Il prodotto NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible
Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and
Emissivity (LST&E) Day Version 1 (VNP21A1D) viene compilato quotidianamente
a partire dai prodotti intermedi L2G (Level 2 Gridded) diurni.
La procedura L2G mappa i granuli giornalieri delle strisciate VNP21 su una griglia sinusoidale MODIS e memorizza tutte le osservazioni che si sovrappongono a una cella della griglia per un determinato giorno. L'algoritmo VNP21A1 esamina tutte queste osservazioni per ogni
cella e stima il valore LST finale come media di tutte le osservazioni
senza nuvole che hanno una buona precisione LST. Per questa media vengono prese in considerazione solo le osservazioni con una copertura superiore a una determinata soglia (15%).
Temperatura della superficie terrestre giornaliera di 1 km.
QC
metri
Controllo qualità giornaliero per la temperatura della superficie terrestre e l'emissività
Bitmask for QC
Bit 0-1: flag QA obbligatori
0: Pixel prodotto, buona qualità, non sono necessarie ulteriori informazioni sul controllo qualità
1: Pixel prodotto ma di qualità inaffidabile
2: Pixel non prodotto a causa del cloud
3: Pixel non prodotto per motivi diversi dal cloud
Bit 2-3: Flag di qualità dei dati
0: Buona qualità dei dati delle bande L1B 14, 15, 16
1: Pixel mancante
2: Abbastanza calibrato
3: Calibrazione scarsa, elaborazione TES ignorata
Bit 4-5: flag nuvola
0: Assenza di nuvole
1: Cirri sottili
2: Pixel entro 2 pixel dalla nuvola più vicina
3: Pixel nuvolosi
Bit 6-7: iterazioni
0: Convergenza lenta
1: Nominale
2: Nominale
3: Veloce
Bit 8-9: opacità atmosferica
0: ≥3 (aria calda e umida o terra fredda)
1: 0,2 - 0,3 (valore nominale)
2: 0,1 - 0,2 (valore nominale)
3: <0, 1 (secco o pixel ad alta quota)
Bit 10-11: MMD
0: >0,15 (la maggior parte delle rocce silicatiche)
1: 0,1 - 0,15 (rocce, sabbia, alcuni terreni)
2: 0,03 - 0,1 (principalmente suoli, pixel misto)
3: <0,03 (vegetazione, neve, acqua, ghiaccio, alcuni terreni)
Bit 12-13: precisione dell'emissività
0: >0,02 (rendimento scarso)
1: 0,015 - 0,02 (rendimento marginale)
2: 0,01 - 0,015 (rendimento buono)
3: <0,01 (prestazioni eccellenti)
Bit 14-15: precisione LST
0: >2000 (rendimento scarso)
1: 1,5 - 2 K (rendimento marginale)
2: 1 - 1,5 K (rendimento buono)
3: <1000 (prestazioni eccellenti)
Emis_14
metri
Emissività giornaliera M14
Emis_15
metri
Emissività giornaliera M15
Emis_16
metri
Emissività giornaliera M16
View_Angle
deg
metri
Visualizzare l'angolo zenitale di LST
View_Time
h
metri
Ora dell'osservazione LST
Termini e condizioni d'uso
Termini e condizioni d'uso
I dati LP DAAC della NASA sono accessibili senza costi; tuttavia, quando un autore
pubblica questi dati o opere basate sui dati, è richiesto che
l'autore citi i set di dati nel testo della pubblicazione e includa un
riferimento a questi nell'elenco dei riferimenti.
