The method creates a radial grid with the station as the grid center, and searching is made with varied steps in epicenter distance and azimuth.

该方法以台站为中心，建立辐射状网格，按可变震中距步长和方位角步长进行搜索。

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At last, taking one earthquake as an example, this paper gives three dimension patterns of radius of the field with epicenter distance and azimuth as well as frequency.

最后，以一次地震为例，给出了孔径随震中距、方位角、频率变化的三维图象。

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