May 9th, 2011 by Robert Simmon
Last week, Jessica Ball of the American Geophysical Union’s Magma Cum Laude blog pointed out this map of natural hazards in the U.S., published by the New York Times:
By MATTHEW ERICSON, JOE BURGESS and BILL MARSH/THE NEW YORK TIMES. Sources: Sperling’s Best Places; National Oceanic and Atmospheric Administration (tornado map); University of Miami (hurricane map); U.S. Geological Survey (earthquake map).
The map has many of the design virtues common in graphics from the Times (clean, focused on the data, clearly labeled, small multiples), but when I first viewed it I had trouble parsing the data. It took me a while to figure out that hazard was indicated by color, and the size of each circle denoted ancilliary information (population).
It turns out that our eyes & brains perceive area more strongly than color. Here’s a list of ways to visually compare quantities (described by Bang Wong in his Points of View column for Nature Methods), in order from easiest to hardest:
- Positions on a common scale
- positions on the same but nonaligned scales
- lengths
- angles, slopes
- area
- volume, color saturation
- color hue
I suspect I’m not the only person who would consider the size of the circles more important than the color, and assume size was correlated with hazard. I had to carefully read the key to figure out the proper way to read the map. Perhaps using size to encode hazard, and color (or opacity, or icons) for population would have worked better.
May 6th, 2011 by Robert Simmon
I recently had the opportunity to attend & give a presentation at the 2011 International Symposium on Remote Sensing of the Environment in lovely Sydney, Australia. (OK, not so recently—the conference ended on the April 15th. I blame jetlag.) Just over 60 people turned up for the talk, which was mostly about our visualization of Eyjafjallajökull. (Which means I had to attempt to learn how to pronounce “Eyjafjallajökull.” Luckily I don’t think anybody made it from Iceland to Sydney to critique me.) If you’re interested, I’ve posted Keynote and PDF copies (originally prepared for last years’s fall AGU).
During sessions many of the talks were a bit on the technical side for me, so I ended up preparing material for NASA’s portable “hyperwall”—9 HDTV screens linked together. It’s useful for either high-res animations, or small multiples. With relatively thick bezels on the monitors, simultaneous display of 9 images worked particularly well:
A sequence of images on the NASA hyperwall at ISRSE 34. These show the continued desiccation of the Aral Sea from 2000 to 2009, with a slight rebound in 2010.
Compare the small multiples on the hyperwall with the sequential display of the same images from the Earth Observatory’s World of Change.
During my talk I promised the audience that I’d update the blog more frequently, so there should be more posts in the future. I sometimes struggle for good ideas, so if you have a suggestion, please drop a note in the comments.
April 22nd, 2011 by Robert Simmon
One of the best things about international travel (at least to a geek like me) is to see how different cultures approach design and signage. Here’s a few from Blue Mountains National Park, near Sydney, Australia.
Hikes near Wentworth Falls.
Limited options along the National Pass trail.
January 20th, 2011 by Robert Simmon
Over the past week or two, there has been severe flooding in Australia, Brazil, Sri Lanka, and the Phillipines, but all we’ve shown on the Earth Observatory is the flooding in Australia. Why? Here’s a sampling of images of Rio de Janeiro since January 12:
January 12, 2011
January 14, 2011
January 16, 2011
January 18, 2011
Earth is cloudy. Especially in the tropics. Even more especially when there’s enough rain to cause flooding. The satellite imagery we have easy, fast, and free access to (for example, check out the twice daily MODIS imagery of São Paulo) is primarily based on visible and infrared light, which can’t penetrate clouds, so for many floods we can’t show anything useful.
In addition, the damage in Brazil, Sri Lanka, and the Philippines was caused by flash floods, landslides, and debris flows, which are all much smaller scale than the rivers overflowing their banks near Brisbane. In satellite imaging there’s a tradeoff between spatial resolution (detail) and temporal resolution (frequency) so there are fewer opportunities to capture the high resolution data necessary to show relatively localized events. To view something like a landslide, we have to have both a break in the clouds and the opportunity to aim a high resolution sensor. Which occurred this morning:
Satellite image of Rio de Janeiro
With clear skies and an overpass of Earth Observing-1, we may have an image of Teresopolis, Brazil by tomorrow.
