Tuesday, April 28, 2009

How to Brew Beer Onboard an Oceanographic Vessel

My friend Maria just sent this my way and I thought I would pass it on. I have definitely seen a lot "mystery cups" while I have been at sea, and even some pretty efficient smuggling techniques, but I have never seen this:

Southern Fried Science: How to brew beer in a coffee maker, using only materials commonly found on a modestly sized oceanographic research vessel.

Fire Safety Training

Today in my Seamanship class, we had something I believe everyone should have at some point in their lives: fire safety training. No, I don't mean like when you were a kid and the fire department came to your elementary school and you got to climb on the truck. I mean actual here-is-a-fire-and-a-fire-extinguisher-now-go-to-town type of fire training. The video we watched beforehand was, admittedly, rather cheesy and may have dated back to the early 90s; however, the information was still good. Then we had some hands-on experience. One of the fire inspectors from the Durham Fire Station and the main inspector for UNH came by and actually set some fires. They set the fire in a water tank using a propane hose and showed us all how to use different types of extinguishers. You can't simply call the fire department on a ship, so in most cases, if you are on a ship, you are a fireman. A lot of bigger vessels have their own specially trained crew that run through drills and exercises, but that does not mean that us scientists are off the hook, especially if we are the first to notice the problem. That is why training like this, along with proper first aid/first responder training is so important.

Below are some pictures from today:

setting the fire

me, extinguishing the blaze

take that, fire!

Monday, April 27, 2009

Right Whales and Healy Now in Google Earth

Kurt Schwehr, a research professor here at CCOM, has been doing a lot of Google Earth visualizations lately and his work is definitely getting noticed. Last year, Kurt was invited to Google to give a Google Tech Talk, and even more recently the folks over at Google asked Kurt to pick one of his visualizations to be highlighted in Google Earth's own blog and added to the extensive list of downloadable visualizations that anyone with the free Google Earth browser can view. Kurt picked his right whale one, which shows North Atlantic right whale sightings for 2009. The Google Earth blog also mentions Kurt's Healy visualization, which tracks the USCG's icebreaker Healy as she makes her way around the Arctic. The positions are updated every hour, along with a new photo captured from Healy's aloftconn camera.
It is really cool to see the kind of data that can be viewed in Google Earth. Not only does GE provide a free way to view geo-referenced data, it does so relatively easily. That is key. Even if you have a GIS software, getting some nice chart images, or world maps or images, properly referenced behind your data is not always a straightforward task. In Google Earth, the spatial context is already there, in the form of an interactive, easy-to-manipulate globe.

Here is a screen shot of Kurt's right whale visualization in Google Earth:

Wednesday, April 22, 2009

Zotero 1.5b: Sync multiple computers and more!

New version of Zotero is now available (though still in Beta form). Version 1.5b2 allows you to back up your library for free on Zotero's server, and thus sync your libraries across multiple computers. Another neat feature is that you can add a PDF to your library and ask Zotero to go and find all the reference information for you! It will capture part of the text and search Google Scholar (other databases to be added soon); if it finds a matching entry, it fills out all the metadata for you (author, journal, etc.) So far I have only actually gotten this to work a couple times (even when I pulled the articles directly from Google Scholar), but this is still a beta version after all. I am sure the main dependency for it working is where the data is found; journal webpage versus someone' s CV publication listing, for example. At any rate, when the journal can be found, it is quite a time saver!

Be sure to check out the new version. Below is a screen grab showing my local library and my library stored on Zotero.org.

CCOM Cover Girl!

The 2008 CCOM Annual Report recently came out, detailing all the activities and research that have been going on at the center during the last year. Yours truly even made the cover! The picture was taken while I was on Healy and I am pointing something out to the other scientists on the screen displaying the real-time multibeam data.

Monday, April 20, 2009

CCOM and Healy make National Geographic!

The Center for Coastal and Ocean Mapping, and all the mapping it has been doing aboard the USCGC Healy, has made this month's National Geographic Magazine!

here is the link:

I like that they go into detail about the Russians planting the flag, rather than just go off the handle and imply that there was a rushed American response and not check their sources for any of it (ahem! *cough* Discover Magazine *cough*). They actually interviewed Larry Mayer and got the story straight.

Here is the accompanying map, provided by Larry Mayer. It even includes that data I helped collect on the cruise this past autumn!

Wednesday, April 8, 2009

Modeling Grating Lobes in Matlab

For a project for my underwater acoustics class, I am modeling acoustic pressure amplitudes and beam patterns in Matlab. The project involves a continuous line array that we are discretizing in order to calculate the contributing pressure of each point on the array to some arbitrary field point at range r. Basically we are breaking up the line source into n number of elements. When you do this, the spacing of your elements becomes an important factor. If your spacing is equal to, or greater than, one wavelength, you end up with grating lobes. Grating lobes have the same pressure amplitude as your main lobe, but they occur off-nadir and get progressively wider. Each grating lobe has its own associated side lobes.

Below are two examples of what I am talking about. In the first figure, I spaced my elements at a distance equal to 1 wavelength of the transducer. In the second figure, the spacing is 2 wavelengths. In both figures, the main lobe is centered on zero degrees, and you can see that the first side lobe occurs at -13.3 dB. In the first figure the grating lobes start at 90 degrees, and in the second they start at 30. In both cases, the side lobes of the grating lobes also start at -13.3 dB.