Yes, the Garmin Approach G80 golf GPS device does measure swing speed. In addition to providing GPS yardages and course maps, the G80 also includes a built-in launch monitor that can measure swing speed, ball speed, smash factor, and more. The device uses a radar sensor to track clubhead speed and ball speed during your swing, and displays the results on the device’s screen. This information can be useful for golfers who are looking to improve their swing mechanics and distance control.