GPS Calibration

Another option for calibration is to use a small USB GPS sensor.  These are remarkably inexpensive and readily available.   

It should be positioned near a widow to get a good signal, so an extension cable is recommended.  The video below shows the device functioning correctly.

You just need to check your computer's Device Manager to see which com port the GPS is using, then set that in the eTimer properties.

Then you select the GPS option in the calibration dropdown.