Bu Global Ecosystem Dynamics Investigation (GEDI) L4B ürünü, 2019-04-18'de başlayan 19. görev haftasından 2021-08-04'te sona eren 138. görev haftasına kadar olan gözlemlere dayalı olarak ortalama yer üstü biyokütle yoğunluğunun (AGBD) 1 km x 1 km tahminlerini sağlar. GEDI L4A Footprint Biomass ürünü, her bir yüksek kaliteli dalga biçimini AGBD tahminine dönüştürür. L4B ürünü ise ortalama AGBD'yi istatistiksel olarak tahmin etmek için her bir 1 km'lik hücrenin sınırları içindeki örneği kullanır.
Global Ecosystem Dynamics Investigation GEDI (Küresel Ekosistem Dinamikleri Araştırması) misyonu, ekosistem yapısını ve dinamiklerini karakterize ederek Dünya'nın karbon döngüsünün ve biyoçeşitliliğinin ölçülmesini ve anlaşılmasını önemli ölçüde iyileştirmeyi amaçlamaktadır. Uluslararası Uzay İstasyonu'na (ISS) bağlı GEDI cihazı, 51,6° N ve 51,6° S enlemleri arasında küresel olarak veri toplar. Bu veriler, Dünya'nın 3 boyutlu yapısının en yüksek çözünürlükte ve en yoğun örneklemesiyle elde edilir. GEDI cihazı, toplam sekiz ışın yer kesiti oluşturan üç lazerden oluşur. Bu lazerler, yaklaşık 60 metre aralıklarla yerleştirilmiş sekiz adet ~25 m ayak izini anında örnekler.
Ortalama yer üstü biyokütle yoğunluğu (MU): Orman ve orman dışı alanlar dahil olmak üzere 1 km'lik ızgara hücresi için tahmini ortalama YBD.
V1
metre
Varyans bileşeni 1 (V1): L4A'da kullanılan saha-GEDI modeli nedeniyle ortalama biyokütle tahminindeki belirsizlik.
V2
metre
Varyans bileşeni 2 (V2)
Çıkarım Modu = 1 ise bu, GEDI'nin 1 km'lik hücreyi örneklemesinden kaynaklanan belirsizliktir.
Çıkarım Modu = 2 ise bu, modelin L4A ayak izi ürünüyle kalibre edilmiş, baştan sona verileri kullanarak biyokütleyi tahmin etmesinden kaynaklanan belirsizliktir.
SE
Mg/ha
metre
Ortalama yer üstü biyokütle yoğunluğu standart hatası (SE): Örnekleme ve modelleme belirsizliğini birleştiren ortalama tahminin standart hatası.
PE
%
metre
Tahmini ortalama AGBD'nin (PE) bir kesri olarak standart hata.
%100'den büyükse hücre değerleri 100 olarak kısaltılır.
NC
metre
Küme sayısı (NC): Izgara hücresini kesen en az bir yüksek kaliteli dalga biçimine sahip benzersiz GEDI yer izlerinin sayısı.
NS
metre
Örnek sayısı (NS): Izgara hücresindeki tüm yer izlerinde bulunan yüksek kaliteli dalga biçimlerinin toplam sayısı.
QF
metre
Kalite işareti (QF)
0=GEDI alanının dışında
1=Arazi yüzeyi
2=Arazi yüzeyi ve GEDI görev L1 şartını karşılıyor
(Yüzde standart hata <%20 veya Standart Hata < 20 Mg ha-1)
PS
metre
Bitki işlevsel türü ve kıtaya göre belirlenen tahmin katmanı (PS). PS, Model Hata Varyansına (Tablo 2) katkıda bulunan bir L4A modeli parametre kovaryans matrisiyle ilişkilidir.
MI
metre
Girişim modu (MI): Belirli bir hücre için kullanılan yöntem.
Görev tamamlanana kadar yalnızca hibrit çıkarımın mümkün olduğu hücreler ortalama biyokütle değeriyle doldurulur.
Dubayah, R.O., J. Armston, S.P. Healey, Z. Yang, P.L. Patterson, S. Saarela,
G. Stahl, L. Duncanson ve J.R. Kellner. 2022. GEDI L4B Gridded Aboveground
Biomass Density, Version 2. ORNL DAAC, Oak Ridge, Tennessee, ABD.
doi:10.3334/ORNLDAAC/2056
Bu Global Ecosystem Dynamics Investigation (GEDI) L4B ürünü, 18.04.2019'da başlayan 19. görev haftasından 04.08.2021'de sona eren 138. görev haftasına kadar olan gözlemlere dayalı olarak ortalama yer üstü biyokütle yoğunluğunun (AGBD) 1 km x 1 km tahminlerini sağlar. GEDI L4A Footprint Biomass ürünü, her yüksek kaliteli dalga biçimini …
[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)"]]
