Produk Global Ecosystem Dynamics Investigation (GEDI) L4B ini memberikan
estimasi kepadatan biomassa di atas permukaan tanah (AGBD) rata-rata 1 km x 1 km berdasarkan
pengamatan dari minggu misi 19 yang dimulai pada 18-04-2019 hingga minggu
misi 138 yang berakhir pada 04-08-2021. Produk Biomasa Jejak Kaki GEDI L4A
mengonversi setiap bentuk gelombang berkualitas tinggi menjadi prediksi AGBD, dan produk L4B menggunakan sampel yang ada dalam batas setiap sel 1 km untuk menyimpulkan AGBD rata-rata secara statistik.
Misi Global Ecosystem Dynamics Investigation GEDI bertujuan untuk mengkarakterisasi struktur dan dinamika ekosistem untuk memungkinkan kuantifikasi dan pemahaman yang jauh lebih baik tentang siklus karbon dan keanekaragaman hayati Bumi. Instrumen GEDI, yang terpasang di Stasiun Luar Angkasa Internasional (ISS), mengumpulkan data secara global antara garis lintang 51,6° N dan 51,6° S pada resolusi tertinggi dan pengambilan sampel terpadat dari struktur 3 dimensi Bumi. Instrumen GEDI terdiri dari tiga
laser yang menghasilkan total delapan transkrip darat sinar, yang secara instan
mengambil sampel delapan jejak kaki ~25 m yang berjarak sekitar 60 m di sepanjang jalur.
Kepadatan biomassa di atas permukaan tanah (MU): Perkiraan AGBD rata-rata untuk sel petak 1 km, termasuk hutan dan non-hutan.
V1
meter
Komponen varians 1 (V1): Ketidakpastian dalam estimasi biomassa rata-rata karena model lapangan-ke-GEDI yang digunakan di L4A.
V2
meter
Komponen varians 2 (V2)
Jika Mode Inferensi = 1,
ini adalah ketidakpastian karena pengambilan sampel sel 1 km GEDI.
Jika Mode Inferensi = 2,
ini adalah ketidakpastian karena model memprediksi biomassa menggunakan
data wall-to-wall, yang dikalibrasi dengan produk footprint L4A.
SE
Mg/ha
meter
Kesalahan baku (SE) kepadatan biomassa di atas permukaan tanah: Kesalahan Baku
perkiraan rata-rata, yang menggabungkan ketidakpastian pengambilan sampel dan pemodelan.
PE
%
meter
Error standar sebagai fraksi dari AGBD (PE) rata-rata yang diperkirakan.
Jika >100%, nilai sel akan dipangkas menjadi 100.
NC
meter
Jumlah cluster (NC): Jumlah jalur darat GEDI unik dengan setidaknya satu bentuk gelombang berkualitas tinggi yang berpotongan dengan sel petak.
NS
meter
Jumlah sampel (NS): Jumlah total bentuk gelombang berkualitas tinggi di semua jalur darat dalam sel petak.
QF
meter
Tanda kualitas (QF)
0=Di luar domain GEDI
1=Permukaan tanah
2=Permukaan daratan dan memenuhi persyaratan L1 misi GEDI
(Persen kesalahan standar <20% atau Kesalahan Standar < 20 Mg ha-1)
PS
meter
Stratum prediksi (PS) ditentukan oleh jenis fungsional tanaman dan
benua. PS dikaitkan dengan matriks kovarians parameter model L4A yang berkontribusi pada Varians Error Model (Tabel 2).
MI
meter
Mode interferensi (MI): Metode yang digunakan untuk sel tertentu.
Hingga misi selesai, hanya sel yang memungkinkan inferensi hibrida
yang akan diisi dengan nilai biomassa rata-rata.
0=Tidak ada yang diterapkan
1=Berbasis Model Hybrid
2=Berbasis Model Hierarkis Umum
Persyaratan Penggunaan
Persyaratan Penggunaan
Set data ini berada di domain publik dan tersedia tanpa batasan penggunaan dan distribusi. Lihat Kebijakan Data & Informasi Ilmu Bumi NASA untuk mengetahui informasi tambahan.
Kutipan
Kutipan:
Dubayah, R.O., J. Armston, S.P. Healey, Z. Yang, P.L. Patterson, S. Saarela,
G. Stahl, L. Duncanson, dan J.R. Kellner. 2022. GEDI L4B Gridded Aboveground
Biomass Density, Versi 2. ORNL DAAC, Oak Ridge, Tennessee, AS.
doi:10.3334/ORNLDAAC/2056
Produk Global Ecosystem Dynamics Investigation (GEDI) L4B ini memberikan estimasi kepadatan biomassa di atas permukaan tanah (AGBD) rata-rata 1 km x 1 km berdasarkan pengamatan dari minggu misi 19 yang dimulai pada 18-04-2019 hingga minggu misi 138 yang berakhir pada 04-08-2021. Produk Biomasa Jejak Kaki GEDI L4A mengonversi setiap bentuk gelombang berkualitas tinggi menjadi …
[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)"]]
