Produk NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Versi 2 memberikan estimasi NBAR pada resolusi 500 meter. Produk VNP43IA4 diproduksi setiap hari menggunakan data VIIRS selama 16 hari dan diberi bobot secara temporal hingga hari kesembilan, yang tercermin dalam nama file. Efek sudut pandang dihapus dari pantulan terarah, sehingga menghasilkan produk NBAR yang stabil dan konsisten. Produk data VNP43 dirancang untuk mempromosikan
kontinuitas rangkaian produk data BRDF/Albedo Moderate Resolution Imaging Spectroradiometer (MODIS) NASA.
Algoritma VNP43 menggunakan model BRDF berbasis kernel semi-empiris RossThick/Li-Sparse-Reciprocal (RTLSR), dengan tiga bobot kernel dari VNP43IA1 untuk merekonstruksi efek anisotropik permukaan, mengoreksi reflektansi terarah ke geometri tampilan umum (VNP43IA4), sekaligus menghitung albedo langit hitam terintegrasi (BSA) pada tengah hari surya lokal dan albedo langit putih (WSA) (VNP43IA3). Peneliti dapat menggunakan parameter model BRDF dengan polinomial sederhana, untuk mendapatkan albedo langit hitam pada sudut iluminasi matahari mana pun. Demikian pula, lapisan Set Data Sains (SDS) BSA dan WSA dapat digunakan dengan polinomial sederhana, untuk memperkirakan albedo aktual instan (albedo langit biru) secara manual. Detail tambahan terkait metodologi tersedia dalam Dokumen Dasar Teoretis Algoritma (ATBD).
Reflektansi BRDF/Albedo Nadir pada tengah hari matahari lokal untuk band
I1
Nadir_Reflectance_I2
meter
Reflektansi BRDF/Albedo Nadir pada tengah hari surya lokal untuk band
I2
Nadir_Reflectance_I3
meter
Reflektansi BRDF/Albedo Nadir pada tengah hari surya lokal untuk band I3
Persyaratan Penggunaan
Persyaratan Penggunaan
Data NASA LP DAAC dapat diakses secara bebas; namun, saat penulis memublikasikan data ini atau karya yang didasarkan pada data tersebut, penulis diminta untuk mengutip set data dalam teks publikasi dan menyertakan referensi ke set data tersebut dalam daftar referensi.
Kutipan
Kutipan:
Schaaf, C., Z. Wang, A. Erb, I. Paynter. VIIRS/NPP BRDF/Albedo Nadir
BRDF-Adjusted Ref Daily L3 Global 500m SIN Grid V002. 2024, didistribusikan oleh
NASA EOSDIS Land Processes Distributed Active Archive Center,
10.5067/VIIRS/VNP43IA4.002.
Produk NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Nadir Bidirectional Reflectance Distribution Function (BRDF) Adjusted Reflectance (NBAR) Versi 2 memberikan estimasi NBAR pada resolusi 500 meter. Produk VNP43IA4 diproduksi setiap hari menggunakan data VIIRS selama 16 hari dan diberi bobot secara temporal untuk …
[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)"]]
