2011 AG5 questions

dkoschny Feb 29, 2012

Hi, can anybody help me? It seems everybody is worried about 2012 DA14 - I am still trying to work on 2011 AG5...

dvk

--- In find_orb@yahoogroups.com, "dkoschny" <Detlef.Koschny@...> wrote:
>
> Oh no, it's me again. I am still trying to figure out what find_orb is doing. I am missing some basic explanation of what's shown in the GUI. I searched in this group and found discussion points related to my questions, but most of them sounded as if all of you already know what you are talking about... I don't. Also I checked the projectpluto web pages, but couldn't find the answers. Maybe I overlooked them. Anyway: here are a few questions:
>
> 1. What is P and Q?
>
> 2. What really does the 'full step' button do? How does it compare to 'auto-solve' - is that the same as pressing 'full step' a large number of times? How does it differ to 'Herget step' (yes, I did read the page on the Herget method - but what does the button really do?).
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> 3. Sometimes the text in the 'orbital elements' box turns red. What does that mean?
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> 4. What's R1 and R2? Is it 'perhelion' and 'aphelion'? I often get R2 > 10000 AU - what does that mean? That the solution is doubtful?
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> 5. I am not yet sure about the 'epoch' field. Will it compute Kepler elements at the given epoch from the observations? I.e. if I have three Earth flybys, will it propagate the orbit determined by the current observations to the elements at that epoch?
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> 6. Is there a way to find the closest flyby times of an NEO? Or do I need to guess when they are and enter that in 'epoch'?
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> 7. What is 'start ranging' really doing? I had the feeling that it's the same as 'Monte Carlo' (which I think I do understand) - but I get different results.
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> 8. What happens when I load data? Is it doing a 'full step' or an 'auto-solve'? Something does happen, but it's not clear to me what.
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> The reason I am asking all these things is that I try to plot a ground plot of the potential intersection of 2011 AG5's path with the Earth in 2040. But I don't get any intersection so far. And anything I type in doesn't compare to what I find on the NEODyS web pages for the object for the next close flybys (http://newton.dm.unipi.it/neodys/index.php?pc=1.1.8&n=2011AG5). Propably I don't understand how to use find_orb properly yet.
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> Thanks in advance for any help!
>
> Detlef.
>