Produkt MOD13A1 V6.1 zawiera wartość indeksu wegetacji (VI) dla każdego piksela. Wyróżniamy 2 główne warstwy roślinności.
Pierwszy z nich to znormalizowany różnicowy wskaźnik wegetacji (NDVI), który jest nazywany wskaźnikiem ciągłości w stosunku do dotychczasowego wskaźnika NDVI pochodzącego z zaawansowanego radiometru o bardzo wysokiej rozdzielczości (AVHRR) Narodowej Administracji Oceanicznej i Atmosferycznej (NOAA). Drugą warstwą wegetacji jest ulepszony wskaźnik wegetacji (EVI), który minimalizuje zmiany tła pokrywy roślinnej i utrzymuje czułość w przypadku gęstej roślinności.
EVI wykorzystuje też pasmo niebieskie do usuwania pozostałych zanieczyszczeń atmosferycznych
spowodowanych przez dym i cienkie chmury o rozmiarze mniejszym niż piksel. Produkty MODIS NDVI i EVI są obliczane na podstawie skorygowanych atmosferycznie dwukierunkowych odbić powierzchniowych, które zostały zamaskowane pod kątem wody, chmur, dużego stężenia aerozoli i cieni chmur.
Produkt MOD13A1 V6.1 zawiera wartość indeksu wegetacji (VI) dla każdego piksela. Wyróżniamy 2 główne warstwy roślinności. Pierwszy to znormalizowany różnicowy wskaźnik wegetacji (NDVI), który jest nazywany wskaźnikiem ciągłości w odniesieniu do istniejącego już radiometru o bardzo wysokiej rozdzielczości NOAA (National Oceanic and Atmospheric Administration) …
[null,null,[],[[["\u003cp\u003eThe MOD13A1 V6.1 product provides Vegetation Index (VI) values, including NDVI and EVI, at a 500-meter resolution.\u003c/p\u003e\n"],["\u003cp\u003eIt is a global, 16-day composite product, derived from atmospherically corrected surface reflectance.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset is available from February 18, 2000, to November 16, 2024, and is provided by NASA LP DAAC at the USGS EROS Center.\u003c/p\u003e\n"],["\u003cp\u003eIt includes quality assessment bands (DetailedQA and SummaryQA) for data reliability and usefulness.\u003c/p\u003e\n"],["\u003cp\u003eMODIS data and products acquired through the LP DAAC have no restrictions on subsequent use, sale, or redistribution.\u003c/p\u003e\n"]]],["The MOD13A1 V6.1 dataset from NASA LP DAAC, available from 2000-02-18 to 2025-02-02, offers 16-day global vegetation index data at 500m resolution. Key layers include the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI), derived from atmospherically corrected surface reflectances. Data is accessible via Google Earth Engine using the `ee.ImageCollection(\"MODIS/061/MOD13A1\")` snippet. The dataset's detailed quality is available through provided quality assurance (QA) bitmask.\n"],null,["# MOD13A1.061 Terra Vegetation Indices 16-Day Global 500m\n\nDataset Availability\n: 2000-02-18T00:00:00Z--2025-07-28T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/MODIS/MOD13A1.061)\n\nCadence\n: 16 Days\n\nTags\n:\n [16-day](/earth-engine/datasets/tags/16-day) [evi](/earth-engine/datasets/tags/evi) [global](/earth-engine/datasets/tags/global) [modis](/earth-engine/datasets/tags/modis) [nasa](/earth-engine/datasets/tags/nasa) [ndvi](/earth-engine/datasets/tags/ndvi) [terra](/earth-engine/datasets/tags/terra) [usgs](/earth-engine/datasets/tags/usgs) [vegetation](/earth-engine/datasets/tags/vegetation) [vegetation-indices](/earth-engine/datasets/tags/vegetation-indices) \nmod13a1 \n\n#### Description\n\nThe MOD13A1 V6.1 product provides a Vegetation Index (VI)\nvalue at a per pixel basis. There are two primary vegetation layers.\nThe first is the Normalized Difference Vegetation Index (NDVI)\nwhich is referred to as the continuity index to the existing National\nOceanic and Atmospheric Administration-Advanced Very High Resolution\nRadiometer (NOAA-AVHRR) derived NDVI. The second vegetation layer\nis the Enhanced Vegetation Index (EVI) that minimizes canopy background\nvariations and maintains sensitivity over dense vegetation conditions.\nThe EVI also uses the blue band to remove residual atmosphere contamination\ncaused by smoke and sub-pixel thin cloud clouds. The MODIS NDVI\nand EVI products are computed from atmospherically corrected bi-directional\nsurface reflectances that have been masked for water, clouds, heavy\naerosols, and cloud shadows.