Tuesday, May 23, 2006

I gotta rave about Noiseware software

Yep, noise reduction software for photos..

Judge for yourself



Sunday, May 21, 2006

Birthday Tattoo

I finally did it. On my 40th birthday, I got a wild hair, and the desire to get a tattoo. It felt impulsive so I stopped myself. A year later, after dwelling on it, I went ahead and did it--at age 41. The theme should be obvious.

My friend Kim did one with me...

Kim and I really like them.

Friday, May 19, 2006

Turning 41 with joy

Tuesday I turn 41. Forty was the hard year, accepting that you can't say you are in your thirties anymore. But it feels good.

So here to celebrate with great friends is this...

Friday, May 12, 2006

Yeti gets knee Surgery

Our Husky, Yeti, tore her cranial cruciate ligament (like a humans Anterior cruciate ligament or ACL). Interestingly, unlike humans who really don't use the ligament unless the joint is overextended, a dogs ligament is used full time to keep the femur from slipping backward on the tibia plateau. Thus, repairing the ligament is almost futile since it will likely tear again.

There is a proceedure that seems kinda radical called Tibial Plateau Leveling Osteotomy or TPLO. In this proceedure the tibia is cut and rotated so that the femur sets level and doesn't need the ligament. It's an interesting proceedure and requires a long recovery time but the dog is suppose to be able to walk and run normally afterward.

Sunday, May 07, 2006

Boulder Kinetics 2006

After a wet couple of days, the weather was perfect for the Kinetics race. I got there in time to see Los Lobos and they were outstanding.

Thursday, May 04, 2006

More about Lidar

Lidar works on the principle that if we send out a short pulse of light, we can look at the scattering of this light (using a telescope) as it propagates away from the transmitter. Since we know the speed of light is 300 million meters per second, we can tell in distance where the light is scattering from how long it takes to be collected by the telescope. Recall when a searchlight is scanning the sky how you can see the beam. Well in a lidar, the telescope is seeing a beam just as you see the searchlight.

The key components of a lidar are:
  1. A short pulse laser source (pulses less that 1 microsecond).
  2. A telescope to collect the return light.
  3. Detectors to detect the light.
  4. Fast analog-to-digital convertor to sample the detected signal.
  5. A fast computer to process this signal.
Here is a Lidar recently built at NOAA. This is for measuring Ozone and operates in the Ultraviolet.

The white tube on the right is a the telescope and the laser is the small silver and black boxes just to the left of it. The large console on the far left with all the cables is te control.

Here is what the signal of a laser pulse looks like as it is received by the telescope.

And here is a special detector called a Photomultiplier tube or PMT. Photomultipliers are so sensitive they can detect individual photons. This type of detector is necessary due to the small amount of light returning from the atmosphere.