Thanks, Bill. That fixed it. I did look in the environ.dat for some filter, but it was not
in mine, so I was not sure how to fix it. It works just fine now.
Clear and dark skies!
- Bert
-------------------------------------------
Bert Stevens
Co-Director
Desert Moon Observatory, MPC #448
Come visit us on the web
http://www.morning-twilight.com/dm448
"I have loved the stars too fondly to be fearful of the night."
-------------------------------------------
-----Original Message-----
From:
find_orb@yahoogroups.com [mailto:
find_orb@yahoogroups.com]
Sent: Sunday, January 03, 2016 10:24 AM
To:
find_orb@yahoogroups.com
Subject: Re: [find_orb] Processing 2016 observations
Hi Bert,
You aren't alone in running into this problem. I heard about it from Reinder Bouma
yesterday. It affects observations made after
2016 January 1.5. To fix this, edit the file 'environ.dat' and look for this line :
TIME_RANGE_OBS=1000,2016
You may not actually have that line, in which case you'd have to add it, changing
2016 to (say) 2020.
This really ought to work even with older versions of Find_Orb, but you may find that
you have to go to
http://www.projectpluto.com/pluto/devel/find_orb.htm
and move to that version. (Which I would recommend doing anyway.
As you'll see, it has a variety of fixes and improvements.)
After Reinder e-mailed me about the 2016 bug, I implemented further fixes for it (not
yet posted). In the next update, the above line will be replaced by a
MAX_OBSERVATION_SPAN line, defaulting to 200 years. If your observations span more than
that, you get a warning message, and some observations are dropped.
Also, if _any_ observations are in the future, you get a warning message about that.
In both cases, the messages are pretty verbose, and you'll know exactly what's going on
and what can be done about it.
Both fixes match up to what I really should have done in the first place. Find_Orb
doesn't really have a problem with "distant" dates, but it can take a very long time on
multi-century arcs (to the point where the user thinks the program has hung). It already
warns you about possible errors in the data, and really should warn you if observations
are provided for times that haven't happened yet.
I'm also investigating an odd issue Man-To Hui reported, in which he got certain
comet non-gravitational parameters when using MPC data and quite different ones when using
AstDyS data. I am pretty sure that this is due to AstDyS having a very different
weighting scheme, one that is assigning excessively low sigmas to some observations, but
am still investigating. (For example, if three observations had near-zero uncertainties,
the orbit would basically be a fit to just those three and the other data would be
ignored.)
So I do want to fix the AstDyS issue, but the 2016 January 1.5 issue is probably
going to be _very_ annoying; I expect to get the fix described above posted later today,
even if the AstDyS problem is still unresolved.
-- Bill
On 01/03/2016 11:46 AM, blslcnm@... [find_orb] wrote:
> Is anyone else having problems processing 2016 observations? I have a
> file with NEOCP observations and when I try to load them into Findorb,
> I get a message saying that no observations were loaded from that file. It loads
observations from 2015 just fine.
------------------------------------
Posted by: Bill Gray <pluto@...>
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