Thursday, April 15, 2010

Google Gadget for SVY21 Coordinates Conversion Calculator

Note: A WebApp version of this Google Gadget is available here http://dominoc925-pages.appspot.com/webapp/calc_svy21/default.html.

SVY21 is a Transverse Mercator projection (with a WGS84 datum) commonly used in Singapore. This Google Gadget will allow you to convert between one or more pairs of SVY21 easting, northing coordinates and geographical latitude, longitude coordinates. The gadget can be embedded to your iGoogle home page or your web page.


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3 comments:

  1. Daniel LidströmMarch 23, 2011 at 12:15 AM

    Hi,

    I tried converting a position using your conversion calculator. Then I compared the result with the result I got from OneMap REST APi. The results differ by a few decimals:
    1.2929838006781431,103.85254262698302 (yours)
    vs
    103.852542627029,1.29298990999197 (theirs)

    The coordinate I converted was 30139.47,30597.782 (location of City Hall Metro Station).

    Regards,

    Daniel Lidström
    Stockholm, Sweden

    ReplyDelete
  2. dominoc925March 23, 2011 at 6:47 AM

    Hi Danne
    Yes, the slight differences are to be expected since the implementations are not the same; OneMap is using ArcGis on the server, I did it in Javascript.

    ReplyDelete
  3. Daniel LidströmMarch 23, 2011 at 9:03 PM

    Ok, sounds like a good explanation. Btw, is the source available?

    ReplyDelete