Fused track in extreme conditions?

[halajos]

The coming weekend I’ll run a race, which has a specialty of going into a cave for 2 km. I’ll be using performance mode. Will fused track be activated in this scenario? What kind of track to expect between the points of losing GPS signal and its recovery?
a) an approximation of the track?
b) a straight line?
c) possibly weird artifacts?

Does any of you have such experience with the S9B?

[isazi]

@halajos I’ve got no experience, but I’d like if you shared the results with us after.

[halajos]

@isazi I will

[Brad_Olwin]

@halajos Fused Track will not activate but the watch should use the information it has gathered on your running to approximate distance and pace.

[DMytro]

@halajos sorry for off-topic, is this cave by chance in Europe?

[Likarnik]

@halajos straightl line and probably it will count twice the distance. At least it does for me when I run through a tunnel. Except if you have old firmware before March 2021, it worker ok before

[freeheeler]

@Brad_Olwin
would it help if @halajos switch battery mode just before the cave and switch back after?
…if so: I would practice the button “workflow” so you can concentrate on the trail and don’t look so much while pressing

[halajos]

@DMytro yes, in Hungary

[halajos]

@Likarnik double-counting is bad, I’d like to avoid. Probably could avoid it by using 'snap to route. I’ve got the track, which has a straight line between the two ends of the cave segment.

[Egika]

@halajos usually you would get a straight line between last and first position with GPS reception. Due to reflections there might be some artifacts (mis-calculations) noone can predict.

[marcrie]

@halajos but not in Balatonfüred on Sunday???

[halajos]

@marcrie no, starting from Aggtelek on Saturday

[halajos]

@isazi the watch produced a straight line between the two ends of the cave and accounted the distance between the two points twice as @Likarnik suspected.
The ‘replay’ of the track in SA looks like this: The time difference between the last point before GPS signal was lost and the first point when it got recovered is only a few seconds (the cave section was about 2km, I’m not that fast ). When GPS signal recovered the watch added the distance between the two points, which is 2km, then it fast-forwarded to the correct time and added the 2km accumulated (probably taken from accelerometer data) during that period again.

[Egika]

@halajos uh? I thought this “tunnel double distance bug had been fixed some time ago?” are you using the latest FW?

@Dimitrios-Kanellopoulos

[halajos]

@Egika yes, my S9B is up to date