The inside dotted butterfly represents average VMG. The outside, maximum VMG. But confess I don't know the time span over which the max and average values are determined.
"A lot of info for square reaching"? I don't understand the question. VMG or speed info? You mean straight downwind?
"Also does the outer butterfly plot max speed vs direction or is the speed taken over a period of time -say 5 seconds or something else."
Good question. I don't know the answer (see above). The GPS unit's max speed should be determined with the shortest fix interval, which is usually one second. I don't know is GPS Action Replay uses that value, or it's own interval for max speed.
BTW if you look at the "speed results" menu you can set yourself the time (or distance) for various speed averages. It would be nice if the user could set the interval used for max speed and both VMGs in polar diagram.
Now there is another setting option which is "anti-aliasing" on (by default) or off. No idea what it does and have to consult the manual for that. Could be some smoothing process.
Slyde wrote: ↑
Wed Apr 12, 2017 8:01 pm
Can someone explain to me what the smaller linear "butterfly" is that is inside the outer "butterfly" on the polars. Also how come the polars also have a lot of info for square reaching. IMHO we almost never go square to the wind by choice. Is this recorded as the rider bears away??? or is it just a phenomenon of the averaging process of the program? Also does the outer butterfly plot max speed vs direction or is the speed taken over a period of time -say 5 seconds or something else. Gunnar's bursts past 30 knots are impressive but only so if sustained.