Senin, 02 Maret 2009

A Look at the Open Topography Portal

It was announced in early December, but I just recently came across the Open Topography Portal. The portal has made a large amount of LIDAR data available for active fault areas in both California and Washington. One of the unique aspects of the portal is that it provides web-based tools for processing raw point cloud data prior to download. The download interface is fairly slick, featuring a Google Maps interface allowing you to interactively select an area and then returning the number of points in your selection (guest downloads are limited to under 50 million points). The system displays the bounding coordinates and then allows for the definition of the delivery format.

The portal provides access to standard DEM products, (e.g. filtered bare earth), point clouds, as well as customized DEMs. Here are some of the options for creating a custom download:

Based on the selection area and processing options, the system provides the estimated processing time and then sends an email when the job is complete and ready for download.

I selected a small area and downloaded the point cloud data, which I then imported into ERDAS IMAGINE and created a shaded relief. Here's what it looks like (note that vegetation and buildings are all included, as filtering has not been applied):

Personally I think the user experience of the Open Topography Portal is more intuitive than the broader USGS CLICK (Center for LIDAR Information Coordination and Knowledge) portal. However portals are developing all the time and it is good to see progress in the ease of use and accessibility of advanced processing and download options.

The other notable news regarding the Open Topography Portal concerns the San Diego Supercomputer Center (SDSC) starting cloud computing research - with a special focus on the GEON LIDAR workflow application. This is something to keep an eye on, as LIDAR data is massive and as of yet I haven't heard of any attempts to use cloud-computing for processing or data management - although there have been initiatives in terms of storing LIDAR data in a database (e.g. the folks at LASERDATA use PostGIS). The Open Topography Portal is a collaboration between scientists at the SDSC and earth scientists at Arizona State University.

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