From b0f5072347ff90937fce8c709d107528dadfc5e3 Mon Sep 17 00:00:00 2001 From: Theerayut Boonkird Date: Fri, 18 Sep 2026 00:41:06 +0100 Subject: [PATCH] docs: record the AIS unavailable-code handling CONTRIBUTING asks for docs/CURRENT-STATE.md and CHANGELOG.md in the same PR as a runtime behaviour change. Co-Authored-By: Claude Opus 5 (1M context) --- CHANGELOG.md | 4 ++++ docs/CURRENT-STATE.md | 8 ++++++++ 2 files changed, 12 insertions(+) diff --git a/CHANGELOG.md b/CHANGELOG.md index 0f3fd7822..2b5622678 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,5 +1,9 @@ # Changelog +- Report AIS speed and course that carry the standard "not available" code as + unknown instead of 102.3 knots and 360 degrees. Genuine readings, including a + stopped vessel's zero and the highest encodable values, are unchanged. + - Distinguish PARTIAL vessel snapshots from STALE data in the layer panel, with accepted-record counts and unchanged retention, freshness and outage safeguards. diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md index b5727f353..a8a313819 100644 --- a/docs/CURRENT-STATE.md +++ b/docs/CURRENT-STATE.md @@ -1,5 +1,13 @@ # God's Eye View Current State +AIS encodes speed over ground in 0.1-knot units and course over ground in +0.1-degree units, reserving the top code of each field for "not available", so +those reports arrive as 102.3 knots and 360 degrees. Both are stored as unknown, +and vessel cards, the HUD and analyst queries show a missing measurement rather +than a reading. Heading keeps its existing separate check for its own sentinel. +Genuine readings are unchanged, including a stopped vessel's zero and the +highest speed and course the fields can encode. + Vessel snapshot completeness is separate from freshness. A current snapshot with rejected or duplicate records shows PARTIAL with accepted/received counts; stale or unknown freshness and transport failures retain their warnings. Partial