Atmosphere-Land Exchange Inverse / Désagrégation de l'inverse de l'échange atmosphère-terre (ALEXI/DisALEXI)
DisALEXI a récemment été porté sur Google Earth Engine dans le cadre du framework OpenET. La structure du modèle de référence ALEXI/DisALEXI est décrite par Anderson et al. (2012, 2018). Le modèle ALEXI d'évapotranspiration (ET) utilise spécifiquement des mesures de température de surface terrestre (LST) à différentiel temporel provenant de plates-formes géostationnaires ou à orbite polaire à résolution modérée pour générer des cartes régionales d'ET. DisALEXI désagrège ensuite l'ET ALEXI régional à des échelles plus fines à l'aide des données Landsat (30 m ; bimensuelles) pour résoudre les champs agricoles individuels et d'autres caractéristiques du paysage.
Informations supplémentaires
Bracelets
Taille des pixels 30 mètres
Bandes de fréquences
Nom
Unités
Taille des pixels
Description
et
mm
mètres
Valeur DisALEXI ET
count
nombre
mètres
Nombre de valeurs sans frais dans le cloud
Propriétés des images
Propriétés de l'image
Nom
Type
Description
build_date
STRING
Date de création des composants
cloud_cover_max
DOUBLE
Valeur maximale du pourcentage CLOUD_COVER_LAND pour les images Landsat incluses dans l'interpolation
collections
STRING
Liste des collections Landsat pour les images Landsat incluses dans l'interpolation
core_version
STRING
Version de la bibliothèque OpenET Core
end_date
STRING
Date de fin du mois
et_reference_band
STRING
Bande dans et_reference_source contenant les données quotidiennes de l'ET de référence
et_reference_resample
STRING
Mode d'interpolation spatiale pour rééchantillonner les données quotidiennes de référence sur l'ET
et_reference_source
STRING
ID de la collection pour les données quotidiennes de référence sur l'ET
interp_days
DOUBLE
Nombre maximal de jours avant et après la date de chaque image à inclure dans l'interpolation
interp_method
STRING
Méthode utilisée pour interpoler entre les estimations du modèle Landsat
interp_source_count
DOUBLE
Nombre d'images disponibles dans la collection d'images source d'interpolation pour le mois cible
mgrs_tile
STRING
ID de la zone de grille MGRS
model_name
STRING
Nom du modèle OpenET
model_version
STRING
Version du modèle OpenET
scale_factor_count
DOUBLE
Facteur de scaling à appliquer à la bande de nombre
scale_factor_et
DOUBLE
Facteur de scaling à appliquer à la bande de l'erreur cible
Anderson, M., Gao, F., Knipper, K., Hain, C., Dulaney, W., Baldocchi, D .,
Eichelmann, E., Hemes, K., Yang, Y., Medellin-Azuara, J. et Kustas, W.,
2018. Évaluation à l'échelle des champs des changements d'utilisation des terres et de l'eau dans le delta de Californie à l'aide de la télédétection. Remote Sensing, 10(6), p.889.
doi:10.3390/rs10060889
Anderson, M.C., Norman, J.M., Mecikalski, J.R., Otkin, J.A. et Kustas,
W.P., 2007. Étude climatologique de l'évapotranspiration et du stress hydrique dans les États-Unis continentaux basée sur la télédétection thermique : 1. Formulation du modèle. Journal of Geophysical Research:
Atmospheres, 112(D10).
