Estimation of Sounding Uncertainty from Measurements of Water Mass Variability

Analysis techniques are introduced that allow for estimation of potential sounding uncertainty due to water mass variability from reconnaissance campaigns in which oceanographic parameters are measured at a high temporal and spatial resolution. The analysis techniques do not require sounding data, thus analyses can be tailored to match any survey system; this allows for pre-analysis campaigns to optimize survey instrumentation and sound speed profiling rates such that a desired survey specification can be maintained. Additionally, the output of the analysis methods can potentially provide a higher fidelity estimation of sounding uncertainty due to water mass variability than uncertainty models in common use

Uncertainty Wedge Analysis: Quantifying the Impact of Sparse Sound Speed Profiling Regimes on Sounding Uncertainty

Recent advances in real-time monitoring of uncertainty due to refraction have demonstrated the power of estimating and visualizing uncertainty over the entire potential sounding space. This representation format, referred to as an uncertainty wedge, can be used to help solve difficult survey planning problems regarding the spatio-temporal variability of the watercolumn. Though initially developed to work in-line with underway watercolumn sampling hardware (e.g. moving vessel profilers), uncertainty wedge analysis techniques are extensible to investigate problems associated with low-density watercolumn sampling in which only a few sound speed casts are gathered per day. As uncertainty wedge analysis techniques require no sounding data, the overhead of post-processing soundings is circumvented in the situation when one needs to quickly ascertain the impact of a particular sampling regime. In keeping with the spirit of the underlying real-time monitoring tools, a just in time analysis of sound speed casts can help the field operator assess the effects of watercolumn variability during acquisition and objectively seek a watercolumn sampling regime which would balance the opposing goals of maximizing survey efficiency and maintaining reasonable sounding accuracy. In this work, we investigate the particular problem of estimating the uncertainty that would be associated with a particular low-density sound speed sampling regime. A pre-analysis technique is proposed in which a high-density set of sound speed profiles provides a baseline against which various low-density sampling regimes can be tested, the end goal being to ascertain the penalty in sounding confidence that would be associated with a particular low-density sampling regime. In other words, by knowing too much about the watercolumn, one can objectively quantify the impact of not knowing enough. In addition to the goal-seeking field application outlined earlier, this allows for more confi- dent attribution of uncertainty to soundings, a marked improvement over current approaches to refraction uncertainty estimation

Automated, objective texture segmentation of multibeam echosounder data - Seafloor survey and substrate maps from James Island to Ozette Lake, Washington Outer Coast

Without knowledge of basic seafloor characteristics, the ability to address any number of critical marine and/or coastal management issues is diminished. For example, management and conservation of essential fish habitat (EFH), a requirement mandated by federally guided fishery management plans (FMPs), requires among other things a description of habitats for federally managed species. Although the list of attributes important to habitat are numerous, the ability to efficiently and effectively describe many, and especially at the scales required, does not exist with the tools currently available. However, several characteristics of seafloor morphology are readily obtainable at multiple scales and can serve as useful descriptors of habitat. Recent advancements in acoustic technology, such as multibeam echosounding (MBES), can provide remote indication of surficial sediment properties such as texture, hardness, or roughness, and further permit highly detailed renderings of seafloor morphology. With acoustic-based surveys providing a relatively efficient method for data acquisition, there exists a need for efficient and reproducible automated segmentation routines to process the data. Using MBES data collected by the Olympic Coast National Marine Sanctuary (OCNMS), and through a contracted seafloor survey, we expanded on the techniques of Cutter et al. (2003) to describe an objective repeatable process that uses parameterized local Fourier histogram (LFH) texture features to automate segmentation of surficial sediments from acoustic imagery using a maximum likelihood decision rule. Sonar signatures and classification performance were evaluated using video imagery obtained from a towed camera sled. Segmented raster images were converted to polygon features and attributed using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999) for use in a geographical information system (GIS). (PDF contains 41 pages.

