Example of a Version 2 GEDI L1B sub-orbit granule over North America from June 19, 2019, with NASA’s Blue Marble from July 2004 as a basemap.
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 (ISS) 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. Each GEDI Version 2 granule encompasses one-fourth of an ISS orbit and includes georeferenced metadata to allow for spatial querying and subsetting.
The GEDI Level 1B Geolocated Waveforms product (GEDI01_B) provides geolocated corrected and smoothed waveforms, geolocation parameters, and geophysical corrections for each laser shot for all eight GEDI beams. GEDI01_B data are created by geolocating the GEDI01_A raw waveform data. The GEDI01_B product is provided in HDF5 format and has a spatial resolution (average footprint) of 25 meters.
The GEDI01_B data product contains 85 layers for each of the eight beams including the geolocated corrected and smoothed waveform datasets and parameters and the accompanying ancillary, geolocation, and geophysical correction. Additional information can be found in the GEDI L1B Product Data Dictionary.
| Characteristic | Description |
|---|---|
| Collection | GEDI |
| DOI | 10.5067/GEDI/GEDI01_B.002 |
| File Size | ~2 GB |
| Temporal Resolution | Varies |
| Temporal Extent | 2019-04-18 to 2023-03-16 |
| Spatial Extent | Global (51.6 °N to 51.6 °S Latitude) |
| Coordinate System | Geographic Latitude and Longitude |
| Datum | World Geodetic System (WGS84) |
| File Format | HDF5 |
| Geographic Dimensions | 4.2 km across-track by one-fourth of an ISS orbit along-track |
| Characteristic | Description |
|---|---|
| Number of Science Dataset (SDS) Layers | 86 |
| Columns/Rows | N/A |
| Pixel Size | 25 m |
| SDS Name | Description | Units | Data Type | Fill Value | No Data Value | Valid Range | Scale Factor |
|---|---|---|---|---|---|---|---|
| all_samples_sum | Sum of all values within the 10 km range window | Number | 32-bit unsigned integer | N/A | N/A | N/A | 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 |
| master_frac | Master time, fractional part | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| master_int | Master time, integer part | Seconds | 32-bit unsigned integer | N/A | N/A | N/A | N/A |
| noise_mean_corrected | Noise mean | Number | 64-bit floating point | N/A | N/A | N/A | N/A |
| noise_stddev_corrected | Corrected noise standard deviation | Number | 64-bit floating point | N/A | N/A | N/A | N/A |
| nsemean_even | Noise mean of the beam's detector channel from even sub-converter | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| nsemean_odd | Noise mean of the beam's odd sub-converter | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| rx_energy | Integrated energy in receive (RX) waveform after subtracting the noise mean | Nanoseconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| rx_offset | Time interval from first stored sample to first downloaded RX sample | Nanoseconds | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| rx_open | Time interval from time 0 to first stored RX sample | Nanoseconds | 32-bit unsigned integer | N/A | N/A | N/A | N/A |
| rx_sample_count | The number of sample intervals (elements) in each RX waveform | Number | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| rx_sample_start_index | The index in the rxwaveform dataset of the first element of each RX waveform starting at 1 | Number | 64-bit unsigned integer | N/A | N/A | N/A | N/A |
| rxwaveform | The corrected receive RX waveforms using rx_sample_count and rx_sample_start_index to identify the location of each waveform | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| selection_stretchers_x | Commanded number of samples added to algorithm section on the left | Nanoseconds | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| selection_stretchers_y | Commanded number of samples added to algorithm section on the right | Nanoseconds | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| shot_number | Unique shot identifier | Number | 64-bit unsigned integer | N/A | N/A | N/A | N/A |
| stale_return_flag | Indicates that a "stale" cue point from the coarse search algorithm is being used | Class Flag | 8-bit unsigned integer | N/A | N/A | 0, 1 | N/A |
| th_left_used | Count values for left threshold used in fine search where two consecutive points at or above this value indicates pulse detection | Number | 16-bit unsigned integer | N/A | N/A | N/A | N/A |
