GPS used WGS84 geoid IS a flattened globe. If it was not, corrections would be much bigger.
But Earth is more like "potatoid". What that means that due irregularities of Earth shape and densities, the sea level has in WGS84 geoid location dependent altitude. The corrections are irregular. Dne 17/02/2018 v 19:14 Harry van der Wolf napsal(a): > What I mean is that the GPS calculations are based on a globe. We all > know that the earth is not a perfect globe, but a flattened globe. > That is reason one for the altitide correction. > > Secondl reason: when using it on this "perfect globe", we also have > mountains or higher plains, which again require an altitude correction. > > For a quite simple tutorial see > here: > https://www.unavco.org/education/resources/tutorials-and-handouts/tutorials/elevation-and-geoid.html > > Harry > > > 2018-02-17 19:09 GMT+01:00 Poutnik <[email protected] > <mailto:[email protected]>>: > > It may be issue of NO -vs CORRECT vs DOUBLE correction. > > As 2 values are about correct and the other 2 values > are having offset about +120' -120' > > Dne 17/02/2018 v 19:05 Harry van der Wolf napsal(a): >> Did you also download the "worldwide altitude correction" map in >> OsmAnd? >> >> Your Garmin is maybe internally corrected for that, butOsmAnd >> does a "clean" calculation based on the GPS info, and uses that >> map for altitude correction. >> >> >> -- >> You received this message because you are subscribed to the >> Google Groups "Osmand" group. >> To unsubscribe from this group and stop receiving emails from it, >> send an email to [email protected] >> <mailto:[email protected]>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > -- > Poutnik ( The Wanderer ) > > My Brouter profiles > https://github.com/poutnikl/Brouter-profiles/wiki > <https://github.com/poutnikl/Brouter-profiles/wiki> > > -- > You received this message because you are subscribed to the Google > Groups "Osmand" group. > To unsubscribe from this group and stop receiving emails from it, > send an email to [email protected] > <mailto:[email protected]>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > > > -- > You received this message because you are subscribed to the Google > Groups "Osmand" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected] > <mailto:[email protected]>. > For more options, visit https://groups.google.com/d/optout. -- Poutnik ( The Wanderer ) My Brouter profiles https://github.com/poutnikl/Brouter-profiles/wiki -- You received this message because you are subscribed to the Google Groups "Osmand" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