\n\nDocumentation:\n\n- [User's Guide](https://lpdaac.usgs.gov/documents/103/MOD13_User_Guide_V6.pdf)\n\n- [Algorithm Theoretical Basis Document (ATBD)](https://lpdaac.usgs.gov/documents/104/MOD13_ATBD.pdf)\n\n- [General Documentation](https://ladsweb.modaps.eosdis.nasa.gov/filespec/MODIS/61/MOD13A1)\n\n### Bands\n\n\n**Pixel Size**\n\n500 meters\n\n**Bands**\n\n| Name | Units | Min | Max | Scale | Pixel Size | Wavelength | Description |\n|-------------------|-------|--------|-------|--------|------------|----------------------|----------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `NDVI` | | -2000 | 10000 | 0.0001 | meters | None | Normalized Difference Vegetation Index |\n| `EVI` | | -2000 | 10000 | 0.0001 | meters | None | Enhanced Vegetation Index |\n| `DetailedQA` | | | | | meters | None | VI quality indicators |\n| Bitmask for DetailedQA - Bits 0-1: VI quality (MODLAND QA Bits) - 0: VI produced with good quality - 1: VI produced, but check other QA - 2: Pixel produced, but most probably cloudy - 3: Pixel not produced due to other reasons than clouds - Bits 2-5: VI usefulness - 0: Highest quality - 1: Lower quality - 2: Decreasing quality - 4: Decreasing quality - 8: Decreasing quality - 9: Decreasing quality - 10: Decreasing quality - 12: Lowest quality - 13: Quality so low that it is not useful - 14: L1B data faulty - 15: Not useful for any other reason/not processed - Bits 6-7: Aerosol Quantity - 0: Climatology - 1: Low - 2: Intermediate - 3: High - Bit 8: Adjacent cloud detected - 0: No - 1: Yes - Bit 9: Atmosphere BRDF correction - 0: No - 1: Yes - Bit 10: Mixed Clouds - 0: No - 1: Yes - Bits 11-13: Land/water mask - 0: Shallow ocean - 1: Land (nothing else but land) - 2: Ocean coastlines and lake shorelines - 3: Shallow inland water - 4: Ephemeral water - 5: Deep inland water - 6: Moderate or continental ocean - 7: Deep ocean - Bit 14: Possible snow/ice - 0: No - 1: Yes - Bit 15: Possible shadow - 0: No - 1: Yes ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n| `sur_refl_b01` | | 0 | 10000 | 0.0001 | meters | 645nm | Red surface reflectance |\n| `sur_refl_b02` | | 0 | 10000 | 0.0001 | meters | 858nm | NIR surface reflectance |\n| `sur_refl_b03` | | 0 | 10000 | 0.0001 | meters | 469nm | Blue surface reflectance |\n| `sur_refl_b07` | | 0 | 10000 | 0.0001 | meters | 2130nm/2105 - 2155nm | MIR surface reflectance |\n| `ViewZenith` | deg | 0 | 18000 | 0.01 | meters | None | View zenith angle |\n| `SolarZenith` | deg | 0 | 18000 | 0.01 | meters | None | Solar zenith angle |\n| `RelativeAzimuth` | deg | -18000 | 18000 | 0.01 | meters | None | Relative azimuth angle |\n| `DayOfYear` | | 1 | 366 | | meters | None | Julian day of year |\n| `SummaryQA` | | | | | meters | None | Quality reliability of VI pixel |\n| Bitmask for SummaryQA - Bits 0-1: VI quality (MODLAND QA Bits) - 0: Good data, use with confidence - 1: Marginal data, useful but look at detailed QA for more information - 2: Pixel covered with snow/ice - 3: Pixel is cloudy ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n\n### Terms of Use\n\n**Terms of Use**\n\nMODIS data and products acquired through the LP DAAC\nhave no restrictions on subsequent use, sale, or redistribution.\n\n### Citations\n\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\n### DOIs\n\n- \u003chttps://doi.org/10.5067/MODIS/MOD13A1.061\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('MODIS/061/MOD13A1')\n .filter(ee.Filter.date('2018-01-01', '2018-05-01'));\nvar ndvi = dataset.select('NDVI');\nvar ndviVis = {\n min: 0,\n max: 9000,\n palette: [\n 'ffffff', 'ce7e45', 'df923d', 'f1b555', 'fcd163', '99b718', '74a901',\n '66a000', '529400', '3e8601', '207401', '056201', '004c00', '023b01',\n '012e01', '011d01', '011301'\n ],\n};\nMap.setCenter(6.746, 46.529, 2);\nMap.addLayer(ndvi, ndviVis, 'NDVI');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/MODIS/MODIS_061_MOD13A1) \n[MOD13A1.061 Terra Vegetation Indices 16-Day Global 500m](/earth-engine/datasets/catalog/MODIS_061_MOD13A1) \nThe MOD13A1 V6.1 product provides a Vegetation Index (VI) value at a per pixel basis. There are two primary vegetation layers. The first is the Normalized Difference Vegetation Index (NDVI) which is referred to as the continuity index to the existing National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer ... \nMODIS/061/MOD13A1, 16-day,evi,global,modis,nasa,ndvi,terra,usgs,vegetation,vegetation-indices \n2000-02-18T00:00:00Z/2025-07-28T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/MODIS/MOD13A1.061](https://doi.org/https://doi.org/10.5067/MODIS/MOD13A1.061)\n- [https://doi.org/10.5067/MODIS/MOD13A1.061](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MOD13A1)"]]
