磁偏角（D）的水平梯度不仅随纬度变化，而且随经度变化。

The horizontal gradient of the declination (D) varies not only with latitude, but also with longitude.

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磁偏角（D）的水平梯度不仅随纬度变化，而且随经度变化。

The horizontal gradient of the declination (D) varies not only with latitude, but also with longitude.

youdao