# Fusion pipeline (ALDER) — working architecture

sensors in -> per-source tracker -> association/gating -> central track -> picture

sources & quirks:
- KINGFISHER ESM: bearing-only, fast, ambiguous (port/stbd). emitter ID is gold.
- KINGFISHER radar/ISAR: range+bearing, good, but emits (EMCON tradeoff).
- OSPREY EO/IR: bearing-only, passive, great for ID/classification, horizon-limited.
- MURRELET acoustic: bearing-only, slow, sees subsurface nobody else does.
- AIS: cooperative only. treat as truth ONLY when corroborated (spoofable).

fuse bearing-only sources by triangulation across platforms (need 2+ geometry).
JPDA for the dense surface picture. keep AIS as a label, not a position prior.