Along-Track Reef Imaging System (ATRIS)
Science Center Objects
ATRIS is a benthic-survey tool that simultaneously acquires geo-located, color, digital images with corresponding water depths.
ATRIS (Along-Track Reef Imaging System) is an effective tool for rapidly mapping the seafloor over large areas. For example, during a 2011 study in Dry Tortugas National Park, over 258,000 color digital images were acquired along 79 km of transect lines in just 26 hours of operation. The system has 3 possible configurations: "Shallow," "Deep," and "Drift." Shallow and Deep ATRIS are typically deployed from a 25-foot boat.
Past uses of ATRIS include habitat mapping in support of sea turtle research within Dry Tortugas National Park and surveying the patch reefs off of Marathon, Florida, after a 2011 coral-bleaching event.
Shallow ATRIS
Shallow ATRIS is a boat-mounted system with the camera, transducer, laser pointers, and GPS antenna all mounted to a movable pole. Maximum pole length is ~4 m, making this configuration suitable for water depths up to 10 m under ideal conditions.
Deep ATRIS
Deep ATRIS is based on a light-weight, computer-controlled, towed vehicle that is capable of following a programmed diving profile. The vehicle is 1.3 m long with a 63-cm wing span and can carry a wide variety of research instruments, including CTDs, fluorometers, transmissometers, and cameras. Deep ATRIS is currently equipped with a high-speed (20 frames per sec.) digital camera, light-emitting-diode (LED) lights, a compass, a 3-axis orientation sensor, and both a downward- and forward-looking altimeters. The latter is part of an obstacle-avoidance system. The vehicle dynamically adjusts its altitude to maintain a fixed height above the seafloor. The camera has a 29° x 22° field-of-view and captures color images that are 1360 x 1024 pixels in size. GPS coordinates are recorded for each image. A gigabit ethernet connection enables the images to be displayed and archived in real time on the surface computer. Deep ATRIS has a maximum tow speed of 2.6 m/sec and a theoretical operating tow-depth limit of 27 m. The operating depth could be extended to 90 m by replacing the data-transmission wires with fiber optics. Mosaicked images illustrate the high-quality imagery that can be obtained with this system. The images also reveal the potential for unobtrusive animal observations; fish and sea turtles are unperturbed by the presence of Deep ATRIS.
Drift ATRIS
For Drift ATRIS, all of the instrumentation is mounted to a frame that can be lowered to 95 m. As the name implies, it is designed to be suspended in the water column as the boat drifts over a region of interest. Both Deep & Drift ATRIS can accommodate additional sensors, depending on size and power requirements.