Thursday, October 7, 2010
A strong first in experimental fluvial geomorphology.
I'm happy to report we've made high quality 3D measurements of channel form in our Em4 model using close range photogrammetry (CRP) in Ana Londono's lab at the Dept. of Earth and Atmospheric Sciences at St. Louis University.
Working with one of our Emriver Em4 geomodels, Ana's student Tim Keenan and our Lily Hwang have produced some amazing first results.
CRP software uses multiple photographs to build a model of a scene. The camera positions are calculated by the software and don't have to be measured. Unlike other forms of photogrammetry, relative camera positions don't have to be measured--the camera can be hand held as long as high quality images are taken.
Software builds a point cloud and calculates camera positions automatically. I won't mention the brand we used because we're hoping to find a company that will work with us--the software is not cheap (and rightly so).
Building high quality point clouds and surfaces-- accurate to <2mm in all dimensions -- is powerful stuff, but in our Em4 we can join that with color coded media to add information on surface particle size! The advance over current state of the art, manual measurement or laser scanning, is huge and obvious, and I'm pretty sure we have a strong first in experimental fluvial geomorphology.
The posibilities for research, teaching, and visualization make my head spin!
We'll be talking more about this as our project develops. Many thanks to our collaborators and to Andrew Podoll with SIUC geology who loaned camera equipment for the trial -- and Lily, she rocked, working two weekends in a row and overcoming many obstacles to get this done.
And we owe much to Neffra Matthews and her colleague Tom Noble with the BLM. Last year Neffra finished a fantastic publication on CRP that focues on its use at larger scales in field settings. And here's a short overview from she wrote. We'll have an Em4 at GSA Denver, and will be ready to talk about this work!