Search & Discovery¶

SpaceLiDAR provides tools to find granules — both locally and from NASA's Common Metadata Repository (CMR).

Local Discovery¶

# Single file:
g = granule("ATL08_20201121151145_08920913_006_01.h5")

# All granules in a folder (recursive):
gs = granules("/data/icesat2/")

The file/folder functions detect the mission and product from the filename automatically.

Remote Search (NASA CMR)¶

using SpaceLiDAR, Dates, Extents

extent = Extent(X=(-10.0, 10.0), Y=(50.0, 60.0))

gs = search(:ICESat2, :ATL08; extent=extent, after=DateTime(2020, 1, 1))

This queries NASA's CMR API and returns a vector of granules with download URLs and spatial footprints.

Search parameters¶

Parameter	Type	Description
`extent`	`Extent`	Bounding box to filter spatially
`version`	`Int`	Data product version (default varies per mission)
`after`	`DateTime`	Only granules acquired after this date
`before`	`DateTime`	Only granules acquired before this date
`id`	`String` / `Vector{String}`	Specific granule ID(s)

Mission-specific defaults¶

Each mission has different default products and providers:

search(:ICESat2)          # defaults to ATL03, version 6
search(:ICESat2, :ATL08)  # ATL08, version 6
search(:GEDI)             # defaults to GEDI02_A, version 2
search(:ICESat)           # defaults to GLAH14, version 34

Cross-product search¶

Find the matching granule of a different product for the same orbit/time:

# Find the ATL03 granule corresponding to an ATL08 granule
g08 = search(:ICESat2, :ATL08; extent=extent)[1]
g03 = search(g08, :ATL03)  # same orbit, different product

Spatial footprints¶

Each granule carries a polygon footprint from the CMR metadata, useful for visualization or precise spatial filtering before downloading large datasets.