Plant Area Volume Density (PAVD) and elevation from the GEDI02_B Product.
View full-size imageThe 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 produces high resolution laser ranging observations of the 3-dimensional structure of the Earth. GEDI is attached to the International Space Station and collects data globally between 51.6° N and 51.6° S latitudes at the highest resolution and densest sampling of any light detection and ranging (lidar) instrument in orbit to date.
The purpose of the GEDI Level 2B Canopy Cover and Vertical Profile Metrics product (GEDI02_B) is to extract biophysical metrics from each GEDI waveform. These metrics are based on the directional gap probability profile derived from the L1B waveform. Metrics provided include canopy cover, Plant Area Index (PAI), Plant Area Volume Density (PAVD), and Foliage Height Diversity (FHD). The GEDI02_B product is provided in HDF-5 format and has a spatial resolution (average footprint) of 25 meters.
The GEDI02_B data product contains 96 layers for each of the eight-beam ground transects (or laser footprints located on the land surface). Datasets provided include precise latitude, longitude, elevation, height, canopy cover, and vertical profile metrics. Additional information for the layers can be found in the GEDI Level 2B Data Dictionary.
| Characteristic | Description |
|---|---|
| Collection | GEDI |
| DOI | 10.5067/GEDI/GEDI02_B.001 |
| File Size | ~2 GB |
| Temporal Resolution | Varies |
| Temporal Extent | 2019-03-25 to 2020-09-03 |
| Spatial Extent | Global (51.6 °N to 51.6 °S Latitude) |
| Coordinate System | Geographic Latitude and Longitude |
| Datum | WGS84/EGM96 |
| File Format | HDF5 |
| Geographic Dimensions | 4.2 km across-track by one full ISS orbit along-track |
| Characteristic | Description |
|---|---|
| Number of Science Dataset (SDS) Layers | 96 |
| Columns/Rows | N/A |
| Pixel Size | 25 m |
| SDS Name | Description | Units | Data Type | Fill Value | No Data Value | Valid Range | Scale Factor |
|---|---|---|---|---|---|---|---|
| algorithmrun_flag | The L2B algorithm is run if this flag is set to 1 indicating data have sufficient waveform fidelity for L2B to run | N/A | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| beam | Beam number | Number | 16-bit unsigned integer | N/A | N/A | 0 to 11 | N/A |
| channel | Channel number | Number | 8-bit unsigned integer | N/A | N/A | 0 to 7 | N/A |
| cover | Total canopy cover | Percent | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| cover_z | Cumulative canopy cover vertical profile | Percent | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| fhd_normal | Foliage Height Diversity | N/A | 32-bit floating point | -9999 | N/A | N/A | N/A |
| master_frac | Master time fractional seconds | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| master_int | Master time integer seconds | Seconds | 32-bit unsigned integer | N/A | N/A | N/A | N/A |
| num_detectedmodes | Number of detected modes in received (RX) waveform | Number | 8-bit unsigned integer | N/A | N/A | N/A | N/A |
| omega | Foliage Clumping Index | N/A | 32-bit floating point | N/A | N/A | 0, 1 | N/A |
| pai | Total Plant Area Index | m²/m² | 32-bit floating point | -9999 | N/A | N/A | N/A |
| pai_z | Plant Area Index profile | m²/m² | 32-bit floating point | -9999 | N/A | N/A | N/A |
| pavd_z | Plant Area Volume Density profile | m²/m³ | 32-bit floating point | -9999 | N/A | N/A | N/A |
| pgap_theta | Total Gap Probability (theta) | N/A | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| pgap_theta_error | Total Pgap (theta) error | N/A | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| pgap_theta_z | Directional gap probability profile | N/A | 32-bit floating point | -9999 | N/A | 0 to 10000 | N/A |
| l2a_quality_flag | L2A quality flag | Quality Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| l2b_quality_flag | L2B quality flag | Quality Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| rg | Integral of the ground component in the RX waveform for the selected L2A processing version | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rh100 | Height above ground of the received waveform signal start (rh[101] from L2A) | cm | 16-bit signed integer | N/A | N/A | -21300 to 21300 | N/A |
| rhog | Volumetric scattering coefficient (rho) of the ground | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rhog_error | Rho (ground) error | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rhov | Volumetric scattering coefficient (rho) of the canopy | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rhov_error | Rho (canopy) error | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rossg | Ross-G function | N/A | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| rv | Integral of the vegetation component in the RX waveform for the selected L2A processing version | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rx_range_highestreturn | Range to signal start | Meters | 64-bit floating point | -9999 | N/A | N/A | N/A |
| rx_sample_count | Received sample count | Number | 64-bit signed integer | N/A | N/A | N/A | N/A |
| rx_sample_start_index | Received sample start index | Number | 64-bit signed integer | N/A | N/A | N/A | N/A |
| selected_l2a_algorithm | Selected L2A algorithm setting | N/A | 8-bit unsigned integer | N/A | N/A | 1 to 6 | N/A |
