I realized that Altitude reported by (A)GPS device reports roughly 40 meters Alt near to sea level.
Tracks from the trim will be available later.
NOTE: I know that Geoid is just approximation.
OpenStreetMap
I realized that Altitude reported by (A)GPS device reports roughly 40 meters Alt near to sea level.
Tracks from the trim will be available later.
NOTE: I know that Geoid is just approximation.
讨论
kaerast 于 2009年07月 5日 11:47 的评论
GPS is generally pretty terrible at altitudes, it just gives a very rough idea. Also, it'll be altitude above mean sea level not actual sea level where you are.
Skippern 于 2009年07月 5日 16:33 的评论
You can callibrate altitude in most advanced handheld units, but mark that Geoid altitude and reality differs around the planet, +/- 60 meter AFAIK.
Biogenesis_ 于 2009年07月 6日 04:55 的评论
Altitude calibration is for any hand held unit which has a barometric altimeter in it. Ie, one which estimates altitude based on changes in air pressure.
Garmin units which have the required hardware include the eTrex Vista HCx (top of the line eTrex) and several of the Summit units.