O produto de refletância ajustada (NBAR) versão 2 da função de distribuição de refletância bidirecional (BRDF) nadir do Visible Infrared Imaging Radiometer Suite (VIIRS) da Parceria Nacional de Órbita Polar Suomi (Suomi NPP) da NASA/NOAA fornece estimativas de NBAR com resolução de 500 metros. O produto VNP43IA4 é produzido diariamente usando 16 dias de dados do VIIRS e é ponderado temporalmente até o nono dia, o que se reflete no nome do arquivo. Os efeitos do ângulo de visão são removidos das refletâncias direcionais, resultando em um produto NBAR estável e consistente. Os produtos de dados VNP43 foram projetados para promover a continuidade da suíte de produtos de dados BRDF/Albedo do Moderate Resolution Imaging Spectroradiometer (MODIS) da NASA.
O algoritmo VNP43 usa o modelo BRDF semiempírico baseado em kernel RossThick/Li-Sparse-Reciprocal (RTLSR), com os três pesos de kernel do VNP43IA1 para reconstruir efeitos anisotrópicos de superfície, corrigindo a refletância direcional para uma geometria de visualização comum (VNP43IA4), além de calcular o albedo integrado de céu preto (BSA) ao meio-dia solar local e o albedo de céu branco (WSA) (VNP43IA3). Os pesquisadores podem usar os parâmetros do modelo BRDF com um polinômio simples para obter o albedo de céu preto em qualquer ângulo de iluminação solar. Da mesma forma, as camadas de dados científicos do BSA e do WSA (SDS) podem ser usadas com um polinômio simples para estimar manualmente o albedo real instantâneo (albedo de céu azul). Mais detalhes sobre a metodologia estão disponíveis no documento de base teórica do algoritmo (ATBD, na sigla em inglês).
Qualidade obrigatória de BRDF/Albedo para a banda I1
BRDF_Albedo_Band_Mandatory_Quality_I2
metros
Qualidade obrigatória de BRDF/Albedo para a banda I2
BRDF_Albedo_Band_Mandatory_Quality_I3
metros
Qualidade obrigatória de BRDF/Albedo para a banda I3
Nadir_Reflectance_I1
metros
Reflectância de BRDF/albedo de nadir ao meio-dia solar local para a banda I1
Nadir_Reflectance_I2
metros
Reflectância de BRDF/albedo de nadir ao meio-dia solar local para a banda I2
Nadir_Reflectance_I3
metros
Reflectância de BRDF/albedo de nadir ao meio-dia solar local para a banda I3
Termos de Uso
Termos de Uso
Os dados da NASA do LP DAAC são de livre acesso. No entanto, quando um autor publica esses dados ou trabalhos baseados neles, é necessário citar os conjuntos de dados no texto da publicação e incluir uma referência a eles na lista de referências.
Citações
Citações:
Schaaf, C., Z. Wang, A. Erb, I. Paynter. VIIRS/NPP BRDF/Albedo Nadir
BRDF-Adjusted Ref Daily L3 Global 500m SIN Grid V002. 2024, distribuído pelo
NASA EOSDIS Land Processes Distributed Active Archive Center,
10.5067/VIIRS/VNP43IA4.002.
O produto da NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) versão 2 fornece estimativas de NBAR com resolução de 500 metros. O produto VNP43IA4 é produzido diariamente usando 16 dias de dados do VIIRS e é ponderado temporalmente para …
[null,null,[],[],[],null,["# VNP43IA4: BRDF/Albedo Quality Daily L3 Global 500m SIN Grid\n\nDataset Availability\n: 2012-01-17T00:00:00Z--2025-08-12T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/VIIRS/VNP43IA4.002)\n\nCadence\n: 1 Day\n\nTags\n:\n[brdf](/earth-engine/datasets/tags/brdf) [land](/earth-engine/datasets/tags/land) [nasa](/earth-engine/datasets/tags/nasa) [noaa](/earth-engine/datasets/tags/noaa) [satellite-imagery](/earth-engine/datasets/tags/satellite-imagery) [surface](/earth-engine/datasets/tags/surface) [viirs](/earth-engine/datasets/tags/viirs) \n\n#### Description\n\nThe NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible\nInfrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance\nDistribution Function (BRDF) Adjusted Reflectance (NBAR) Version 2 product\nprovides NBAR estimates at 500 meter resolution. The VNP43IA4 product is\nproduced daily using 16 days of VIIRS data and is weighted temporally to the\nninth day, which is reflected in the file name. The view angle effects are\nremoved from the directional reflectances, resulting in a stable and\nconsistent NBAR product. The VNP43 data products are designed to promote the\ncontinuity of NASA's Moderate Resolution Imaging Spectroradiometer (MODIS)\nBRDF/Albedo data product suite.