SpaceLiDAR
A Julia toolbox for ICESat-2 and GEDI data.
This is a research package now, things are quick to change.
Currently supports the following data products:
| data product | User Guide (UG) | Algorithm Theoretical Basis Document (ATBD) |
|---|---|---|
| ICESat GLAH14 v34 | UG | ATBD |
| ICESat-2 ATL03 v4 | UG | ATBD |
| ICESat-2 ATL08 v4 | UG | ATBD |
| ICESat-2 ATL12 v4 | UG | ATBD |
| GEDI L2A v2 | UG | ATBD |
For a quick overview, see the FOSS4G Pluto notebook here
Install
] add SpaceLiDARUsage
Search for data
using SpaceLiDAR
# Find all ATL08 granules
granules = find(:ICESat2, "ATL08")
# Find only ATL03 granules in a part of Vietnam
vietnam = (min_x = 102., min_y = 8.0, max_x = 107.0, max_y = 12.0)
granules = find(:ICESat2, "ATL08", vietnam, "004")
# Find GEDI granules in the same way
granules = find(:GEDI, "GEDI02_A")
# A granule is pretty simple
granule = granules[1]
granule.id # filename
granule.url # download url
granule.info # derived information from id
# Downloading granules requires a setup .netrc with an NASA EarthData account
# we provide a helper function, that creates/updates a ~/.netrc or ~/_netrc
SpaceLiDAR.netrc!(<username>, <password>) # replace with your credentials
# Afterward you can download (requires curl to be available on PATH)
fn = SpaceLiDAR.download!(granule)
# You can also load a granule from disk
granule = granule_from_file(fn)
# Or from a folder
local_granules = granules_from_folder(<folder>)
# Instantiate search results locally (useful for GEDI location indexing)
local_granules = instantiate(granules, <folder>)Derive linestrings
using DataFrames
fn = "ATL03_20181110072251_06520101_003_01.h5"
g = SpaceLiDAR.granule_from_file(fn)
tlines = DataFrame(SpaceLiDAR.lines(g, step=10000))
Table with 4 columns and 6 rows:
geom sun_angle track t
┌───────────────────────────────────────────────────────────────────────────
1 │ wkbLineString25D geometry 38.3864 gt1l_weak 2018-11-10T07:28:01.688
2 │ wkbLineString25D geometry 38.375 gt1r_strong 2018-11-10T07:28:02.266
3 │ wkbLineString25D geometry 38.2487 gt2l_weak 2018-11-10T07:28:04.474
4 │ wkbLineString25D geometry 38.1424 gt2r_strong 2018-11-10T07:28:07.374
5 │ wkbLineString25D geometry 38.2016 gt3l_weak 2018-11-10T07:28:05.051
6 │ wkbLineString25D geometry 38.1611 gt3r_strong 2018-11-10T07:28:06.344
SpaceLiDAR.GDF.write("lines.gpkg", tlines)