Saturday, January 7, 2012

iPhone altitude is totally off

I've been using my iPhone to log all of my rides since I got it back in 2010. The thing is, using GPS to calculate altitude is horrendously inaccurate. According to Google Earth, my home altitude is 815 feet. Right now I'm looking at the altitude in MotionX and it fluctuates between 835 and 880 feet. Granted I am indoors, but even out on my drive way, it rarely shows 815 feet.

This week I bought myself a new Sigma sport Rox 8 bike computer. This one can record speed, cadence, heart rate and altitude. It uses barometric pressure to measure the altitude. Of course weather can affect the measurement, but it should be much better than GPS calculation. I hope the next iPhone gets a built-in barometer. That would improve the altitude measurement.

Today the weather was great in the mid 40's around 1pm. I managed to get out for a 25 mile ride around Holden. I hope we get a few more days of good weather this month. During my ride, I saw 3 other cyclist. One thing I'm thinking about is how to record Mount Greylock century this year. It would be cool to record the climbs of the century and the descent down Route 2 Mohawk Trail.

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