Thursday, July 31, 2008

Barrow Sea Ice Webcam

A webcam mounted on top of the ASRC (Arctic Slope Regional Corporation) building in Barrow, AK monitors the sea ice formation along the coast.


Images are updated every 5 minutes. You can check out the webcam webpage here.


Below is an image taken in January 2006. Can you tell where the coastline is?




Check out their webcam video (using one still a day) for the 2006-2007 sea ice season, it is pretty amazing.

Tuesday, July 29, 2008

USCGC Healy Webcam

The US Coast Guard Cutter Healy (the ice-breaker that I will be on in a little over two weeks - yeah!) has a webcam.
Pictures are posted every hour and can be viewed here.

Here is a great shot from Healy as she breaks through the ice:


I believe this one is in transit to Alaska:

Thursday, July 24, 2008

Raging Waters

We had some pretty severe storms today in New Hampshire. Twice the severe weather sirens went off at school, and there were tornado touch downs in a few of the surrounding counties. I live right on the river, and the basement of my building even started to flood.

Below are some pictures of the dam right behind my building. The water is just raging through the flood gates.

Wednesday, July 23, 2008

Shoals 400 lidar data

Today I got my first glimpse of lidar data processing using Shoals NT, the Shoals 400 Hz Post-Flight Processing System. It took me a little time to muddle through everything and I am still not entirely sure what all the different functions do (even with a slightly out-of-date manual), but I am starting to get the hang of it. I am definitely itching to start really digging into this data.

Here is a screen shot of some Lake Tahoe data displayed in the software. You can see the overview area in the top left window and the zoomed in area in the box on the right. In both windows, lidar returns with a depth confidence of less than 50 are returned as no data (white). The rest of the returns are color-coded by depth. Land returns are brown. By clicking on individual soundings in the zoom window I can view more detailed information, including the full waveform.

(click on the image for a larger version)

Thursday, July 17, 2008

.e00 files in Arc 9.2 - solution

So I just got back to looking at the .e00 files in Arc to see why I could not get them to with Import71 (prior .eoo post). Turns out my file pathname had a space (" ") in it. How frustrating. Any file on your desktop or in your program files will therefore not work with the Import71 tool. I moved the file folder to my C drive, and now the data converts just fine. I wish the tool would show you an error message so you would know what was wrong.

Wednesday, July 16, 2008

binary file comparison on Windows

I found a handy little tool today for visual text/binary file comparison. I compressed a bunch of raw multibeam data into a .rar file (23.5 GB down to 7.2!) and wanted to ensure that the decompressed files were identical to the original.

The tool, AptDiff, is developed by Brother Technology and is availble here.

The best part? freeware!

Friday, July 11, 2008

Lidar Data Organization in Google Earth

The USGS has really impressed me with their lidar data organization. You can view and download their data in a KML format using any KML viewer. One click on their data markers allows you to download the data in various formats (e.g. DEM, GeoTiff, XYZ, etc.) After playing around with it in Google Earth, I definitely think I will be following their example as a model for my own data organization.

Check it out for yourself here.

Here is a screen shot of the KML file from Biscayne Bay National Park displayed in Google Earth. The arrows represent areas of lidar data. The yellow dots are SCUBA dive site locations.

Wednesday, July 9, 2008

.e00 files in ArcMap 9.2?

Bringing in .e00 (Arc interchange format) files into ArcMap 9.2 seems straightforward enough. I followed directions I found online and used the Import71 application that is hiding away in the ArcGIS bin folder to convert the files to coverages. I was then able to bring the coverages into my ArcMap project and see them listed on the display tab, but I could not view the data or zoom to the layer. I realized that part of the problem was that none of the spatial referencing information was preserved; no units, no extents, nada. I tried reassigning the extents by going through the properties tab on the coverages, but every time I clicked apply, the southern and eastern extents kept reverting back to their original (and seemingly random) values. Grrrrr. I know I must be missing something simple, but I have no idea what it is. If anybody has any experience with .e00 files in ArcMap 9.x I would love to hear from you.

Update - I just noticed that some folks happening upon this post are not finding the solution post. My issue was that I had a space in my pathname, so while the tool appeared to work and even generated a coverage with the right name, the coverage itself was empty. I moved the files to a folder on the C drive so that the pathname had no spaces and the import71 tool worked great. Any files on the desktop or in the "My Documents" folder will therefore not work because of the spaces.

Tuesday, July 8, 2008

dunes...errr sand waves... err, dunes...oy vey!

Sedimentary bedform classification is messy. Several classification schemes exist and they certainly do not all agree. A sand wave to some folks is a dune to others and a mega-ripple to still others. As Gail Ashley (1990) put it, bedform classification "is analogous to the story of the blind men and the elephant." Despite the efforts by Ashley and others almost twenty years ago, there still does not seem to be one agreed upon classification scheme. This has been my headache today, as I try to wade through them all and find one that is widely-accepted and easy to work with.

Monday, July 7, 2008

Saturday, July 5, 2008

fireworks!

some pics from Janice and Yifty's 4th of July party and the fireworks over the river behind my place.







Tuesday, July 1, 2008

Ice-free Arctic? Not in my year!

There has been a lot of speculation lately that the Arctic might be ice-free this summer. In fact, scientists are actually placing the odds at 50-50.
I do not believe this. Not because I do not believe in global warming or anything, but rather because I simply refuse to accept that this year, the year I am actually GOING to the Arctic, is the year that it will happen. In August I am headed out to Barrow, AK to meet up with the USCGC Healy, an icebreaker surveying the North Atlantic as part of the United Nations Convention on the Law of the Sea (UNCLOS). I have been excited for this trip all year, and when I finally cross the Arctic Circle I expect to see two things:

1. Polar bears in the wild
2. Ice, lots of ice.

What is the point on being on an icebreaker if there is no ice to break?

If you ask me, 2009 would be a much better year for the Arctic to go ice-free...