Thanks Amanda, Guy and Brian for your prompt replies. So MapInfo's datum numbers 12 for AGD66 13 for AGD84
are preset numbers derived similarly to the custom datum parameters in appendix G of the ref. manual. But use the same ellipsoid number (2) and different dx,dy,dz,rotx,roty,rotz parameters ie excerpt from Amanda's reply: The following are the shift parameters for AGD66 and AGD84: DatumCode Description EllipsoidCode dxWGS84 dyWGS84 dzWGS84 rotxWGS84 rotyWGS84 rotzWGS84 ScaleCorrection AGD66 Australian Geodetic Datum 1966 AUST -127.8 -52.3 152.9 AGD84 Australian Geodetic Datum 1984 AUST -128.5 -53 153.4 The scale correction (m) and prime meridian would be the same? I have tried to find the rest of the parameters from the AMG tech. manual on the ANZLIC website but not with any success yet, any links please? I did come up with this http://www.auslig.gov.au/geodesy/datums/ but still did not find the full parameters. What I want to do is prove that these different parameters are used by MapInfo when selecting the 12 or 13 datum numbers in the projection statement. Then explain that MapInfo uses the Bursa-Wolfe datum transformation method when converting between the two datums (AGD66 & AGD84). Please correct me if I am wrong. Chris Brown - Cartographer Resources Planning, Hamersley Iron P/L Tel. +61 8 9327 2176 Fax. +61 8 9327 2478 mailto:[EMAIL PROTECTED] ---------------------------------------------- This email (including all attachments) may be confidential. If you are not the intended recipient, you must not use the information contained in it. If you have received this email in error, please delete the email and notify the sender. --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
