Multibeam echosounders: Multibeam echosounders: error modeling evolutionerror modeling evolution

Multibeam sonar workshop, 3-4 April 2005Multibeam sonar workshop, 3-4 April 2005St. Andrews, NBSt. Andrews, NB

Rob Hare, P. Eng., C.L.S.Rob Hare, P. Eng., C.L.S.Canadian Hydrographic ServiceCanadian Hydrographic Service

1994 - First USCHC multibeam 1994 - First USCHC multibeam course (Top Gun Hydro team)course (Top Gun Hydro team)

Professional Paper No. 25 – single-beam Professional Paper No. 25 – single-beam echosounder error budgets (1990)echosounder error budgets (1990)S-44 Edition 3 still in effectS-44 Edition 3 still in effect– Work on 4Work on 4thth edition begun edition begun

Multibeam error modelling in development Multibeam error modelling in development (Hare, Godin, Mayer)(Hare, Godin, Mayer)– PPøøhner model for Simrad MB (EM100, EM1000) - hner model for Simrad MB (EM100, EM1000) -

19931993– Empirical models for Elac, Reson (RAN Hydro Empirical models for Elac, Reson (RAN Hydro

project)project)– EXCEL spreadsheets (pre-analysis)EXCEL spreadsheets (pre-analysis)

Random errors onlyRandom errors only

19951995

Hammerstad error model for all EMHammerstad error model for all EM– Firmer theoretical footing for amplitude Firmer theoretical footing for amplitude

detectiondetection

Canadian MB accuracy estimation report Canadian MB accuracy estimation report (Hare, Godin, Mayer)(Hare, Godin, Mayer)– Sweep and SwathSweep and Swath

Dinn et al. paper on effects of surface Dinn et al. paper on effects of surface sound speedsound speed– Effect of transducer design, installation, rollEffect of transducer design, installation, roll

19981998

Fourth edition of S-44 releasedFourth edition of S-44 released– 95% confidence level chosen95% confidence level chosen– Multiple orders of surveyMultiple orders of survey– Total bottom coverage requirementTotal bottom coverage requirement– Target detection requirementTarget detection requirement– Mandatory accuracy attribution of soundingsMandatory accuracy attribution of soundings

More refinementsMore refinements

1998 - Rijkswaterstaat (de Koning) 1998 - Rijkswaterstaat (de Koning) develops MEETdevelops MEET– Addition of systematic errorsAddition of systematic errors– Slick interfaceSlick interface– Still just preanalysis spreadsheetStill just preanalysis spreadsheet

1999 - NAVO (Reed et al.) applies models 1999 - NAVO (Reed et al.) applies models to real data (post-mission)to real data (post-mission)– Modified GSF to store accuracy attributesModified GSF to store accuracy attributes

Shallow-waterShallow-water

Interferometric sidescan systems gaining Interferometric sidescan systems gaining prominenceprominence– Improved coverage, target detectionImproved coverage, target detection– Ability to map geology and habitat up to Ability to map geology and habitat up to

shorelineshoreline

2000 - Lurton analyses phase detection 2000 - Lurton analyses phase detection measurement precisionmeasurement precision

20012001

NCOEH formed at USMNCOEH formed at USM– Assessment of NAVO hydrographic survey systems Assessment of NAVO hydrographic survey systems

(Simrad, Reson)(Simrad, Reson)– Consideration of lidar (SHOALS) errors, but no modelConsideration of lidar (SHOALS) errors, but no model

NAVO implementing error estimation in real-timeNAVO implementing error estimation in real-time– Part of RTQA softwarePart of RTQA software

Lurton considers effects of S/N on four MB error Lurton considers effects of S/N on four MB error models (English treatment, 2003 International models (English treatment, 2003 International Hydrographic Review)Hydrographic Review)

Putting those error estimates to Putting those error estimates to good usegood use

NAVO depth and position error mapsNAVO depth and position error maps– Assessment of individual soundingsAssessment of individual soundings– Colour coding attributesColour coding attributes– Real-time assessment of sounding qualityReal-time assessment of sounding quality

Using logged parametersUsing logged parameters

Development of CUBEDevelopment of CUBE– Attributed soundings as a means to an endAttributed soundings as a means to an end– Automated post-processingAutomated post-processing– Statistical analysis of incoming soundingsStatistical analysis of incoming soundings– Rejection of ambiguous depth hypothesesRejection of ambiguous depth hypotheses– Identification and iterative rejection of systematic Identification and iterative rejection of systematic

biasesbiases

Future prospects 2005 - 2015Future prospects 2005 - 2015

Error model for lidarError model for lidar– USM/Guenther examining?USM/Guenther examining?

Real-time data cleaning and QCReal-time data cleaning and QC– CUBE in SIS (CHS)CUBE in SIS (CHS)– CUBE in QINSy?CUBE in QINSy?– NOAA/UNH developments?NOAA/UNH developments?– Hypack??Hypack??

More realistic sound speed error models?More realistic sound speed error models?Application of Reliability Theory?Application of Reliability Theory?Fine tuning error models on-the-fly?Fine tuning error models on-the-fly?

More future prospectsMore future prospects

Implementation of 4 Lurton models Implementation of 4 Lurton models – including S/N components for phase including S/N components for phase

measurementmeasurement

Better removal of systematic errors, Better removal of systematic errors, cyclical errors (Hughes Clarke)cyclical errors (Hughes Clarke)

Error (or quality) visualizationError (or quality) visualization– For hydrographersFor hydrographers– For end-usersFor end-users

Training 2005 - 2015Training 2005 - 2015

Understanding error modelingUnderstanding error modeling– TPE (HIPS 5.4)TPE (HIPS 5.4)– CUBECUBE

For SIS (real-time)For SIS (real-time)For HIPS 6.0 (post-mission)For HIPS 6.0 (post-mission)

Uncertainty managementUncertainty management– Identifying blunders, systematic errors, random error Identifying blunders, systematic errors, random error

contributionscontributions– PreanalysisPreanalysis– Real-time QAReal-time QA– Post-mission assessmentPost-mission assessment

Metadata – S-57, FGDC, ISO 19115, BAG format??Metadata – S-57, FGDC, ISO 19115, BAG format??Certification of data sets (uncertainty, reliability, completeness?)Certification of data sets (uncertainty, reliability, completeness?)Standards?Standards?