版本 6.1 1 级 B (L1B) 产品经过了各种校准更改，包括：更改了响应与扫描角度 (RVS) 方法，该方法会影响 Aqua 和 Terra MODIS 的反射率波段；进行了校正，以调整 Terra MODIS 红外 (IR) 波段中的光学串扰；以及针对 2012 年至 2017 年期间更新了 Terra MODIS 前向查找表 (LUT)。已对 L1B 反射太阳带 (RSB) 应用偏振校正。该产品使用气候学 LAI/FPAR 作为操作型 LAI/FPAR 的备份。
[null,null,[],[[["\u003cp\u003eMOD16A2 V6.1 provides 8-day global evapotranspiration and latent heat flux data at 500m resolution from 2001 to 2024.\u003c/p\u003e\n"],["\u003cp\u003eIt's based on the Penman-Monteith equation using daily meteorological reanalysis and MODIS data like vegetation properties, albedo, and land cover.\u003c/p\u003e\n"],["\u003cp\u003eThe product includes layers for total evapotranspiration (ET), latent heat flux (LE), potential evapotranspiration (PET), and potential latent heat flux (PLE).\u003c/p\u003e\n"],["\u003cp\u003eThe MODIS Science Team recommends using the gap-filled MOD16A2GF 6.1 product for data from 2000 to 2021 for improved quality.\u003c/p\u003e\n"],["\u003cp\u003eData can be accessed and analyzed using Google Earth Engine.\u003c/p\u003e\n"]]],[],null,["Dataset Availability\n: 2021-01-01T00:00:00Z--2025-08-13T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/MODIS/MOD16A2.061)\n\nCadence\n: 8 Days\n\nTags\n:\n[8-day](/earth-engine/datasets/tags/8-day) [evapotranspiration](/earth-engine/datasets/tags/evapotranspiration) [global](/earth-engine/datasets/tags/global) [mod16a2](/earth-engine/datasets/tags/mod16a2) [modis](/earth-engine/datasets/tags/modis) [nasa](/earth-engine/datasets/tags/nasa) [water-vapor](/earth-engine/datasets/tags/water-vapor) \n\nDescription \nThe MOD16A2 Version 6.1 Evapotranspiration/Latent Heat Flux product is an\n8-day composite product produced at 500 meter pixel resolution. The\nalgorithm used for the MOD16 data product collection is based on the logic\nof the Penman-Monteith equation, which includes inputs of daily\nmeteorological reanalysis data along with MODIS remotely sensed data\nproducts such as vegetation property dynamics, albedo, and land cover.\n\nThe pixel values for the two Evapotranspiration layers (ET \\& PET) are the\nsum of all eight days within the composite period. The pixel values for\nthe two Latent Heat layers (LE \\& PLE) are the average of all eight days\nwithin the composite period. Note that the last 8-day period of each year\nis a 5 or 6-day composite period, depending on the year.\n\nClass assignment in fill values 32761 through 32767 might be inaccurate.\nThey are not included in the EE assets.\n\nThe Version 6.1 Level-1B (L1B) products have been improved by undergoing\nvarious calibration changes that include: changes to the\nresponse-versus-scan angle (RVS) approach that affects reflectance bands\nfor Aqua and Terra MODIS, corrections to adjust for the optical crosstalk\nin Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS\nforward look-up table (LUT) update for the period 2012 - 2017.\nA polarization correction has been applied to the L1B Reflective Solar\nBands (RSB). The product uses Climatology LAI/FPAR as back up to the\noperational LAI/FPAR.\n\nAccording to [the MODIS Science Team](https://forum.earthdata.nasa.gov/viewtopic.php?p=15070#p15070),\nThe MOD16A2 6.1 product will not have data prior to 2021. The MODIS Science\nteam recommends using the gap-filled MOD16A2GF 6.1 product for data from\n2000 to 2021 -- and then also 2022 when the data are available.\nThey recommend this as the gap-filled product is expected to be superior in\nproduct quality, especially over areas where otherwise the routine product\nperformance would have been negatively impacted by cloudy or poor quality\ninput observations. For the current year, there will not be a gap-filled\nproduct until early the following year (i.e. 2023 data should be available\nin early 2024). So, if a user needs MOD16A2GF 6.1 data for the year 2023\n(or the \"current\" year in the future), they recommend using the MOD16A2 6.1\nproduct, which is generated using the daily observation with climatology\nobservation replacing for the cloudy or poor quality observations.