Streaming notes

Street map

The Atlas now opens over Melbourne using OpenStreetMap community vector tiles, with roads, labels, water and building-footprint switches. It needs no Bitbop key. The separate 3D terrain view still uses the signed terrain feed. OSM vectors are not yet draped onto that terrain.

Tiles are fetched for the visible viewport through the Atlas Cloudflare Worker. Fresh browser or shared edge-cache entries are reused; expired entries are conditionally revalidated. Cache storage can be evicted. No offline packs, peer tile distribution or route prefetch are provided for this community layer. Building outlines do not imply known building heights. Provider policy · OSM attribution and licence.

Live origin

The World Atlas reads map.bitbop.dev through a fixed-origin, read-only relay on this Site. Authorization remains with the map server. The regional Thule pack is retained separately as a standalone archive.

Verification and coverage

Each visit resolves the current release, pins its ID, verifies its Ed25519 signature against the embedded operator public key, and verifies the SHA-256 and length of every chunk before rendering. Source metadata, credits and resolution come from that release. An unknown signing key fails closed and requires an Atlas trust-anchor update.

The current global fallback is approximately 500 m GEBCO height data and NASA Blue Marble imagery. ArcticDEM 10 m elevation and WorldCover Sentinel-2 10 m imagery are regional. The pinned Copernicus 30 m source collection has downloaded, but detailed global publication and gap validation remain pending. Missing heights remain holes. ArcticDEM ellipsoid heights and GEBCO mean-sea-level heights are not blended or treated as interchangeable.

Cache and access

Public Thule chunks and one signed release envelope use best-effort IndexedDB storage. Every stored chunk is reverified. The browser may evict this storage; it is a cache, not guaranteed offline storage. Protected chunks use a bounded 96 MiB in-memory cache and are cleared on key changes. The live working set is capped at 80 MiB. No bearer keys are stored on disk, in URLs, in the public source, or in the relay.

The signed manifest is currently large (about 29 MB decoded JSON). It is fetched once per release unless browser storage is unavailable or evicted. The monitor separates metadata from object payload. Values report decoded application bytes, not compressed wire traffic. Peer sharing and persistent protected/offline packs are not enabled here.

Flight and rendering

The flyover uses a moving local view, three concurrent downloads, look-ahead coverage, bounded chunk reuse, and cancellation on destination changes. Source grids are projected to a local metre frame. Longitudes wrap at the date line. Rendering uses a coarser mesh and bilinear terrain heights at 1× vertical scale; draped imagery is sampled to vertex colours. The inspector reports nearest native height samples. This is a streaming demonstration, not a navigation or flight simulation system.

Routes pause on unavailable terrain or authorization failures. Nearby loaded chunks may stay in RAM for return visits. Camera movement across a chunk boundary does not redownload an already cached chunk.