How to convert the coordinate system of a layer?

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06-21-2017 07:31 PM
rajasekar
New Contributor

Hi, I have a layer in the SVY21(local) coordinate system in which I cannot use SQL STIntersects fuction and only works with PCS transverse Mercator system. When I try to convert the project system in ArcMap it fails. Will be grateful, if someone can help me provide the steps to convert layer. or any alternative ways to intersect the layer?arcmap dektop# #arccatalog

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5 Replies
DanPatterson_Retired
MVP Emeritus

You will need to get your local coordinate system referenced to an existing defined coordinate system, prior to using the Project tool to accomplish the change.  How is your local system referenced to the real world?

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rajasekar
New Contributor

Hi Dan Patterson,
Thanks for replying!

My local projection is SVY21 Singapore TM, WKID: 3414 Authority:EPSG.

How do I use the project tool? is it in Arcmap? sorry i'm quite new to GIS

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DanPatterson_Retired
MVP Emeritus

Well it is in ArcToolbox in the Data Management, Projections and Transformations toolset... Project tool help link

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JayantaPoddar
MVP Esteemed Contributor

I guess the problem is that there is no suggested Transformation method while reprojecting.

Sharing with Melita Kennedy‌ , Coordinate Reference Systems‌.



Think Location
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MelitaKennedy
Esri Notable Contributor

What coordinate system are you trying to convert to? Or what coordinate system is the data you want to intersect with using?

They have released a projected-to-projected transformation but ArcGIS doesn't support that type of transformation. It converts to Kertau 1968 Singapore Grid. It does have zero parameters. That is, it appears to assume the two systems have the same coordinates (within 2 meters). 

There haven't been any datum transformations released that I know about. SVY21 may be equivalent to WGS84, but that's a bit unclear to me too. If you want datum transformation parameters for SVY21, you may need to contact the government. 

Melita