TeamSurv presentation to UK Hydrographic Society, 2011
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Tim Thornton – Smartcom Software
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Transcript of TeamSurv presentation to UK Hydrographic Society, 2011
Tim Thornton – Smartcom Software
• Exceptional accuracy and coverage
• Exceptional accuracy and coverage• Quick to survey an area
• Exceptional accuracy and coverage• Quick to survey an area• Small number of highly skilled operators
• Exceptional accuracy and coverage• Quick to survey an area• Small number of highly skilled operators• Large investment in equipment and staff
• Exceptional accuracy and coverage• Quick to survey an area• Small number of highly skilled operators• Large investment in equipment and staff• Expensive for customers
• Exceptional accuracy and coverage• Quick to survey an area• Small number of highly skilled operators• Large investment in equipment and staff• Expensive for customers• Many surveys used older technology
• Exceptional accuracy and coverage• Quick to survey an area• Small number of highly skilled operators• Large investment in equipment and staff• Expensive for customers• Many surveys used older technology• New Zealand charts only stopped using data from Captain Cook (~ 1750) a few years ago!
• Many boats logging data as they go about their normal business
• Many boats logging data as they go about their normal business
• Many boats logging data as they go about their normal business• Build up good coverage with time
• Many boats logging data as they go about their normal business• Build up good coverage with time• Use standard instruments – GPS, depth sounder, compass
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• Many boats logging data as they go about their normal business• Build up good coverage with time• Use standard instruments – GPS, depth sounder, compass• Accuracy and coverage good enough for most purposes up to ~ 100m depth, and better than old surveys
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• Many boats logging data as they go about their normal business• Build up good coverage with time• Use standard instruments – GPS, depth sounder, compass• Accuracy and coverage good enough for most purposes up to ~ 100m depth, and better than old surveys• Low cost, low investment solution
• Can crowdsourcing be used as part of the hydrographer’s toolkit?
• Where does it fit with other technologies?
• How accurate is it?
Autonomous Remote Global Underwater Surveillance• US based, using small craft around Annapolis with WiFi link to send data ashore• Funded by US Navy to develop unmanned remote controlled survey vessels for military use
Software package for commercial fishing• Users can upload logged data to the server for sharing with other users• Simple 5m sq. binning and averaging, no tidal or speed of sound corrections• Augmented with data from other sources
Open Street Map
User Generated Content
Autonomous Remote Global Underwater Surveillance• US based, using small craft around Annapolis with WiFi link to send data ashore• Funded by US Navy to develop unmanned remote controlled survey vessels for military use
Software package for commercial fishing• Users can upload logged data to the server for sharing with other users• Simple 5m sq. binning and averaging, no tidal or speed of sound corrections• Augmented with data from other sources
Software for leisure fishing and divers• Uses NMEA data or Lowrance/Eagle/Humminbird sonar log files• Can do bottom hardness from sonar data• Basic water level corrections• Simple data logging and map creation
Software package for commercial fishing, with Bathy3D depth module• Users can switch on depth logging• Simple depth tracks, no tidal or speed of sound corrections• Depths used to augment charted depths
Different crowdsourcing projects use the crowd in different ways. Here are the key points for TeamSurv participants:
Must have a boat and suitable instruments
Motivated by altruism, fun and community
Minimal skill or effort required to participate
Data is aggregated and processed by us on server before publication
Loggers engaged by free access to our data, other users will be charged when the FP7 project closes
Processing on server is key to data quality.
The greater the data density, the more accurate our results.
This differentiates us from projects like OpenStreetMap, where data from each user is basically treated discretely
We have more in common with mass traffic speed models like TomTom
On Board
•Calibration
•Data Logging
Track Ingest
•Upload to web
•Remove bad data
•Ingest data
Corrections
•Geometry
•Speed of sound
•Sea level
•(Vessel motions)
Synthesis
•Combine data
•Remove outliers
Chart Creation
•Geostatistics
•Gridding
•Surface generation
Error analysis
Data display
Must be painless for user to install and use
Hardware logger – 2 channels NMEA or Seatalk to USB
Software logger works in parallel with PC navigation software
Now getting support from equipment manufacturers:
GPSTests carried out on 10 typical light marine and leisure receiversEven the cheapest GPS receivers accurate to 2m rms2
EGNOS found to have little or no benefit
Depth SoundersNo tests carried out as yet – on the to do listManufacturers typically state depth accurate to 1%Transducer beam angle 6 – 15 degrees
Two levels of interpolationPrimary: Tide height predictionsSecondary: Residuals from tide gaugesSpeed of sound is similar, using salinity and sea temperature data
• much less critical than for multi-beam, as beam is ~ vertical• wider beam angle helps accommodate motions – we are measuring this• processing a large amount of data minimises the effect of motions• at present just modelled in error analysis, as no data from NMEA stream• analyses based on studies of vessel motions, plus environmental data
Motion Vessel dynamics Waves
Heave Sinkage in displacement boats and rising of planing boats, typically < 10cm
Mean heave is centered on static WL so no nett effect
Pitch Bow rises with speed, normally <5°, absorbed by beam angle
More bow up than down causes slight over reading
Roll In sailing boats causes over reading, mean error 1%. Power vessel zero sum
In strong winds bias to one side causes over reading
Adaptive grid generated according to the data density and consistency
Only generate depths where data meets a quality threshold
Non-normal depth distribution, with fat tail to deeper depths, so use of robust statistics
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Depth (m)
Depth vs. Frequency
Number of points =2 67
Calculate and output a quality of data measure as well as a depth value
Quality of data is dependent upon number of points in the grid square and also the spread of the data
MultibeamTeamSurv
Mean depth difference: 0.04mStandard deviation: 0.21m
Depth differences. 0.1m contours
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Team
Surv
Multibeam
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Depth difference histogram
Now:
Shape
X, y, z CSV
BSB
Garmin
Magellan
Later:
Web Server e.g. WMS/WFS
Navico
Fugawi
S-57, S-100, S-102
…
It takes time to recruit the crowd
Important to minimise barriers to participation
A two way process – must be a benefit for the participant as well as for the project
Be aware of cultural issues
Extend out of initial trials areas
Change of depth with time, e.g. to monitor silting or scouring
Additional data, e.g. tidal streams and currents, sea surface temperature, winds
Commercialisation to support the project
