单项选择题
A.Less signal energy is necessary for receiver operation B.More signal energy is available at the receiver C.It significantly increases the peak power D.It increases the signal capacity
Loran-C is which type of system（）.A.Reflected electronB...
单项选择题Loran-C is which type of system（）.
A.Reflected electron B.Electrical radiation C.Quarterpoint electrical navigation D.Hyperbolic radio navigation
In using Loran-C，skywave reception gives greater range ...
单项选择题In using Loran-C，skywave reception gives greater range but is（）.
A.only accurate during daylight hours B.much less accurate C.only accurate at twilight D.more accurate than using ground waves
If the radio signal ground wave extends out for less di...
单项选择题If the radio signal ground wave extends out for less distance than the minimum skywave distance，there is an area in which no signal is received．This is called the（）.
A.Skip zone B.Blackout zone C.Diffraction zone D.Shadow zone