Temporal summation in a neuromimetic micropillar laser

Neuromimetic systems are systems mimicking the functionalities orarchitecture of biological neurons and may present an alternativepath for efficient computing and information processing. We demonstratehere experimentally temporal summation in a neuromimetic micropillarlaser with integrated saturable absorber. Temporal summation is theproperty of neurons to integrate delayed input stimuli and to respondby an all-or-none kind of response if the inputs arrive in a sufficientlysmall time window. Our system alone may act as a fast optical coincidence detector and paves the way to fast photonic spike processing networks

Optimizing Sound Speed Profiling for Hydrographic Surveys

The IHO Standards for Hydrographic Surveys (S-44) requires that hydrographic surveys account for sound speed uncertainties in order to determine the Total Propagated Uncertainty. If variations in sound speed are significant, the horizontal and vertical position of a sounding can vary by as much as several meters. Refraction artefacts can be typically dealt with in post-processing. This can be time consuming and require specialized processing expertise, especially in area of significant bathymetric relief and/or environmental variations in the water column. In this paper, we examine the application of recent advances in refraction based uncertainty to the ODIM Moving Vessel Profiler (MVP) controller software in order to optimize sound speed profiling operations.Las Normas de la OHI para Levantamientos Hidrográficos (S-44) requiere que los levantamientos hidrográficos tengan en cuenta la cuenta la incertidumbre sobre la velocidad del sonido con el objeto de determinar la Incertidumbre Total Propagada. Si las variaciones en la velocidad del sonido son significativas, la posición horizontal y vertical de una sonda puede variar tanto como varios metros. Típicamente se puede considerar los elementos refractarios durante el post procesado. Esto puede tomar tiempo y requerir experiencia especializada en procesamiento, especialmente en áreas de relieve batimétrico significativo y/o variaciones ambientales en la columna de agua. En este trabajo examinamos la aplicación de recientes progresos en la determinación de las incertidumbres basado en la refracción con el software de control del Perfilador del Movimiento de la Nave ODIM (MVP) con el objeto de optimizar las operaciones de perfilar la velocidad del sonido.Les normes de l’OHI pour les levés hydrographiques (S-44) exigent que les levés hydrographiques tiennent compte des incertitudes liées à la vitesse du son afin de déterminer l’incertitude totale propagée. Si les variations de la vitesse du son sont importantes, la position horizontale et verticale d’une sonde peut subir des variations de l’ordre de plusieurs mètres. D’une manière générale, les éléments de réfraction peuvent être pris en compte dans le cadre du post-traitement. Ceci peut prendre un certain temps et requiert des compétences spécialisées dans le traitement, notamment pour un relief bathymétrique significatif et/ou pour des variations environnementales dans la colonne d’eau. Dans cet article, nous examinons l’application des dernières avancées en matière d’incertitude basée sur la réfraction, au logiciel MVP (enregistreur de profils à partir d’un navire en mouvement) d’ODIM afin d’optimiser les opérations de détermination des profils de la vitesse du son

Automated Grain Yield Behavior Classification

A method for classifying grain stress evolution behaviors using unsupervised learning techniques is presented. The method is applied to analyze grain stress histories measured in-situ using high-energy X-ray diffraction microscopy (HEDM) from the aluminum-lithium alloy Al-Li 2099 at the elastic-plastic transition (yield). The unsupervised learning process automatically classified the grain stress histories into four groups: major softening, no work-hardening or softening, moderate work-hardening, and major work-hardening. The orientation and spatial dependence of these four groups are discussed. In addition, the generality of the classification process to other samples is explored

Teratogenicity of polybrominated biphenyls in rats

The teratogenic potential of a mixture of polybrominated biphenyls (PBB) was investigated. Pregnant Wistar albino rats were given single doses of PBB in seasame oil by gavage on one day of pregnancy, from day 6 through 14 (sperm DAY = 0). The dose ranged from 40 to 800 mg/kg maternal body weight. At autopsy (day 20) fetuses were recovered and subsequently examined for skeletal and soft-tissue abnormalities. Resorptions followed treatment at all days. No skeletal malformations were seen at any dose level. The majority of soft tissue defects were found following 800 mg/kg PBB at day 11, 12, or 13. Only two malformations were produced, cleft palate and diaphragmatic hernia. It is concluded that a single high dose of PBB can be embryolethal and teratogenic to the rat embryo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22859/1/0000421.pd