H3 hexagons

H3 is Uber's open-source hexagonal hierarchical spatial index. We use it as the atomic unit of every Bharat-scale signal we produce.

Why hexagons

• Near-equal-area neighbours — squares and lat/lng tiles distort unevenly across a country-scale grid.
• Uniform adjacency — every interior cell has six neighbours, well-suited to diffusion / smoothing.
• Hierarchical — a single resolution choice fixes the atomic unit cleanly.

The resolution we ship

Bharat Strata pins locality cells at H3 resolution 11 (~0.002 km², building-cluster scale). Each witnessed cell carries its h3_r11_index (an 8b… token) alongside its admin/cluster identity.

"h3_r11_index": "8b3cb696029afff"   // resolution 11, building-cluster scale

Resolve a point

You never compute the index yourself — resolve_locality(lat, lng) returns the locality cell a coordinate falls in.

resolve_locality { "lat": 19.0760, "lng": 72.8777 }
  → { "admin_code": 483, "cluster_id": 4830000073 }