[Proj] GK31_Tirol (Austria)

[Helmut Kudrnovsky]

hi jens,

you are writing of "GK31_Tirol" which means Gauss-Krüger M(eridian)31. 

but be aware where your data is in Tirol:

   North-Tirol is in GK28 (Meridian 28)
   East-Tirol is in GK31 (Meridian 31)

you can have a look at my homepage, where i prepared the parameter (inclusive towgs-parameter) for the 3 meridians in austria in wkt-format.

http://www.alectoria.at/content/view/17/1/

greetings form Lienz in East-Tirol (GK31_Tirol)
helli


>Hello, I have to deal with data from Austria which is in GK31_Tirol. We preprocess our data with ESRI and use postgis >and so proj4) for our web applications. Our web application must convert GK31_Tirol to WGS84 for GPS tracks and kml >exports. We transformed some coordinates succesfully with ESRI's ArcMap. But proj and cs2cs give me different >coordinates. The coordinates ESRI produces match e.g. Google: >http://maps.google.de/maps?f=q&hl=de&q=47.487218+12.254853&layer=&ie=UTF8&z=16&ll=47.486948,12.254992&spn=0.009295,0.013003&om=1 >(street crossing) The point was digitized with projection GK31_Tirol and then converted with ESRI. (GCS Transformation >using MGI_To_WGS_1984_3 which lists exactly the same parameters as the towgs84 parameters used below.) I'm >interested in the transformation GK31_Tirol to WGS84 in postgis. I always got a significant shift with proj4 (see below). >Thanks for your help. cheers Jens Schwarz >###################################################### ESRI: PROJCS["GK31_Tirol", >GEOGCS["GCS_MGI", DATUM["Militar_Geographische_Institute", SPHEROID["Bessel_1841",6377397.155,299.1528128]], >PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Transverse_Mercator"], >PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",-5000000.0], >PARAMETER["Central_Meridian",13.33333333333333], PARAMETER["Scale_Factor",1.0], >PARAMETER["Latitude_Of_Origin",0.0], UNIT["Meter",1.0]] >MGI_To_WGS_1984_3=577.326,90.129,463.919,5.1366,1.4742,5.2970,2.4232 Tranformation with ESRI: 47.487218 >12.254853 --> -81220.587815 261502.093597 >###################################################### proj4: proj +proj=tmerc >towgs84=577.326,90.129,463.919,-5.1366,-1.4742,-5.2970,-0.4126774513 +lat_0=0 +lon_0=13.33333333333333 >+k=1.000000 +x_0=0 +y_0=-5000000 +ellps=bessel +units=m +no_defs -r &lt;<EOF
> > 47.487218 12.254853
> > EOF
>-81265.99       261441.61
>
>cs2cs:
>
>cs2cs +proj=latlong +datum=WGS84 +to +proj=tmerc +ellps=bessel +lat_0=0 +lon_0=13.333333 +k=1.000000 +x_0=0 >+y_0=-5000000 +towgs=577.326,90.129,463.919,5.1366,1.4742,5.2970,2.4232 -r &lt;<EOF
>> > 47.487218 12.254853
>> > EOF
>-81266.89       261375.36 703.77













-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
helmut kudrnovsky
www.alectoria.at
_______________________________________________________________
SMS schreiben mit WEB.DE FreeMail - einfach, schnell und
kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192