Archive for the 'Imagery' Category

Google Earth vs. NASA World Wind

Published
by
thadk
on 2005/7/22
in General and Imagery
. 0 Comments

World Wind

I tried out “NASA’s World Wind”:http://www.worldwindcentral.com/wiki/Main_Page today and was reasonably impressed. It in similiar to “Google Earth”:http://earth.google.com in the sense that it renders topological data from “LandSat”:http://www2.jpl.nasa.gov/srtm/ in 3D using graphics hardware and as yet it only works on Windows. They say their primary concern is Education, not commerce, that is the difference.

It is “Open Source’d”:http://worldwind.arc.nasa.gov/worldwind-nosa-1.3.html, though written in .NET (not that that’s a terrible thing, “necessarily”:http://www.go-mono.com) Their dataset is much better in some ways than Google’s and the interface is a little clearer on some things (altitude) and significantly less efficient on others (navigation and data sources). They have something like 3 million data points for everything including government buildings at public universities to what must be most of the tiny villages in underdeveloped countries..They’ve also got the time-sensitive 250m resolution MODIS photographs in there for things like fires, floods, dust storms and algal blooms.

The WW performance is lacking. World Wind pretty much keeps your computer at maximum utilization the whole time. The required system specs are comparable, as are the rendering qualities, though for those I’d say google edges WW out, possibly through Ansio-filtering that I’ve enabled. I think the main difference is that GE does a better job cancelling any rendering and things when it isn’t necessary.

Google strategy

I idly wonder whether WW played any role in the opening of Keyhole’s licensing. Google’s mission has always been “searching, searching, searching” so it sort of justifies their aquisition but still. World Wind was relatively new, is starting to really get moving. Maybe it just reflects the fact that the world (ahem) is “ready for something like it”:http://www.xml.com/pub/a/2005/05/31/electionmaps.html . The data to back it up exists, the open formats behind it are clear enough, and the hardware exists, why not?

KML Toys

In the meantime I’ve still been pouncing on every data source I can find in KMZ (Google Earth) format. That is one thing NASA is missing out on–easy open standards and interfaces for data exchange. The community has assembled several overlays for the Appalachian Trail and Norwegian fjords but it doesn’t look like there is an easy way to import your own, at least nothing like ‘Earth. The most interesting sources I have found for Earth are below:

* Tagged Wikipedia Entries
* Geoblogger’s Flickr tag scraper
* Andy Fowler’s EarthCache Geocache stash KML generator (gentle please, I’m hosting this code with my server’s measely 30kb upstream, takes a couple refreshes because of initial fetch timeouts.)
* Simple overlay with live airplane tracking
* “Regional scope, by major city, Weather radar”:http://www.weatherstationmaps.info/weather/index.jsp full alpha for clean integration.It is at the bottom right.
* “Global time zone overlay and labeled clock”:http://bbs.keyhole.com/ubb/showthreaded.php/Cat/0/Number/42607/page/0 (click Open this Placemark link)
* “Dynamic Data Overlays forum”:http://bbs.keyhole.com/ubb/postlist.php/Cat/0/Board/EarthExternalData/page/0

As I said on my linkblog, I am working on a scraper which pitches together facebook people’s names with addresses from my uni’s people finder and google earth so everyone can know who lives around. That’ll be fun.

!http://www.thadk.net/~thadk/photos/lightning/100_2602-scale.JPG!

Storming

Right now I’m photographing a lightning storm. It can be a little frustrating that my mediocre 6.1mp digicam (nice paradox?) which allows 64 second exposures takes another 64 seconds to multiply out said 64 second exposure–I missed some nice scrumptious bolts of light. But I also caught three for an hour and a half of flickering. I bagged a grand finale a bit ago and it is mostly wound down now with an occasional streak. The conditions are less than perfect but my 3rd story window works well enough. Much tougher than canned and clocked fireworks!

Home again

Published
by
thadk
on 2005/7/4
in General, Imagery and Life
. 0 Comments

!http://www.thadk.net/~thadk/photos/fireworks%2005/qdig-converted/med_100_25331.jpg!

Fireworks on my return

“My favorites of the shoot”:http://www.thadk.net/~thadk/photos/index.php?Qwd=./fireworks%2005&Qif=100_25431.jpg&Qiv=thumbs&Qis=M

I got to test out the “Digital Photography Hacks”:http://proquest.safaribooksonline.com/0596006667 book I read on O’Reilly’s Safari free on campus. It gave some tips on the counter intuitive shooting of the bright things. Conveniently the fireworks were right out my third story bathroom window, no water to play with but you can’t have everything.

Now, set your aperture to f-8—even more counterintuitiveness, I’m afraid. If you were to open it up all the way to something like f-2.8, something you’re probably inclined to do, your fireworks would actually be overexposed, thereby producing that sickening feeling in your stomach and waves of bitter disappointment. Avoid all of that by starting with f-8.

Once the fireworks begin, take some initial shots. You want to anticipate the action. When you think a series is about to begin, put the black cardboard or baseball cap over your lens and trip the shutter. As the explosions begin, quickly pull back the cardboard and let the camera capture the action. I like this technique because you can control the cardboard faster than you can the camera. … As the fireworks explode, move the cardboard aside. Put it back over the lens until the next series appears, and then remove it again. This way, you won’t overexpose the image with the ambient light in the scene; you’ll record only the bursts of fireworks. What you’re really doing is creating a multiple-exposure shot. Try it; it’s really fun.

I think I overexposed a bit. Ah well.

Home was nice, I probably won’t be back until the middle of October. Played with my collge-bound younger brother’s new mac quite extensively. Also went on a four hour bike excursion, eating all sorts of glorious fruits the whole way–we brought blueberries, plums, and nectarines, and found blackberries, sour-sweet cherries, and bing cherries. Mm. And then returned for a full summertime harvest meal, corn, beans, the fixins. Nice being home.

Now I’m back, which means back to calculus, wee. Off I go.