits 14-15: LST accuracy 0: >2K (Poor performance) 1: 1.5 - 2K (Marginal performance) 2: 1 - 1.5K (Good performance) 3: <1K (Excellent performance)
Emis_14		meters	Daily M14 emissivity
Emis_15		meters	Daily M15 emissivity
Emis_16		meters	Daily M16 emissivity
View_Angle	deg	meters	View zenith angle of LST
View_Time	h	meters	Time of LST observation

Terms of Use

Terms of Use

LP DAAC NASA data are freely accessible; however, when an author publishes these data or works based on the data, it is requested that the author cite the datasets within the text of the publication and include a reference to them in the reference list.

Citations

Citations:

• Please visit LP DAAC 'Citing Our Data' page for information on citing LP DAAC datasets.

DOIs

• https://doi.org/10.5067/VIIRS/VNP21A1D.002

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Code Editor (JavaScript)

var dataset = ee.ImageCollection('NASA/VIIRS/002/VNP21A1D')
                  .filter(ee.Filter.date('2022-11-01', '2022-12-01'));

var visualization = {
  bands: ['LST_1KM'],
  min: [150],
  max: [300],
  palette: [
    'a50026',
    'd73027',
    'f46d43',
    'fdae61',
    'fee08b',
    'ffffbf',
    'd9ef8b',
    'a6d96a',
    '66bd63',
    '1a9850',
    '006837',
  ]
};
Map.setCenter(41.2, 38.84, 3);
Map.addLayer(dataset, visualization, 'LST');

Open in Code Editor

VNP21A1D.002: Day Land Surface Temperature and Emissivity Daily 1km

The NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Day Version 1 product (VNP21A1D) is compiled daily from daytime Level 2 Gridded (L2G) intermediate products. The L2G process maps the daily VNP21 swath granules onto a sinusoidal MODIS grid …

NASA/VIIRS/002/VNP21A1D, climate,daily,day,land,nasa,noaa,surface,temperature,viirs

2012-01-19T00:00:00Z/2025-10-15T00:00:00Z

-90 -180 90 180

Google Earth Engine

https://developers.google.com/earth-engine/datasets

• https://doi.org/10.5067/VIIRS/VNP21A1D.002
• https://doi.org/10.5067/VIIRS/VNP21A1D.002