Howland Jonathan C.

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Jonathan C.

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  • Article
    Submeter bathymetric mapping of volcanic and hydrothermal features on the East Pacific Rise crest at 9°50′N
    (American Geophysical Union, 2007-01-19) Ferrini, Vicki L. ; Fornari, Daniel J. ; Shank, Timothy M. ; Kinsey, James C. ; Tivey, Maurice A. ; Soule, Samuel A. ; Carbotte, Suzanne M. ; Whitcomb, Louis L. ; Yoerger, Dana R. ; Howland, Jonathan C.
    Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during low-altitude (~5 m) surveys conducted with DSV Alvin were used to produce submeter resolution bathymetric maps of five hydrothermal vent areas at the East Pacific Rise (EPR) Ridge2000 Integrated Study Site (9°50′N, “bull's-eye”). Data were collected during 29 dives in 2004 and 2005 and were merged through a grid rectification technique to create high-resolution (0.5 m grid) composite maps. These are the first submeter bathymetric maps generated with a scanning sonar mounted on Alvin. The composite maps can be used to quantify the dimensions of meter-scale volcanic and hydrothermal features within the EPR axial summit trough (AST) including hydrothermal vent structures, lava pillars, collapse areas, the trough walls, and primary volcanic fissures. Existing Autonomous Benthic Explorer (ABE) bathymetry data (675 kHz scanning sonar) collected at this site provide the broader geologic context necessary to interpret the meter-scale features resolved in the composite maps. The grid rectification technique we employed can be used to optimize vehicle time by permitting the creation of high-resolution bathymetry maps from data collected during multiple, coordinated, short-duration surveys after primary dive objectives are met. This method can also be used to colocate future near-bottom sonar data sets within the high-resolution composite maps, enabling quantification of bathymetric changes associated with active volcanic, hydrothermal and tectonic processes.
  • Technical Report
    Electronic still camera processing and mosaicking
    (Woods Hole Oceanographic Institution, 1999-12-23) Howland, Jonathan C. ; Lerner, Steven A.
    Since 1990, the Deep Submergence Laboratory and Deep Submergence Group of the Woods Hole Oceanographic Institution have been collecting large quantities of digital imagery and creating digital photomosaics of the sea floor. Initially, the digital image collection, processing, and mosaicking processes were all highly specialized "one of a kind" efforts. Over the past decade, this process has been refined, standardized, and made into a robust "pipeline." The collection , processing, and mosaicking can be reliably carried out on a routine basis. Deep Submergence Group personnel perform collection, processing, and archiving, while science party users can be trained in mosaicking. This report will describe the pipeline, yielding insight into the evolution and purposes of each step.
  • Preprint
    A 3D stereo camera system for precisely positioning animals in space and time
    ( 2015-02) Macfarlane, Nicholas B. W. ; Howland, Jonathan C. ; Jensen, Frants H. ; Tyack, Peter L.
    Here we describe a portable stereo camera system that integrates a GPS receiver, an attitude sensor, and 3D stereo photogrammetry to rapidly estimate the position of multiple animals in space and time. We demonstrate the performance of the system during a field test by simultaneously tracking the individual positions of 6 long-­‐ finned pilot whales, Globicephala melas. In shore-­‐based accuracy trials, a system with a 50 cm stereo baseline had an average range estimation error of 0.09 m at a 5 m distance increasing up to 3.2 m at 50 m. The system is especially useful in field situations where it is necessary to follow groups of animals traveling over relatively long distances and time periods while obtaining individual positions with high spatial and temporal resolution (up to 8Hz). These positions provide quantitative estimates of a variety of key parameters and indicators for behavioural studies such as inter-­‐animal distances, group dispersion, speed and heading. This system can additionally be integrated with other techniques such as archival tags, photo-­‐ identification methods or acoustic playback experiments to facilitate fieldwork investigating topics ranging from natural social behaviour to how animals respond to anthropogenic disturbance. By grounding observations in quantitative metrics the system can characterize fine-­‐scale behaviour or detect changes as a result of disturbance that might otherwise be difficult to observe.
  • Technical Report
    NDSF technical operations via telecommunications
    (Woods Hole Oceanographic Institution, 2017-12) Howland, Jonathan C. ; Peligian, Willis ; Soule, Samuel A.
    In 2015, the Woods Hole Oceanographic Institution (WHOI) commissioned an external study concerning the use of modern telecommunications and telepresence technologies in the potential reduction of manpower in National Deep Submergence Operations. That study has been completed, and the final report is attached as Appendix A.
  • Technical Report
    Digital data logging and processing, Derbyshire Survey, 1997
    (Woods Hole Oceanographic Institution, 1999-07) Howland, Jonathan C.
    In 1997, the Deep Submergence Group (DSG) of the Woods Hole Oceanographic Institution (WHOI) surveyed the wreckage field of the M.V. Derbyshire. The motivation for the survey and its results are described elsewhere (Williams et al, 1998). The purpose of this report is to describe the digital data logging and processing systems that were used by the Deep Submergence Group during the survey. The report is divided into four sections: this Introduction, a description of the collection mechanisms, a description of the processing schemes and series of appendices. The appendices include a glossary of terms, a description of data formats, and a comparison of electronic still camera processing choices. Readers desiring information on the equipment used, on the operations, or on the analysis effort performed by the on-board Inspection and Verification (I & V) Team or by the Assessors ashore are directed to (Williams et al, 1998), (Ballard, 1993) and (Bowen, et al, 1993).