Hi, Proj 4 and 5 uses a different conversion than Proj 6+ resulting in the height difference.
Actually, the behaviour of Therion was inconsistent: when doing internal conversions it transformed only x and y coordinates, but when creating e.g. KML output it transformed all x, y and z coordinates. The latest commit (b6bcc92) unifies this to converting just x and y for all coordinate systems transformations. If there is a real need for a switch between converting and not converting the heights, let us know. Martin On Fri, Feb 19, 2021 at 8:41 PM Balambér Hakapesz <holl.balaz...@gmail.com> wrote: > therion 5.5.7+0df52bd+dev (2021-02-18) > - using Proj 5.1.0, compiled against 5.1.0 > > On Fri, Feb 19, 2021 at 8:40 PM Balambér Hakapesz <holl.balaz...@gmail.com> > wrote: > >> latest Therion 5.5.7 (now install): >> >> <LineString><coordinates> >> 19.00961011626948,47.52649337576408,*291*.08568208824045 >> 19.00961011450532,47.52649337534078,281.08568208855468 >> 19.00962225574169,47.52658294585592,281.08562306819113 >> 19.00975449765885,47.52657472222689,281.08549506128293 >> </coordinates></LineString> >> >> On Fri, Feb 19, 2021 at 8:19 PM Martin Budaj <m.bu...@gmail.com> wrote: >> >>> 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 < >>> holl.balaz...@gmail.com> 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_1264032343771874480_m_-3468513418640853693_m_2109412960721514408_m_-5536043658431662593_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >>>> >>>> On Fri, Feb 19, 2021 at 11:06 AM Benedikt Hallinger <b...@hallinger.org> >>>> 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 >>>>> > <b...@hallinger.org> 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 >>>>> >>> Therion@speleo.sk >>>>> >>> https://mailman.speleo.sk/listinfo/therion >>>>> >> _______________________________________________ >>>>> >> Therion mailing list >>>>> >> Therion@speleo.sk >>>>> >> 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 >>>>> > Therion@speleo.sk >>>>> > https://mailman.speleo.sk/listinfo/therion >>>>> _______________________________________________ >>>>> Therion mailing list >>>>> Therion@speleo.sk >>>>> 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_1264032343771874480_m_-3468513418640853693_m_2109412960721514408_m_-5536043658431662593_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >>>> _______________________________________________ >>>> Therion mailing list >>>> Therion@speleo.sk >>>> https://mailman.speleo.sk/listinfo/therion >>>> >>> _______________________________________________ >>> Therion mailing list >>> Therion@speleo.sk >>> https://mailman.speleo.sk/listinfo/therion >>> >> _______________________________________________ > Therion mailing list > Therion@speleo.sk > https://mailman.speleo.sk/listinfo/therion >
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