| selected_rg_algorithm | Selected R (ground) algorithm | N/A | 8-bit unsigned integer | N/A | N/A | N/A | N/A |
| sensitivity | Maxmimum canopy cover that can be penetrated | N/A | 32-bit floating point | N/A | N/A | 0, 1 | N/A |
| shot_number | Shot number | Number | 64-bit unsigned integer | N/A | N/A | N/A | N/A |
| stale_return_flag | Stale return flag | Class Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| surface_flag | Surface flag indicating elevation of lowest mode | Class Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| dz | Vertical step size of foliage profile | Meters | 64-bit floating point | N/A | N/A | N/A | N/A |
| l2a_alg_count | Number of candidate algorithms available in the corresponding GEDI L2A data product | Number | 64-bit signed integer | N/A | N/A | N/A | N/A |
| maxheight_cuttoff | The maximum height above ground value used for foliage profile calculation | Meters | 64-bit floating point | N/A | N/A | 0 to 150 | N/A |
| rg_eg_constraint_center_buffer | Buffer size used to constrain the center parameter in the exponentially modified Gaussian fit to R (ground) | Nanoseconds | 32-bit signed integer | N/A | N/A | N/A | N/A |
| rg_eg_mpfit_max_func_evals | MPFIT maximum number of function evaluations | N/A | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| rg_eg_mpfit_maxiters | MPFIT maximum number of iterations | N/A | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| rg_eg_mpfit_tolerance | MPFIT convergence criterium | N/A | 64-bit floating point | N/A | N/A | N/A | N/A |
| signal_search_buff | Buffer size used to extend above toploc and below botloc | Nanoseconds | 64-bit floating point | N/A | N/A | 0 to 255 | N/A |
| tx_noise_stddev_multiplier | Multiplier on the transmit waveform noise standard deviation used R (ground) estimation | N/A | 64-bit floating point | N/A | N/A | 0 to 255 | N/A |
| degrade_flag | Degrade flag is set to greater than zero if the shot occurs during a degrade period, zero otherwise | Class Flag | 8-bit signed integer | N/A | N/A | 0, 1 | N/A |
| delta_time | Transmit time of the shot, measured in seconds from the master_time_epoch since 2018-01-01 | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| digital_elevation_model | Digital elevation model height above the WGS84 ellipsoid | Meters | 32-bit floating point | -999999.0 | N/A | -962 to 10038 | N/A |
| elev_highestreturn | Elevation of highest detected return relative to reference ellipsoid | Meters | 32-bit floating point | N/A | N/A | -1000 to 25000 | N/A |
| elev_lowestmode | Elevation of center of lowest mode relative to reference ellipsoid | Meters | 32-bit floating point | N/A | N/A | -1000 to 25000 | N/A |
| elevation_bin0 | Elevation of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Meters | 64-bit floating point | -9999 | N/A | N/A | N/A |
| elevation_bin0_error | Error in elevation of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Meters | 32-bit floating point | -9999 | N/A | N/A | N/A |
| elevation_lastbin | Elevation of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Meters | 64-bit floating point | -9999 | N/A | N/A | N/A |
| elevation_lastbin_error | Error in elevation of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Meters | 32-bit floating point | -9999 | N/A | N/A | N/A |
| height_bin0 | Height of the first bin of the pgap_theta_z, relative to the ground | Meters | 32-bit floating point | -9999 | N/A | N/A | N/A |
| height_lastbin | Height of the last bin of the pgap_theta_z, relative to the ground | Meters | 32-bit floating point | -9999 | N/A | N/A | N/A |
| lat_highestreturn | Latitude of highest detected return | Degree | 64-bit floating point | N/A | N/A | -55 to 55 | N/A |
| lat_lowestmode | Latitude of center of lowest mode | Degree | 64-bit floating point | N/A | N/A | -55 to 55 | N/A |
| latitude_bin0 | Latitude of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 64-bit floating point | -9999 | N/A | N/A | N/A |
| latitude_bin0_error | Error in latitude of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 32-bit floating point | -9999 | N/A | N/A | N/A |
| latitude_lastbin | Latitude of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 64-bit floating point | -9999 | N/A | N/A | N/A |
| latitude_lastbin_error | Error in latitude of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 32-bit floating point | -9999 | N/A | N/A | N/A |
| local_beam_azimuth | Azimuth of the unit pointing vector for the laser in the local ENU frame measured from North and positive towards East | Radians | 32-bit floating point | N/A | N/A | -180 to 180 | N/A |
| local_beam_elevation | Elevation of the unit pointing vector for the laser in the local ENU frame measured from East-North plane and positive towards Up | Radians | 32-bit floating point | N/A | N/A | 1.3962634 to 1.5707964 | N/A |
| lon_highestreturn | Longitude of highest detected return | Degree | 64-bit floating point | N/A | N/A | -180 to 180 | N/A |
| lon_lowestmode | Longitude of center of lowest mode | Degree | 64-bit floating point | N/A | N/A | -180 to 180 | N/A |
| longitude_bin0 | Longitude of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 64-bit floating point | -9999 | N/A | N/A | N/A |
