16 | | There is no such thing as an accurate "default" set of datum transformation parameters for a datum. OGR uses (NADCON) by default, which is the most accurate available for North America, but in the general case (worldwide) this is very hard to determine and there normally is no such thing as a default. The transformation that should be used depends on the exact area covered, accuracy required etc. In other words, user beware and do your homework. [http://casoilresource.lawr.ucdavis.edu/drupal/node/259 1], [http://www.nabble.com/issue-warning-to-user-when-performing-datum-shift-%28OGR%2C-GDAL%29-t2029971.html 2] |
| 16 | There is no such thing as an accurate "default" set of datum transformation parameters for a datum. OGR uses (NADCON) by default, which is the most accurate available for North America, but in the general case (worldwide) this is very hard to determine and there normally is no such thing as a default. The transformation that should be used depends on the exact area covered, accuracy required etc. In other words, user beware and do your homework. [http://casoilresource.lawr.ucdavis.edu/drupal/node/259 1], [http://www.nabble.com/issue-warning-to-user-when-performing-datum-shift-%28OGR%2C-GDAL%29-t2029971.html 2] |