然而，卫星的覆盖范围并非常常可以拍到清晰的快照；由于有云层的遮挡，气候也无法保证快照的效果。
Yet satellite coverage doesn't always allow for good snapshots; nor does the weather, which can put clouds in the way.
通过对地面卫星信号覆盖区内的多普勒频率偏移及不确定性范围的计算，给出了卫星导航系统信号的多普勒频率偏移与接收机位置之间的关系。
By calculating the Doppler shift and its uncertainty in the signal covering area, the relation between Doppler shift and the position of the receiver is obtained.
实践证明遥感卫星数据时效性好、覆盖范围大、成本相对低廉。
It is proved that the remote sensing satellite data is timely, widely covered and costs relatively lower.
应用推荐