Hello Mike and Group, The altitude shown by Th is the WGS84 ellipsoidal altitude, so if you wish to know your MSL, or ortometric altitude, it´s necessary to take into account the undulation or difference between the geoid and the WGS84 ellipsoid for your location.
You can see a wordwide map for such differences: http://www.colorado.edu/geography/gcraft/notes/datum/gif/geoid2.gif Hope this helps......José, EA1PX ----- Original Message ----- From: "Michael Baker" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, August 30, 2008 10:30 AM Subject: [time-nuts] Thunderbolt self-survey results... > Hello, All-- > > My Thunderbolt seems to be able to determine its > Lat and Lon location coordinates with reasonable accuracy. > > However, after completing its self-survey it thinks > its elevation is 11.2 meters when the actual elevation > of its antenna (on my house roof) is 28.4 meters. > > I arrived at this value by looking at the USGS topo > map of my property, noting the elevation ABMSL where > my house is located and adding the distance from > the ground to the GPS antenna on my roof and coming up > with 28.4 meters. > > Should I store this value into POSITION/ALTITUDE? > > If I enter this value into ALTITUDE, then what? > Should I then SAVE SEGMENT? SET ACCURATE POSITION? > > Thanks, > > Mike Baker > WA4HFR > Micanopy, FL > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > -- > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.526 / Virus Database: 270.6.13/1641 - Release Date: > 29/08/2008 7:07 > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