\n\nDocumentation:\n\n- [User's Guide](https://lpdaac.usgs.gov/documents/494/MOD16_User_Guide_V6.pdf)\n\n- [Algorithm Theoretical Basis Document (ATBD)](https://lpdaac.usgs.gov/documents/93/MOD16_ATBD.pdf)\n\n- [General Documentation](https://ladsweb.modaps.eosdis.nasa.gov/filespec/MODIS/6/MOD16A2)\n\nBands\n\n\n**Pixel Size**\n\n500 meters\n\n**Bands**\n\n| Name | Units | Min | Max | Scale | Pixel Size | Description |\n|---------|--------------|--------|-------|-------|------------|------------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `ET` | kg/m\\^2/8day | -32767 | 32700 | 0.1 | meters | Total evapotranspiration |\n| `LE` | J/m\\^2/day | -32767 | 32700 | 10000 | meters | Average latent heat flux |\n| `PET` | kg/m\\^2/8day | -32767 | 32700 | 0.1 | meters | Total potential evapotranspiration |\n| `PLE` | J/m\\^2/day | -32767 | 32700 | 10000 | meters | Average potential latent heat flux |\n| `ET_QC` | | | | | meters | Evapotranspiration quality control flags |\n| Bitmask for ET_QC - Bit 0: MODLAND_QC bits - 0: Good quality (main algorithm with or without saturation) - 1: Other quality (back-up algorithm or fill values) - Bit 1: Sensor - 0: Terra - 1: Aqua - Bit 2: Dead detector - 0: Detectors apparently fine for up to 50% of channels 1, 2 - 1: Dead detectors caused \\\u003e50% adjacent detector retrieval - Bits 3-4: Cloud state - 0: Significant clouds NOT present (clear) - 1: Significant clouds WERE present - 2: Mixed cloud present on pixel - 3: Cloud state not defined, assumed clear - Bits 5-7: SCF_QC 5-level confidence quality score - 0: Main (RT) method used, best result possible (no saturation) - 1: Main (RT) method used with saturation. Good, very usable - 2: Main (RT) method failed due to bad geometry, empirical algorithm used - 3: Main (RT) method failed due to problems other than geometry, empirical algorithm used - 4: Pixel not produced at all, value couldn't be retrieved (possible reasons: bad L1B data, unusable MOD09GA data) ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n\nImage Properties\n\n**Image Properties**\n\n| Name | Type | Description |\n|-----------|------|----------------------------------------------------------------------|\n| num_tiles | INT | The number of source tiles that were mosaicked to create this image. |\n\nTerms 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\nCitations \nCitations:\n\n- Please visit\n [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/MODIS/MOD16A2.061\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('MODIS/061/MOD16A2')\n .filter(ee.Filter.date('2022-01-01', '2022-05-01'));\nvar evapotranspiration = dataset.select('ET');\nvar evapotranspirationVis = {\n min: 0,\n max: 300,\n palette: [\n 'ffffff', 'fcd163', '99b718', '66a000', '3e8601', '207401', '056201',\n '004c00', '011301'\n ],\n};\nMap.setCenter(0, 0, 2);\nMap.addLayer(evapotranspiration, evapotranspirationVis, 'Evapotranspiration');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/MODIS/MODIS_061_MOD16A2) \n[MOD16A2.061: Terra Net Evapotranspiration 8-Day Global 500m](/earth-engine/datasets/catalog/MODIS_061_MOD16A2) \nThe MOD16A2 Version 6.1 Evapotranspiration/Latent Heat Flux product is an 8-day composite product produced at 500 meter pixel resolution. The algorithm used for the MOD16 data product collection is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with MODIS remotely sensed ... \nMODIS/061/MOD16A2, 8-day,evapotranspiration,global,mod16a2,modis,nasa,water-vapor \n2021-01-01T00:00:00Z/2025-08-13T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/MODIS/MOD16A2.061](https://doi.org/https://doi.org/10.5067/MODIS/MOD16A2.061)\n- [https://doi.org/10.5067/MODIS/MOD16A2.061](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MOD16A2)"]]