\n\nThe VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR)\nsemi-empirical kernel-driven BRDF model, with the three kernel weights from\nVNP43IA1 to reconstruct surface anisotropic effects, correcting the\ndirectional reflectance to a common view geometry (VNP43IA4), while\nalso computing integrated black-sky albedo (BSA) at local solar noon and\nwhite-sky albedo (WSA) (VNP43IA3). Researchers can use the BRDF model\nparameters with a simple polynomial, to obtain black-sky albedo at any solar\nillumination angle. Likewise, both the BSA and WSA Science Dataset (SDS)\nlayers can be used with a simple polynomial, to manually estimate\ninstantaneous actual albedo (blue-sky albedo). Additional details regarding\nthe methodology are available in the Algorithm Theoretical Basis Document\n(ATBD).\n\nDocumentation:\n\n- [User's Guide](https://www.umb.edu/spectralmass/viirs-user-guides-c1-and-c2/vnp43ia4-and-vnpma4-nbar-products/)\n\n- [Algorithm Theoretical Basis Document (ATBD)](https://lpdaac.usgs.gov/documents/194/VNP43_ATBD_V1.pdf)\n\n- [General Documentation](https://lpdaac.usgs.gov/products/vnp43ia4v002/)\n\n### Bands\n\n\n**Pixel Size**\n\n500 meters\n\n**Bands**\n\n| Name | Pixel Size | Description |\n|-----------------------------------------|------------|---------------------------------------------------------------|\n| `BRDF_Albedo_Band_Mandatory_Quality_I1` | meters | BRDF/Albedo mandatory quality for band I1 |\n| `BRDF_Albedo_Band_Mandatory_Quality_I2` | meters | BRDF/Albedo mandatory quality for band I2 |\n| `BRDF_Albedo_Band_Mandatory_Quality_I3` | meters | BRDF/Albedo mandatory quality for band I3 |\n| `Nadir_Reflectance_I1` | meters | Nadir BRDF/Albedo Reflectance at local solar noon for band I1 |\n| `Nadir_Reflectance_I2` | meters | Nadir BRDF/Albedo Reflectance at local solar noon for band I2 |\n| `Nadir_Reflectance_I3` | meters | Nadir BRDF/Albedo Reflectance at local solar noon for band I3 |\n\n### Terms 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\n### Citations\n\nCitations:\n\n- Schaaf, C., Z. Wang, A. Erb, I. Paynter. VIIRS/NPP BRDF/Albedo Nadir\n BRDF-Adjusted Ref Daily L3 Global 500m SIN Grid V002. 2024, distributed by\n NASA EOSDIS Land Processes Distributed Active Archive Center,\n [10.5067/VIIRS/VNP43IA4.002](https://doi.org/10.5067/VIIRS/VNP43IA4.002).\n\n### DOIs\n\n- \u003chttps://doi.org/10.5067/VIIRS/VNP43IA4.002\u003e\n\n### Explore with Earth Engine\n\n| **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\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.ImageCollection('NASA/VIIRS/002/VNP43IA4')\n .filter(ee.Filter.date('2021-06-01', '2021-06-03'));\n\nvar nadir_reflectance_I1 = dataset.select('Nadir_Reflectance_I1').first();\nvar palette = [\n '000080',\n '0000d9',\n '4000ff',\n '8000ff',\n '0080ff',\n '00ffff',\n '00ff80',\n '80ff00',\n 'daff00',\n 'ffff00',\n 'fff500',\n 'ffda00',\n 'ffb000',\n 'ffa400',\n 'ff4f00',\n 'ff2500',\n 'ff0a00',\n 'ff00ff',\n];\nvar visParams = {\n min: 0,\n max: 10000,\n palette: palette,\n};\n\n// cadetblue\nvar background = ee.Image.rgb(95, 158, 160).visualize({min: 0, max: 255});\nvar image = nadir_reflectance_I1.visualize(visParams);\n\nvar lon = -8;\nvar lat = 60;\n\nMap.addLayer(background, {}, 'background');\nMap.addLayer(image, {}, 'Nadir BRDF/Albedo Reflectance I1');\nMap.setCenter(lon, lat, 3);\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/NASA/NASA_VIIRS_002_VNP43IA4) \n[VNP43IA4: BRDF/Albedo Quality Daily L3 Global 500m SIN Grid](/earth-engine/datasets/catalog/NASA_VIIRS_002_VNP43IA4) \nThe NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Version 2 product provides NBAR estimates at 500 meter resolution. The VNP43IA4 product is produced daily using 16 days of VIIRS data and is weighted temporally to ... \nNASA/VIIRS/002/VNP43IA4, brdf,land,nasa,noaa,satellite-imagery,surface,viirs \n2012-01-17T00:00:00Z/2025-08-12T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/VIIRS/VNP43IA4.002](https://doi.org/https://doi.org/10.5067/VIIRS/VNP43IA4.002)\n- [https://doi.org/10.5067/VIIRS/VNP43IA4.002](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/NASA_VIIRS_002_VNP43IA4)"]]
