이 Global Ecosystem Dynamics Investigation (GEDI) L4B 제품은 2019년 4월 18일에 시작된 미션 19주차부터 2021년 8월 4일에 종료된 미션 138주차까지의 관측을 기반으로 한 평균 지상 바이오매스 밀도 (AGBD)의 1km x 1km 추정치를 제공합니다. GEDI L4A Footprint Biomass 제품은 각 고품질 파형을 AGBD 예측으로 변환하고 L4B 제품은 각 1km 셀의 경계 내에 있는 샘플을 사용하여 평균 AGBD를 통계적으로 추론합니다.
글로벌 생태계 역학 조사GEDI 미션은 생태계 구조와 역학을 특징지어 지구의 탄소 순환과 생물 다양성을 획기적으로 개선된 방식으로 정량화하고 이해하는 것을 목표로 합니다. 국제우주정거장 (ISS)에 부착된 GEDI 장비는 지구의 3차원 구조를 최고 해상도와 가장 밀도 높은 샘플링으로 위도 51.6°N과 51.6°S 사이에서 전 세계 데이터를 수집합니다. GEDI 장비는 총 8개의 빔 지상 트랜섹트를 생성하는 3개의 레이저로 구성되어 있으며, 이는 트랙을 따라 약 60m 간격으로 배치된 8개의 ~25m 풋프린트를 즉시 샘플링합니다.
Dubayah, R.O., J. Armston, S.P. Healey, Z. Yang, P.L. Patterson, S. Saarela,
G. Stahl, L. Duncanson, J.R. Kellner. 2022년. GEDI L4B 격자형 지상 바이오매스 밀도, 버전 2. ORNL DAAC, Oak Ridge, Tennessee, USA.
doi:10.3334/ORNLDAAC/2056
이 Global Ecosystem Dynamics Investigation (GEDI) L4B 제품은 2019년 4월 18일에 시작된 미션 주 19부터 2021년 8월 4일에 종료된 미션 주 138까지의 관측을 기반으로 한 평균 지상 바이오매스 밀도 (AGBD)의 1km x 1km 추정치를 제공합니다. GEDI L4A Footprint Biomass 제품은 각 고품질 파형을 다음으로 변환합니다.
[null,null,[],[[["\u003cp\u003eThe LARSE/GEDI/GEDI04_B_002 dataset provides 1 km x 1 km estimates of mean aboveground biomass density (AGBD) from April 18, 2019, to August 4, 2021.\u003c/p\u003e\n"],["\u003cp\u003eThis GEDI L4B product uses high-quality waveforms to predict AGBD and infers mean AGBD within each 1 km grid cell.\u003c/p\u003e\n"],["\u003cp\u003eData is derived from the GEDI mission, which aims to characterize ecosystem structure and dynamics for better understanding of the Earth's carbon cycle and biodiversity.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset includes bands representing mean biomass, standard error, quality flags, and other relevant metrics for analysis.\u003c/p\u003e\n"],["\u003cp\u003eThis dataset is in the public domain and available without restriction on use and distribution, according to NASA's Earth Science Data & Information Policy.\u003c/p\u003e\n"]]],[],null,["# GEDI L4B Gridded Aboveground Biomass Density (Version 2)\n\nDataset Availability\n: 2019-04-18T00:00:00Z--2021-08-04T00:00:00Z\n\nDataset Provider\n:\n\n\n [USFS Laboratory for Applications of Remote Sensing in Ecology (LARSE)](https://www.fs.usda.gov/)\n\n\n [NASA GEDI mission, accessed through the USGS LP DAAC](https://lpdaac.usgs.gov/products/gedi02_av002/)\n\nTags\n:\n[elevation](/earth-engine/datasets/tags/elevation) [forest-biomass](/earth-engine/datasets/tags/forest-biomass) [gedi](/earth-engine/datasets/tags/gedi) [larse](/earth-engine/datasets/tags/larse) [nasa](/earth-engine/datasets/tags/nasa) [tree-cover](/earth-engine/datasets/tags/tree-cover) [usgs](/earth-engine/datasets/tags/usgs) \n\n#### Description\n\nThis Global Ecosystem Dynamics Investigation (GEDI) L4B product provides\n1 km x 1 km estimates of mean aboveground biomass density (AGBD) based on\nobservations from mission week 19 starting on 2019-04-18 to mission\nweek 138 ending on 2021-08-04. The GEDI L4A Footprint Biomass product\nconverts each high-quality waveform to an AGBD prediction, and the\nL4B product uses the sample present within the borders of each 1 km cell to\nstatistically infer mean AGBD.\n\nPlease see [User Guide](https://daac.ornl.gov/GEDI/guides/GEDI_L4B_Gridded_Biomass.html)\nfor more information.\n\nThe Global Ecosystem Dynamics Investigation [GEDI](https://gedi.umd.edu/)\nmission aims to characterize ecosystem structure and dynamics to enable\nradically improved quantification and understanding of the Earth's carbon cycle\nand biodiversity. The GEDI instrument, attached to the International Space\nStation (ISS), collects data globally between 51.6° N and 51.6° S\nlatitudes at the highest resolution and densest sampling of the\n3-dimensional structure of the Earth. The GEDI instrument consists of three\nlasers producing a total of eight beam ground transects, which instantaneously\nsample eight \\~25 m footprints spaced approximately every 60 m along-track.\n\n| Product | Description |\n|--------------------|---------------------------------------------------------------------------------------------------|\n| L2A Vector | [LARSE/GEDI/GEDI02_A_002](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_A_002) |\n| L2A Monthly raster | [LARSE/GEDI/GEDI02_A_002_MONTHLY](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_A_002_MONTHLY) |\n| L2A table index | [LARSE/GEDI/GEDI02_A_002_INDEX](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_A_002_INDEX) |\n| L2B Vector | [LARSE/GEDI/GEDI02_B_002](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_B_002) |\n| L2B Monthly raster | [LARSE/GEDI/GEDI02_B_002_MONTHLY](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_B_002_MONTHLY) |\n| L2B table index | [LARSE/GEDI/GEDI02_B_002_INDEX](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI02_B_002_INDEX) |\n| L4A Biomass Vector | [LARSE/GEDI/GEDI04_A_002](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_A_002) |\n| L4A Monthly raster | [LARSE/GEDI/GEDI04_A_002_MONTHLY](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_A_002_MONTHLY) |\n| L4A table index | [LARSE/GEDI/GEDI04_A_002_INDEX](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_A_002_INDEX) |\n| L4B Biomass | [LARSE/GEDI/GEDI04_B_002](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_B_002) |\n\n### Bands\n\n\n**Pixel Size**\n\n1000 meters\n\n**Bands**\n\n| Name | Units | Pixel Size | Description |\n|------|-------|------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `MU` | Mg/ha | meters | Mean aboveground biomass density (MU): Estimated mean AGBD for the 1 km grid cell, including forest and non-forest. |\n| `V1` | | meters | Variance component 1 (V1): Uncertainty in the estimate of mean biomass due to the field-to-GEDI model used in L4A. |\n| `V2` | | meters | Variance component 2 (V2) - If Mode of Inference = 1, this is the uncertainty due to GEDI's sampling of the 1 km cell. - If Mode of Inference = 2, this is uncertainty owing to the model predicting biomass using wall-to-wall data, calibrated with the L4A footprint product. |\n| `SE` | Mg/ha | meters | Mean aboveground biomass density standard error (SE): Standard Error of the mean estimate, combining sampling and modeling uncertainty. |\n| `PE` | % | meters | Standard error as a fraction of the estimated mean AGBD (PE). If \\\u003e100%, the cell values are truncated to 100. |\n| `NC` | | meters | Number of clusters (NC): Number of unique GEDI ground tracks with at least one high-quality waveform intersecting the grid cell. |\n| `NS` | | meters | Number of samples (NS): Total number of high-quality waveforms across all ground tracks within the grid cell. |\n| `QF` | | meters | Quality flag (QF) - 0=Outside the GEDI domain - 1=Land surface - 2=Land surface and meets GEDI mission L1 requirement (Percent standard error \\\u003c20% or Standard Error \\\u003c 20 Mg ha-1) |\n| `PS` | | meters | Prediction stratum (PS) determined by plant functional type and continent. PS is associated with an L4A model parameter covariance matrix that contributes to the Model Error Variance (Table 2). |\n| `MI` | | meters | Mode of interference (MI): Method used for a particular cell. Until mission completion, only those cells where hybrid inference is possible will be populated with a mean biomass value. - 0=None applied - 1=Hybrid Model-Based - 2=Generalized Hierarchical Model-Based |\n\n### Terms of Use\n\n**Terms of Use**\n\nThis dataset is in the public domain and is available\nwithout restriction on use and distribution. See [NASA's\nEarth Science Data \\& Information Policy](https://www.earthdata.nasa.gov/engage/open-data-services-and-software/data-and-information-policy)\nfor additional information.\n\n### Citations\n\nCitations:\n\n- Dubayah, R.O., J. Armston, S.P. Healey, Z. Yang, P.L. Patterson, S. Saarela,\n G. Stahl, L. Duncanson, and J.R. Kellner. 2022. GEDI L4B Gridded Aboveground\n Biomass Density, Version 2. ORNL DAAC, Oak Ridge, Tennessee, USA.\n [doi:10.3334/ORNLDAAC/2056](https://doi.org/10.3334/ORNLDAAC/2056)\n\n### DOIs\n\n- \u003chttps://doi.org/10.3334/ORNLDAAC/2056\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 l4b = ee.Image('LARSE/GEDI/GEDI04_B_002')\n\nMap.addLayer(\n l4b.select('MU'),\n {min: 10, max: 250, palette: '440154,414387,2a788e,23a884,7ad151,fde725'},\n 'Mean Biomass');\nMap.addLayer(\n l4b.select('SE'),\n {min: 10, max: 50, palette: '000004,3b0f6f,8c2981,dd4a69,fe9f6d,fcfdbf'},\n 'Standard Error');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/LARSE/LARSE_GEDI_GEDI04_B_002) \n[GEDI L4B Gridded Aboveground Biomass Density (Version 2)](/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_B_002) \nThis Global Ecosystem Dynamics Investigation (GEDI) L4B product provides 1 km x 1 km estimates of mean aboveground biomass density (AGBD) based on observations from mission week 19 starting on 2019-04-18 to mission week 138 ending on 2021-08-04. The GEDI L4A Footprint Biomass product converts each high-quality waveform to an ... \nLARSE/GEDI/GEDI04_B_002, elevation,forest-biomass,gedi,larse,nasa,tree-cover,usgs \n2019-04-18T00:00:00Z/2021-08-04T00:00:00Z \n-52 -180 52 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.3334/ORNLDAAC/2056](https://doi.org/https://www.fs.usda.gov/)\n- [https://doi.org/10.3334/ORNLDAAC/2056](https://doi.org/https://lpdaac.usgs.gov/products/gedi02_av002/)\n- [https://doi.org/10.3334/ORNLDAAC/2056](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/LARSE_GEDI_GEDI04_B_002)"]]
