✨ StackSTACStackerIterDataPipe for stacking STAC items

[weiji14]

An iterable-style DataPipe to stack STAC items! Uses stackstac to do the reprojection and stacking along time.

Preview at https://zen3geo--61.org.readthedocs.build/en/61/api.html#zen3geo.datapipes.StackSTACStacker

Usage:

import pystac
import stackstac

from torchdata.datapipes.iter import IterableWrapper
from zen3geo.datapipes import StackSTACStacker

# Stack different bands in a STAC Item using DataPipe
item_url: str = "https://planetarycomputer.microsoft.com/api/stac/v1/collections/sentinel-1-grd/items/S1A_IW_GRDH_1SDV_20220914T093226_20220914T093252_044999_056053"
stac_item = pystac.Item.from_file(href=item_url)
dp = IterableWrapper(iterable=[stac_item])
dp_stackstac = dp.stack_stac_items(assets=["vh", "vv"], epsg=32652, resolution=10)

# Loop or iterate over the DataPipe stream
it = iter(dp_stackstac)
dataarray = next(it)
print(dataarray.sizes)
# Frozen({'time': 1, 'band': 2, 'y': 20686, 'x': 28043})

print(dataarray.coords)
# Coordinates:
#   * time                                   (time) datetime64[ns] 2022-09-14T0...
#     id                                     (time) <U62 'S1A_IW_GRDH_1SDV_2022...
#   * band                                   (band) <U2 'vh' 'vv'
#   * x                                      (x) float64 1.354e+05 ... 4.158e+05
#   * y                                      (y) float64 4.305e+06 ... 4.098e+06
# ...

print(dataarray.attrs["spec"])
# RasterSpec(epsg=32652, bounds=(135370, 4098080, 415800, 4304940), resolutions_xy=(10, 10))

TODO:

• Initial implementation with a doctest
• Add unit test
• Handle different values of epsg (TODO in a follow-up PR)

Consider handling different values of resolution/bounds/bounds_latlon in the future. Limitation is that torchdata.datapipes.iter.ZipperLongest's fill_value only allows for one fill_value for all IterDataPipes, rather than individual fill_values for each IterDataPipe as is needed here. OR, have a parametrized IterDataPipe that holds a dictionary instead of a single variable?

Part of #48

References:

• https://stackstac.readthedocs.io/en/v0.4.3/basic.html
• Add STACAPI dataset microsoft/torchgeo#412 (comment)