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Old September 17th 04, 07:35 AM
Terje Mathisen
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Marsh Jones wrote:
I'm still curious about the update period for the barometric units. I
wonder if they can be accurate enough to handle the short, quick
transitions at somewhere like the Birkie at ski speeds. Hiking, they
certainly should. In any case, they are all cool toys. I'm still not
sure I'll take it to the BWCA next week, though.


The barometer is used together with the GPS signals to compute a new 3D
position every second, but as you note, it is possible that a very
short/quick dump might be skipped entirely.

At the same time as the barometer is used for short-term altitude
differences, the GPS altitude is used to calibrate the barometer, with a
time constant of about 3 hours.

Terje

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"almost all programming can be viewed as an exercise in caching"
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