[amsat-bb] Tracking Non Earth Orbit Spacecraft......how?

[Nico Janssen]

John,

That is what everybody is looking for. But such programs do not
exist. That is why Zach is looking at possibilities to develop such
a solution for amateur use.

73,
Nico PA0DLO


On 18-10-16 18:16, John Toscano wrote:
> I  have wondered about Zach's question about tracking of bodies in other
> than simple Earth orbit, particularly in Trans-Lunar Trajectory or Lunar
> Orbit (as in the Cube Quest Challenge). I would be particularly interested
> in a solution that could run on a PC without concurrent internet
> connectivity. Are there any programs like that out there?
>
> On Tue, Oct 18, 2016 at 8:45 AM, Nico Janssen <hamsat at xs4all.nl> wrote:
>
>> Zach,
>>
>> Don't worry too much about frequent updates of ephemerides. Deep
>> space spacecraft don't experience as many perturbations as satellites
>> in low Earth orbit, like (variable) atmospheric drag.
>>
>> If you really want to dive into serious orbit modeling and tracking,
>> also for deep space, you should have a look at the General Mission
>> Analysis Tool (GMAT):
>> http://gmatcentral.org/display/GW/GMAT+Wiki+Home
>> http://gmatcentral.org/pages/viewrecentblogposts.action?key=GW
>> http://gmat.sourceforge.net/docs/
>>
>> 73,
>> Nico PA0DLO
>>
>>
>> On 18-10-16 00:24, Zach Leffke wrote:
>>
>>> Thanks for the response Nico.  Pete, WA6WOA, also recommend I take a look
>>> at the Horizons system as well.  I gave it a quick once over, and actually
>>> logged into the telnet interface and played around a bit.  It definitely
>>> looks like the type of thing I'm looking for.  Next step for me is to learn
>>> the API and figure out how to integrate with my existing Python tools.
>>> Also, changing how I think about satellite orbits and tracking algorithms
>>> is also probably a requirement for me (I'm an EE type, not an AOE type, so
>>> probably time to learn a little more about how these tracking algorithms
>>> actually work).
>>>
>>> Not being familiar with the system yet (or deep space tracking in
>>> general), my only concern at the moment is the frequency with which they
>>> update the system.  TLEs get updated pretty regularly and need to be
>>> refreshed by the client software.  My cursory examination of the HORIZONS
>>> system seems to indicate that they give ephemerides that cover much longer
>>> windows, possibly indicating that they don't update the data as frequently?
>>> Hopefully there is something about Deep Space tracking that is different,
>>> not requiring such frequent updates.  I have a sense that I'm not thinking
>>> about 'scale' correctly yet.  Like maybe these objects are so far out, that
>>> errors that might creep into the SGP4+TLE algorithms relatively quickly
>>> (requiring the weekly or bi-weekly updates) take a lot longer to creep up
>>> and matter with the deep space trajectories.
>>>
>>> My concern here is primarily related to the Cube Quest Challenge stuff.
>>> I think this is being launched as part of the Orion mission to the Moon in
>>> the next couple years.  Can we expect ephemeris data to be quickly added to
>>> the HORIZONS system soon after launch and after the TLI burn for the Orion
>>> mission?  Maybe I'm just wrong about how frequently they update the info.
>>> Since this system is being run by JPL, I'm assuming (maybe hoping?) that
>>> the datasets on HORIZONS get updated every time they conduct ranging
>>> operations on active missions with the DSN (kind of like TLEs get updated
>>> every time NORAD does RADAR tracking for things closer in)?  Hopefully,
>>> this will then include the Orion Mission relatively quickly so that the
>>> community can quickly pull the tracking data required to compute pointing
>>> angles for their ground stations to monitor the CQC bird.
>>>
>>> Thanks for the pointers folks.  In only a few emails, I've got some great
>>> stuff to look into, and a whole new area to look into and learn about!  Fun
>>> stuff!  Keep them coming!
>>>
>>>
>>> Thanks,
>>>
>>> Zach, KJ4QLP
>>>
>>> Research Associate
>>> Ted & Karyn Hume Center for National Security & Technology
>>> Virginia Polytechnic Institute & State University
>>> Work Phone: 540-231-4174
>>> Cell Phone: 540-808-6305
>>>
>>> _______________________________________________
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