Tuesday, September 30, 2008

Caught up on pictures.

The observing run from the 24th to 28th did a number of things. One is it made me very tired. The other is that I finally found the time, because I was forced to sit in a chair for maybe 15 hours per day, to photoshop all the pictures I had sitting around. I've finally gotten the Burning Man, Ko'olau Gliding and Maui trip pics all processed. At least to a 'decent' level.

Check out my pics website: http://www.ifa.hawaii.edu/~dmh/WEBSITE-Pictures/index.html

They'll be the first three links under 'New Pictures'.

Monday, September 29, 2008

Sad Sad IfA

IfA full professor salaries for 2001-2002 and average credits taught for that year show a negative correlation between salary and amount of teaching. A simple fit shows that if you teach over 4 credits, you make $0 and you gain $26,000 in salary for every credit you don't teach. Lots of scatter too. Maybe that says teaching is irrelevant to professorships. Either satement isn't great. I wonder why people say we're slipping....

Saturday, September 27, 2008

Big Island NIR

The channel was amazingly clear and the cliffs were out on the Big Isle...

Sunday, September 21, 2008

Gliding Part 2

Gliding is actually getting really fun. I feel comfortable shutting down the engine, gliding, and turning it back on again. I've got the glide-landing thing down fairly well (landing with no engine), even glide slipped-landings (no engine, no airbrakes). I spent Sunday unwinding at the airfield. I went up and did some gliding on the Mokuleia ridge, took a trip to the windward side, then did some more gliding. I'm at 35 flight hours and 190 landings. Pretty fun. And I'm only a check-ride away!

Kahana from the north.
North shore with turtle bay in the bottom right.
One thing I did was glide on the ridge to 2000ft and cool the engine down (to 50C), then restart and climb till the engine was at the warm limit of shutdown (75C). I got up to about 4500ft. I then shut down again and did glide training (stalls, turns etc) but from way up high and over the ocean. Stalling and falling at 45 degrees down through 4000ft to blue is a neat feeling.

Abstract Art With Optics?

Who would have thought that with a macro lens, flash, diffraction grating, beam-splitter, lenslet array and calcite that you could do some pretty funky abstract art. What a weird tool.... I think I like it.

Flash off a diffraction grating.
Lenslet array for the wavefront-sensor of the Maui adaptive-optics bench.
Beamsplitter on a post.
My keys.

Saturday, September 20, 2008

Flying Home

Molokai was amazingly clear on the way home...

Closed Loop!!!

Finally. Today was a very long day. Lots of lab work, but we finally installed the lenslet array, put in the deformable mirror and closed the loop on an aberrated source. We're not done but this was a major step in getting the AO system aligned... Damn I'm tired. Got to bed around 2am then came in at 7 to take some people from the AMOS conference through the building with Mike and JD. Now I'm home on O'ahu. Weird to think that early this morning I was 'closing loop'.

A not-quite pupil image. It's starting to converge.
Jeff being jeff.
Lenslet array! A bunch of small lenses cut and glued in to place to form a nice symmetric pattern to sense the curvature of a wavefront in small sections (that pupil chopped up into little bits).
Lightpath! Kind of hard to see but the simulator in the lower right launches light off a fold onto the deformable mirror in the bottom middle. There's actually a flat in there in this shot. The DM is on the left of the flat. The DM sends the light through a lens and a fold mirror on to a membrane. A beamsplitter picks off 1% of the light to the 'science camera' off on the far left. The rest goes off the membrane to another powered mirror that puts the pupil onto the lenslets (cable in the upper left).
No arrows.
Already one casualty... a chipped beam-splitter. We replaced the cube 50/50 beam-splitter for a different on-axis one and moved the science camera to the far table. This 99%/01% beam-splitter actually works fine broken since the beam is only 1", not 2. Somebody dropped it and chipped the corner. $600. Not so cool. Glad it wasn't me!
A tilted wavefront has been sensed! The left side shows flux in the lenslet - something like 400-800 photons per channel read out at 2kHz. The right side shows the wavefront curvature/derivative signal.
We put in the phase screen on the motor and saw this 'star' dance!!! An aberrated 'star' point-spread function is a bunch of speckles. On the sky, if you average over say 30 seconds, you get a nice fat gaussian about as wide as the speckles. That's your turbulent PSF. Tons of speckles, lots of 'turbulence' in this one.
Watch Nick Kaisers's aberrated wavefront simulation videos... He took a flat wavefront, put it through atmospheric turbulence, then focused it using a telescope of varying sizes.


A small telescope's PSF in normal turbulence - you only catch a few 'patches' of turbulence so the star looks more or less like a point.

A big telescope's PSF in normal turbulence - lots more speckles because the bigger telescope mirror catches more 'patches' of turbulence.


Friday, September 19, 2008

Submitted part 3!!!

The referee report on the giant ApJS paper came in Tuesday. This one was a lot shorter and much easier to handle. Just a few little issues worth clearing up. I spent the better part of yesterday and this morning getting the reply done. Awesome. Hopefully this will be the last round and I'll be able to call this one "in press" in time for proposal season! And it can go on the Arxiv! 60 pages and a bunch of data out in the public. Sweet!

Thursday, September 18, 2008

Rebuilding H85 3.5

I didn't take many pictures today, mostly sicne it was photographically boring paperwork and the uninterestingness of subtly moving lots of random pieces and putting tables in place. But we're slowly getting there.... Still building.

Wednesday, September 17, 2008

Building H85 Stage 2.2

We spent the day scratching our heads, putting lenses and mirrors in place and getting things where they should be. What a long day...

Macro Lens Investigation....

I've spent an hour going through pictures now trying to figure out the best way to use my new 'cheap' macro lens. A $20 metal tube extends the lens away from the camera body. I can't use the aperture so I jam a piece of paper in the mechanism... With the new flash though, I can get good lighting at f/40. Awesome. Good depth of focus. With something like 2" of extension and the 55mm lens focused at "infinity", real focus is reached something like 3" from the front of the lens. Short! But crazy...

Flash and the extender tube.
My keys.
This bug has to be blind from all the flashes it sat through....

Tuesday, September 16, 2008

Crazy Pretty Gliding

I decided to take the afternoon to go fly and do some solo work. The day was nearly cloudless so it was a great day to bring the camera's along. I spent an hour gliding the Mokuleia ridge, an hour going over to Kaneohe and back and finally an hour with Billy in the later afternoon doing a circle around the Waianae range. The pics are pretty incredible. It's fun crusing around up there alone, especially on the windward ridges. You feel like you're a bird....