Andre, It works brilliantly (though I can not make any sense on the addition due to my limited knowledge). Now, my two shapefiles - one in RSO and another one in WGS 84 - overlay perfectly. No more shift like before (when I used the Kertau RSO/RSO Malaya (m)) where the two shapefiles did not overlay perfectly on one another (around 180 meter shfit). So I guess it works ...
Many thanks Best wishes, Kamarul On Mon, Jun 1, 2015 at 1:04 AM, Andre Joost <[email protected]> wrote: > Am 31.05.2015 um 16:33 schrieb K Imran M: > >> Dear Andre, >> >> Is it possible, because of the different WKT string specification, my >> shape >> files was misaligned for about 200 meters to 300 meters when I chose >> Kertau >> (RSO)/RSO Malaya (m) (EPSG:3168) as the projection (OTF)? >> > > I have not tested the two versions to measure the offset, but generally > the epsg and WKT definitions have no datum shift parameters. See this > mailing list entry for possible values and background: > > http://lists.maptools.org/pipermail/proj/2011-April/005656.html > > In view of that issue, can you advise me if I >> 1) can I still use the Kertau (RSO)/RSO Malaya (m) (EPSG:3168) projection? >> Or >> > > This will not solve the datum shift issue. > > 2) should I transform the projection to any other projection? >> > > > Not a good idea, because the hotine oblique mercator is the right > mathematical model for the projection. > > Or > >> 3) should I use the User-define CRS? If yes, how can I do that? >> > > This seems to be the best way: > - Copy the proj.4 string definition of EPSG:3168 to the clipboard > - Under Settings -> Custom CRS, fill in the string at the bottom > - add the datum shift +towgs84=-11,851,5,0,0,0,0 > - give the CRS a good name > - click on the green to add it to the list > - delete the empty "new CRS" entry from the list > - click on Ok > - Rightclick on your layer, Set CRS for layer > - scroll to the bottom to get your custom CRS > > > HTH, > André Joost > > _______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user > -- Dr. Kamarul Imran Musa, M.D. M.Community.Med. Associate Professor (Epidemiology and Biostatistics) & Public Health Physician Dept of Community Medicine School of Medical Sciences 16150 Universiti Sains Malaysia, Kbg Kerian Kelantan Thomson Reuters researchID: http://www.researcherid.com/rid/G-4864-2010 Google-scholar: http://scholar.google.co.uk/citations?user=aZyayMgAAAAJ&hl=en&authuser=1 blog: http://designdataanalysis.wordpress.com email : [email protected] <[email protected]> , [email protected]
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