I noticed a significant decline of precision over the day, which I cannot explain. The track day was split in 7 segments, RacheChrono was stopped after every run and the session resumed before driving out again. From “session resume 4” on, the velocity graph looks quite bad and lap times seem to be imprecise. I am surprised because the location of the cell phone (Motorola Defy on the front of the bike) and GPS receiver (IBlue 747+ on the tail of the bike) have not been changed. It would be great if somebody could tell me a reason and I could avoid this next time.
Download of the session: https://www.dropbox.com/s/r9mm10dllj9twvl/session_copy_of_anneau_du_rhin_2013-09-23_10-37_3.rcz
Thanks in advance!