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.

Along-Track Reef Imaging System specifications

Shallow, Deep, and Drift ATRIS (Along-Track Reef Imaging System) and system specifications. (Public domain.)

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.

ATRIS photo of coral rubble

ATRIS photo of coral rubble. (Credit: David Zawada, USGS. Public domain.)

ATRIS photo of sand

ATRIS photo of sand. (Credit: David Zawada, USGS. Public domain.)

ATRIS photo of senile reef

ATRIS photo of senile reef. (Credit: David Zawada, USGS. Public domain.)

ATRIS photo of seagrass

ATRIS photo of seagrass. (Credit: David Zawada, USGS. Public domain.)

 

Deep ATRIS

Along-Track Reef Imaging System

 ATRIS (Along-Track Reef Imaging System) equipped for deep water survey. (Public domain.)

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.

octocorals, sponges, and the zoanthid Palythoa caribaeorum

A 6-image mosaic of an area dominated by various octocorals, sponges, and the zoanthid Palythoa caribaeorum. A midnight parrotfish (Scarus coelestinus) is visible in the central portion of the mosaic. The areal coverage is approximately 5 meters by 13 meters. Water depth at the base of the ledge was 10.4 m and Deep ATRIS was 9.7 m above the bottom. (Credit: David Zawada, USGS. Public domain.)

Grey Angelfish

 Grey Angelfish (Ponacanthus arcualus). Water depth was 8.8 m, and Deep ATRIS was 2.4 m above the bottom. Image resolution is 0.9 mm/pixel.  (Credit: David Zawada, USGS. Public domain.)

Spadefish

Spadefish (Chaetodipterus faber) are in the foreground with several grunts (Haemulon sp.) hovering above a brain coral head (Diploria sp.) in the background. Water depth was 9.2 m, and Deep ATRIS was 2.35 m above the bottom. Image resolution is 0.9 mm/pixel. (Credit: David Zawada, USGS. Public domain.)

Hawksbill turtle

 A Hawksbill turtle (Eretmochelys imbricata) resting on the sea-floor. Water depth was 9.2 m, and Deep ATRIS was 2.93 m above the bottom. Image resolution is 1.1 mm/pixel. (Credit: David Zawada, USGS. Public domain.)

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.

Along-Track Reef Imaging System

Drift ATRIS (Along-Track Reef Imaging System). (Credit: David Zawada, USGS. Public domain.)