The annual American Society for Photogrammetry and Remote Sensing Annual Conference took place in Sacramento, Calif. from March 19-23, 2012. This event drew an international audience of more than 1,200 people, with the theme, “Imaging and Geospatial Technologies Into the Future”. To highlight the future, the event embraced both Google and their Google Earth Engine as well as cloud computing as a platform for imagery archiving and analysis.
David Thau, senior developer advocate for Google Earth Engine, gave the keynote speech. The talk began with a discussion of Stewart Brand’s campaign to see a picture of the whole earth from space, which has been said to have kicked off earth day, the ecology movement, global politics, and a greater awareness of remote sensing. Google believes in the power of this greater earth awareness, with the aim of bringing geographic literacy to everyone.
With image acquisition we’re seeing gigapixel images, such as the GigaPan camera, and we’re starting to see terrapixel images, where you can zoom into great detail. This advance comes from the combination of the resolution of the camera, many images at different zoom levels, and computer stitching that combines all the scenes and allows for full exploration. It has been expensive to capture remote sensing imagery, but now today with drones, kites and balloons more people are able to capture and analyze imagery. While this low-end technology is democratizing remote sensing, there is a lot of work taking place at the high end of professional capture as well. The Carnegie Airborne Observatory is at the forefront of high-end imagery with a combination of sensors to capture and reveal new levels of forestry information.
Image processing has come a long way as well, but faces challenges because there are more and more data coming every day. Processing via the cloud is the focus of Google Earth Engine, a remote sensing data analysis platform, with data from multiple satellites and sensors. At this point they have 1.3 million Landsat 5 and 7 scenes, MODIS, SRTM, and processed data that has been shared from researchers via an open platform. The platform provides on-demand processing capacity, and the ability to batch-mode your analysis.
Earth Engine Classify, is a cloud-based resource that Thau demonstrated, where you can add different data sets from the various sensors, and overlay them on the scene with various classification algorithms that allow you to classify for such things as forest, non-forest, etc. The Classifier works on the analysis on the fly, analyzing just the imagery that appears on the screen. With access to multiple processes via the cloud, more people are able to do sophisticated imagery analysis at a large scale, and in countries where computing and bandwidth resources are a constraint.
With the open cloud computing platform, people can see the algorithms and data that produced the results. The data and algorithms are versioned, which allows you to go backward to understand the products that were produced, and swap in newer algorithms to test them and enhance the results.
With such large datasets, it’s been difficult to visualize, but now with today’s computers and optimized browsers, we’re now able to view rendered imagery on the fly, without a round-trip to a server. Google is now rendering new vectors on the fly, such as 3D models that have shadows based on the time of day.
Google Earth Engine is working to democratize environmental monitoring to help inform policy, and to expand the communication capabilities of researchers worldwide.
Responding to Climate Change
Several sessions at the conference directly addressed the use of imagery to understand and adapt to climate change. Cal-Adapt is a data clearinghouse and visualization portal that consolidates details related to climate change and impacts for the state of California, bringing global issues down to the local level. The website provides details to the general public, to local planners, and to researchers (with access to raw data). The site includes more than 150 peer-reviewed papers, data, four modeled scenarios, charts and map visualizations.
Kevin Koy, from the Geospatial Innovation Facility at the College of Natural Resources, UC Berkeley, gave a presentation on Cal-Adapt. A review of the site included a tour of site features, with models for low emissions and high emissions, and animations to illustrate temperature averages for both the past and projections into the future.
The Extreme Heat tool provides daily temperature values, and indicates the number of days that exceed daily and evening heat records. The evening highs are projected to rise more quickly than daily highs, which has broad implications for energy use, with people running air conditioners longer.
The site is a project of the Public Interest Energy Research (PIER) program. There is an ongoing effort to expand the features and data sets. Among the list of features coming soon are a visualization of the certainty of data, boundaries on the map for counties and other geographies, and a larger map interface that will allow for comparisons of data models.
Throughout the sessions at ASPRS, the attendees received a deep dive into how their peers have applied imagery and remote sensing technology. The emphasis on analysis rigor was fitting for a largely research-oriented audience that are working to provide insight into issues of global change.
Overall, the ASPRS Annual Conference, provided a good snapshot of the imagery side of the geospatial industry.