NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Day Version 1 ürünü (VNP21A1D), günlük olarak gündüz saatlerindeki Level 2 Gridded (L2G) ara ürünlerinden derlenir.
L2G işlemi, günlük VNP21 şerit granüllerini sinüs şeklinde bir MODIS ızgarasına eşler ve belirli bir güne ait ızgaralı bir hücreyle çakışan tüm gözlemleri depolar. VNP21A1 algoritması, her hücre için tüm bu gözlemleri sıralar ve son LST değerini, iyi LST doğruluğuna sahip tüm bulutsuz gözlemlerin ortalaması olarak tahmin eder. Bu ortalama hesaplamasında yalnızca belirli bir eşiğin (%15) üzerinde gözlem kapsamına sahip gözlemler dikkate alınır.
0: Pixel tarafından üretilmiş, iyi kalitede, başka kalite kontrol bilgisi gerekmiyor
1: Pixel üretildi ancak kalite güvenilir değil
2: Bulut nedeniyle Pixel üretilmedi
3: Pixel, bulut dışındaki nedenlerle üretilmedi
Bit 2-3: Veri kalitesi işareti
0: L1B bantları 14, 15, 16'nın iyi veri kalitesi
1: Eksik piksel
2: Oldukça iyi kalibre edilmiş
3: Kötü kalibre edilmiş, TES işleme atlandı
4-5. bitler: Bulut İşareti
0: Bulutsuz
1: İnce sirüs
2: En yakın bulutun 2 piksel içindeki Pixel
3: Bulutlu pikseller
6-7. bitler: İterasyonlar
0: Yavaş yakınsama
1: Nominal
2: Nominal
3: Hızlı
8-9. bitler: Atmosferik Opaklık
0: ≥3 (Sıcak, nemli hava veya soğuk kara)
1: 0,2 - 0,3 (Nominal değer)
2: 0,1 - 0,2 (Nominal değer)
3: <0, 1 (Kuru veya yüksek rakımlı piksel)
10-11. bitler: MMD
0: >0,15 (Çoğu silikat kayası)
1: 0,1 - 0,15 (Kayalar, kum, bazı topraklar)
2: 0,03 - 0,1 (Çoğunlukla toprak, karışık piksel)
3: <0,03 (Bitki örtüsü, kar, su, buz, bazı topraklar)
Bit 12-13: Emisyon oranı doğruluğu
0: >0,02 (Düşük performans)
1: 0,015 - 0,02 (Sınırlı performans)
2: 0,01 - 0,015 (İyi performans)
3: <0,01 (Mükemmel performans)
14-15. bitler: LST doğruluğu
0: >2K (Düşük performans)
1: 1,5-2 bin (Marjinal performans)
2: 1 - 1,5 bin (İyi performans)
3: <1.000 (Mükemmel performans)
Emis_14
metre
Günlük M14 emisyon oranı
Emis_15
metre
Günlük M15 emisyon oranı
Emis_16
metre
Günlük M16 emisyon oranı
View_Angle
drc
metre
LST'nin tepe açısını görüntüleme
View_Time
sa.
metre
LST gözleminin yapıldığı saat
Kullanım Şartları
Kullanım Şartları
LP DAAC NASA verilerine ücretsiz olarak erişilebilir. Ancak bir yazar bu verileri veya verilere dayalı çalışmaları yayınladığında, yayın metninde veri kümelerini alıntılaması ve referans listesine bunlarla ilgili bir referans eklemesi istenir.
NASA Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Land Surface Temperature and Emissivity (LST&E) Day Version 1 ürünü (VNP21A1D), günlük olarak gündüz saatlerinde elde edilen 2. Seviye Izgaralı (L2G) ara ürünlerden derlenir. L2G işlemi, günlük VNP21 şerit granüllerini sinüs şeklinde bir MODIS ızgarasına eşler…
[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)"]]
