Datum shift not working

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Datum shift not working

Paul Boettinger
Hello,
i want to do a transformation with the EPSG Code 3440
In my epsg file 3440 references the following parameters:
+proj=utm +zone=40 +ellps=clrk80 +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m +no_defs

Executing proj 4.8.0_0 from the MacPorts Repository on OSX 10.9.4 makes no differences using the transformation with or without the datum shift.
Any help welcome,

Paul

proj +proj=utm +zone=40 +ellps=clrk80 +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m +no_defs -f "%.6f"
59.28632619 24.27334106
732098.167370 2686171.824604

proj +proj=utm +zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
59.28632619 24.27334106
732098.167370 2686171.824604
_______________________________________________
Proj mailing list
[hidden email]
http://lists.maptools.org/mailman/listinfo/proj
Reply | Threaded
Open this post in threaded view
|

Re: Datum shift not working

Even Rouault-2
Paul,

as far as I know, the proj utility doesn't do datum shifts. You should rather
use cs2cs (and as per
http://trac.osgeo.org/proj/wiki/FAQ#WhydoIgetdifferentresultswith4.5.0and4.6.0,
"PROJ.4 will now only apply a datum shift if both the source and destination
coordinate system have valid datum shift information") :

$ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm
+zone=40 +ellps=clrk80
+towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
+no_defs -f "%.6f"
59.28632619 24.27334106
731801.730465 2685882.517256 82.812593

$ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm
+zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
59.28632619 24.27334106
732098.167370 2686171.824604 0.000000

Even


Le samedi 30 août 2014 10:26:28, Paul Boettinger a écrit :

> Hello,
> i want to do a transformation with the EPSG Code 3440
> In my epsg file 3440 references the following parameters:
> +proj=utm +zone=40 +ellps=clrk80
> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
> +no_defs
>
> Executing proj 4.8.0_0 from the MacPorts Repository on OSX 10.9.4 makes no
> differences using the transformation with or without the datum shift. Any
> help welcome,
>
> Paul
>
> proj +proj=utm +zone=40 +ellps=clrk80
> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
> +no_defs -f "%.6f" 59.28632619 24.27334106
> 732098.167370 2686171.824604
>
> proj +proj=utm +zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
> 59.28632619 24.27334106
> 732098.167370 2686171.824604
> _______________________________________________
> Proj mailing list
> [hidden email]
> http://lists.maptools.org/mailman/listinfo/proj

--
Spatialys - Geospatial professional services
http://www.spatialys.com
_______________________________________________
Proj mailing list
[hidden email]
http://lists.maptools.org/mailman/listinfo/proj
Reply | Threaded
Open this post in threaded view
|

Re: Datum shift not working

Paul Boettinger
Hi Even,
thank you very much for the fast response.

Paul
Am 30.08.2014 um 12:40 schrieb Even Rouault <[hidden email]>:

> Paul,
>
> as far as I know, the proj utility doesn't do datum shifts. You should rather
> use cs2cs (and as per
> http://trac.osgeo.org/proj/wiki/FAQ#WhydoIgetdifferentresultswith4.5.0and4.6.0,
> "PROJ.4 will now only apply a datum shift if both the source and destination
> coordinate system have valid datum shift information") :
>
> $ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm
> +zone=40 +ellps=clrk80
> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
> +no_defs -f "%.6f"
> 59.28632619 24.27334106
> 731801.730465 2685882.517256 82.812593
>
> $ cs2cs +proj=longlat +ellps=clrk80 +towgs84=0,0,0 +no_defs +to +proj=utm
> +zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
> 59.28632619 24.27334106
> 732098.167370 2686171.824604 0.000000
>
> Even
>
>
> Le samedi 30 août 2014 10:26:28, Paul Boettinger a écrit :
>> Hello,
>> i want to do a transformation with the EPSG Code 3440
>> In my epsg file 3440 references the following parameters:
>> +proj=utm +zone=40 +ellps=clrk80
>> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
>> +no_defs
>>
>> Executing proj 4.8.0_0 from the MacPorts Repository on OSX 10.9.4 makes no
>> differences using the transformation with or without the datum shift. Any
>> help welcome,
>>
>> Paul
>>
>> proj +proj=utm +zone=40 +ellps=clrk80
>> +towgs84=-180.624,-225.516,173.919,-0.81,-1.898,8.336,16.7101 +units=m
>> +no_defs -f "%.6f" 59.28632619 24.27334106
>> 732098.167370 2686171.824604
>>
>> proj +proj=utm +zone=40 +ellps=clrk80 +units=m +no_defs -f "%.6f"
>> 59.28632619 24.27334106
>> 732098.167370 2686171.824604
>> _______________________________________________
>> Proj mailing list
>> [hidden email]
>> http://lists.maptools.org/mailman/listinfo/proj
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com

_______________________________________________
Proj mailing list
[hidden email]
http://lists.maptools.org/mailman/listinfo/proj