Where should SK get magnetic variation from? - Printable Version +- OpenMarine (https://forum.openmarine.net) +-- Forum: OpenPlotter (https://forum.openmarine.net/forumdisplay.php?fid=1) +--- Forum: How do I...? (https://forum.openmarine.net/forumdisplay.php?fid=3) +--- Thread: Where should SK get magnetic variation from? (/showthread.php?tid=522) |
Where should SK get magnetic variation from? - Littlechay - 2017-06-02 I'm trying to see if I can generate a true heading for OCPN somehow. I think one way should be to generate the full HDG NMEA 0183 sentence. This included fields for magnetic deviation and variation. There is Signal K key for magnetic variation but it is empty; or rather zero value. Another way would be to calculate true heading but we still need a source of variation (and ideally deviation). Where would/should Signal K get magnetic variation from? Am I missing something obvious? RPi 3 OP 0.11.9a MPU9150 BME280 an RTC and some 1W temp sensors and a few switches and relays hanging of GPIOs RE: Where should SK get magnetic variation from? - Sailoog - 2017-06-02 On OP 0.8.0 there were these options and we have still to adapt them to 0.10.0. Look at menu tools>calculate, there is an approach but is not working yet. We calculate: - Variation from date and position - True heading from magnetic heading and variation - Rate of turn from heading variation - True wind from either STW or SOG And we set accuracy controls We generate signal k data but you will be able to convert to NMEA with NMEA generator. All this is the next task, working on it RE: Where should SK get magnetic variation from? - Sailoog - 2017-06-02 Something like this: RE: Where should SK get magnetic variation from? - Littlechay - 2017-06-03 (2017-06-02, 06:15 PM)Sailoog Wrote: Something like this: That looks like it will do the job .. thanks I look forward to trying it |