Observing satellites,
Posted: Sun Aug 30, 2009 1:38 pm
Hi,
One thing I always wanted to be able to do is track satellites with the scope.
With the old LX200 mount I had up until recently, this was always a hit and miss affair as the scope had a small number of slew speeds so you were always either going faster or slower then the satellite, leap frogging it so only ever seeing it as a fast moving thing cris-crossing the field of view.
As it happens, the old mount passed onto a better existance in recent times so I got my hand on one of the newer GPS/R mounts, this one has 256 (I think) descrete speeds and so is well able to track these dots in the sky alot better.
So, having discovered this, I joined the satellite tracking yahoo group and downloaded the tracker program from there,
I'm amazed at how easy this is to do, I can pickout convienent satellites in starrynight and select to track them with the tracker program, the scope has 2 serial ports so each program can communicate with the scope simultaneously, one seeing exactly where it is and the other telling it where to go.
oh man, this is great fun, the system is able to place all satellites in a low power eyepiece and using a joystick I can make small offset adjustments to roughly center the satellite and get fab views of them in the eyepiece, with lower speed ones I can use a 9mm eyepiece, its cool to watch them zoom through starfields and one passed very close to M81, all satellites I've tracked so far have been nearly if not invisible to the naked eye.
I spent the clear sky hours tonight tracking these things, here is a quick summary of what I got tonight.
(all these sats appeared as gold or white dots, no detail was visible)
isis1:: faint, occasional low flare, slow speed
cosmos 482 decent craft:: slow faint, very easy to center and follow
alos (daichi):: bright, fast, steady no flaring
iridium 44:: bright, regular 10sec+flashes ~+2 mags, very nice!
iridium 40:: steady bright, no flashes, medium fast
iridium80:: medium bright, no flashes, medium fast.
seasat1:: bright, fast but faided quickly
iridium 77:: not so bright, lost in cloud
cloud came in and ended the night
I know the autostar can be updated with satellite telemetry data but since the scope is in a dome with a PC, I prefer not to use the autostar for this.
Another thing is you need to be real carefull about is hitting the scopes hard stops, cable wrap and running the diagonal into the base of the mount, last thing I want to do is make mince meat of the drives in this mount.
One thing I've noticed is that the satellite appears to be slowely wandering in the field of view, I put this down to the fact that I put my original OTA on this fork mount and aligned it by "best looking fit", so its basically not aligned at all, this would make imaging these satellites difficult as it would be an effort to get one of these things to stay in the field of view of the tiny toucam chip, although the canon should be alot easier if I were so bothered to do it
Anyway, once more favourable passes of the ISS come along, this is going to be great fun, I expect alot of detail to be visible
One thing I always wanted to be able to do is track satellites with the scope.
With the old LX200 mount I had up until recently, this was always a hit and miss affair as the scope had a small number of slew speeds so you were always either going faster or slower then the satellite, leap frogging it so only ever seeing it as a fast moving thing cris-crossing the field of view.
As it happens, the old mount passed onto a better existance in recent times so I got my hand on one of the newer GPS/R mounts, this one has 256 (I think) descrete speeds and so is well able to track these dots in the sky alot better.
So, having discovered this, I joined the satellite tracking yahoo group and downloaded the tracker program from there,
I'm amazed at how easy this is to do, I can pickout convienent satellites in starrynight and select to track them with the tracker program, the scope has 2 serial ports so each program can communicate with the scope simultaneously, one seeing exactly where it is and the other telling it where to go.
oh man, this is great fun, the system is able to place all satellites in a low power eyepiece and using a joystick I can make small offset adjustments to roughly center the satellite and get fab views of them in the eyepiece, with lower speed ones I can use a 9mm eyepiece, its cool to watch them zoom through starfields and one passed very close to M81, all satellites I've tracked so far have been nearly if not invisible to the naked eye.
I spent the clear sky hours tonight tracking these things, here is a quick summary of what I got tonight.
(all these sats appeared as gold or white dots, no detail was visible)
isis1:: faint, occasional low flare, slow speed
cosmos 482 decent craft:: slow faint, very easy to center and follow
alos (daichi):: bright, fast, steady no flaring
iridium 44:: bright, regular 10sec+flashes ~+2 mags, very nice!
iridium 40:: steady bright, no flashes, medium fast
iridium80:: medium bright, no flashes, medium fast.
seasat1:: bright, fast but faided quickly
iridium 77:: not so bright, lost in cloud
cloud came in and ended the night
I know the autostar can be updated with satellite telemetry data but since the scope is in a dome with a PC, I prefer not to use the autostar for this.
Another thing is you need to be real carefull about is hitting the scopes hard stops, cable wrap and running the diagonal into the base of the mount, last thing I want to do is make mince meat of the drives in this mount.
One thing I've noticed is that the satellite appears to be slowely wandering in the field of view, I put this down to the fact that I put my original OTA on this fork mount and aligned it by "best looking fit", so its basically not aligned at all, this would make imaging these satellites difficult as it would be an effort to get one of these things to stay in the field of view of the tiny toucam chip, although the canon should be alot easier if I were so bothered to do it
Anyway, once more favourable passes of the ISS come along, this is going to be great fun, I expect alot of detail to be visible
