USGS - science for a changing world

St. Petersburg Coastal and Marine Science Center

St. Petersburg Coastal and Marine Science Center > Advanced Remote Sensing Methods for Coastal Science and Management > Research > Along-Track Reef Imaging System (ATRIS)

Advanced Remote Sensing Methods for Coastal Science and Management

Along-Track Reef Imaging System (ATRIS)

ATRIS 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.

Recent 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, Fla., after a 2011 coral-bleaching event.

Three types of ATRIS equipment
Above: Shallow, Deep, and Drift ATRIS and system specifications. [larger version]

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.

coral rubble
coral rubble
sand
sand
senile coral reef
senile reef
sea grass
sea grass
Above: Example ATRIS photos. Click on photos for larger versions. Photo credit: Dave Zawada, USGS.

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.

 
Above left: Deep ATRIS. Photo credit: Dave Zawada, USGS. [larger version]

Above right: 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. Photo credit: Dave Zawada, USGS. [larger version]

3-image mosaic showing grey angelfish (Ponacanthus arcualus). 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. Photo credit: Dave Zawada, USGS.

[larger version]

3-image mosaic showing Spadefish (Chaetodipterus faber) with several grunts (Haemulon sp.) 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. Photo credit: Dave Zawada, USGS.

[larger version]

3-image mosaic showing a Hawksbill turtle (Eretmochelys imbricata) resting on the sea-floor 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. Photo credit: Dave Zawada, USGS.

[larger version]

Above: Deep ATRIS animal image sequences. Given that fish and sea turtles are seemingly unfazed by its presence, there are likely fisheries applications for 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.

Drift ATRIS
Above: Drift ATRIS. Photo credit: Dave Zawada, USGS. [larger version]

Deep ATRIS Publications

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://coastal.er.usgs.gov/adv-rs-methods/research/atris.html
Page Contact Information: Feedback
Page Last Modified: December 05, 2016 @ 11:24 AM (JSG)