STAC.jl

SpatioTemporal Asset Catalog (STAC) julia client
Author JuliaClimate
Popularity
28 Stars
Updated Last
2 Months Ago
Started In
October 2021

STAC

Dev Build Status Coverage

This package is an experimental implementation of the SpatioTemporal Asset Catalogs (STAC) client in Julia.

Opening an issue to notify about a missing feature is not helpful for the momement. However, if somebody is interested to make a pull request to implement a missing feature, an issue is a good way to discuss its implementation.

Installation

You need Julia (version 1.6 or later). Inside a Julia terminal, you can download and install STAC issuing these Julia commands:

using Pkg
Pkg.add("STAC")

Example

Accessing a catalog and sub-catalogs are indexed with their identitiers. To find all subcatalog identifiers, one can simply display the catalog structure in a julia session.

using STAC
url = "https://raw.githubusercontent.com/sat-utils/sat-stac/master/test/catalog/catalog.json"
catalog = STAC.Catalog(url)
subcat = catalog["stac-catalog-eo"]
subcat1 = subcat["landsat-8-l1"]
@show subcat1

item = subcat1.items["LC08_L1TP_152038_20200611_20200611_01_RT"]
@show href(item.assets["B4"])

Searching by date range and bounding box:

using STAC, Dates
collections = ["landsat-8-c2-l2"]
time_range = (DateTime(2018,01,01), DateTime(2018,01,02)) # start and end time
lon_range = (2.51357303225, 6.15665815596)  # west, east
lat_range = (49.5294835476, 51.4750237087)  # south, north

catalog = STAC.Catalog("https://planetarycomputer.microsoft.com/api/stac/v1")

search_results = collect(search(catalog, collections, lon_range, lat_range, time_range))

NASA EarthData

Retrieve a list of OPeNDAP URLs from the NASA Common Metadata Repository (CMR) of the collection C1996881146-POCLOUD. If asked, a token can be obtained from https://urs.earthdata.nasa.gov/home (after registration and login) and clicking on Generate Token:

using STAC, Dates

timerange = (DateTime(2019,1,1),DateTime(2019,12,31))
collection_concept_id = "C1996881146-POCLOUD"
baseurl = "https://cmr.earthdata.nasa.gov/search/granules.stac"

query = Dict(
    "collection_concept_id" => collection_concept_id,
    "temporal" => join(string.(timerange),','),
    "pageSize" => 1000,
)

url = baseurl
collection = STAC.FeatureCollection(url,query)

opendap_url = [href(item.assets["opendap"]) for item in collection]
@show length(opendap_url)
# output 365, one URL per day

To load the dataset, the NetCDF library need to be made aware of your EarthData username and password as explained here.

Used By Packages

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