|
This is for to see where the gray line propagation is occuring. Also very helpful for NDB, LW broadcast DXer's who need a map to see when the propagation is present or not. Remember you must be between the path of darkness to receive long wave broadcasts in your area. Shortwave broadcasts work the same way too, it has to be dark in that area for the F layer to appear and the D layer to disappear. When its daylight the F1 and F2 , D layer and E layer propagation occurs in the lighted area. Soon we will have a layer absorption map up here to show you have strong the D layer is. For the night, the AM and SW propagaiton reles on the F layer altogether.
Gray Line Propagation: Gray line propagation happens during the dawn and dusk hours before and after sunrise. That's when the AM bands get more active and even more at night.
Ground Wave Propagation - Groundwave propagation occurs mostly during the daytime and below 300 kHz when the signal bounces off the curvature of the Earth over saltwater. This is called salt and ground water propagation. Only happens below 530 KHz during the peak of darkness hours.
. |
|
