Wrong CRS assumed

data_quality

Coordinates delivered in a projected or regional CRS (e.g. State Plane, UTM) but consumed as if they were WGS84 lat/lng place points thousands of kilometers off with no error thrown.

Detection

Coordinate magnitudes inconsistent with WGS84 range (e.g. values in the millions typical of a projected CRS false easting/northing).

Mitigation

Require and validate an explicit CRS tag on every geometry source
Reproject to WGS84 (EPSG:4326) before any H3 indexing step

Affected conversions

Polygon → H3 (intersects) expansive
Point → H3 exact