Both geographic and projected coordinate systems include a definition of the assumed shape of the earth (a flattened sphere); this is called the geodetic datum.

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。

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Besides of uniform spatial reference and positioning datum, modern war must unite all the geographic spatial information needed by all arms of services to a organic integer scientific and reasonably.

除了要求有统一的空间参照和定位基准以外，还必须将诸军兵种所需的地理空间信息科学合理地统一在一起，形成一个有机整体。

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