> If the variances are minimal then I don't really need them. All I am doing > is providing an automatically calculated magnetic declination for any > location in NZ. I know that the total variance across the country is only > about 2-3 degrees (although this can be quite significant over long > distances), but wasn't sure of the scale of local anomalies.
But again, what for? What instrument will be measuring the declination and does it have the sensitivity to detect the change. If the instrument is a compass, then forget it (but get away from that electric fence or car) > Is the IGRF model very different from the WMM model? I had a quick look at > the IGRF coefficients and they look fairly similar. No. Same basic data. ---------------------------------------------------------- Phil Scadden, Institute of Geological and Nuclear Sciences 764 Cumberland St, Private Bag 1930, Dunedin, New Zealand Ph +64 3 4799663, fax +64 3 477 5232 _______________________________________________ Delphi mailing list [EMAIL PROTECTED] http://ns3.123.co.nz/mailman/listinfo/delphi
