telescope track
Bryan Lowe (king@classics.nu)
Tue, 27 Jul 1999 16:17:07 -0700
For no particularly good reason I like the idea of having a scope track
satellites. SInce this is one of my many interests I would prefer to not
spend lots.
So here is where I have gotten so far.
The only scope I have found so far that can easily track sats is the Meade
ETX90 and 125. But now celestron has come out with another scope like the
ETX series that looks better. The problem is it does not have sat tracking
ability in its built in computer, but it does allow a computer to control
the scope through an rs232 port.
So.....
is there any software out there that you think might be able to control the
scope to allow it to follow sats? Thanks for any thoughts on this!
Bryan
Seattle, WA USA
In case you doubt the ability of a scope such as the ETX to follow a sat
here is a report from England:
Having just spent a beautiful night's viewing under crystal-clear U.K.
skies, I thought I'd share my experiences of satellite tracking with the
EC/Autostar platform.
The Russian space-station Mir has been making some high passes over
England during recent nights, so I decided to obtain the latest orbital
elements from the web in order to update the information stored on my
Autostar (1.1j) - incidentally, I'll explain how to interpret Keplerian
elements and to manually update Autostar data in a subsequent posting!
In the field I used an 'Easy' two star alignment in Alt-az mode, after
ensuring that the base of the ETX-90EC was accurately levelled (I'm
using a home-made tripod) and that the date/time/location data had been
entered as accurately as possible.
The Autostar correctly identified the start of the pass as occurring
shortly after 11:30pm local time and the 'scope slewed in readiness to a
point about 15 degrees above the WSW horizon. The Autostar began its
'countdown' in seconds until Mir would pass through the field, prompting
me to press 'ENTER' when ready to track.
Sure enough, Mir rose in the west at the predicted time, but I had to
hit 'ENTER' some 9 seconds before the countdown finished in order to
catch it as it crossed the finder field. Motors whirring! Transferring
to the 26mm eyepiece, Mir was on the edge of the field, so a few
corrective manoeuvres with the slow motion controls were required to
keep it on course, but it was thrilling to be able to keep the station
in view until it went into shadow as the stars streamed through the
field of view at 48x!
Any detail? No structure, but Mir was definitely more than a 'dot' with
a distinctly yellow/orange hue as it began to enter the periphery of the
Earth's shadow!