Development of a Marine Mammal Marker (MAMARK) for In-Situ Environmental Monitoring

G.H. Elkaim, E.B. Decker, G. Oliver, and B. Wright

Abstract:	Current understanding of the behavior of marine mammals (or pinnipeds) is quite limited by the observation technology used. Surface tracking using geolocation and Service Argos tags have shown that these mammals range much farther than previously thought. Relatively simple time/depth recorders (TDR's) have shown that they dive to depths of over 1000 meters deep and for durations of over one hour. In order to further the understanding of these aquatic creatures, a smaller and more capable tag was developed that can be deployed for longer durations and with more sensing capabilities. The tag, called the MAMMARK, which measures approximately 2.5 x 4 cm., has a low-power microprocessor, and a set of sensors that can be multiplexed through a high resolution analog-to-digital converter. The sensing suite consists of temperature, depth, speed, salinity, three axes of magnetic field, three axes of acceleration, and GPS. GPS measurements are, of course, only available at the surface, however, the GPS receiver is kept in a hot-start mode such that it can reacquire the satellite signals in less than 10 seconds after returning to the surface. The three-axis magnetometer and three-axis accelerometer are used to construct the attitude of the creature (or three-dimensional orientation). Integrating this attitude with water speed, and an initial estimate of position from GPS, a full underwater trajectory can be reconstructed (using error correction from the return surface position and depth measurement to improve the accuracy and estimate the ocean currents). The tag is equipped with an RF beeper for ease of recovery, and dumps its data to a high capacity external flash card. As currently configured, it can withstand extreme pressures and record data for up to one year.
Published in:	Proceedings of the 2006 National Technical Meeting of The Institute of Navigation January 18 - 20, 2006 Hyatt Regency Hotel Monterey, CA
Pages:	206 - 216
Cite this article:	Elkaim, G.H., Decker, E.B., Oliver, G., Wright, B., "Development of a Marine Mammal Marker (MAMARK) for In-Situ Environmental Monitoring," Proceedings of the 2006 National Technical Meeting of The Institute of Navigation, Monterey, CA, January 2006, pp. 206-216.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In