Know what the phone is measuring

iPhone Location Services can use several signals, including GPS, Wi-Fi, cellular networks and Bluetooth. Mountain terrain, dense trees and buildings can obstruct the view of satellites. The location estimate can take time to improve when conditions change.

Source: Apple: Location Services and GPS

Look at the route around an odd result

A single high speed can be caused by a short, misplaced segment. Open the day and inspect the points or replay around that moment. A line that crosses a valley in seconds deserves a different interpretation from a smooth section following the run you actually skied.

Vertical and distance are also calculated from recorded information. Two apps may filter points, classify lifts or handle gaps differently, so their totals can differ even on the same phone. Compare the route and the measurement definitions before assuming the larger total is more accurate.

Make a simple pre-recording check

Before your first lift, open the tracking screen while stopped outdoors. Check that the position is plausible and that any required location access is enabled. Give the device a moment if it has just been indoors or has not been used at that resort.

Use a secure pocket and a charged phone. If you change a permission or power setting during the day, check the active recording afterwards. Do not repeatedly stop and restart a session just to chase a single noisy point.

  • Verify the correct resort and activity.
  • Confirm that a session is active before locking the screen.
  • Check for gaps after a deliberate pause.
  • Review the saved route before sharing an exceptional speed.

Distinguish a recording gap from a display problem

A blank section of map imagery does not necessarily mean that location recording stopped. Conversely, a fully loaded map does not prove that every point was recorded. Look at the session timeline and the saved route rather than judging only the background map.

In SnowVisor, the Logbook summary and replay give you two ways to review the same day. Keep the original entry while you investigate a discrepancy, and note roughly when it happened if you need to contact support.

Use statistics as context

A day record is most useful when it helps you remember where you went and how the day unfolded. Avoid turning an uncertain maximum speed into a target for your next run. The trace should explain the day you had.

Further reading