doi:10.1029/2006JD007506
La méthode ALEXI / DisALEXI (Atmosphere-Land Exchange Inverse/Disaggregation of the Atmosphere-Land Exchange Inverse) a récemment été portée sur Google Earth Engine dans le cadre du framework OpenET. La structure de modèle ALEXI/DisALEXI de référence est décrite par Anderson et al. (2012, 2018). Le modèle d'évapotranspiration (ET) ALEXI utilise spécifiquement la surface terrestre à différentiel temporel…
[null,null,[],[[["\u003cp\u003eThe OpenET DisALEXI dataset provides monthly evapotranspiration (ET) data for the contiguous United States (CONUS) at a 30-meter resolution, derived from Landsat and GRIDMET data.\u003c/p\u003e\n"],["\u003cp\u003eDisALEXI, part of the OpenET framework, uses a model based on land surface temperature changes to estimate ET and is further disaggregated using Landsat for finer-scale detail.\u003c/p\u003e\n"],["\u003cp\u003eData is available from January 2008 to December 2023 and is provided by OpenET, Inc.under a CC-BY-4.0 license.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset includes two bands: 'et' representing the DisALEXI ET value in millimeters and 'count' indicating the number of cloud-free values used in the calculation.\u003c/p\u003e\n"],["\u003cp\u003eUsers can explore and analyze this dataset within Google Earth Engine for research, education, and non-profit purposes.\u003c/p\u003e\n"]]],["The OpenET DisALEXI dataset, available from 2001-01-01 to 2023-12-01, provides monthly evapotranspiration (ET) data at a 30-meter resolution. It uses the ALEXI/DisALEXI model, which combines land surface temperature data with Landsat data to estimate ET, including a band with the 'et' value and a 'count' of cloud-free observations. The data can be accessed via Earth Engine using a provided code snippet and is licenced with a CC-BY-4.0 use license.\n"],null,["# OpenET DisALEXI Monthly Evapotranspiration v2.0\n\nDataset Availability\n: 2001-01-01T00:00:00Z--2024-12-01T00:00:00Z\n\nDataset Provider\n:\n\n\n [OpenET, Inc.](https://openetdata.org/)\n\nCadence\n: 1 Month\n\nTags\n:\n[evapotranspiration](/earth-engine/datasets/tags/evapotranspiration) [gridmet-derived](/earth-engine/datasets/tags/gridmet-derived) [landsat-derived](/earth-engine/datasets/tags/landsat-derived) [monthly](/earth-engine/datasets/tags/monthly) [openet](/earth-engine/datasets/tags/openet) [water](/earth-engine/datasets/tags/water) [water-vapor](/earth-engine/datasets/tags/water-vapor) \n\n#### Description\n\nAtmosphere-Land Exchange Inverse / Disaggregation of the Atmosphere-Land\nExchange Inverse (ALEXI/DisALEXI)\n\nDisALEXI was recently ported to Google Earth Engine as part of the OpenET\nframework and the baseline ALEXI/DisALEXI model structure is described by\nAnderson et al. (2012, 2018). The ALEXI evapotranspiration (ET) model\nspecifically uses time differential land surface temperature (LST)\nmeasurements from geostationary or moderate resolution polar orbiting\nplatforms to generate regional ET maps. DisALEXI then disaggregates the\nregional ALEXI ET to finer scales using Landsat data (30 m; biweekly) to\nresolve individual farm fields and other landscape features.\n[Additional information](https://openetdata.org/methodologies/)\n\n### Bands\n\n\n**Pixel Size**\n\n30 meters\n\n**Bands**\n\n| Name | Units | Pixel Size | Description |\n|---------|-------|------------|-----------------------------|\n| `et` | mm | meters | DisALEXI ET value |\n| `count` | count | meters | Number of cloud free values |\n\n### Image Properties\n\n**Image Properties**\n\n| Name | Type | Description |\n|-----------------------|--------|----------------------------------------------------------------------------------------------|\n| build_date | STRING | Date assets were built |\n| cloud_cover_max | DOUBLE | Maximum CLOUD_COVER_LAND percent value for Landsat images