HR: 1330h
AN: OS32A-0225    [PDF]
TI: Navigation Upgrades to the National Deep Submergence Facility Vehicles D.S.V. Alvin, Jason 2, and the DSL-120A
AU: * Whitcomb, L L
EM: llw@jhu.edu
AF: Johns Hopkins University, Department of Mechanical Engineering, Baltimore, MD 21218 United States
AU: Kinsey, J C
EM: jkinsey@jhu.edu
AF: Johns Hopkins University, Department of Mechanical Engineering, Baltimore, MD 21218 United States
AU: Yoerger, D R
EM: dyoerger@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Applied Ocean Physics & Engineering, Woods Hole, MA 21218 United States
AU: Taylor, C L
EM: cltaylor@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Applied Ocean Physics & Engineering, Woods Hole, MA 21218 United States
AU: Bowen, A D
EM: abowen@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Applied Ocean Physics & Engineering, Woods Hole, MA 21218 United States
AU: Walden, B B
EM: bwalden@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Applied Ocean Physics & Engineering, Woods Hole, MA 21218 United States
AU: Fornari, D J
EM: dfornari@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA 21218 United States
AB: We report on recently completed enhancements to the navigation systems employed on the 4500m submersible Alvin and the 6500m ROV Jason 2 and DSL-120A sonar system of the UNOLS National Deep Submergence Facility (NDSF) of the Woods Hole Oceanographic Institution (WHOI). Over the last two years we have significantly improved the accuracy and update rate of the six degree-of-freedom vehicle position and velocity navigation data available for these vehicles, thus improving the quantitative accuracy of acoustic surveys, optical surveys, and sampling operations. The navigation upgrades have also enabled improvements in the closed-loop dynamic positioning accuracy of the Jason 2 ROV, thus improving the vehicle tracking precision during survey and sampling operations. We have sought to employ more a uniform suite of navigation instruments, navigation data processing software systems, and data logging format standards for NDSF vehicles to improve the utility and ease-of-use of data by science users. Improved navigation instruments deployed on each of these vehicles in 2001 and 2002 include the following: (a) A 1200 KHz Bottom Lock Doppler Sonar (RDInstruments Inc.) providing three dimensional vehicle velocity information with respect to the ocean floor and the water column at an update rate of up to 10 Hz, providing a single-ping beam-velocity error standard deviation of 0.3% for a nominal advance velocity of 1 meter/sec. (b) A north-seeking fiber-optic gyroscope (IXSEA Inc.) providing true-north heading, pitch, and roll with a rated accuracy of 0.1 degree. Improved navigation data processing software systems deployed on these vehicles in 2001 and 2002 includes Dvlnav, an interactive navigation program developed at JHU for precision navigation of underwater vehicles and submersibles. DVLNAV employs a variety of sensors including bottom lock Doppler sonar, long baseline (LBL) acoustic navigation, gyro compasses, magnetic compasses, depth sensors, altimeters, and (when available) GPS. All navigation data are logged in ASCII data files time-stamped to 0.001 second, and also logged in simple spreadsheet files with headers containing navigation data at one second intervals, enabling simplified transfer to popular data processing programs. Operational results (e.g. Rzhanov et. al. poster in OS-10 session) indicate the utility of this navigation system. Elements of this navigation system have been adopted for use by the University of Southampton's (UK) new ISIS ROV. We anticipate that future improvements to this navigation system will include improved LBL navigation hardware, an improved LBL navigation processing software application, inertial navigation sensors, and improved post-processing software tools. http://www.whoi.edu/marops/vehicles http://robotics.me.jhu.edu/dscl/dvlnav
DE: 0994 Instruments and techniques
DE: 4594 Instruments and techniques
DE: 4894 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting