kinavis-signalk 0.1.0

Signal K deltas in and out of the KINAVIS navigation crates: the traffic picture from a Signal K server, and CPA, TCPA and the COLREGs ruling for every target back as deltas and notifications.
Documentation

kinavis-signalk

Signal K deltas in and out of the KINAVIS navigation crates.

A Signal K server merges a vessel's NMEA 0183, NMEA 2000 and AIS into one JSON model and streams changes as deltas. This crate reads them into a picture of own vessel and every target, and assesses it: CPA and TCPA of each target, and for a dangerous or developing approach the COLREGs ruling — the encounter, who gives way, and what each may do. The results go back as navigation.closestApproach deltas in each target's context and as notifications on own vessel:

notifications.navigation.closestApproach.urn:mrn:imo:mmsi:244000001
  state: alarm
  message: ANNA: CPA 0.00 NM in 15:00; crossing, target on starboard, give way (Rule 15): alter to starboard, or slow down
  • Units converted at the boundary: Signal K's radians and metres per second in, KINAVIS types inside.
  • COLREGs category from navigation.state, else the AIS ship type; a vessel at anchor, moored or aground gets a CPA but no ruling.
  • An alarm for a dangerous CPA within the TCPA limit, a warning for one within the warning horizon; a notification is sent when a target's level changes, and cleared when it is no longer dangerous, stale or gone.
  • No ruling while own vessel is at rest: the steering rules are for vessels under way.

An aid to the watch, not a substitute for it: a proper lookout (COLREGs Rule 5) comes first, the ruling takes every target to be what AIS says it is, and Rules 9 and 10 are not applied.

Requires the standard library. The Signal K server plugin built on it is signalk-kinavis.

The navigation algorithms and the list of the other KINAVIS crates are in kinavis.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.