included in interpolation |\n| collections | STRING | List of Landsat collections for Landsat images included in the interpolation |\n| core_version | STRING | OpenET core library version |\n| end_date | STRING | End date of month |\n| et_reference_band | STRING | Band in et_reference_source that contains the daily reference ET data |\n| et_reference_resample | STRING | Spatial interpolation mode to resample daily reference ET data |\n| et_reference_source | STRING | Collection ID for the daily reference ET data |\n| interp_days | DOUBLE | Maximum number of days before and after each image date to include in interpolation |\n| interp_method | STRING | Method used to interpolate between Landsat model estimates |\n| interp_source_count | DOUBLE | Number of available images in the interpolation source image collection for the target month |\n| mgrs_tile | STRING | MGRS grid zone ID |\n| model_name | STRING | OpenET model name |\n| model_version | STRING | OpenET model version |\n| scale_factor_count | DOUBLE | Scaling factor that should be applied to the count band |\n| scale_factor_et | DOUBLE | Scaling factor that should be applied to the et band |\n| start_date | STRING | Start date of month |\n\n### Terms of Use\n\n**Terms of Use**\n\n[CC-BY-4.0](https://spdx.org/licenses/CC-BY-4.0.html)\n\n### Citations\n\nCitations:\n\n- Anderson, M., Gao, F., Knipper, K., Hain, C., Dulaney, W., Baldocchi, D .,\n Eichelmann, E., Hemes, K., Yang, Y., Medellin-Azuara, J. and Kustas, W.,\n 2018. Field-scale assessment of land and water use change over the\n California Delta using remote sensing. Remote Sensing, 10(6), p.889.\n [doi:10.3390/rs10060889](https://doi.org/10.3390/rs10060889)\n- Anderson, M.C., Norman, J.M., Mecikalski, J.R., Otkin, J.A. and Kustas,\n W.P., 2007. A climatological study of evapotranspiration and moisture\n stress across the continental United States based on thermal remote\n sensing: 1. Model formulation. Journal of Geophysical Research:\n Atmospheres, 112(D10).\n [doi:10.1029/2006JD007506](https://doi.org/10.1029/2006JD007506)\n\n### DOIs\n\n- \u003chttps://doi.org/10.3390/rs10060889\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('OpenET/DISALEXI/CONUS/GRIDMET/MONTHLY/v2_0')\n .filterDate('2020-01-01', '2021-01-01');\n\n// Compute the annual evapotranspiration (ET) as the sum of the monthly ET\n// images for the year.\nvar et = dataset.select('et').sum();\n\nvar visualization = {\n min: 0,\n max: 1400,\n palette: [\n '9e6212', 'ac7d1d', 'ba9829', 'c8b434', 'd6cf40', 'bed44b', '9fcb51',\n '80c256', '61b95c', '42b062', '45b677', '49bc8d', '4dc2a2', '51c8b8',\n '55cece', '4db4ba', '459aa7', '3d8094', '356681', '2d4c6e',\n ]\n};\n\nMap.setCenter(-100, 38, 5);\n\nMap.addLayer(et, visualization, 'OpenET DisALEXI Annual ET');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/OpenET/OpenET_DISALEXI_CONUS_GRIDMET_MONTHLY_v2_0) \n[OpenET DisALEXI Monthly Evapotranspiration v2.0](/earth-engine/datasets/catalog/OpenET_DISALEXI_CONUS_GRIDMET_MONTHLY_v2_0) \nAtmosphere-Land Exchange Inverse / Disaggregation of the Atmosphere-Land Exchange Inverse (ALEXI/DisALEXI) DisALEXI was recently ported to Google Earth Engine as part of the OpenET framework and the baseline ALEXI/DisALEXI model structure is described by Anderson et al. (2012, 2018). The ALEXI evapotranspiration (ET) model specifically uses time differential land surface ... \nOpenET/DISALEXI/CONUS/GRIDMET/MONTHLY/v2_0, evapotranspiration,gridmet-derived,landsat-derived,monthly,openet,water,water-vapor \n2001-01-01T00:00:00Z/2024-12-01T00:00:00Z \n25 -126 50 -66 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.3390/rs10060889](https://doi.org/https://openetdata.org/)\n- [https://doi.org/10.3390/rs10060889](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/OpenET_DISALEXI_CONUS_GRIDMET_MONTHLY_v2_0)"]]
