[Qgis-user] Re: [Qgis-developer] Wrong reprojection if using different datums?
Micha Silver
micha at arava.co.il
Mon Jul 13 00:37:59 PDT 2009
Paolo Cavallini wrote:
> Agustin Lobo ha scritto:
>
>> different in both datums? I suspect that proj4 (behind QGIS)
>> is not using the +towgs= field.
>>
>> Any opinions on this problem?
>>
>
> Hi Agus.
> I think QGIS is mostly ignoring +twgs parameters. This is the root of
> several bugs, and I think is one of the major issues to be solved.
> Mentioned also in our bug squashing initiative:
> http://www.qgis.org/wiki/Bugs#Projections
> Unfortunately, it did not attract much specific funding jet.
> All the best.
>
The Israeli CRS also uses a +towgs parameter. This did not appear in the
srs.db until about a year ago. After I asked on the list, the entry for
EPSG:2039 was fixed in the srs.db (now equivalent to the proj4
definition) and since then QGIS has done reprojection with datum
correction properly (i.e. using v.proj in GRASS gives the same results
as QGIS projection).
Agus- can you check the entry for your EPSG code in
/usr/share/qgis/resources/srs.db (sqlitebrowser) and compare with the
same entry in /usr/share/proj/epsg?
--
Micha
More information about the Qgis-user
mailing list