- Send 20 points per request, not 50: above ~20 Kartverket answers the
extra points from contour lines (hoydekurver) or not at all. At 20,
nearly every camera resolves from dtm1, so the null-retry pass is gone.
Eight requests in flight keep a cold lookup ~6 s.
- Cache misses: positions with no height are not asked again for 6 h.
- Transport failures: the first 429, 5xx or network error stops the
lookup with no retries, and no lookup starts until the backoff ends
(Retry-After when sent, else 10 min; bounded to 1 min-1 h).
- Budget the 12 s wait from the start of the loader, catalog fetch
included.
- Record answers only for the points each request asked about.
- Send the CCTV User-Agent; link CC BY 4.0 in the credit.
- Docs: bridge cameras sit at the water surface, below the deck.
- Tests: batching, 8-in-flight cap, request count on failure, the shared
deadline, Retry-After bounds, null TTL, backoff, the -20 m bound and
each water marker on its own.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
The Vegvesen camera feed is 2D, so every camera shared one flat 150 m
ground prior and mountain-pass cameras could sit hundreds of metres below
the terrain where neither the point-height prior nor the ground snap
resolves. Each camera now gets its terrain height from Kartverket's
keyless point-height API (CC BY 4.0): ~840 of ~845 cameras.
- 50 points per request, six in flight; points a full batch answers null
for are retried once in batches of 10 (the API drops points from large
batches).
- Sea-floor depths (dybdekurver / Havflate) under bridges and quays
count as the water surface, 0 m.
- Heights are cached by position, so the 15-minute refresh only asks
about new or moved cameras. A catalog load waits at most 12 s; a slower
lookup keeps filling the cache for the next refresh.
- CCTV_VEGVESEN_HEIGHTS=0 turns it off; Kartverket is credited beside
Statens vegvesen in the attribution popover.
Follow-up to #929.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Trygve Hemminghytt