What are the observed train timestamps in the GTFS-R feed based on? I’m seeing evidence that the times are 30-40 seconds off GPS or UTC time.
I’m trying to match an app user’s location with train trips and have an issue where phone timestamps differ from the time when a user’s train passed that section of the line.
e.g. In the attached image - I have a user point and a train point 30m apart (yellow = user, red = train) that have a time difference of 33 seconds. The phone is a recent iPhone with iOS 12 so it is unlikely the user’s GPS timestamp is incorrect. Also, the GPS accuracy for the user is good (5m).
This issue is present along the entire trip - note: the green user locations are the only user GPS points that occur within timestamps of the train points (blue and red), the yellow user points do not.