Usually, the database itself contains no information about its geodeticdatum, so you must find this out from the application that created the coordinates.
数据库本身往往不包含关于大地基准点的信息，所以您必须从创建坐标的应用程序中查明大地基准点。
2
Both geographic and projected coordinate systems include a definition of the assumed shape of the earth (a flattened sphere); this is called the geodeticdatum.
地理和投影坐标系都包含对地球形状的假设(一个略扁的球体)；这称为大地基准点。
3
Usually, , the database itself contains no information about its geodeticdatum, so you must findthis out from the application that created the coordinates.