Update posted

Bill Gray Feb 26, 2013

Hi folks,

Yet another development version update :

http://www.projectpluto.com/pluto/devel/find_orb.htm

Quite a few improvements in this, mostly involving asteroid
perturbers. As has been discussed a bit on this list, the program
can now handle the 300 perturbers in BC-405. I think you'll find
it's not too difficult to use this capability. You _do_ have to be
a little patient, though. I still think some advanced trickery is
possible to reduce the computational workload by a big factor (most
of those 300 perturbers will be forever strangers to our object of
interest... but which ones?), but the current version is at least
useable. Also, the program appears to be quite stable now. If
further testing confirms this, I'd like to make this the "official"
release before doing more experimenting.

Anyway. The other significant improvements in this version are
the ability to do asteroid mass determination, and to get
asteroid-centric ephemerides. All of this is documented at the
above URL.

Somewhat less significantly, when you click on a radar observation,
you get info on the observed round-trip time and Doppler shift, and
the computed round-trip time and Doppler shift. Not a big thing by
itself; but it allows me to get things ready so that Find_Orb can
include radar observations in orbit determination. That should lead
to a tremendous increase in accuracy... at least, for the relatively
few objects that have radar data.

Also: observations can now be fed to Find_Orb with times given
in HH:MM:SS.SSS format, or with calendar dates or JDs given to
1e-9 day ("nanoday", or 86.4 microsecond) precision. Details,
again, are at the above URL.

-- Bill