Seafloor Segmentation Based on Bathymetric Measurements from Multibeam Echosounders Data

Bathymetric data depicts the geomorphology of the seabottom and allows characterization of spatial distributions of apparent benthic habitats. The variability of seafloor topography can be defined as a texture. This prompts for the application of well developed image processing techniques for automatic delineation of regions with clucially different physiographic characteristics. In the present paper histograms of biologically motivated invariant image attributes are used for characterization of local geomorphological feahires. This technique can be naturally applied in a range of spatial scales. Local feature vectors are then submitted to a procedure which divides the set into a number of clusters each representing a distinct type of the seafloor. Prior knowledge about benthic habitat locations allows the use of supervised classification, by training a Suppolt Vector Machine on a chosen data set, and then applying the developed model to a full set. The classification method is shown to perform well on the multibeam echosounder (MBES) data from Piscataqua River, New Hampshire, USA

Structuration, ICTs, and Community Work

This paper reports upon the outcomes of an action research project which took place with a network of neighbourhood houses (community-based organisations) in the Western Region of Melbourne, Australia. Our first aim was to engage community-based organisations, through participatory action research techniques, to develop information and knowledge management plans for an electronic community network. Our second was to integrate structuration theory and theories of participatory action research, in order to provide a new context for understanding how ICTs can be used with community-based organisations. The paper reports on the major issues found in the research, and plans developed to address those issues

Sensor-assisted Video Mapping of the Seafloor

In recent years video surveys have become an increasingly important ground-truthing of acousticseafloor characterization and benthic habitat mapping studies. However, the ground-truthing and detailed characterization provided by video are still typically done using sparse sample imagery supplemented by physical samples. Combining single video frames in a seamless mosaic can provide a tool by which imagery has significant areal coverage, while at the same time showing small fauna and biological features at mm resolution. The generation of such a mosaic is a challenging task due to height variations of the imaged terrain and decimeter scale knowledge of camera position. This paper discusses the current role of underwater video survey, and the potential for generating consistent, quantitative image maps using video data, accompanied by data that can be measured by auxiliary sensors with sufficient accuracy, such as camera tilt and heading, and their use in automated mosaicking techniques. The camera attitude data also provide the necessary information to support the development of a video collage. The collage provides a quick look at the large spatial scale features in a scene and can be used to pinpoint regions that are likely to yield useful information when rendered into high-resolution mosaics. It is proposed that high quality mosaics can be produced using consumer-grade cameras and low-cost sensors, thereby allowing for the economical scientific video surveys. A case study is presented with the results from benthic habitat mapping and the ground-truthing ofseafloor acoustic data using both real underwater imagery and simulations. A computer modeling of the process of video data acquisition (in particular on a non-flat terrain) allows for a better understanding of the main sources of error in mosaic generation and for the choice of near-optimal processing strategies. Various spatial patterns of video survey coverage are compared and it is shown that some patterns have certain advantages in the sense of accumulated error and overall mosaic accuracy

North Massif lithologies and chemical compositions viewed from 2-4 mm particles of soil sample 76503

We identify the lithologic and compositional components of soil 76503 based on INAA of 243 2-4-mm particles and 72 thin sections from these and associated 1-2-mm particles (76502). We present a statistical distribution of the major compositional types as the first step of a detailed comparative study of the North and South Massifs. The soil sample was collected well away from any boulder and is more representative of typical North Massif material than any single large rock or boulder sample. So far, our examination of the 76503 particles has provided a better definition of precursor igneous lithologies and their petrogenetic relationships. It has enabled us to refine the nature of mixing components for the North Massif less than 1-mm fines. It has confirmed the differences in lithologies and their proportions between materials of the North and South Massifs; e.g., the North Massif is distinguished by the absence of a 72275-type KREEP component, the abundance of a highly magnesian igneous component, and the absence of certain types of melt compositions found in the South Massif samples

Interfacing LabVIEW With Instrumentation for Electronic Failure Analysis and Beyond

The Laboratory Virtual Instrumentation Engineering Workstation (LabVIEW) software is designed such that equipment and processes related to control systems can be operationally lined and controlled by the use of a computer. Various processes within the failure analysis laboratories of NASA's Kennedy Space Center (KSC) demonstrate the need for modernization and, in some cases, automation, using LabVIEW. An examination of procedures and practices with the Failure Analaysis Laboratory resulted in the conclusion that some device was necessary to elevate the potential users of LabVIEW to an operational level in minimum time. This paper outlines the process involved in creating a tutorial application to enable personnel to apply LabVIEW to their specific projects. Suggestions for furthering the extent to which LabVIEW is used are provided in the areas of data acquisition and process control

Autonomous mission planning and scheduling: Innovative, integrated, responsive

Autonomous mission scheduling, a new concept for NASA ground data systems, is a decentralized and distributed approach to scientific spacecraft planning, scheduling, and command management. Systems and services are provided that enable investigators to operate their own instruments. In autonomous mission scheduling, separate nodes exist for each instrument and one or more operations nodes exist for the spacecraft. Each node is responsible for its own operations which include planning, scheduling, and commanding; and for resolving conflicts with other nodes. One or more database servers accessible to all nodes enable each to share mission and science planning, scheduling, and commanding information. The architecture for autonomous mission scheduling is based upon a realistic mix of state-of-the-art and emerging technology and services, e.g., high performance individual workstations, high speed communications, client-server computing, and relational databases. The concept is particularly suited to the smaller, less complex missions of the future

Ariel - Volume 12 Number 2

Executive Editors David G. Polin Larry H. Pastor Business Manager Alex Macones Jean Lien Editorial Page Editor Deepak Kapoor Sports Editor Todd Hoover Photography Editors Lois Leach Ken Yonemur

Theory and Anti-theory in the Work of Allan Farnsworth

When Allan Farnsworth passed away on January 31, 2005, the world lost a titan in the field of contracts. Immediately following his death, the tributes from fellow contracts scholars came in droves