IS 2008-12-18 First version.
How to track moving objects
With autoguiding, using box motion
preset to the object
bo-mo-sta (with 1, 10 or 100 times rate)
bo-mo-sto (direction found)
place the box and move telescope or guide probe to get guide star in box
bo-mo-star (with actual set rate)
The star box can be told to move across the autoguider screen with a speed
that corresponds to the object set rate. At the same time telescope set rate
is set so that the autoguider only has to correct for the pointing errors.
Since the limitation here is the distance the star box can move between
the edges on the autoguider display this is useful for a maximum movement of
about 60" during an exposure, relative to the stars. The rate is given in
RA/DEC coordinates so the RA movement relative to the stars decreases the
closer to the pole one gets.box-at-center
Do the preset to the object to get a proper guide star.
If You are not sure of the direction the box will move in, just put the
box at center with
box-motion-start (or bo-mo-sta)
with the desired rate. Look at status page 2 about middle right to see
how long time it
takes before reaching an edge. If the movement of the box in the autoguider
screen is slow then just try it with a factor 10 or even 100 to clearly see
the direction. Status page 24 can also be used to see the box position.
When the direction is established then do
box-motion-stop (or bo-mo-sto)
and place the star box at a proper starting position.
Move either the telescope or the guide probe to put the guide star in the
box, then do
with the object RA/DEC rates in coordinates. Check status page 2
for the time before an edge is reached. If this happens during
autoguiding the box motion and autoguiding will automatically be stopped
and the telescope will continue with blind tracking with the applied set
rates. The box can now be placed at the opposite side and the guide probe
moved to once again place the guide star in it,
then ag-on and bo-mo-start
again (use command recall with arrow keys). Note that this can be
repeated as long as the guide probe does not
reach its own limits and it does not obscure the image.
When all is done do
Without autoguiding, for fast moving objects
Preset to the object and useset-rate
with the actual RA/DEC rate in coordinates. If the object moves very fast
when passing the earth then it might be necessary to give new set rates
a few times every minute.