Groundtruthing examples

TOP COLLAGE: Examples of video observations over shaded relief bathymetry and corresponding seafloor photographs. The red dots on the map indicate observations of sediment (sand or mud), while blue dots indicate observations of hard ground (rock, boulder). The photograph taken at the hard ground observation (top) over a pinnacle shows an almost vertical rock wall. The photograph taken over a flat seafloor with a sediment observation (bottom) shows a seafloor covered in coarse sands. [larger version] 

BOTTOM COLLAGE: Example of video observations over backscatter imagery and corresponding seafloor photographs. The red dots on the map indicate observations of sediment (sand or mud), while blue dots indicate observations of hard ground (rock, boulder). The photograph taken at the hard ground observation (top) with high backscatter shows a seafloor of boulders and red gorgonia. The photograph taken at a sediment observation (bottom) with lower backscatter shows a seafloor covered in sands with white sea urchins and an octopus. [larger version]