+x

T67M - 8/15/2016 7:07:20 PM

+x[quote]

Tim Dawson - 8/15/2016 2:10:24 PM

I took a look around inside our routing engine to remind myself of how we used to allow the switch between rhumb lines and great circles, and it turns out the architecture is all still there. For anyone interested, I have produced a beta build of SkyDemon Plan which treats all legs as great circles instead of rhumb lines. That doesn't mean we will necessarily ship something, but it would be nice to get some feedback on how it works.

Thanks Tim - the difference in the ground track on long legs is clearly noticeable, but the confusion of having the reverse leg not being a reciprocal heading is clearly apparent, and obviously the heading given on the PLog is only valid at the point of departure.

I like your idea of keeping the Rhumb Line as the default and using that for the PLog, but also drawing a (thinner) Great Circle line where the mid-point cross track difference is greater than a user configurable distance to guide the creation of additional waypoints in the leg if/when the user understands and wants Great Circle Navigation. I feel that the the default value for the cross-track threshold should be quite large so that existing users aren't confused by the changed behaviour.

+x

Stratajet - 1/18/2017 4:53:03 PM

+x

T67M - 8/15/2016 7:07:20 PM

+x[quote]

Tim Dawson - 8/15/2016 2:10:24 PM

I took a look around inside our routing engine to remind myself of how we used to allow the switch between rhumb lines and great circles, and it turns out the architecture is all still there. For anyone interested, I have produced a beta build of SkyDemon Plan which treats all legs as great circles instead of rhumb lines. That doesn't mean we will necessarily ship something, but it would be nice to get some feedback on how it works.

Thanks Tim - the difference in the ground track on long legs is clearly noticeable, but the confusion of having the reverse leg not being a reciprocal heading is clearly apparent, and obviously the heading given on the PLog is only valid at the point of departure.

I like your idea of keeping the Rhumb Line as the default and using that for the PLog, but also drawing a (thinner) Great Circle line where the mid-point cross track difference is greater than a user configurable distance to guide the creation of additional waypoints in the leg if/when the user understands and wants Great Circle Navigation. I feel that the the default value for the cross-track threshold should be quite large so that existing users aren't confused by the changed behaviour.

I'd like to +1 the Great Circle line with heading as a Rhumb on the PLog. It's really frustrating having the GPS being better at getting me there more direct. It was a particular pain when I was in Greenland a few months ago.