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Multibeam echosounders: error modeling evolution

Multibeam echosounders: error modeling evolution. Multibeam sonar workshop, 3-4 April 2005 St. Andrews, NB Rob Hare, P. Eng., C.L.S. Canadian Hydrographic Service. 1994 - First USCHC multibeam course (Top Gun Hydro team).

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Multibeam echosounders: error modeling evolution

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  1. Multibeam echosounders: error modeling evolution Multibeam sonar workshop, 3-4 April 2005 St. Andrews, NB Rob Hare, P. Eng., C.L.S. Canadian Hydrographic Service

  2. 1994 - First USCHC multibeam course (Top Gun Hydro team) • Professional Paper No. 25 – single-beam echosounder error budgets (1990) • S-44 Edition 3 still in effect • Work on 4th edition begun • Multibeam error modelling in development (Hare, Godin, Mayer) • Pøhner model for Simrad MB (EM100, EM1000) - 1993 • Empirical models for Elac, Reson (RAN Hydro project) • EXCEL spreadsheets (pre-analysis) • Random errors only

  3. 1995 • Hammerstad error model for all EM • Firmer theoretical footing for amplitude detection • Canadian MB accuracy estimation report (Hare, Godin, Mayer) • Sweep and Swath • Dinn et al. paper on effects of surface sound speed • Effect of transducer design, installation, roll

  4. 1998 • Fourth edition of S-44 released • 95% confidence level chosen • Multiple orders of survey • Total bottom coverage requirement • Target detection requirement • Mandatory accuracy attribution of soundings

  5. More refinements • 1998 - Rijkswaterstaat (de Koning) develops MEET • Addition of systematic errors • Slick interface • Still just preanalysis spreadsheet • 1999 - NAVO (Reed et al.) applies models to real data (post-mission) • Modified GSF to store accuracy attributes

  6. Shallow-water • Interferometric sidescan systems gaining prominence • Improved coverage, target detection • Ability to map geology and habitat up to shoreline • 2000 - Lurton analyses phase detection measurement precision

  7. 2001 • NCOEH formed at USM • Assessment of NAVO hydrographic survey systems (Simrad, Reson) • Consideration of lidar (SHOALS) errors, but no model • NAVO implementing error estimation in real-time • Part of RTQA software • Lurton considers effects of S/N on four MB error models (English treatment, 2003 International Hydrographic Review)

  8. Putting those error estimates to good use • NAVO depth and position error maps • Assessment of individual soundings • Colour coding attributes • Real-time assessment of sounding quality • Using logged parameters • Development of CUBE • Attributed soundings as a means to an end • Automated post-processing • Statistical analysis of incoming soundings • Rejection of ambiguous depth hypotheses • Identification and iterative rejection of systematic biases

  9. Future prospects 2005 - 2015 • Error model for lidar • USM/Guenther examining? • Real-time data cleaning and QC • CUBE in SIS (CHS) • CUBE in QINSy? • NOAA/UNH developments? • Hypack?? • More realistic sound speed error models? • Application of Reliability Theory? • Fine tuning error models on-the-fly?

  10. More future prospects • Implementation of 4 Lurton models • including S/N components for phase measurement • Better removal of systematic errors, cyclical errors (Hughes Clarke) • Error (or quality) visualization • For hydrographers • For end-users

  11. Training 2005 - 2015 • Understanding error modeling • TPE (HIPS 5.4) • CUBE • For SIS (real-time) • For HIPS 6.0 (post-mission) • Uncertainty management • Identifying blunders, systematic errors, random error contributions • Preanalysis • Real-time QA • Post-mission assessment • Metadata – S-57, FGDC, ISO 19115, BAG format?? • Certification of data sets (uncertainty, reliability, completeness?) • Standards?

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