Hi, which version of Therion and Proj are you using? I get 19.00961002698361,47.52649340144701,262.00000000000000 in the kml export with the latest Therion and Proj 7.2.1
Best wishes Martin On Fri, Feb 19, 2021 at 11:25 AM Balambér Hakapesz <[email protected]> wrote: > thconfig: > #cs long-lat > #fix 0 19.009617 47.526453 262 > cs EPSG:23700 # Hungarian EOV > fix 0 647151 242509 262 > > kml: > <LineString><coordinates> > 19.00961011626948,47.52649337576407,291.08568208889801 > > 291-262 = 29 m = 44m geoid height - 15m Proj4 error > > > > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > Mentes > a vírusoktól. www.avg.com > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_-5536043658431662593_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > On Fri, Feb 19, 2021 at 11:06 AM Benedikt Hallinger <[email protected]> > wrote: > >> Isn't EGM84 the reference ellipsoid currently used by WGS84? >> What you get with GPS is *not* sea level, but the altitude above that >> reference geoid (which takes into account gravital anonalys). >> >> If you calibrate your barometric altimeter to the hieght given by a >> height coordinate of WGS84 (like read from your car's navi at the >> parking lot, or from a map calibrated to WGS84) then you should get >> about the same altitude. >> If you take the cave location from GPS and enter that coordinates into >> the therion dataset wirh correct "cs" marking, the conversion should >> yield the correct result. >> If you take the altitude from a map (or an altimeter calibrated to that >> map) in another coordinate system, you have to either apply an offset >> manually, add an instrument correction factor in therion, or supply the >> correct coordinate system (which then probalby demands conversion of the >> lat/lon coordinates). >> >> If generating 3D surfce meshes, you also need to supply matching >> coordinate systems data and/or specify the correct "cs" parameter. >> >> I think your problem comes from mixing coordinate systems in respect to >> the height model, either at data input or when using the height mesh. >> >> >> Am 2021-02-19 9:49, schrieb Balambér Hakapesz: >> > Very rarely can anyone work at ellipsoidal heights. In local >> > coordinate systems, it only makes sense for upper geodetic >> > calculations. Only for GPS measurements we get an ellipsoidal >> > altitude, even there the devices can immediately calculate the >> > altitude of the EGM96 model with an altitude above sea level (with a >> > few meters error which is not significant compared to the 15m altitude >> > error of handheld GPS). >> > Proj4 calculates the horizontal coordinates well, but there is a >> > serious error in the height coordinates (for special national >> > projections >> > (http://www.agt.bme.hu/gis/workshop4/eloadasok/proj_poszter_3d.pdf)), >> > so it would be better if not we would count on it but leave the >> > altitude unchanged. >> > Could it be an option not to change the height with Therion? >> > >> > [2] >> > Mentes a vírusoktól. www.avg.com [2] >> > >> > On Fri, Feb 19, 2021 at 9:18 AM Benedikt Hallinger >> > <[email protected]> wrote: >> > >> >> Hi there, >> >> if you measure the altitude with a barometric device, you do not get >> >> the >> >> altitude above the ellipsoid. You have to account for that at the >> >> input >> >> of your data. >> >> >> >> With the "cs" command you define your input data to be in a specific >> >> >> >> coordinate system, and also your altitude has to be given in that >> >> system. If you just put the barometric altitude there (which you >> >> usually >> >> did calibrate to a map, didn't you?) you have to transform the >> >> altitude >> >> manually if the reference altitude differs. >> >> >> >> Am 2021-02-19 8:44, schrieb Balambér Hakapesz: >> >>> Hi! >> >>> >> >>> When generating 3D models, Proj4 transforms between different >> >>> coordinate systems. >> >>> This also transforms the ellipsoidal altitude, but the data always >> >>> refer to altitude above sea level and should not be changed. >> >>> The finished models do not fit the topography, you have to cheat >> >> with >> >>> the height to be good. >> >>> >> >>> Balázs Holl. >> >>> >> >>> [1] >> >>> Mentes a vírusoktól. www.avg.com [1] [1] >> >>> >> >>> >> >>> >> >>> Links: >> >>> ------ >> >>> [1] >> >>> >> >> >> > >> http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail >> >>> _______________________________________________ >> >>> Therion mailing list >> >>> [email protected] >> >>> https://mailman.speleo.sk/listinfo/therion >> >> _______________________________________________ >> >> Therion mailing list >> >> [email protected] >> >> https://mailman.speleo.sk/listinfo/therion >> > >> > >> > Links: >> > ------ >> > [1] http://www.avg.com >> > [2] >> > >> http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail >> > _______________________________________________ >> > Therion mailing list >> > [email protected] >> > https://mailman.speleo.sk/listinfo/therion >> _______________________________________________ >> Therion mailing list >> [email protected] >> https://mailman.speleo.sk/listinfo/therion >> > > > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > Mentes > a vírusoktól. www.avg.com > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_-5536043658431662593_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > _______________________________________________ > Therion mailing list > [email protected] > https://mailman.speleo.sk/listinfo/therion >
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