Just sent my tracks off to snides for verification to get em on the WA speed table, and got bac some interesting results; 40.44 max on gps pro and 40.37 on realspeed. Just wondering what would cause these differences, since the figures come from the same data????
Interesting, I've just replied to 25 on Dylans on line results thread.
Basically GpsarPro, averages 2 doppler samples and realspeed averages 3.
As a doppler reading is instantaneous 2 samples only span 1 second, it takes 3 samples to span 2 seconds.
So in effect Gpsar is giving a 1 sec average, and realspeed is giving a 2sec average.
That's how I understand it anyway, there'll probably be more technical answers from the gurus.
Thanks Mike, you are right on the money. Each trackpoint is a sample so to find the speed over each second we get a more accurate result by takng the average of the start and end speed for that second. This means for a two second result we need three track points. Yann informed me today that this method is also available in GPS AR Pro and is referred to as the trapezoidal method.
Hopefully all sailors will choose this method due to the better accuracy.
