getLevel1BGeo: Get GEDI Full Waveform Geolocations (GEDI Level1B)

In carlos-alberto-silva/rGEDI: NASA's Global Ecosystem Dynamics Investigation (GEDI) Data Visualization and Processing

Get GEDI Full Waveform Geolocations (GEDI Level1B)

Description

This function extracts Pulse Full Waveform Geolocations from GEDI gedi.level1b data

Usage

getLevel1BGeo(level1b, select)

Arguments

level1b	A gedi.level1b object (output of getLevel1BGeo() function).
select	A character vector specifying the fields to extract from GEDI Level1B data. If NULL, by default it will extract latitude_bin0, latitude_lastbin, longitude_bin0, longitude_lastbin, and shot_number. See details for more options.

Details

Additional fields to be extracted from GEDI level 1B:

• all_samples_sum Sum of all values within the 10 km range window.

• beam Beam number Number.

• channel Channel number.

• master_frac Master time, fractional part.

• master_int Master time, integer part.

• noise_mean_corrected Noise mean.

• noise_stddev_corrected Corrected noise standard deviation.

• nsemean_even Noise mean of the beam's detector channel from even sub-converter.

• nsemean_odd Noise mean of the beam's odd sub-converter.

• rx_energy Integrated energy in receive (RX) waveform after subtracting the noise mean.

• rx_offset Time interval from first stored sample to first downloaded RX sample.

• rx_open Time interval from time 0 to first stored RX sample.

• rx_sample_count The number of sample intervals (elements) in each RX waveform.

• rx_sample_start_index The index in the rxwaveform dataset of the first element of each RX waveform starting at 1.

• selection_stretchers_x Commanded number of samples added to the algorithm section on the left.

• selection_stretchers_y Commanded number of samples added to the algorithm section on the right.

• shot_number Unique shot identifier.

• stale_return_flag Indicates that a "stale" cue point from the coarse search algorithm is being used.

• th_left_used Count values for the left threshold used in fine search where two consecutive points at or above this value indicate pulse detection.

• tx_egamplitude Amplitude of the extended Gaussian fit to the transmit (TX) waveform.

• tx_egamplitude_error Error on tx_egamplitude.

• tx_egbias Bias of the extended Gaussian fit to the TX waveform.

• tx_egbias_error Error on tx_egbias.

• tx_egflag Extended Gaussian fit status flag.

• tx_eggamma Gamma value of the extended Gaussian fit to the TX waveform.

• tx_eggamma_error Error on tx_eggamma.

• tx_egsigma Sigma of the extended Gaussian fit to the TX waveform.

• tx_egsigma_error Error on tx_egsigma.

• tx_gloc Location (mean) of the Gaussian fit to the TX waveform.

• tx_gloc_error Error on tx_gloc.

• tx_pulseflag Set to 1 if a pulse is detected in the TX waveform.

• tx_sample_count The number of sample intervals (elements) in each transmit waveform.

• tx_sample_start_index The index in the rxwaveform dataset of the first element of each RX waveform starting at 1.

• altitude_instrument Height of the instrument diffractive optical element (DOE) above the WGS84 ellipsoid.

• altitude_instrument_error Error on altitude_instrument.

• bounce_time_offset_bin0 The difference between the TX time and the time at the start of the RX window.

• bounce_time_offset_bin0_error Error on bounce_time_offset_bin0.

• bounce_time_offset_lastbin The difference between the TX time and the time at the end of the RX window.

• bounce_time_offset_lastbin_error Error on bounce_time_offset_lastbin.

• degrade Greater than zero if the shot occurs during a degrade period, zero otherwise.

• delta_time Transmit time of the shot, measured in seconds since 2018-01-01.

• digital_elevation_model Digital elevation model height above the WGS84 ellipsoid.

• elevation_bin0 Height of the start of the RX window, relative to the WGS-84 ellipsoid.

• elevation_bin0_error Error on elevation_bin0.

• elevation_lastbin Height of the end of the RX window, relative to the WGS-84 ellipsoid.

• elevation_lastbin_error Error on elevation_lastbin.

• latitude_bin0 Latitude of the start of the RX window.

• latitude_bin0_error Error on latitude_bin0.

• latitude_lastbin Latitude of the end of the RX window.

• latitude_lastbin_error Error on latitude_lastbin.

• latitude_instrument Latitude of the instrument diffractive optical element (DOE) at laser transmit time.

• latitude_instrument_error Error on latitude_instrument.

• local_beam_azimuth Azimuth of the unit pointing vector for the laser in the local East, North, Up (ENU) frame.

• local_beam_azimuth_error Error on local_beam_azimuth.

• local_beam_elevation Elevation of the unit pointing vector for the laser in the local ENU frame.

• local_beam_elevation_error Error on local_beam_elevation.

• longitude_bin0 Longitude of the start of the RX window.

• longitude_bin0_error Error on longitude_bin0.

• longitude_lastbin Longitude of the end of the RX window.

• longitude_lastbin_error Error on longitude_lastbin.

• longitude_instrument Longitude of the instrument diffractive optical element (DOE) at laser transmit time.

• longitude_instrument_error Error on longitude_instrument.

• mean_sea_surface Mean sea surface height above the WGS84 ellipsoid, includes the geoid .

• neutat_delay_derivative_bin0 Change in neutral atmospheric delay per height change for the start of the RX window.

• neutat_delay_derivative_lastbin Change in neutral atmospheric delay per height change for the end of the RX window.

• neutat_delay_total_bin0 Total neutral atmosphere delay correction (wet+dry) from the TX pulse to the start of the RX window.

• neutat_delay_total_lastbin Total neutral atmosphere delay correction (wet+dry) from the TX pulse to the end of the RX window.

• range_bias_correction The range bias applied to the range measurement.

• shot_number Unique shot identifier Number.

• solar_azimuth The azimuth of the sun position vector.

• solar_elevation The elevation of the sun position vector.

• surface_type Flags describing which surface types.

• dynamic_atmosphere_correction Dynamic Atmospheric Correction (DAC) includes inverted barometer (IB) effect.

• geoid Geoid height above WGS-84 reference ellipsoid.

• tide_earth Solid Earth tides.

• tide_load Load Tide - Local displacement due to Ocean Loading.

• tide_ocean Ocean Tides including diurnal and semi-diurnal, and longerperiod tides.

• tide_ocean_pole Oceanic surface rotational deformation due to polar motion.

• tide_pole Solid Earth Pole Tide. Rotational deformation due to polar motion.

Value

Returns an S4 object of class data.table::data.table containing the GEDI Full Waveform Geolocations

See Also

https://lpdaac.usgs.gov/products/gedi01_bv002/

Examples

# specify the path to GEDI level1B data (zip file)
outdir = tempdir()
level1B_fp_zip <- system.file("extdata",
                  "GEDI01_B_2019108080338_O01964_T05337_02_003_01_sub.zip",
                  package="rGEDI")

# Unzipping GEDI level1B data
level1Bpath <- unzip(level1B_fp_zip,exdir = outdir)

# Reading GEDI level1B data (h5 file)
level1b<-readLevel1B(level1Bpath=level1Bpath)

# Extracting GEDI level1B geolocations
level1bGeo<-getLevel1BGeo(level1b,select=c("elevation_bin0", "elevation_lastbin"))
head(level1bGeo)

close(level1b)

carlos-alberto-silva/rGEDI documentation built on Oct. 18, 2024, 4:46 a.m.