| tx_egamplitude | Amplitude of the extended Gaussian fit to the transmit (TX) waveform | Number | 64-bit floating point | N/A | N/A | N/A | N/A |
| tx_egamplitude_error | Error on tx_egamplitude | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_egbias | Bias of the extended Gaussian fit to the TX waveform | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_egbias_error | Error on tx_egbias | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_egflag | Extended Gaussian fit status flag | Class Flag | 8-bit unsigned integer | N/A | N/A | 1 to 8 | N/A |
| tx_eggamma | Gamma value of the extended Gaussian fit to the TX waveform | N/A | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_eggamma_error | Error on tx_eggamma | N/A | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_egsigma | Sigma of the extended Gaussian fit to the TX waveform | Nanoseconds | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_egsigma_error | Error on tx_egsigma | Nanoseconds | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_gloc | Location (mean) of the Gaussian fit to the TX waveform | Nanoseconds | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_gloc_error | Error on tx_gloc | Nanoseconds | 32-bit floating point | N/A | N/A | N/A | N/A |
| tx_pulseflag | Set to 1 if a pulse is detected in the TX waveform | Class Flag | 8-bit unsigned integer | N/A | N/A | 0 to 1 | N/A |
| tx_sample_count | The number of sample intervals (elements) in each transmit waveform | Number | 16-bit unsigned integer | N/A | N/A | 0 to 1 | N/A |
| tx_sample_start_index | The index in the rxwaveform dataset of the first element of each RX waveform starting at 1 | Number | 64-bit unsigned integer | N/A | N/A | 0 to 1 | N/A |
| txwaveform | The corrected TX waveforms using tx_sample_count and tx_sample_start_index to identify the location of each waveform | Number | 32-bit floating point | N/A | N/A | N/A | N/A |
| master_time_epoch | Number of GPS seconds between the GPS epoch (1980-01-06T00:00:00Z) and the GEDI epoch (2018-01-01T00:00:00Z) | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| mean_samples | Averaging window (shots) for non-repeated odd-even measurements from housekeeping | Number | 64-bit signed integer | N/A | N/A | N/A | N/A |
| smoothing_width | The 1-sigma width of the gaussian kernel used to smooth the corrected waveform | Nanoseconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| altitude_instrument | Height of the instrument diffractive optical element (DOE) above the WGS84 ellipsoid | Meters | 64-bit floating point | N/A | N/A | N/A | N/A |
| altitude_instrument_error | Error on altitude_instrument | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| bounce_time_offset_bin0 | The difference between the TX time and the time at the start of the RX window | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| bounce_time_offset_bin0_error | Error on bounce_time_offset_bin0 | Seconds | 32-bit floating point | N/A | N/A | N/A | N/A |
| bounce_time_offset_lastbin | The difference between the TX time and the time at the end of the RX window | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| bounce_time_offset_lastbin_error | Error on bounce_time_offset_lastbin | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| degrade | Greater than zero if the shot occurs during a degrade period, zero otherwise | Class Flag | 8-bit signed integer | N/A | N/A | 0 to 99 | N/A |
| delta_time | Transmit time of the shot, measured in seconds 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 | N/A | -962.0,10038.0 | N/A |
| digital_elevation_model_srtm | Digital elevation model height above the WGS84 ellipsoid | Meters | 32-bit floating point | -999999 | N/A | -962, 10038 | N/A |
| elevation_bin0 | Height of the start of the RX window, relative to the WGS-84 ellipsoid | Meters | 64-bit floating point | N/A | N/A | N/A | N/A |
| elevation_bin0_error | Error on elevation_bin0 | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| elevation_lastbin | Height of the end of the RX window, relative to the WGS-84 ellipsoid | Meters | 64-bit floating point | N/A | N/A | N/A | N/A |
| elevation_lastbin_error | Error on elevation_lastbin | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| latitude_bin0 | Latitude of the start of the RX window | Degree | 64-bit floating point | N/A | N/A | -90 to 90 | N/A |
