Last weekend, RoadSkater & I were talking about elevation data while on the scenic 51-mile "Hannah" route... I unfortunately lost my data from that skate due to a hard drive crash, so I can't compare against his. But it did get me thinking...
Which elevation data is most accurate?
1) Polar's barometric sensor
2) Garmin's GPS sensor
3) NASA's 30m elevation data (i.e., on gpsvisualizer.com)