Hello Jacques, Quite correct, my apologies, that should have read 900,000 Gold Coast Feet. Good eye.
Regards, Sam Knight Applications Specialist Blue Marble Geographics [EMAIL PROTECTED] Ph: 800-616-2725 ext. 24 Ph: 207-582-6747 ext. 24 Fax: 207-582-7001 http://www.bluemarblegeo.com and http://www.beyondgeo.com ---------- Original Message ---------- FROM: "Jacques Paris" <[EMAIL PROTECTED]> TO: "Sam Knight" <[EMAIL PROTECTED]>, "MAPINFO-L" <mapinfo-l@lists.directionsmag.com> DATE: Thu, 5 Jan 2006 15:56:04 -0500 SUBJECT: RE: [MI-L] Ghana National (War Office Spheroid) UTM coordinates It may be a problem of transcription but there is some thing strange in that line: False Easting: 274319.51 m (90,000 Gold Coast Feet) with 1 Gold Coast foot = 0.3047997101815 m Perhaps it is 900,000 Gold Coast feet? Jacques Paris -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Sam Knight Sent: January 5, 2006 14:19 To: MAPINFO-L Subject: re: [MI-L] Ghana National (War Office Spheroid) UTM coordinates Hello Karl, The EPSG database (http://www.epsg.org) lists off some different parameters than you have listed there. The Molodensky parameters for the datum shift match up exactly, but for the system itself, under code 2136 it lists: Official Name: Ghana National Grid Datum: Accra (on War Office ellipsoid) Projection: Transverse Mercator Origin Latitude: N 4~ 40' 0" Central Meridian: W 1~ 0' 0" Scale Factor: 0.99975 False Easting: 274319.51 m (90,000 Gold Coast Feet) False Northing: 0 m (0 Gold Coast Feet) with 1 Gold Coast foot = 0.3047997101815 m Then for the War Office ellipsoid, it lists: Semi-major axis (a) of: 6378300 m Inverse Flattening: 296 (which calculates to a semi-minor (b) of 6356751.69 m) I hope that helps. Regards, Sam Knight Applications Specialist Blue Marble Geographics [EMAIL PROTECTED] Ph: 800-616-2725 ext. 24 Ph: 207-582-6747 ext. 24 Fax: 207-582-7001 http://www.bluemarblegeo.com and http://www.beyondgeo.com ---------- Original Message ---------- FROM: Karl K <[EMAIL PROTECTED]> TO: mapinfo <mapinfo-l@lists.directionsmag.com> DATE: Thu, 5 Jan 2006 08:50:23 -0800 (PST) SUBJECT: [MI-L] Ghana National (War Office Spheroid) UTM coordinates Hi everyone. Has anyone put together the projection parameters for the Ghana National (War Office Spheriod) UTM coordinates that they could send to me? Most appear to be straightforward, but I'm not too sure about what to do with the local datum shift info. See details below. Thanks for your help! Karl The Ghana National (War Office Spheroid) UTM coordinates in meters uses the following projection parameters: Spheroid Semi-major axis (a) Semi-Minor (b) WGS 84 6378137.0000 6356752.3142 Ghana National 6378306.0648 6356757.9242 Local datum shift applied: Delta X : -199 Delta Y : 32 Delta Z : 322 UTM central meridian = 1~ W False Easting : 274,320 False Northing : -515,883 Scaling factor : 0.99975 McElhanney Consulting Services Ltd. L100 - 780 Beatty Street 450 - 999 8th Ave SW Vancouver, BC Canada Calgary, AB Canada V6B 2M1 T2R 1J5 Tel (604) 683-8521 Tel (403) 612-8521 --------------------------------- Yahoo! DSL Something to write home about. Just $16.99/mo. or less _______________________________________________ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l _______________________________________________ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l _______________________________________________ MapInfo-L mailing list MapInfo-L@lists.directionsmag.com http://www.directionsmag.com/mailman/listinfo/mapinfo-l
