VNP21A1N.001: Night Land Surface Temperature and Emissivity Daily 1km [deprecated]

NOAA/VIIRS/001/VNP21A1N
Dataset Availability
2012-01-19T00:00:00Z–2024-05-01T00:00:00Z
Dataset Provider
Earth Engine Snippet
ee.ImageCollection("NOAA/VIIRS/001/VNP21A1N")
Cadence
1 Day
Tags
daily
land
nasa
night
noaa
surface
temperature
viirs

The NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Night Version 1 product (VNP21A1N) is compiled daily from nighttime 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 night. 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:

Resolution
1000 meters

Bands

Name Units Description
LST_1KM K

Daily 1 km Land Surface Temperature.

QC

Daily Quality control for LST and emissivity

  • 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

Daily M14 emissivity

Emis_15

Daily M15 emissivity

Emis_16

Daily M16 emissivity

View_Angle deg

View zenith angle of LST

View_Time h

Time of LST observation

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:

Explore with Earth Engine

var dataset = ee.ImageCollection('NOAA/VIIRS/001/VNP21A1N')
                  .filter(ee.Filter.date('2022-11-01', '2022-12-01'));

var visualization = {
  bands: ['LST_1KM'],
  min: 200,
  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