Ni‘ihau: Optical Validation

[ Bathymetry | Backscatter | Optical Validation | Geomorphology ]

Optical Validation

The collection and analysis of photographic data to ground truth and interpret multibeam data layers with the goal of characterizing seafloor habitats.

Coral Cover Map

TOAD map for Ni‘ihau.
Click thumbnail map to view a high-resolution JPG.

Descriptions of optical data products.
Download: Accessory Files

The map above shows percent cover values of scleractinian coral derived from classified photos and videos collected at Ni‘ihau in 2005. Each point represents an analyzed video frame or photo. Note that the percent classes are unevenly sized to better display this relatively low-abundance bottom type.

The optical data are classified by substrate type, type of live growth on bottom, geomorphic zone, and the size and abundance of holes in the substrate. Although what we show here is the percentage of coral, the shapefiles contain data on all those categories, enabling users to map the occurrence of any combination of characteristics that are included in the classification scheme. (See sidebar for shapefiles.)





Benthic Habitat Data


Zipped data files contain 1) grid data file (GMT or ASCII), 2) high-res JPG of image, and 3) explanatory metadata text file (identical to linked file listed below).
* Ikonos imagery & USGS Digital Ortho Quarter Quads NOT included with download.

5m Bathymetric data files
5m WV-2 derived depths data files
5m WV-2 derived depths, and multibeam from NOAA Ship Hi'ialakai & R/V AHI data files
  • View: Metadata
    2005 | Map
  • Download: Shapefiles, JPG & metadata

Zipped data files contain 1) Arc ASCII file, 2) layer (.lyr) file for symbology, 3) high-res JPG/PDF of image, and 4) explanatory metadata text file (identical to linked file listed below).

5m grid data