Il prodotto NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Day Version 1 (VNP21A1D) viene compilato quotidianamente a partire dai prodotti intermedi di livello 2 grigliati (L2G) diurni. La procedura L2G mappa i granuli giornalieri delle strisciate VNP21 su una griglia MODIS sinusoidale…
[null,null,[],[[["\u003cp\u003eThe NASA VIIRS VNP21A1D dataset provides daily land surface temperature and emissivity data at a 1km resolution.\u003c/p\u003e\n"],["\u003cp\u003eThe data is derived from the Suomi NPP satellite and covers the period from 2012-01-19 to 2024-12-10.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset includes quality control flags for cloud cover, atmospheric opacity, and emissivity/LST accuracy.\u003c/p\u003e\n"],["\u003cp\u003eUsers can access and analyze the data using Google Earth Engine.\u003c/p\u003e\n"],["\u003cp\u003eThe data is freely accessible and requires citation when used in publications.\u003c/p\u003e\n"]]],[],null,["Dataset Availability\n: 2012-01-19T00:00:00Z--2025-08-30T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/VIIRS/VNP21A1D.002)\n\nCadence\n: 1 Day\n\nTags\n:\n[climate](/earth-engine/datasets/tags/climate) [daily](/earth-engine/datasets/tags/daily) [day](/earth-engine/datasets/tags/day) [land](/earth-engine/datasets/tags/land) [nasa](/earth-engine/datasets/tags/nasa) [noaa](/earth-engine/datasets/tags/noaa) [surface](/earth-engine/datasets/tags/surface) [temperature](/earth-engine/datasets/tags/temperature) [viirs](/earth-engine/datasets/tags/viirs) \n\nDescription \nThe NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible\nInfrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and\nEmissivity (LST\\&E) Day Version 1 product (VNP21A1D) is compiled daily\nfrom daytime Level 2 Gridded (L2G) intermediate products.\n\nThe L2G process maps the daily VNP21 swath granules onto a sinusoidal MODIS\ngrid and stores all observations overlapping a gridded cell for a given\nday. The VNP21A1 algorithm sorts through all these observations for each\ncell and estimates the final LST value as an average from all cloud-free\nobservations that have good LST accuracies. Only observations having\nobservation coverage more than a certain threshold (15%) are considered for\nthis averaging.\n\nDocumentation:\n\n- [User's Guide](https://lpdaac.usgs.gov/documents/429/VNP21_User_Guide_V1.pdf)\n\n- [Algorithm Theoretical Basis Document (ATBD)](https://lpdaac.usgs.gov/documents/1332/VNP21_ATBD_V1.pdf)\n\n- [General Documentation](https://lpdaac.usgs.gov/products/vnp21a1dv002/)\n\n- [Land Product Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/browse?sensor=VIIRS&sat=SNPP)\n\nBands\n\n\n**Pixel Size**\n\n1000 meters\n\n**Bands**\n\n| Name | Units | Pixel Size | Description |\n|--------------|-------|------------|----------------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `LST_1KM` | K | meters | Daily 1 km Land Surface Temperature. |\n| `QC` | | meters | Daily Quality control for LST and emissivity |\n| 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: \\\u003c0.1 (Dry, or high altitude pixel) - Bits 10-11: MMD - 0: \\\u003e0.15 (Most silicate rocks) - 1: 0.1 - 0.15 (Rocks, sand, some soils) - 2: 0.03 - 0.1 (Mostly soils, mixed pixel) - 3: \\\u003c0.03 (Vegetation, snow, water, ice, some soils) - Bits 12-13: Emissivity accuracy - 0: \\\u003e0.02 (Poor performance) - 1: 0.015 - 0.02 (Marginal performance) - 2: 0.01 - 0.015 (Good performance) - 3: \\\u003c0.01 (Excellent performance) - Bits 14-15: LST accuracy - 0: \\\u003e2K (Poor performance) - 1: 1.5 - 2K (Marginal performance) - 2: 1 - 1.5K (Good performance) - 3: \\\u003c1K (Excellent performance) ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n| `Emis_14` | | meters | Daily M14 emissivity |\n| `Emis_15` | | meters | Daily M15 emissivity |\n| `Emis_16` | | meters | Daily M16 emissivity |\n| `View_Angle` | deg | meters | View zenith angle of LST |\n| `View_Time` | h | meters | Time of LST observation |\n\nTerms of Use\n\n**Terms of Use**\n\nLP DAAC NASA data are freely accessible; however, when an author\npublishes these data or works based on the data, it is requested that the\nauthor cite the datasets within the text of the publication and include a\nreference to them in the reference list.\n\nCitations \nCitations:\n\n- Please visit [LP DAAC 'Citing Our Data' page](https://lpdaac.usgs.gov/citing_our_data)\n for information on citing LP DAAC datasets.\n\nDOIs\n\n- \u003chttps://doi.org/10.5067/VIIRS/VNP21A1D.002\u003e\n\nExplore with Earth Engine **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\nCode Editor (JavaScript) \n\n```javascript\nvar dataset = ee.ImageCollection('NASA/VIIRS/002/VNP21A1D')\n .filter(ee.Filter.date('2022-11-01', '2022-12-01'));\n\nvar visualization = {\n bands: ['LST_1KM'],\n min: [150],\n max: [300],\n palette: [\n 'a50026',\n 'd73027',\n 'f46d43',\n 'fdae61',\n 'fee08b',\n 'ffffbf',\n 'd9ef8b',\n 'a6d96a',\n '66bd63',\n '1a9850',\n '006837',\n ]\n};\nMap.setCenter(41.2, 38.84, 3);\nMap.addLayer(dataset, visualization, 'LST');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/NASA/NASA_VIIRS_002_VNP21A1D) \n[VNP21A1D.002: Day Land Surface Temperature and Emissivity Daily 1km](/earth-engine/datasets/catalog/NASA_VIIRS_002_VNP21A1D) \nThe 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 ... \nNASA/VIIRS/002/VNP21A1D, climate,daily,day,land,nasa,noaa,surface,temperature,viirs \n2012-01-19T00:00:00Z/2025-08-30T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/VIIRS/VNP21A1D.002](https://doi.org/https://doi.org/10.5067/VIIRS/VNP21A1D.002)\n- [https://doi.org/10.5067/VIIRS/VNP21A1D.002](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/NASA_VIIRS_002_VNP21A1D)"]]
