Global Multi-Resolution Topography (GMRT)Synthesis

Vicki Ferrini, Suzanne Carbotte, William Ryan, Suzanne O’Hara

Lamont-Doherty Earth Observatory

Columbia University

MBES Data Workflow

Increasing Emphasis on Open Data Access

• Acquisition Costs• Spatial & Temporal Change• Scientific Reproducibility• Federal Data Policy Compliance• New Possibilities• Big Data

MBES Data Available via NGDC

Broad access to content for:• Interdisciplinary research• Citizen scientists• Educators

How can we make data accessible to non-specialists?

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Swath files & grids

GMRT Synthesis- Dynamically maintained

- Multi-resolution

- Images, grids, mask

- 9 resolution levels to 100 m*

- Full attribution to sources & contributing scientists

- Source Data Includes: - ASTER, NED, GEBCO_08,

IBCAO, BEDMAP -Contributed grids -Swath data from 687 cruises

*50 m in places

GMRT Overview

100m swath data and grids

Global coverage

User experiences seamless transition between resolutions based on chosen zoom level

• 1992 – Ridge Multibeam Synthesis Project

• 2003 – Expanded to include US-funded data from Southern Ocean

• 2004 – present -- Expanded to include public domain data from throughout global oceans GMRTv2.4 - 687cruises (April 2013)

GMRT History

http://gmrt.marine-geo.org

ongoing growth by ~ 80 cruises/yr

GMRT Components

LDEO 100-m compilation* (raw & processed swath files in public domain)

Contributed Grids (< 500 m res.)

Global & RegionalGrids (>= 500 m res.)e.g. GEBCO_08, IBCAO

*LDEO team performs QC of ping filesMB files metadata

GMRT Evolution – MBES Content

+ 44 regional contributed grids from international sources

GMRT v1.x

GMRT v2.4

MBES Source Data in GMRTv2.4

• Kongsberg**• EM120, EM122, EM300, EM302,

EM1002, EM3000• SeaBeam

• Classic, 2000, 2100, 2101, 2102, 2112• Hydrosweep

• DS, DS2

**Majority of ships US Academic Research Fleet now carry Kongsberg MBES

year of cruise

# cr

uise

sMBES Source Data in GMRT v2.4

GMRT: MB Data Preparation

• Bad navigation• Noisy outer beams• Attitude problems• Bad soundings• Instrument problems• Bad weather• Sound velocity• Slow speed in turns• Quality assessment

for grid weighting and resolution

Preprocess & Auto-QA

MB files

Manualassessment

Problems

Reprocess

Address Problems

*MB System*

No problems

Approval Phase

Problems

Approved

GMRT MB Prep Workflow

Add to tile set

Tools for Quality Assessment

*Interface can be used to QA/QC swath data & gridded data

Tools for Quality Assessment

GMRT: Access• Images & gridded data• Desktop Apps

• GeoMapApp• Virtual Ocean

• Web App• CM&G

• Web Map Service• Images & Mask

• iPad/iPhone• Earth Observer

GMRT : Attribution

GMRT : Attribution

GMRT: Attribution & Source Data Access

GMRT : Attribution

Complementary Fleet-Wide Efforts

GMRTR2RMAC

GOAL: Well-documented high-quality publicly available data

199220092011

MBES Raw Data Preservation• 680 file sets• 253,681 files• ~ 6.1 TB • from 601 cruises as of Apr 15, 2013

Broadening Access through Collaboration

• GEBCO

• Google

• Microsoft

• ESRI

To Learn More about GMRT…

Ryan et al., 2009

http://gmrt.marine-geo.org

Questions?

ferrini@ldeo.columbia.edu