This program is used to support the collection of astrometric observations
of asteroids with a particular emphasis on Trans-Neptunian and Centaurs.
The internal help files provide information and strategies on use of the
program.  For help on invoking the program in the first place, try:

doc_library,'tnorecov'

This program shows a plot of airmass versus hour angle for selected targets
from the master list in the input file.  Only those objects that meet the
acceptance criteria will be shown.  Typically, the input file contains far
more objects than are of interest but this tool lets you pare down the list
to a more reasonable set.  It is also assumed that a "valid" observation of
any target come from a pair of images separated by some critical time.

The basic use of this tool is to use it to decide which object to do next.
When the observation begins, click the "UT1" button to record the time of
the first observation.  This object now is tagged as being "in progress".
Once enough time has passed that the object has moved more than "MinSep"
arcsec, the plot will change to reflect its new status.  At the second
observation, click "UT2" to record the second observation.  After the second
observation completes, it is removed from the candidate list.

Your progress in working through the list of objects is saved into a file
named with the same filename root as the object list but with a suffix of
.tim.  For instance, if you loaded 010309.dat, the time file is 010309.tim
and is written your current directory.  When working a set of objects during
a continuous observing run, you will most likely want to use the same list
and thus the same time file throughout.

This tool permits viewing the objects from any observatory with a standard MPC
code.  You can also fiddle with the time for the plot with the "Tools-->Delta T'
option.  If you are not plotting at the current time, the offset is shown.