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More interesting stuff from the Mountain.
First, the road up is being repaved so expect lengthy delays for the next month. I got caught in a 1/2 hour wait only 3 miles from the top Friday. BTW, I worked a double shift, back to back, Friday and Saturday so I'm verrrry tired.
Moving on to astronomical stuff, I had a chance to study and ask a few questions about the Shane auto tracking system. Seems its not that sophisticated by today's standards but it gets the job done. It does not have the accuracy of the MAXIM DL system at Vulcan. Basically, the Shane uses image video amplitudes for autotracking.
Star images produce white video images (unless reverse video is selected). This video signal is then converted into an amplitude number by A to D conversion. An auto track cursor is placed on the object. The cursor is split into 4 quadrants. Each quadrant has its own video amplitude level number reported to the tracking computer. The tracking computer then takes all 4 resulting video amplitude values from the quadrants and tries to keep them all approximately equal by moving the telescope. Walla, tracking of the object.
Problems: The system gets confused with dark sky with no stars and will aimlessly wander the sky if allowed to do so. Clouds, fog, smoke and haze will affect the image and therefore the tracking accuracy and the ability to maintain lock. Also faint objects may not produce enough video amplitude to lock consistently. Of course that can be a problem with any of these systems, even MAXIM DL.
This weekends Shane research involved studying "QSO's", Quasi Stellar Objects (Quasars to the rest of us). The goal was to look at QSO's previously recorded several years ago and compare them to recent measurements. Specifically, spectral composition, red shift, and object shape were being measured. Seems there are definite changes going on in these objects over time. But we don't really know how QSO's change over time or even what to expect so this is pretty new and challenging research. Over at Vulcan, I've finally gotten the hang of our new star field and tracking star 1 Perseus. Takes a bit of practice and some educated guesses in moving the dome so as not to image the dome. Gotta do this every 90 minutes too.
Had a aircraft "bloom" out MAXIM DL for a couple of minutes during my Friday shift. I was sitting there monitoring tracking when all of a sudden the guide star got huge an bright. It went back to normal after a few minutes. When I could do my next dome entry (there only certain times I can enter the dome), I looked out the slit and saw about 5 aircraft in our star field. So I concluded my blooming was caused by United Airlines (hahahaha)!
Also Friday, I was blessed by a surprise visit from my NASA Principle Investigator (The Boss) and his wife. I showed them the evenings work and we chatted about how the Vulcan program is going, objects we have found, and improvements in the works. Apparently, we are hoping for a new 2 ton Telescope pier and mount. Also, there are going to be MAXIM DL software changes to get tracking accuracy improvements. Even though we are currently tracking the guide star to tenths of pixels, we are still experiencing 1 to 2 pixel errors across the 6 degree field of view. The new software hopes to bring the total field error down to tenths of pixels. We also are going to be getting a new telescope with an improved lens and CCD. And those CCD's are expensive. Ours is a $70K CCD. Shane brags theirs is $100K+...so maybe whoever spends the most on CCD's wins?
Friday night turned into Saturday morning with my images getting a bit dim. I ran a MIRA image check and had evidence of a "nebula" so I knew something was going wrong. At my next dome entry, I examined my desiccant dryer system for the CCD and found that the inlet hose had become disconnected from the pump. A quick fix with a Ty-wrap solved the problem and after letting the CCD dry out for a bit, the nebula was gone and images back to normal.
Saturday's shift was uneventful save a minor problem with CD disks that were giving me write errors. Sunday morning, I had a tough time driving home down the Mountain for lack of sleep so I went slow. Showered and hit the sheets and finally woke at 4:30 PM Sunday afternoon. The day and the weekend were gone - such is the life of a professional astronomer.