The Global Ecosystem Dynamics Investigation (GEDI) mission aims to characterize ecosystem structure and dynamics to enable radically improved quantification and understanding of the Earth's carbon cycle and biodiversity. The GEDI instrument, attached to the International Space Station (ISS), collects data globally between 51.6° N and 51.6° S latitudes at the highest resolution and densest sampling of the 3-dimensional structure of the Earth.
GEDI's Level 2A Geolocated Elevation and Height Metrics Product (GEDI02_A) is primarily composed of 100 Relative Height (RH) metrics, which collectively describe the waveform collected by GEDI.
The original GEDI02_A product is a table of point with a spatial resolution (average footprint) of 25 meters. The dataset LARSE/GEDI/GEDI02_A_002_MONTHLY is a raster version of the original GEDI02_A product. The raster images are organized as monthly composites of individual orbits in the corresponding month. Only root-level RH values and their associated quality flags and metadata are preserved as raster bands. Each GEDI02_A_002 raster has 136 bands.
See User Guide for more information.
全球生态系统动态调查（GEDI）任务的目的是描述生态系统的结构和动态，以便从根本上改善对地球碳循环和生物多样性的量化和理解。附属于国际空间站（ISS）的GEDI仪器在全球范围内收集北纬51.6°和南纬51.6°之间的数据，对地球的三维结构进行最高分辨率和最密集的采样。
GEDI的2A级地理位置海拔和高度指标产品（GEDI02_A）主要由100个相对高度（RH）指标组成，它们共同描述了GEDI收集的波形。
原始的GEDI02_A产品是一个点的表格，空间分辨率（平均足迹）为25米。数据集LARSE/GEDI/GEDI02_A_002_MONTHLY是原始GEDI02_A产品的栅格版本。光栅图像被组织为相应月份的单个轨道的月度合成。只有根级相对湿度值及其相关的质量标志和元数据被保留为栅格带。每个GEDI02_A_002栅格有136个波段。
GEDI L2A Canopy Top Height (Version 2)
Dataset Availability
2019-03-25T00:00:00Z - 2021-09-01T00:00:00
Dataset Provider
NASA GEDI mission, accessed through the USGS LP DAAC Rasterization: Google and USFS Laboratory for Applications of Remote Sensing in Ecology (LARSE)
Earth Engine Snippet
ee.ImageCollection("LARSE/GEDI/GEDI02_A_002_MONTHLY") open_in_new
波段：
Resolution
25 meters
Bands
| Name | Description |
|---|---|
beam |
Beam identifier |
degrade_flag |
Flag indicating degraded state of pointing and/or positioning information.
|
delta_time |
Time delta since Jan 1 00:00 2018 |
digital_elevation_model |
TanDEM-X elevation at GEDI footprint location |
digital_elevation_model_srtm |
STRM elevation at GEDI footprint location |
elev_highestreturn |
Elevation of highest detected return relative to reference ellipsoid |
elev_lowestmode |
Elevation of center of lowest mode relative to reference ellipsoid |
elevation_bias_flag |
Elevations potentially affected by 4bin (~60 cm) ranging error |
landsat_treecover |
Tree cover in the year 2010, defined as canopy closure for all vegetation taller than 5 m in height as a percentage per output grid cell |
landsat_water_persistence |
Percent UMD GLAD Landsat observations with classified surface water |
lat_highestreturn |
Latitude of highest detected return |
leaf_off_doy |
GEDI 1 km EASE 2.0 grid leaf-off start day-of-year |
leaf_off_flag |
GEDI 1 km EASE 2.0 grid flag |
leaf_on_cycle |
Flag that indicates the vegetation growing cycle for leaf-on observations |
leaf_on_doy |
GEDI 1 km EASE 2.0 grid leaf-on start day-of-year |
lon_highestreturn |
Longitude of highest detected return |
modis_nonvegetated |
Percent non-vegetated from MODIS MOD44B V6 data |
modis_nonvegetated_sd |
Percent non-vegetated standard deviation from MODIS MOD44B V6 data |
modis_treecover |
Percent tree cover from MODIS MOD44B V6 data |
modis_treecover_sd |
Percent tree cover standard deviation from MODIS MOD44B V6 data |
num_detectedmodes |
Number of detected modes in rxwaveform |
pft_class |
GEDI 1 km EASE 2.0 grid Plant Functional Type (PFT) |
quality_flag |
Flag indicating likely invalid waveform (1=valid, 0=invalid) |
region_class |
GEDI 1 km EASE 2.0 grid world continental regions |
selected_algorithm |
Identifier of algorithm selected as identifying the lowest non-noise mode |
selected_mode |
Identifier of mode selected as lowest non-noise mode |
selected_mode_flag |
Flag indicating status of selected_mode |
sensitivity |
Maxmimum canopy cover that can be penetrated |
shot_number |
Shot number, a unique identifier. This field is truncated on some images that are being reprocessed to properly show it (as of March 2022). This field has the format of OOOOOBBRRGNNNNNNNN, where:
|
solar_azimuth |
Solar azimuth |
solar_elevation |
Solar elevation |
surface_flag |
Indicates elev_lowestmode is within 300 m of DEM or MSS |
urban_focal_window_size |
The focal window size used to calculate urban_proportion |
urban_proportion |
