How does Ionic tracks distance with/without GPS?

[VahanJ]

When you hit the "Start" icon in "Run" mode and start running before the Ionic connects to the satellite, does it start measuring distance right away, or does it start measuring distance only after connecting to the satellite?  

Moderator Edit: Clarified subject

[SilviaFitbit]

@VahanJ A warm welcome to the Community. I'll be happy to clarify your inquiry. 

All devices with GPS sensors require a direct path to GPS satellites to calculate location. A weak GPS signal might affect the accuracy of your route and other activity data. Your device uses your step count to calculate distance until it finds a signal, so the total distance calculated for a workout may be slightly less accurate when GPS isn't available for the entire time.

As a side note, you may want to check this article: How do I use GPS on my Fitbit device? 

I'll be around if you have any additional questions.