Slice 1: extract real ICESat-2 ATL03 land-ice signal photons (strong beams, medium+high confidence) over an area and create a 3D scene with an imagery base layer. Area = region name, bbox [W,S,E,N], or polygon [[lon,lat],...]. Uses the H3 chunk index + byte-range reads + Parquet lake: first touch of an area fetches only the chunks it needs, later calls hit the lake. Returns the widget URL to open plus extraction/access provenance.

URL of the unified UI: Explore (imagery map, draw a box or polygon on Sentinel-2 imagery, coverage check, build scenes, open the 3-D viewer) and Lake (H3 grid with per-cell stats, storage limit, background loading, eviction).

Slice 2: add ICESat/GLAS GLAH06 40 Hz shots (2003-2009 campaigns) to an existing scene, in native coordinates (ITRF2008; heights converted TOPEX/Poseidon -> WGS84 ellipsoid). Returns provenance by campaign.

Slice 3: run the ITRF2014 + epoch co-registration (plate motion, ITRF2014-PMM NOAM) on both missions in a scene, co-locate GLAS shots with ICESat-2 photons, and compute delta-h statistics in native and co-registered coordinates. Live pyproj on first call, cached after. Returns the comparability block. exaggeration <= 0 picks a display exaggeration automatically (~3% of scene span); it is always labelled on screen.

Named candidate Greenland demo regions (bbox = west, south, east, north) with validation notes.

Scenes built so far (newest first) with status ready | loading | error, area, series present, and widget URL.

Parquet lake summary: cells, files, rows, bytes, storage limit and usage, recent evictions.

Materialize H3 (res 6) cells into the lake in the background (cell ids as decimal strings); returns a job id.

Status and log of a background build job (scene or cell load).

How many ATL03 (ICESat-2) and GLAH06 (ICESat/GLAS) granules touch a region, by month / laser campaign. Give either a region name (see list_regions) or an explicit bbox [W, S, E, N]. No data is fetched.