GPS Tunnel & Blackout Signal Fixer - Bridge Signal Gaps
Did GPS disconnect inside a tunnel or city corridor? Fill missing coordinates smoothly without creating false high-speed spikes on Strava.
How to Use Tunnel GPS Fixer in 3 Simple Steps
Step 1: Upload
Drag & drop your .FIT, .GPX, or .TCX activity file. All processing is 100% private in your browser.
Step 2: Process
FitCrop inspects telemetry streams, removes anomalies, recalibrates metrics, or fixes binary checksums.
Step 3: Export
Download your clean Strava, Garmin, and Zwift compatible file with 1 click. Zero server wait.
Frequently Asked Questions
Why does Strava show a 400 km/h speed spike after exiting a tunnel?
When GPS drops in a tunnel and reconnects hundreds of meters ahead, sports platforms calculate speed by dividing distance by the time gap, causing false trophy-invalidating speed spikes.
How does FitCrop bridge the tunnel blackout?
FitCrop performs linear dead reckoning interpolation, placing trackpoints every few seconds between the tunnel entry and exit points.