Re: [find_orb] baffled by longer arcs

Andy Puckett Nov 26, 2014

I actually had great success with this last night. With each one of my objects, I was able to get sub-arcsecond residuals simply by turning on all perturbers and hitting "Full Step" a few times. I was reluctant to "Filter Obs" because I didn't want to toss out a bunch of observations. Although I probably should have been more careful to let (or force) Find_Orb to exclude the same observations that the MPC is.

I had also become very dependent on the "Auto-Solve" button, but I guess that was because I often dealt with shorter arcs and unnumbered asteroids in need of orbit refinement. 

Andy Puckett

On Nov 25, 2014, at 11:46 PM, Andrew Hood ajhood@... [find_orb] <find_orb@yahoogroups.com> wrote:

 

On 26/11/2014 2:30 PM, puck2017@... [find_orb] wrote:
>
>
> .. as soon as I hit Auto-Solve, the residual really goes to hell. For
> K13E00A, for example, the first time I hit "AS," it jumps to e=28.4
> and residual=119102"! I also feel like an undergraduate student that
> I work with was able to get a better orbit fit than I was on some data
> set - so all of this is making me wonder if I have some fault in my
> installation.
>
> Does anybody else see the issues I'm outlining here? Or is it just me
> and my particular installation?
>
>
I get that too. When I load a long set of observations the solution that
comes up immediately might have small residuals and only use some of the
observations. I make any sort of tweek to the conditions and autosolve
and the residual goes off into the thousands or hundreds of thousands of
arcsec.

I'll try Bill's suggestion but I've tried something similar and it works
sometimes but not always.

Andrew

--
There's no point in being grown up if you can't be childish sometimes.
-- Dr. Who