Mirsky program

R.B. Minton (rbminton@sembilan.UCHSC.edu)
Mon, 22 Jul 1996 13:19:41 -0600

I used your Mirsky program last night and found it very useful in a variety
of ways.  I used the TiPS elements to verify my pervious abservations and it
confirmed my results.  I believe I know how to use it, but still cannot find
how to print a hardcopy of the satellite and its background of stars.  Is 
there a way to get printout of the satellite path?
I have also just read your account of the negative observation of TiPS using
a CCD video camera (alone).  I too have used a video camera alone with poor
results on very faint objects.  My solution was to buy an image intensifier
tube and put it between the telescope and the video camera.
I have seen image intensifiers advertised in some of the electronic, gun, and
astronomy magazines.  I use a Litton intensifier that has a fiber optic screen
on both the input and output side.  I'm not too sure what the gain (amplifica-
tion) is but any amount is better than none.  The Soviet Union and Israel sell
these tubes and you might find them cheaper in Europe than in the USA.  I 
purchased a Soviet tube and judged its output to be about 1/4 the brightness of
my Litton (USA) tube.  It was under warranty and I returned it for a refund.
The lower output of the Soviet tube may not be of consequence since you have a
very sensitive CCD video camera to follow it.  My CCD camera has 1-lux sensiti-
vity and I would guess that yours is about 1/20 lux (does it say?).
The important factor is to focus your telescope on the front side of the image
tube, and focus your video camera on the back side of the image tube.  The 
first requires no additional optics, but the latter may require a short focal
length "transfer" lens (about 3/4 inch in diameter with a focal length of 1 to
2 inches).  It should be well corrected with 3 or 4 elements in it.
I hope this discussion will lead the way to greater sensitivity in your video
system.  Good luck & best regards.

R. B. Minton
Astronomers not only do it at night, they start during strong twilight.