In the previous post I displayed some problems we were having in mirror flop.
To test this I performed three tests all while telescope tracking.
1. Take exposures without doing any focusing
2. Take exposures while only locking/unlocking focus knob
3. Take exposures while slightly adjusting focus
Results:
They all had stars dancing between frames. After discussing with Mike we have pinpointed the root issue to something in the sidereal mechanical drive. Mike pointed out that because it is periodic this points to the drive. Our next action is to visit the fork features called Smart Drive from Meade that is supposed to compensate for mechanical defects in the drive.
Now tests 1 and 3 have the same looking drift/jump of stars. Test 2 did reveal that the mirror lock is causing mirror flop. So for now we decided to not use the mirror lock and will revisit the issue soon.
With all this being said, the better news is the starting of observations. At this point all that is needed is starup/shutdown scripts to hammered out and then we can let the observatory run itself. Again being another landmark :)
Stay tuned!
Thursday, August 23, 2012
Sunday, August 19, 2012
Issues as of 8/19/2012
Set Back
It seems that as soon as something is fixed another thing breaks. This time it was the CCD. For some unkown reason the CCD failed to readout the image after the exposure. It would only happen to the BORAT server and only with the Debian install. Changing the distro fixed the issue.
I took the Debian install, took an exposure, camera locked up (from the server perspective). Hot swap to another distrobution and magically the CCD works perfectly, without resetting the CCD.
I think this may have been due to a library update on Debian. Which library heck if I know. The local debian update repo was messed up so instead of fixing (already killed two nights), rebuilt the BORAT server with Ubuntu, which only took about 6 hours. I would have really liked to figure out what really went wrong, but this issue put the entire project on hold.
I do NOT place the blame on Debian, it was some thing messed up with our local install.
New Problem YAY!
Another issue that is a kick in the groin is the home grown focusing unit may not work for scientific work. Initial test of using the focuser shows that between focus adjustment the stars seem to skip to a new position. If further testing confirms this that is bad, this is really bad. Why you ask?
In short when the stars randomly move around it messes with the autofocus. The autofocus expects stars to be in the same position, assuming tracking works and no fork problems, so when the star moves out of it's spot the FWHM for that star is incorrect. Take this and apply to all the stars in a field and this creates a very big problem.
The autofocus script does do radial detection of stars, but if the stars jump a whole lot, like in the video, we can't perform miracles.
The astrometry tracking correction, I assume, is also effected. A new pointing model is created with each new image thus a telescope adjustment could become quite frequent. This could become an issue too.
Software
It seems that as soon as something is fixed another thing breaks. This time it was the CCD. For some unkown reason the CCD failed to readout the image after the exposure. It would only happen to the BORAT server and only with the Debian install. Changing the distro fixed the issue.
I took the Debian install, took an exposure, camera locked up (from the server perspective). Hot swap to another distrobution and magically the CCD works perfectly, without resetting the CCD.
I think this may have been due to a library update on Debian. Which library heck if I know. The local debian update repo was messed up so instead of fixing (already killed two nights), rebuilt the BORAT server with Ubuntu, which only took about 6 hours. I would have really liked to figure out what really went wrong, but this issue put the entire project on hold.
I do NOT place the blame on Debian, it was some thing messed up with our local install.
New Problem YAY!
Another issue that is a kick in the groin is the home grown focusing unit may not work for scientific work. Initial test of using the focuser shows that between focus adjustment the stars seem to skip to a new position. If further testing confirms this that is bad, this is really bad. Why you ask?
Focusing Test, tele @ park, focusing between exposures
Stationary Test, tele @ park, taking exposures
The autofocus script does do radial detection of stars, but if the stars jump a whole lot, like in the video, we can't perform miracles.
The astrometry tracking correction, I assume, is also effected. A new pointing model is created with each new image thus a telescope adjustment could become quite frequent. This could become an issue too.
Software
- Modify focus driver to test independent pieces to pinpoint cause of mirror flop- More testing Needed
- RTS2 LX200GPS driver getting overhauled to actually work, and to support LX200GPS specific features like sleep etc - In Progress
- Astrometry - FIXED by using sextractor instead of built in star detection :)
- Autofocus - Before BORAT rebuilt we got mixed results, main issues due to focuser altering star position (see above)
- Add user friendly GUI to control primitive features of the system - On Hold
- Startup/Shutdown observatory scripts - Done, NEEDS TESTING
- Night report
- Deadman switch for dome in driver - Done, Needs Testing
- Motion sensor wiring done, just need to connect each sensor via breadboard/connectors - On Hold
- Boltwood sensor reporting clear skies as cloudy - Fixed (testing)
- Fan need to be added to focuser/fan controller box - Ordered
- Motion detectors need to be wired in and fully tested
- Need some minor integration with IR+ZM+Lights work in combination
- Bluecherry Capture Card module causing kernel panics, need to grab new version and compile
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