Michael, If your SRID is not in UTM, you will need to use the utmzone function to transform it into the correct UTM SRID. This will result in the distance being measured in meters.
Have a look at http://postgis.com/support/wiki/index.php?How%20to%20get%20distance%20measurement%20in%20meters%3Fand http://postgis.com/support/wiki/index.php?plpgsqlfunctions This is the query I use. My wkb_geometry is in SRID 4326. Select distance(transform(wkb_geometry,utmzone(GeomFromText( 'POINT($lon $lat)', 4326 ))),transform(GeomFromText( 'POINT($lon $lat)', 4326 ),utmzone(GeomFromText( 'POINT($lon $lat)', 4326 )))) On Fri, Nov 7, 2008 at 5:55 AM, Michael Signup <[EMAIL PROTECTED]>wrote: > Hi, > > This is probably a very simple question but I am unable to find anything to > point me in the right direction. > > I am trying to understand how I can make distance related queries with > PostGIS. To do this, I am attempting to calculate the distance between: > > in Lat/Long > Point A(-38.034031,145.201711) and Point B(-37.899854,145.087116) > > I have tried several methods and am still getting the distance as 92072.62 > (I don't know what units this is in, but I am trying to get it in meters). > > Google Earth calculates the distance as 17.4 km (approximately). > > Regards, > Michael > > > > > ------------------------------ > Find great deals on eBay Net yourself a > bargain<http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Frover%2Eebay%2Ecom%2Frover%2F1%2F705%2D10129%2D5668%2D323%2F4%3Fid%3D10&_t=763807330&_r=hotmailTAGLINES&_m=EXT> > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > -- Thank you, Chris Story Developer Federal Flood Certification Corporation 4000 Horizon Way Irving, TX 75063 Phone: (800) 449-3322 ext 15931 FAX: (800) 929-3322
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