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Is there an azimuth where the moon will not be?

David Kirkby All Messages By This Member #3941 Hi, I have not downloaded XEphem, but will do. I'm a Unix/Linux fan - in fact I still use Solaris as part of my business, but intend phasing that out, as Oracle have killed off Solaris. I run Ubuntu for my daily tasks, so I will download XEphem for Ubuntu, or build from the source code. My computer, a Dell 7920,? has 2 x 26-core CPUs and 368 GB of RAM, so I should have enough resources. ?? I'm hoping someone can help me with a more general astronomy problem. I'm interested in amateur radio, and are hoping to do moonbouce, which as the name implies, means sending a signal to the moon, bouncing it off the moon and someone else on earth hearing it. (Actually, voice is quite difficult due to the path loss, but morse code is easier). But due to the immense path loss, a reasonably powerful transmitter and sensitive receiver are required. In order to do this, we need to point the antenna at the moon, which will have a rotator for azimuth and a screw jack to elevate the antenna. Since the antenna has cables going to it, there's obviously a need to restrict its rotation to prevent the cables being caught up - typically to 360 degrees, or maybe a little over 360 degrees. The rotator has to have a "stop". Typically for amateur radio applications the "stop" is north, but we are wondering if there's a better place to have the stop. Ideally we would like it in a direction where the moon never is, so when tracking the moon, we never hit the stop. We are located in the UK, at approximately 51.6576 N and 0.7607 E. We are only interested in the azimuth when the moon is above the horizon. If there's no single direction the moon will never be, can I use XEphem to log the azimuth and elevation every 30 minutes for the next 5 years, to determine where the moon is least often when above the horizon? I could post-process data in other software (Mathematica for example). Or would it simply be that the moon can be any direction, with no more likelihood of it being in one direction than another? Dave
[email protected] All Messages By This Member #3942 XEphem can give you azimuth and elevation for the moon at any time and create a list of positions for intervals of your choosing easily. But to answer your initial question, just like the sun, the moon will never be in the north (to be precise that is only true on the the northern hemisphere 5? inside the tropic of cancer and the arctic circle, i.e. between ~29? N and ~ 61? N).
David Kirkby All Messages By This Member #3943 On Thu, 18 Nov 2021 at 23:27, <randolf0klein@...> wrote: XEphem can give you azimuth and elevation for the moon at any time and create a list of positions for intervals of your choosing easily. But to answer your initial question, just like the sun, the moon will never be in the north (to be precise that is only true on the the northern hemisphere 5? inside the tropic of cancer and the arctic circle, i.e. between ~29? N and ~ 61? N). Thank you, that's great. I used to be interested in astronomy as a child, but taking the telescope in/out of the house got a bit laborious, and the condensation on the mirrors. So I lost interest. The moonbouce project at the radio club has certainly shown the need to know a bit more about astronomy. Dave
Bernie Walp All Messages By This Member #3944 Good luck! 73 de WB6PIO toggle quoted message Show quoted text On 11/18/21 1:38 PM, David Kirkby wrote: On Thu, 18 Nov 2021 at 23:27, <randolf0klein@... <mailto:randolf0klein@...>> wrote: XEphem can give you azimuth and elevation for the moon at any time and create a list of positions for intervals of your choosing easily. But to answer your initial question, just like the sun, the moon will never be in the north (to be precise that is only true on the the northern hemisphere 5? inside the tropic of cancer and the arctic circle, i.e. between ~29? N and ~ 61? N). Thank you, that's great. I used to be interested in astronomy as a child, but taking the telescope in/out of the house got a bit laborious, and the condensation on the mirrors. So I lost interest. The moonbouce project at the radio club has certainly shown the need to know a bit more about astronomy. Dave
Elwood Downey All Messages By This Member #3945 North will work fine for your az stop. But although XEphem will compute all things lunar, with the kind indulgence of the other members of this group I would like to mention another program I wrote that provides additional info just for ham operators called ?It also provides doppler shifts for 2m and 440 which are critical for reliable moon bounce and the information is available via a simple tcp socket for utilization by other control programs. Good luck with your project.? 73, Elwood, WB0OEW
Bruce Skelly All Messages By This Member #3946 开云体育 Yes, and it depends. Just like the sun, the “no-go” azimuths change through out the year. Here is a diagram that shows many of the variables at work. In case the diagram doesn’t make it here is the url Sent by Magic!
David Kirkby All Messages By This Member #3947 On Fri, 19 Nov 2021 at 22:35, Bruce Skelly <Bruce.Star.Guy@...> wrote: Yes, and it depends. Just like the sun, the “no-go” azimuths change through out the year. Here is a diagram that shows many of the variables at work. In case the diagram doesn’t make it here is the url Sent by Magic! ? What of those are variables, and what are fixed? The inclination of 5.144 degrees, does that mean its a) Always constant at 5.144 degrees b) Changes from -5.144 to +5.144 c) Changes from 0 to + 5.144 From what I understood from others, from my latitude (around 51 degrees north), the moon will never be north.?

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