2023-12-16, 03:52 AM
(2023-12-12, 08:43 PM)SCarns Wrote: So here's a follow up:
If we can get ETA and TTG for next waypoint, is it possible to calculate ETA to destination (end of route)? From a practical standpoint, TTG to next waypoint is all you kind of need, as that the next time you have to "do something". However, knowing what time you'll arrive at a destination could be useful, based on current VMG.
Thoughts?
I would love to do that, however, OpenCPN does not output any data back to Signal K that carries the distance to the last waypoint, route distance, etc. To get that we would have to see if we can get the OCPN team to output that. I am not even sure there is a NMEA0183 for the RMB talks about "Range to destination in nautical miles", but that is the next point, not end point. They could possibly use an alternate to RMB, like BEC:
BEC - Bearing and distance to waypoint - dead reckoning
Category: Autopilot
Example: $GPBEC,220516,5130.02,N,00046.34,W,213.8,T,218.0,M,0004.6,N,EGLM*11
Field# Example Description
1. 220516 UTC Time, HHMMSS format
2. 5130.02 Latitude of waypoint
3. N (N)orth or (S)outh hemisphere
4. 00046.34 Longitude of waypoint
5. W (E)ast or (W)est from central meridian
6. 213.8 True bearing in degrees
7. T True bearing indicator
8. 218.0 Magnetic bearing in degrees
9. M Magnetic bearing indicator
10. 0004.6 Distance to waypoint in nautical miles
11. N (N)autical miles indicator
12. EGLM Waypoint name
we would have agree some way of differentiating