L2A — Ground Elevation & Canopy Height¶

Overview¶

GEDI L2A provides ground elevation, canopy height metrics, and relative height (RH) metrics for each GEDI footprint. Data is organized by 8 beams.

Quick Start¶

using SpaceAltimetry, DataFrames

g = granule("GEDI02_A_2019242104318_O04046_01_T02343_02_003_02_V002.h5")
t = table(g)
df = DataFrame(t)

Default Columns¶

Column	HDF5 Path	Type
`longitude`	`lon_lowestmode`	Float64
`latitude`	`lat_lowestmode`	Float64
`height`	`elev_lowestmode`	Float32
`height_error`	`elevation_bin0_error`	Float32
`datetime`	`delta_time`	DateTime
`intensity`	`energy_total`	Float32
`sensitivity`	`sensitivity`	Float32
`surface`	`surface_flag`	Bool
`quality`	`quality_flag`	Bool
`nmodes`	`num_detectedmodes`	UInt8
`sun_angle`	`solar_elevation`	Float32
`height_reference`	`digital_elevation_model`	Float32
`strong_beam`	attribute	—

Default Tracks¶

SpaceAltimetry.default_tracks(g)

("BEAM0000", "BEAM0001", "BEAM0010", "BEAM0011", "BEAM0101", "BEAM0110", "BEAM1000", "BEAM1011")

Canopy Heights¶

Use gedi_l2a_canopy_variables() to read highest return instead of lowest mode:

t = table(g; variables=gedi_l2a_canopy_variables())

This reads elev_highestreturn / lon_highestreturn / lat_highestreturn.

Quality Filtering¶

filtered = t |>
    GEDI.Quality() |>
    GEDI.Sensitivity(gt = 0.9) |>
    collect

The GEDI.Quality filter auto-loads the receive assessment, stale/degrade, amplitude, and selected algorithm fields required by the full points(g; filtered=true) predicate. The optional GEDI.Sensitivity filter keeps gt < sensitivity <= 1.0; gt defaults to 0.9.