Monday, August 31, 2009


And finally, the empirical demodulation paper goes in!

Saturday, August 29, 2009

First Honolulu Flight!

Billy and I spent a very long time in the air today. But.... we did our first professional transitions through Honolulu class B airspace today. It was a little scarry thinking about it, but I was surprised how easy it was. We flew all over the place. There were several upgrades that made it nice - a new transponder, new camera, better laptop with a bigger battery and a wider lens. Fantastic! And I finally passed 100 hours of flight.

Thursday, August 27, 2009

Parking Lot Telescope

Mark and I spent the last few days (long days I'll add) getting the curvature AO system up and running in the lab with the parking-lot 1-meter telescope. We learned a lot but it was super difficult to deal with. The seeing was pretty horrible. We couldn't really align things well so we were off on the side of the field with really bad coma... The stars had tails....

A 5-second exposure..... not exactly a Gaussian.

A 'pupil mask' image pointing at the sun.
A comet? No, just a star.....
Lots of mirrors to align.
A video to prove just how bad it was.

Tuesday, August 25, 2009

Blaze Functions

In trying to understand and make LoVIS, I took the time to finally wrestle with all things blazed.... How do 'blazed diffraction gratings' map what colors at what incident angles to what output angles. It's not mathematically pretty but you do end up with some pretty funky looking squiggles.

Monday, August 24, 2009

New Home!

Finally, Heather and I managed to get most of our stuff unpacked and our new apartment looking decent. I have to say - it's huge. Way more space than we thought we'd be getting but there were several factors pushing us to take this place. I now live in the same house as my boss.... but we couldn't pass up the deal.

Bedroom (with a *giant* walk-in closet).
Office. Still messy....
Bathroom! Two shower heads and a Japanese style soaking tub thingy.
Living room....
Kitchen. There's a pantry and washer / dryer in the room behind me....
Sun-room or whatever.
The view walking in.
Patio / Yard.

Sunday, August 23, 2009

Spica Paper Accepted!

Finally - the paper on Spica was accepted. Have a read on the arxiv - just click on pdf.

Friday, August 21, 2009

Hacking HiVIS

I went to the summit with Z tasked with turning HiVIS into LoVIS. We wanted to implement a low-resolution mode by bypassing the echelle (high-angle grating). It was pretty simple to implement and align. And there's a ton of light now in a low-resolution spectrum!

First - make a mirror mount out of some metal and drill some holes in it. Then glue on your favorite flat mirror. Use set screws and nuts as a kinematic mount for alignment.

Then pull a slit mirror and rotate it.Put in the flat mirror to bypass the echelle then align everything so that you turn your old cross-dispersed echelle spectrograph.....
into a simple low-resolution spectrograph.

It was a lot of fun getting this to work.....

Thursday, August 20, 2009

Closing Loop on Curvature AO

18 hours after coming back from California, I went over to Maui to work on the Curvature AO system. We re-built the simulator to minimize the number of mounts that were causing alignment drifts. It was actually nice to make a bunch of progress on this type of thing.

Here's the simulator image in-focus. Nice tight point source with the normal diffraction pattern for a cirular aperture with a the normal telescope type obscuration - a secondary mirror with support spiders.

You go through the system and put a voltage on each actuator of the deformable mirror then measure what happens:

This gives you a measure of how each of the 85 actuators changes the wavefront in each of the 85 sensors:
Turn that around (invert the matrix) so you have a measure of how a measurement on a sensor should be corrected with a voltage on the DM:
Mark taught me how to drive the sysem. It's a little scarry knowing that if I screw up the software or forget to block the wave-front sensor I could blow out 85 avalanche photo diodes that cost a few grand each.....

Monday, August 17, 2009

Updating Research and Pictures Pages

I've been updating my research and pictures pages. Thoughts on the research page? It should take me the next week to get all the fixes to my pictures page, but there's a bunch of new pics up there now....

Sunday, August 16, 2009

Basically Accepted

I'm fully relieved to be basically done with this paper on Spica. The latest referee report came in with three suggestions for clarifying and re-phrasing, not requring another review. Thank god that's over with. I really appreciate some of this review process. I've had / seen some peer reviews that were fairly ridiculous. This one was long but having somebody who actually reads the paper and tries to chew it up makes for a (long but) good review. One less thing to worry about....

Kayaking Sausalito

We took an afternoon to kayak around the Sausalito harbor. The seals were pretty much indifferent to us and the house boats everywhere made me think we were in Venice at some point.

Saturday, August 15, 2009

Marin Headlands Hike

We hiked the Tennessee Valley in the Marin Headlands with Jesse, Liz and Bekka today. It was a great combo of cool and warm.

AO Slides

These are some images about adaptive optics from Wikipedia as well as the lectures from the short course. It's a pretty neat topic. There's all kinds of theory and real hardware - how you understand light and how one actually corrects for imperfections in the eye, telescope etc.

Zernike Polynomials - how one represents errors in a wave of light.
A screen shot of a point-like object imaged through a "messed up" optic, like my eye...

How turbulent air as well as diffracted light "mess with" a pure point imaged by a telescope.

How one might imagine errors caused by a lens with a 'rough' surface - pure waves come in and a more-or-less focused beam comes out.
How the eye focuses light versus how it 'should' focus light.

Friday, August 14, 2009

Mount Tamalpais

After the big hike, we got to head up to the summit and take some panoramas then head to Stinson Beach to catch a sunset.