ATRIS - Boat-Mounted, Georeferenced, Digital Imaging System
Ecologists and managers require highly detailed and accurately geo-located benthic-substrate observations for the monitoring and mapping of coral reef ecosystems. To meet this need, the U.S. Geological Survey has developed the Along Track Reef Imaging System (ATRIS), a boat-mounted instrument that acquires continuous digital still EXIF-format images of shallow-marine substrates.
Images are acquired via a Nikon D1x digital still camera mounted in a waterproof housing that is deployed on a pole attached to a survey vessel. Images are instantaneously transferred to a shipboard computer and stored on a bank of hard drives whose total capacity of 0.5 terabytes eliminates any practical constraint on the duration of daily survey operations. Position and acquisition time obtained from a precision Wide Area Augmentation System (WAAS)-capable GPS receiver is sent to the camera, where it is incorporated into the header files of the EXIF-format images. Simultaneously, navigation software in a separate computer is used to follow pre-planned transect lines and to collect a continuous log of the vessel's position. Instantaneous camera-to-seafloor ranges acquired by a precision bathymetric sounder are captured to allow the geometric scaling of each individual image. A forward-looking underwater video camera provides an oblique view of the approaching bottom to the survey operator on a separate monitor. Open-source Linux PC software written for ATRIS datasets allows the interactive geographic browsing, scaling, and extraction of specific substrate images for further quantitative analysis. The ATRIS Data Analysis and Processing Tool (ADAPT) also includes a Classification tool that allows the user to define and classify the substrate for each image. The USGS seeks to develop partnerships to test the application of the ATRIS in diverse coastal-marine environments throughout the Caribbean region. For more information, contact John Brock.
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| Sample images acquired by ATRIS at Dry Tortugas National Park (DRTO), FL. The high-resolution underwater imagery of the sea floor depict various types of reef substrates at DRTO. The reef substrates as seen in the images (starting from top left and moving clockwise) : (1) hard or stoney coral (2) a star coral on a largely rocky substrate, (3) soft 'finger' corals, (4) dense mixed corals, (5) star coral surrounded by macroalgae, (6) gargonians and soft corals. Click on each individual image to view the larger version. |
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