While adjusting DX Atlas – which is a “must” tool to have if you are interested in Low Band DX-ing, I actually started wondering about the difference between these twilights. I am sometimes really amazed that even after what seems like sunrise there is that “enhancement” you get for just minutes on 160M, but that on 40M, the long path can stay open for hours after sunrise or before sunset.
Here is the full story:
And under “settings” in DX Atlas:
An easy way to remember which is which:
Civil – Nautical – Astronomical
6 – 12 – 18
This is important not just for DX-ing but when I ride my bike – its always interesting when I need to use my bike light or when I can still see well enough without it.
Now that’s an interesting analogy!