The quick-start guide to the Palomar Autoguider.
If you look at the Autoguider display, you will see a column of
controls to the right of the image-display window. These are the only
controls that you are likely to need. The row of controls beneath the
panel will rarely need adjusting, so you can, and probably should,
ignore them. Note that the controls to the right of the display are
organized such that the most important controls are near the top of
To get started do the following:
The rest of the facilities on the display are described in the main
part of the user manual.
- Move the cursor to the fifth panel down from the top of the
display (the one labeled FRAME GRABBER). If its
ENABLE button is bright yellow, the camera is disabled, so
move the cursor over the ENABLE button and depress it by
clicking the left mouse button.
- Within the same panel you should see a FRAMES PER
INTEGRATION slider and an INTEGRATIONS TO AVERAGE
slider. If the values to the left of the sliders aren't both 1,
then change each of them to 1 as follows. First move the cursor
over the black rectangle of the slider. Now, with the left mouse
button held down, move the cursor left until the displayed value
becomes unity. The black rectangle should now be at the left end
of the slider. With these settings a new camera frame will be
displayed every 30th of a second.
- Now move the cursor to the third panel down from the top of the
display (the one labeled GRAY-SCALE) and find the
ADJUST button. If this button isn't already depressed,
push it by clicking the left mouse button. It should turn bright
green to indicate that the gray-scale adjustment function is now
active. If it doesn't, click again.
- Now move the cursor into the image-display window and click the
left mouse button briefly, somewhere near the middle of the
window. The image may now turn black or white, depending on
where you clicked the button. You should change this to a dull
grey color as follows. If the image is black, move the cursor
right to increase its brightness. If it is white, move the cursor
left to decrease its brightness. Now move the cursor up, to
increase the contrast, or down to decrease it, until you can see
unsaturated readout noise. When you are happy with the results,
press the left mouse button again to adopt the new settings.
- Skip this step if you are using the COSMIC guider camera.
It doesn't have an adjustable image intensifier. The other
supported guide cameras do.
Move the cursor to the CAMERA SENSITIVITY panel and find
the INTENSIFIER GAIN slider. Move the cursor over the
black rectangle of the slider and slowly move the cursor
to the right while holding down the left mouse button. Stop when
features (eg. a star or saturated speckles) appear in the image.
- To increase the signal to noise ratio of the image, you will
probably need to average a number of 30th second frames. To do
this, move the cursor to the FRAME GRABBER panel and again
find the INTEGRATIONS TO AVERAGE slider. This time drag
the black rectangle of the slider to the right, until the number
displayed to its left is roughly 30. Then let go to adopt this
value. The image will now update only once per second, but
because it is the average of 30 frames, it should look much
cleaner. To make it look even cleaner, further increase the
- If a potential guide-star is evident in the image, you can now
select it for autoguiding by moving the target box over it. To do
this, move the cursor into the TARGET panel (the topmost
panel), find the POSITION button and depress it by
clicking the left mouse button over it. The POSITION
button should now turn bright green to indicate that the
target-positioning function is now active. Notice that the single
line of text below the image window contains terse instructions
on what to do next. First move the cursor into the image display
window and briefly press the left mouse button. A target box
should now appear next to the cursor. Move the cursor until the
target box is approximately centered on the guide star, then
press the left mouse button to adopt the new position.
- Now move to the AUTOGUIDER panel and press its
GUIDER button if it isn't already depressed. Then find the
ENABLE button and depress it. If the star has sufficient
signal to noise, the guider will now attempt to keep the guide
star near the center of the target box by moving the telescope.
Note that at most one telescope move will be performed every time
that two successive camera images have been displayed. A hard
limit of one correction per second is also enforced. If the star
doesn't have sufficient contrast against the background, then the
Autoguider won't attempt to guide. If this is the case, try
adjusting the image contrast, the intensifier gain and/or the
number of frames being averaged, to increase the contrast of the
- If the guider doesn't appear to be doing a good job, this may
mean that the camera orientation calibration isn't correct. The
best way to test whether the calibration is ok is to use the
cursor, as described below, to move the telescope, and then watch
to see if it goes where you asked it to. If it doesn't, then you
should use the automatic pixel calibration facility, as described
in the main user manual.
- The most convenient way to move an object within the image is to
use the cursor to command the required telescope move. To do
this, first press the GOTO button in the FIDUCIAL
MARKER FUNCTIONS panel. It should turn bright green to
indicate that the goto function is now active. Now move the
cursor into the image window and click the left button over the
destination position of the object. An arrow head should now
appear there, and you should now move the other end of the arrow
to the object to be moved. If you now click the left mouse button
again, the object should move to the specified position. Note
that (as with all other image-window functions) press the right
mouse button instead of the left button to back out of what you
Martin Shepherd (email@example.com).