P.S.: Despite the dispassionate view afforded by satellites, my thoughts go out to the victims and their families.
Update: For some reason the satellite never acquired the data, and the next viewing opportunity won’t be for another few days.
December 21st, 2010 by Robert Simmon
I got back from AGU last Saturday, picked up the pups from the kennel, and now I’m getting things together here so I can go on vacation right after Christmas.
Visualizing dogs can be harder than visualizing data.
As always it’s an overwhelming conference—there’s probably 1,000 posters on the floor at any given time, and at least ten simultaneous sessions. I got some very good ideas wandering through the posters (a map of ice flow speed for all of Antarctica, research on a paleo lake in Kenya, and a global dataset of limiting factors for tree growth being highlights) that I’ll hopefully be working on in the New Year. Tuesday’s special session on communicating climate change was also worthwhile (and packed). I think both my talks went pretty well, even if I can’t pronounce Eyjafjallajökull—despite professional help from a native Icelandic speaker. One conclusion we came to in the visualization session: it would be helpful for AGU to start promoting good visualization techniques. I plan on following up on that, hopefully I’ll have more to say soon.
A few words of advice for poster presenters (I originally planned on showing some examples of good and bad design, but chickened out). White space is good: try not to jam your poster full of every last detail of your research. Do not use Comic Sans (avoid it on slides, too). Seriously. Your research may be groundbreaking, but it’s hard for me to take you seriously if you try to be cute. Especially since the new Microsoft typefaces that ship with Vista, Windows 7, and recent versions of Office are very, very good. Make your graphics big. Avoid the rainbow palette. (I’ll have more to say about this—a lot more—soon. It was a big part of my Eyjafjallajökull talk.) Print up a one-page summary to distribute. Include a conclusion, written for non-experts. Your poster will be up all day, you’ll only be there for an hour or two. Finally: if you can figure out a way to add multimedia, do it. Rolf Hut of the Delft University of Technology had an amazing, temperature-sensing interactive LED display:
Rolf Hut, Delft University of Technology, presents his poster at the 2010 Fall Agu.
December 7th, 2010 by Robert Simmon
If anyone is going to the AGU fall meeting in San Francisco and would like to know more about the Earth Observatory and/or data visualization, I’ll be giving two talks, both on Thursday the 16th:
The Communication Strategy of NASA’s Earth Observatory at 8:45 a.m. in session ED41D. Climate Change Adaptation: Education and Communication I.
Visualization Case Study: Eyjafjallajökull Ash at 1:55 p.m. in session ED43B. Visualization of Geophysical Processes for Science, Education, and Outreach II.
I’ll be there all week, so if you want to meet to chat (or know of any sessions you think I’d be interested in, or excellent restaurants), send a message to the “Design Feedback” topic on our contact page, and I’ll get back to you.
November 3rd, 2010 by Robert Simmon
In the process of researching captions I can run into some amazing stuff, like this photo (taken yesterday) of incandescent rocks arcing through the sky during the collapse of a lava bench near Kilauea:
© Leigh Hilbert Photography 2010.
The USGS explains: “lava can instantly transform seawater to steam, causing explosions that blasts hot rocks, water, and molten lava fragments into the air.” No kidding.
Leigh’s site, Hawaiian Lava Daily, has some of the best photos of Hawaii’s active lava flows I’ve ever seen. He also pointed me to this description and photo essay of the last moments of Gary Sleik’s house in Kapana Gardens—destroyed by lava in July—as well as a recent “wake” for the house. An intimate look at events that can appear quite impersonal from space.
October 15th, 2010 by Robert Simmon
Strong convection created these “hot towers” near the eye of Tropical Storm Danielle.
Astronaut photograph ISS024-E-12954, taken August 30, 2010.
October 5th, 2010 by Robert Simmon
I found these while researching the caption for a satellite image of lava flowing into the ocean on Hawaii’s Big Island. Large versions (and more photos) on the USGS Kilauea Images site.
Glowing lava visible through a skylight on the Pulama pali (steep hill/cliff), Hawaii.
Exploding lava at the Puhi-o-Kalaikini ocean entry.
October 1st, 2010 by Robert Simmon
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