| longitude_bin0_error | Error in longitude of first bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 32-bit floating point | -9999 | N/A | N/A | N/A |
| longitude_lastbin | Longitude of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 64-bit floating point | -9999 | N/A | N/A | N/A |
| longitude_lastbin_error | Error in longitude of last bin of the pgap_theta_z, interpolated from L1B waveform coordinate | Degree | 32-bit floating point | -9999 | N/A | N/A | N/A |
| shot_number | Unique shot identifier | Number | 64-bit floating point | N/A | N/A | N/A | N/A |
| solar_azimuth | The azimuth of the sun position vector from the laser bounce point position in the local ENU frame measured from North and is positive towards East | Degree | 32-bit floating point | N/A | N/A | -180 to 180 | N/A |
| solar_elevation | The elevation of the sun position vector from the laser bounce point position in the local ENU frame measured from the East-North plane and is positive Up | Degree | 32-bit floating point | N/A | N/A | -90 to 90 | N/A |
| landsat_treecover | Tree cover in the year 2010, defined as canopy closure for all vegetation taller than 5 m in height encoded as a percentage per output grid cell | Percent | 64-bit floating point | -9999 | N/A | N/A | N/A |
| modis_nonvegetated | Percent non-vegetated from MODIS MOD44B V6 data | Percent | 64-bit floating point | -9999 | N/A | N/A | N/A |
| modis_nonvegetated_sd | Percent non-vegetated standard deviation from MODIS MOD44B V6 data | Percent | 64-bit floating point | -9999 | N/A | N/A | N/A |
| modis_treecover | Percent tree cover from MODIS MOD44B V6 data | Percent | 64-bit floating point | -9999 | N/A | N/A | N/A |
| modis_treecover_sd | Percent tree cover standard deviation from MODIS MOD44B V6 data | Percent | 64-bit floating point | -9999 | N/A | N/A | N/A |
| algorithmrun_flag_aN | For each L2A algorithm, the L2B algorithm is run if this flag is set to 1 which indicates sufficient waveform fidelity | Class Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| pgap_theta_aN | Estimated Pgap (theta) from ground finding algorithm for each L2A processing version | N/A | 32-bit floating point | -9999 | N/A | 0, 1 | N/A |
| pgap_theta_error_aN | Uncertainty of Pgap (theta) caused by ground finding algorithm for each L2A processing version | N/A | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_aN | Integral of the ground component in the received waveform for each L2A processing version | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_amplitude_aN | Amplitude of the extended Gaussian fit to the ground of RX waveform | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_amplitude_error_aN | Error in amplitude of the extended Gaussian fit to the ground of RX waveform | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_center_aN | Center of the extended Gaussian fit to the ground of RX waveform | Nanoseconds | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_center_error_aN | Error in center of the extended Gaussian fit to the ground of RX waveform | Nanoseconds | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_chisq_aN | Chi square of R (ground) fit | N/A | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_flag_aN | Extended Gaussian fit status flag | Class Flag | 8-bit signed integer | N/A | N/A | 0 to 255 | N/A |
| rg_eg_gamma_aN | Gamma value of the extended Gaussian fit to the ground of RX waveform | N/A | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_gamma_error_aN | Error in gamma value of the extended Gaussian fit to the ground of RX waveform | N/A | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_niter_aN | Number of iterations to converge extended Gaussian fit to RX waveform | N/A | 8-bit unsigned integer | N/A | N/A | N/A | N/A |
| rg_eg_sigma_aN | Sigma value of the extended Gaussian fit to the ground of RX waveform | Nanoseconds | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_eg_sigma_error_aN | Error in sigma value of the extended Gaussian fit to the ground of RX waveform | Nanoseconds | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rg_error_aN | Error of the integral of the ground component in the received waveform for each L2A processing version | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rv_aN | Integral of the vegetation component in the received waveform for each L2A processing version | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| rx_energy_aN | Received waveform energy | Number | 32-bit floating point | -9999 | N/A | N/A | N/A |
| shot_number | Unique shot identifier | Number | 64-bit floating point | N/A | N/A | N/A | N/A |
All beams included in the data product will contain the same sets of SDS layers.
| Value | Description |
|---|---|
| 1 | Convergence in chi² value |
| 2 | Convergence in parameter value |
| 3 | Convergence in chi² and parameter values |
| 4 | Convergence in orthogonality |
| 5 | Maximum number of iterations reached |
| 6 | Ftol too small (no further improvement) |
| 7 | Xtol too small (no further improvement) |
| 8 | Gtol too small (no further improvement) |
Quality information is provided in section 6 of the User Guide.
Known Issues: Section 7 of the User Guide provides additional information on known issues.
Data acquisition gaps: GEDI data acquisitions were suspended on December 19, 2019 (2019 Day 353) and resumed on January 8, 2020 (2020 Day 8).