[postgis-users] Custom CRS/SRS

[Bruce Foster]

HI Paul

Thanks for the heads up and the information contained is quite useful.
I'll try to get some quality transformation points soon. Meantime,
hope you can help me with the logic;

Let me get the workflow right;

At present, the files are in MapInfo TAB files, using local cassini
projection; the details about mapinfo projection is here;
http://203.121.120.25/index.php?page=projection&lang=eng

"--- Malaysia RSO Projection ---"
"Peninsular Malaysia", 7, 47, 7, 105.236442875, -0.0001719694,
323.130102389, 0.99984, 804671.29978, 0
"Sabah & Sarawak", 7, 96, 7, 115.0, 4.0, 53.3158204722, 0.99984,
2590476.872, 5442857.653, 0

"--- Malaysia State Cassini-Soldner Systems ---"
"Cassini-Soldner Kelantan", 30, 47, 7, 102.1772917,5.893922222,0,0


I intend to convert these files to postGIS and give a custom EPSG code
in postgis. (thru insert method you mentioned)

Customise the GeoServer with the same EPSG code.

how do i verify that the projection of esri below and mapinfo above are same?

PROJCS["Malaysia_Cassini_Kelantan",GEOGCS["GCS_Kertau",DATUM["D_Kertau",SPHEROID["Everest_1830_Modified",6377304.063,300.8017]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Cassini"],PARAMETER["False_Easting",0],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",102.8952083],PARAMETER["Scale_Factor",1],PARAMETER["Latitude_Of_Origin",4.946141667],UNIT["Meter",1]]


http://miqptroy.mapinfo.com/TechSupp/MIProd.nsf/8248bf2b72f6949585257125006b035a/bfa42e1599b981f185256273006da795?OpenDocument&Click=

I dont want to be in a position that we find that the whole process
and conversion is wrong after we do the project .

Thanks a lot for your help

Regards
Bruce







On Thu, May 28, 2009 at 11:37 PM, Paul Ramsey <pramsey at opengeo.org> wrote:
>
> Bruce,
> Can you provide a known projected point?
> (x,y) in the old system
> (lat,lon) in WGS84
> Would help verify.
> P
>
> On Thu, May 28, 2009 at 9:25 AM, Bruce Foster <gis.foster at gmail.com> wrote:
> > All,
> > Apologies if this has been asked before and cross posting. Well, in dire
> > situation.
> > I'm working on a project in Malaysia and the ran into major road block
> > because of the local projection. All existing datasets are in
> > older Cassini projection. They have 9 state level Cassini projection for
> > cadastal work and they have different origin. It uses Everest 1830 Modified
> > for spheroid.
> > They are moving to their new projection called GDM2000 and they have EPSG
> > entries. But the older cassini dont have EPSG entries. this puts me in real
> > fix.
> > ArcGIS has the projection parameters for cassini and I dont find any details
> > in spatialreferece or EPSG.org.
> > My work involves GeoServer and PostGIS. Can you plesae guide and help me
> > with this? How do I put a custom projection and how do I work on a
> > projection that dont have EPSG? Since we work lot on EPSG with GeoServer and
> > PostGIS, how can we support the non standard one.
> > This is the CRS parameters;
> > PROJCS["Malaysia_Cassini_Kelantan",GEOGCS["GCS_Kertau",DATUM["D_Kertau",SPHEROID["Everest_1830_Modified",6377304.063,300.8017]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Cassini"],PARAMETER["False_Easting",0],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",102.8952083],PARAMETER["Scale_Factor",1],PARAMETER["Latitude_Of_Origin",4.946141667],UNIT["Meter",1]]
> > any guru out there help me?
> > another question, can this be reprojected to WGS84 using on the fly
> > reprojection in GeoServer and PostGIS?
> > Thanks a lot
> > Bruce Foster
> >
> >
> >
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