The percentage proportion of land area within a focal area surrounding each shot that is urban land cover. |
rh0 |
Relative height metrics at 0% |
rh1 |
Relative height metrics at 1% |
rh2 |
Relative height metrics at 2% |
rh3 |
Relative height metrics at 3% |
rh4 |
Relative height metrics at 4% |
rh5 |
Relative height metrics at 5% |
rh6 |
Relative height metrics at 6% |
rh7 |
Relative height metrics at 7% |
rh8 |
Relative height metrics at 8% |
rh9 |
Relative height metrics at 9% |
rh10 |
Relative height metrics at 10% |
rh11 |
Relative height metrics at 11% |
rh12 |
Relative height metrics at 12% |
rh13 |
Relative height metrics at 13% |
rh14 |
Relative height metrics at 14% |
rh15 |
Relative height metrics at 15% |
rh16 |
Relative height metrics at 16% |
rh17 |
Relative height metrics at 17% |
rh18 |
Relative height metrics at 18% |
rh19 |
Relative height metrics at 19% |
rh20 |
Relative height metrics at 20% |
rh21 |
Relative height metrics at 21% |
rh22 |
Relative height metrics at 22% |
rh23 |
Relative height metrics at 23% |
rh24 |
Relative height metrics at 24% |
rh25 |
Relative height metrics at 25% |
rh26 |
Relative height metrics at 26% |
rh27 |
Relative height metrics at 27% |
rh28 |
Relative height metrics at 28% |
rh29 |
Relative height metrics at 29% |
rh30 |
Relative height metrics at 30% |
rh31 |
Relative height metrics at 31% |
rh32 |
Relative height metrics at 32% |
rh33 |
Relative height metrics at 33% |
rh34 |
Relative height metrics at 34% |
rh35 |
Relative height metrics at 35% |
rh36 |
Relative height metrics at 36% |
rh37 |
Relative height metrics at 37% |
rh38 |
Relative height metrics at 38% |
rh39 |
Relative height metrics at 39% |
rh40 |
Relative height metrics at 40% |
rh41 |
Relative height metrics at 41% |
rh42 |
Relative height metrics at 42% |
rh43 |
Relative height metrics at 43% |
rh44 |
Relative height metrics at 44% |
rh45 |
Relative height metrics at 45% |
rh46 |
Relative height metrics at 46% |
rh47 |
Relative height metrics at 47% |
rh48 |
Relative height metrics at 48% |
rh49 |
Relative height metrics at 49% |
rh50 |
Relative height metrics at 50% |
rh51 |
Relative height metrics at 51% |
rh52 |
Relative height metrics at 52% |
rh53 |
Relative height metrics at 53% |
rh54 |
Relative height metrics at 54% |
rh55 |
Relative height metrics at 55% |
rh56 |
Relative height metrics at 56% |
rh57 |
Relative height metrics at 57% |
rh58 |
Relative height metrics at 58% |
rh59 |
Relative height metrics at 59% |
rh60 |
Relative height metrics at 60% |
rh61 |
Relative height metrics at 61% |
rh62 |
Relative height metrics at 62% |
rh63 |
Relative height metrics at 63% |
rh64 |
Relative height metrics at 64% |
rh65 |
Relative height metrics at 65% |
rh66 |
Relative height metrics at 66% |
rh67 |
Relative height metrics at 67% |
rh68 |
Relative height metrics at 68% |
rh69 |
Relative height metrics at 69% |
rh70 |
Relative height metrics at 70% |
rh71 |
Relative height metrics at 71% |
rh72 |
Relative height metrics at 72% |
rh73 |
Relative height metrics at 73% |
rh74 |
Relative height metrics at 74% |
rh75 |
Relative height metrics at 75% |
rh76 |
Relative height metrics at 76% |
rh77 |
Relative height metrics at 77% |
rh78 |
Relative height metrics at 78% |
rh79 |
Relative height metrics at 79% |
rh80 |
Relative height metrics at 80% |
rh81 |
Relative height metrics at 81% |
rh82 |
Relative height metrics at 82% |
rh83 |
Relative height metrics at 83% |
rh84 |
Relative height metrics at 84% |
rh85 |
Relative height metrics at 85% |
rh86 |
Relative height metrics at 86% |
rh87 |
Relative height metrics at 87% |
rh88 |
Relative height metrics at 88% |
rh89 |
Relative height metrics at 89% |
rh90 |
Relative height metrics at 90% |
rh91 |
Relative height metrics at 91% |
rh92 |
Relative height metrics at 92% |
rh93 |
Relative height metrics at 93% |
rh94 |
Relative height metrics at 94% |
rh95 |
Relative height metrics at 95% |
rh96 |
Relative height metrics at 96% |
rh97 |
Relative height metrics at 97% |
rh98 |
Relative height metrics at 98% |
rh99 |
Relative height metrics at 99% |
rh100 |
Relative height metrics at 100% |
代码：
var qualityMask = function(im) {
return im.updateMask(im.select('quality_flag').eq(1))
.updateMask(im.select('degrade_flag').eq(0));
};
var dataset = ee.ImageCollection('LARSE/GEDI/GEDI02_A_002_MONTHLY')
.map(qualityMask)
.select('rh98');
var gediVis = {
min: 1,
max: 60,
palette: 'darkred,red,orange,green,darkgreen',
};
Map.setCenter(-74.803466, -9.342209, 10);
Map.addLayer(dataset, gediVis, 'rh98');
