Hi,
I've got a file (my own) which has been submitted to the challenge, where two different programs give significantly different numbers for total distance travelled.
The problem was that my GPS wasn't getting a clear signal, so it has a sudden jump to about 10 km away. In one program, that jump occurs in the "map view", and the total distance travelled is around 90 km. In the other program, that jump is automatically edited out, and distance travelled is 60 km.
Which figure do I use?
i think it's important to mention the first program is realspeed (showing the sudden jump) and the second program is gpsresults.
cheers
nebs.
Neb's
Just check the dates, you may have 2 different sessions there, if thats the case then it's easily fixed.
Just make sure you have kept the original download file unedited.
If you want to send it to me I can have a Butchers at it for you.
I think Realspeed will make the jump/spike invalid so it should discard the distance. Is this correct? You should enter the real distance sailed as close as possible anyhow which would seem to be about 60km. Still a fair days sailing! 
If it's caused by a break in satellite communication for a short time, that equates well with 10km traveled, then surely the "real" distance is closer to 90km. In fact it's going to be greater, because you wouldn't have gone from point a to point b in a straight line.
Thanks to Gestalt, Elmo and SailQuik for having a look at the file.
Gestalt showed me how to delete the bad data, and once that happened we got some reasonable figures in RealSpeed.
Definitely a learning experience, this GPS lark!
