Feature request #2332
please add +towgs parameters
|Pull Request or Patch supplied:||No||Resolution:|
|Easy fix?:||No||Copied to github as #:||12392|
Standard EPSG code for Italian projections (3003 and 3004) do not include datum; as a result, reprojection is always wrong by about 100 m. Can we add 4 more projection definition to our SRS database?
It should only be added the +towgs84 parameter so that we'll have:
3003 corrected, mainland: same as 3003, with
3004 corrected, mainland: same as 3004, with
3003 corrected, Sardinia: same as 3003, with
3004 corrected, Sicily: same as 3004, with
In GRASS this has been solved by a similar approach:
I think this can be done now, as it does not impact anything else, and it would make life a lot easier for Italian users (remember, the second largest QGIS user community!).
Details in http://www.crs-geo.eu/
New custom codes should be in the 32,768-100,000 range; 39031, 39032, 39041, 39042 should be ok.
#1 Updated by Giovanni Manghi over 9 years ago
Italy is not the only case, there are obviously others (in my case I'm referring to Portugal).
My suggestion is to implement this #1908 and then just maintain the list of datum association (3 and 7 parameters transformation).
Missing/correct definitions for Portugal
- [D73HG] HAYFORD-GAUSS DATUM 73
+proj=tmerc +lat_0=39.66666666666666 +lon_0=-8.131906111111112 +k=1 +x_0=180.598 +y_0=-86.98999999999999 +ellps=intl +towgs84=-239.749,88.181,30.488,0.263,0.082,1.211,2.229
- [DLXHG] HAYFORD-GAUSS DATUM LISBOA (IGP)
+proj=tmerc +lat_0=39.66666666666666 +lon_0=-8.131906111111112 +k=1 +x_0=0 +y_0=0 +ellps=intl +towgs84=-288.885,-91.744,126.244,-1.691,0.410,-0.211,-4.598
- [DLXHGMIL] HAYFORD-GAUSS DATUM LISBOA (Militar)
+proj=tmerc +lat_0=39.66666666666666 +lon_0=-8.131906111111112 +k=1 +x_0=200000 +y_0=300000 +ellps=intl +towgs84=-288.885,-91.744,126.244,-1.691,0.410,-0.211,-4.598