elem_pop.txt

Right-clicking on the orbital elements gets you a popup dialog with the
following options.

COPY ELEMENTS TO CLIPBOARD
SAVE ELEMENTS

   These actually copy,  or save to a file,  both the currently displayed
elements plus some auxiliary information : MOIDs,  encounter velocities with
the earth,  perturbers used,  state vectors,  and so on.  You may find
that you want to edit the results a bit.

REFERENCE=

   Find_Orb defaults to showing the reference in the elements as 'Find_Orb'.
(On-line Find_Orb will show 'Auto-Find',  and the on-line NEOCP pages list
the reference as 'AutoNEOCP'.)  It's generally good practice to change this
so that anyone looking at the elements will know who computed them.

EPOCH

   The epoch of the elements defaults to somewhere near the date of the last
observation,  but can be reset freely.  It's unusual to see epochs that are
not at 00:00 UTC,  but that's just a convention.  MPC likes to use epochs
that are a multiple of 200 in MJD form,  such as 2020 Dec 17.0 = JD 2459200.5.

FRAME=Default frame

   "Normally",  geocentric elements are in the J2000 equatorial frame,  and
others are in the J2000 ecliptic frame;  Find_Orb will use those by default.
Sometimes,  the other frame is used;  sometimes,  elements are in the frame
of the body being orbited (this tends to happen for inner satellites of the
other planets;  elements for,  say,  Deimos or Ganymede would usually be
referenced to the equators of Mars or Jupiter.)

CONSTRAINTS=

   Here,  you can enter 'e=1' to constrain the orbit to be parabolic,  or
'a=2.3' to constrain the semimajor axis to be 2.3 AU.  Having done so,
'full steps' will generate orbits of the specified sort,  or as close to
it as it can.  Constraints can be combined;  'q=13000km,e=0.3' to get that
periapsis distance and eccentricity,  for example.

   Constraints can be in the following quantities :

   q  (periapsis distance)             a (semimajor axis)
   Q  (apoapsis distance)              e (eccentricity)
   i  (inclination)                    O (Omega=ascending node)
   P  (period)                         o (omega=argument of periapsis)
   n  (mean motion, deg/day)           T, Tp (time of periapsis)
   A  (area/mass ratio, m^2/kg)
   A1, A2, A3 (Marsden-Sekanina comet params)

INCREASE PRECISION
DECREASE PRECISION

   Add/subtract a digit to the precision of most orbital element quantities.

ELEMENT CENTER=Automatic

   By default,  Find_Orb chooses the center of the orbit 'automatically' :
usually heliocentric,  unless the object at the time of the epoch would
be close to a planet or moon,  within its "sphere of influence".  In that
case,  Find_Orb will shift to (say) geocentric or Neptune-centric elements.

   You can,  however,  tell Find_Orb that you want a specific central object.