[Proj] 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 <even.rouault at spatialys.com>:

> 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
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