I understand your point of view well! I use DX Atlas since several years, too (don't remember the exact year), and I use IonoProbe and HamCap as well. I love these programs, they are really useful for SW. For the tropical bands and medium wave, things are different but the DX Atlas twilight zone indicator is a great assistant there.
In the past, I felt that the nautical setting usually fits fading in and fading out of transmitting stations somehow well. Being an inactive HAM but an active BCL/SWL for the last years, I am dealing with fixed signals like radio stations, utility stations, and beacons rather than with random signals like amateur radio. So, it should be possible to find an answer for the proper twilight zone setting by keeping track of grey line signals over a long time in a methodical way. Before starting that, I wanted to know if someone has already applicable research results and the right answer.
Thank you very much for your input, John!
--- In email@example.com, JOHN <log2112@...> wrote:
> Fritz :
> The reason I use "Astonomical" setting is because Astronomical denotes ACTUAL darkness.I find this setting to be the MOST ACCURATE,when determineing Gray Line position.Nautical twilight can be as much as a 1/2 hour(or more) off actual "dark time"
> It can make a big difference sometimes,as far as my ability to pull in really distant stations during "Gray Line DX" sessions.I hope you find my explaination useful.
> I have been useing DX Atlas for over 6 years.I find it very useful in my "travels" around the Short Wave Spectrum.Also other programs such as DX Keeper,MultiPSK and others
> interface with DX Atlas,makeing it even more useful in so many more ways.IonoProbe is an excellent Propagation predictor,and Band Master is good for seeing who is on the Amateur Bands.I use all of them.I hope this was helpful.
> 73's and Good DX
> John (Grid EL29kn)
> [Non-text portions of this message have been removed]