这样就改变了GPS信号的传播，减小了地球底层轨道上空间碎块的衰减速度。
This altered the propagation of GPS signals and slowed the rate of decay of space debris in low Earth orbit.
但是电力线信道上存在的各种噪声、衰减和多径传播等问题，这些都大大提高了通信的难度。
But the noises, the attenuation and the multipath propagation inhering in the powerline make it very difficult to realize such kind of communication system.
由于电磁信号在地下传播时不断衰减，瞬变电磁测深法有一个最大探测深度。
The transient electromagnetic method has a maximum depth because of continuous attenuation by transmission of electromagnetic signal in underground.
应用推荐