Satellites have given earth scientists tremendous tools for assessing environmental conditions all over the globe, including places where it’s impractical for them to go. Scanning from above, they can measure soil moisture, ocean waves and currents, sea ice, urban heat islands, bird migration, oil spills, volcanic lava flows, and more. But when nearly 2000 people meet at the International Geoscience and Remote Sensing Symposium (IGARSS) from 25 to 30 July in Honolulu, the highlight is expected to be on closer-to-home ways to gather and use information. Under the theme “Remote Sensing: Global Vision for Local Action,” the conference addresses new ways of collecting, sharing, and analyzing such information, much of it at the local level.
Traditional topics such as land, ocean, atmospheric, and cryospheric (ice and snow) sensing still make up a substantial portion of the 2000 or so papers to be presented at the symposium, as do such technical topics as analysis techniques, electromagnetics, radiative transfer, and sensors and platforms. But the conference is kicking off with a plenary session on community remote sensing (CRS)—a new field that incorporates observations made by ordinary citizens, as well as social networks and crowd-sourcing. Organizers with IGARSS and its sponsor, the IEEE Geoscience and Remote Sensing Society, have spent the last year uncovering such projects.
One function of CRS, says IEEE Senior Member Bill Gail, chair of the plenary session, is to fill in gaps left by remote sensing. Gail is a director with Microsoft’s Startup Business Group, in Redmond, Wash.
“Satellite images of coral reefs tell us general information about the reef but are too low in resolution to provide specific details,” he says. In Fiji, for example, locals have been instructed in snorkeling with a GPS unit and camera to fill in some missing details. Their information on coral composition can then be summarized and superimposed on satellite images.
Sometimes, CRS makes use of existing information. Washington University in St. Louis, through its Air Twitter project, monitors social networking sites for mentions of air-quality problems, then aggregates that data statistically to identify where the problems are. The results can be used to trigger further analysis using data from satellites. The university is part of the Federation of Earth Science Information Partners program, a consortium of more than 110 organizations that collect, interpret, and develop applications for Earth observation information.
The U.S. National Center for Atmospheric Research in Boulder, Colo., is collecting weather data from cars’ pressure sensors, temperature sensors, and other detectors, along with windshield-wiper usage.
“So far it’s just experimental,” Gail says, “but when wireless car networks become common in a few years, this data will complement the U.S. National Weather Service sensor system and enable better forecasting of severe weather such as tornadoes.”
Community efforts can augment remote sensing’s traditional role in monitoring, assessing, and sometimes even forecasting natural disasters such as tsunamis, volcanic eruptions, and floods. In the aftermath of the Haiti earthquake on 12 January, a CRS project called the Virtual Disaster Viewer helped relief agencies and infrastructure organizations coordinate their efforts through before-and-after satellite and aerial observations, as well as photos taken on the ground, via an ad hoc Web portal.
Meanwhile, the Neptune underwater observatory is making its data (and eventually some measure of control) available on the Web for community-contributed quality control, validation, and analysis of networked ocean sensor data.
Cellphones outfitted with a camera and a GPS application add even more to localized remote sensing possibilities. With smartphones, augmented-reality software can help users access information about anything their phone cameras see. The Internet adds further possibilities. Google Earth and Bing Maps offer detailed maps as well as satellite, aerial, and ground-level images that are available to everyone. Web sites such as Wikimapia enhance maps with user-generated data.
There are plenty of organizations involved in CRS, from governments to indigenous South American tribes. But, according to Gail, it’s been ad hoc—a project here, a project there. “I haven’t found anything other than this IGARSS session that aggregates what’s going on in the field. We’re the first to recognize it as a discipline to be nurtured and advanced.”