| latitude_bin0_error | Error on latitude_bin0 | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| latitude_lastbin | Latitude of the end of the RX window | Degree | 64-bit floating point | N/A | N/A | -90 to 90 | N/A |
| latitude_lastbin_error | Error on latitude_lastbin | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| latitude_instrument | Latitude of the instrument diffractive optical element (DOE) at laser transmit time | Degree | 64-bit floating point | N/A | N/A | -90 to 90 | N/A |
| latitude_instrument_error | Error on latitude_instrument | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| local_beam_azimuth | Azimuth of the unit pointing vector for the laser in the local East, North, Up (ENU) frame | Radians | 32-bit floating point | N/A | N/A | -180 to 180 | N/A |
| local_beam_azimuth_error | Error on local_beam_azimuth | Radians | 32-bit floating point | N/A | N/A | N/A | N/A |
| local_beam_elevation | Elevation of the unit pointing vector for the laser in the local ENU frame | Radians | 32-bit floating point | N/A | N/A | 1.3962634 to 1.5707964 | N/A |
| local_beam_elevation_error | Error on local_beam_elevation | Radians | 32-bit floating point | N/A | N/A | N/A | N/A |
| longitude_bin0 | Longitude of the start of the RX window | Degree | 64-bit floating point | N/A | N/A | -180 to 180 | N/A |
| longitude_bin0_error | Error on longitude_bin0 | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| longitude_lastbin | Longitude of the end of the RX window | Degree | 64-bit floating point | N/A | N/A | -180 to 180 | N/A |
| longitude_lastbin_error | Error on longitude_lastbin | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| longitude_instrument | Longitude of the instrument diffractive optical element (DOE) at laser transmit time | Degree | 64-bit floating point | N/A | N/A | -180 to 180 | N/A |
| longitude_instrument_error | Error on longitude_instrument | Degree | 32-bit floating point | N/A | N/A | N/A | N/A |
| mean_sea_surface | Mean sea surface height above the WGS84 ellipsoid, includes the geoid | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| neutat_delay_derivative_bin0 | Change in neutral atmospheric delay per height change for the start of the RX window | m/m | 32-bit floating point | N/A | N/A | N/A | N/A |
| neutat_delay_derivative_lastbin | Change in neutral atmospheric delay per height change for the end of the RX window | m/m | 32-bit floating point | N/A | N/A | N/A | N/A |
| neutat_delay_total_bin0 | Total neutral atmosphere delay correction (wet+dry) from the TX pulse tothe start of the RX window | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| neutat_delay_total_lastbin | Total neutral atmosphere delay correction (wet+dry) from the TX pulse tothe end of the RX window | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| range_bias_correction | The range bias applied to the range measurement | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| shot_number | Unique shot identifier | Number | 64-bit unsigned integer | N/A | N/A | N/A | N/A |
| solar_azimuth | The azimuth of the sun position vector | Degree | 32-bit floating point | N/A | N/A | -180 to 180 | N/A |
| solar_elevation | The elevation of the sun position vector | Degree | 32-bit floating point | N/A | N/A | -90 to 90 | N/A |
| surface_type | Flags describing which surface types | Class Flag | 8-bit signed integer | N/A | N/A | 0 to 1 | N/A |
| delta_time | Transmit time of the shot | Seconds | 64-bit floating point | N/A | N/A | N/A | N/A |
| dynamic_atmosphere_correction | Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| geoid | Geoid height above WGS-84 reference ellipsoid | Meters | 32-bit floating point | N/A | N/A | -107 to 86 | N/A |
| tide_earth | Solid Earth tides | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| tide_load | Load Tide - Local displacement due to Ocean Loading | cm | 32-bit floating point | N/A | N/A | -6 to 0 | 0.01 |
| tide_ocean | Ocean Tides including diurnal and semi-diurnal, and longerperiod tides | Meters | 32-bit floating point | N/A | N/A | N/A | N/A |
| tide_ocean_pole | Oceanic surface rotational deformation due to polar motion | mm | 32-bit floating point | N/A | N/A | -2 to 2 | N/A |
| tide_pole | Solid Earth Pole Tide -- Rotational deformation due to polar motion | cm | 32-bit floating point | N/A | N/A | -1.5 to 1.5 | N/A |
All beams included in the data product will contain the same sets of Science Dataset (SDS) layers.
Known Issues: Section 8 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).