My GPS reading is about 850 +- 1 The "official" height ASL = 920 This calculator gives me ~936
So what should I use ? Thanks Raj At 10-02-10, you wrote: >Try to find your correct height here: >http://sps.unavco.org/geoid/ > >If you put in your correct coordinates without any input for the elevation, >you will get theorthometric height, which is the GPS ellipsoidal height >minus geoid height. That is the amount you need to subtract from >your Thunderbolt GPS height in order to get your local geodetic height >(WGS84). > >Filling in the Thunderbolt GPS height you will get the 'real' height >for your antenna... > >Some explanations: >http://www.unavco.org/edu_outreach/tutorial/geoidcorr.html > >On my location I have always to reduce the GPS height by 46.623 m. >Good luck with TB and the Lady Heather, > >Arnold, DK2WT > > > >On Wed, 10 Feb 2010 14:20:36 +0100, EB4APL wrote: > >>Raj, > >>Ask them about ellipsoidal and orthometric heights, or the local >>difference between the geoid and the WGS84 ellipsoid. Also your long >>and lat may change depending of the Geodetic Reference System chosen. >>By default GPS receivers use WGS84 and ellipsoidal height. > >>73 de Ignacio, EB4APL > >>-------------------------------------------------------------------------------------- >>Raj wrote: >>> Thanks Stan, >>> >>> That worked, I did not see the control menu properly! >>> >>> I set the co-ords to 0 0 0 and started survey. The Tbolt found the Lat long >>> withing a few minutes and only the altitude is about 70 M below the >>> official figure for my place. I live a a few hundred meters from Bangalore >>> center and I am at the same height.. must check with the survey dept. down >>> the road!! >>> >>> 73 >>> Raj vu2zap >>> >>> >>> At 10-02-10, you wrote: >>> >>>> Hello Raj, >>>> >>>> using the trimble T'boltMON software: >>>> >>>> Start with a "factory reset" in the control menu >>>> >>>> follow previous guidance of enabling the "save position" capability, >>>> >>>> Then to restart a survey >>>> >>>> go to the control menu (on left), >>>> select "restart self survey" >>>> >>>> >>>> In lady Heather V3.0 beta of 21 Jan '10 ( available from the KE5FX >>>> website): >>>> keyboard enter a "s", for survey >>>> then "s" for a standard survey, >>>> use the default of 2000 samples, for a start >>>> Then "enter" >>>> >>>> Time for me to go to bed. >>>> >>>> Please advise of progress. >>>> >>>> Stan, W1LE >>>> >>>> >>>> Raj wrote: >>>> >>>>> Thanks Stan, >>>>> >>>>> I did that but I can't where to "start the survey" in TBolt. In lady >>>>> heather there >>>>> is a key for it. >>>>> >>>>> At 09-02-10, you wrote: >>>>> >>>>> >>>>>> Hello Raj, >>>>>> >>>>>> that location is probably where the coordinates were last saved. or >>>>>> there abouts.... >>>>>> Or those are the default factory settings from memory, >>>>>> and new coordinates were never saved. >>>>>> >>>>>> redo the survey and save the results. >>>>>> >>>>>> using T'boltMON V2.60 on a PC: >>>>>> >>>>>> go to menu "set up", then "self survey", click on the "save position >>>>>> flag" >>>>>> then "set survey", >>>>>> then "save segment", >>>>>> then "close" >>>>>> >>>>>> redo the survey and afterwards verify the local coordinates were saved. >>>>>> >>>>>> Lady Heather (software) can also be utilzed for these functions. >>>>>> >>>>>> Any problems, please advise. >>>>>> >>>>>> Stan, W1LE >>>>>> >>>>>> >>>>>> >>>>>> Raj wrote: >>>>>> >>>>>> >>>>>>> Can someone point me to info that would clarify why my Tbolt's >>>>>>> self survey puts my house (AFAIK ~920M ASL, 13N 77.35E) in the Pacific >>>>>>> ocean, south of Vancouver and west of Seattle and about 10 meters under >>>>>>> water. I am doing something wrong for sure! >>>>>>> >>>>>>> My sons iPhone gives me right co-ordinates but it's way off the >>>>>>> altitude. >>>>>>> >>>>>>> Regards >>>>>>> > > > > >_______________________________________________ >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. -- Raj, VU2ZAP Bangalore, India. _______________________________________________ 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.
