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Bathymetric data quality and autonomous navigation related research projects



A brief presentation of data quality and autonomous ship navigation related projects at the Center for Coastal and Ocean Mapping, University of New Hampshire.
The expected depth must
not appear deeper than
the source information”.
“Triangle test
“No actual sounding
exists within a triangle of
selected soundings which
is less than the least of
any of the soundings
forming the triangle“
“Edge test”
“No actual sounding exists
between two adjacent
selected soundings forming
an edge of the triangle which
is less than the lesser of the
two selected soundings “
Intrinsic Limitation
Surface Test
Vertical uncertainty
Validation Toolbox
Depth area
appears deeper
Depth area
appears shallower
Sabre Zenith
Length: 40.5 m
Draft: 1.5 m
Error Inspection Error Remediation
(attribute fixes 1)
Attribute fixes 2
Geometry fixes
Areas of Dominance
Development of comprehensive algorithm that
Respects cartographic rules
Terrain characteristics
Complementary to existing chart features
Two-fold project:
Hydrographic Sounding Selection
Cartographic Sounding Selection Prime
“Digital Smooth Sheet”
Sounding Selection
Phase Surface Critical
Points Extraction
Sounding Selection
Enrichment Phase
Obscure high-quality more than low-quality data
Not intuitive
May not fit in small areas
Continuous zoom-in/out is required
Dominate the screen
ECDIS Day Blackback Mode
Obscure high-quality more than low-quality data
Not intuitive
May not fit in small areas
Continuous zoom-in/out is required
Dominate the screen
Minimize the occlusion of navigational
Increase visual weight with the increase
of data uncertainty.
Unambiguously visualize the different
uncertainty levels.
Be easy to memorize
Maintain effectiveness in all ECDIS
Minimally used
Minimally interfere with chart information
The combination can be intuitive
Good visual hierarchy
Proposed Solution:
Sequence of textures,
created by combining two or more visual variables
5 Coding Schemes :
Line textures
Dot clusters
Color lightness and transparency
Opaque colors
Color stripes
An online survey has been developed for
their evaluation in 4 different areas
Online Survey: 21
Online Survey:
4 Areas (3 in day bright, 1 in dusk ECDIS mode)
Individual Features:
Position uncertainty
Depth Uncertainty
Cartographic uncertainty
Decision Tree
Network of routes and ports from AIS data
Routes will be classification by max. ship draft
Route probability
Ship Route Suggestion System
Ship Route Prediction System
Web Application
Challenges in OM industry
25 professionals from six countries (Brazil, Denmark, France, Greece, Taiwan, and USA)
Focus of first phase: data, processing methods, requirements for the deliverables,
verification methods, and deficiencies of the process
-- 31
1. Kastrisios, C., C. Ware, B.R. Calder, T. Butkiewicz, and L. Alexander. 2020. “Improved Techniques for Depth Quality Information on Navigational Charts.
Proceedings of the 8th International Conference on Cartography and GIS, vol. 1, Nessebar, Bulgaria, p. 73 80.
2. Kastrisios, C., B.R. Calder, and M. Bartlett. 2020. “Inspection and Error Remediation of Bathymetric Relationships of Adjoining Geo-Objects in Electronic
Navigational Charts.” Proceedings of the 8th International Conference on Cartography and GIS, vol. 1, 18-23 June 2018, Nessebar, Bulgaria, p. 116 123.
3. Cordero J.M., and C. Kastrisios. 2020. “Characterizing free and open-source tools for ocean-mapping.” Proceedings of the 6th Hydrographic Engineering
Conference, Lisbon, Portugal.
4. Kastrisios, C., B.R. Calder, G. Masetti, B. Martinez, and P. Holmberg. 2020. “Soundings Validation Toolbox: Research to Operations.” Canadian Hydrographic
Conference, 24-27 February 2020, Quebec City, QC, Canada.
5. Kastrisios, C., B.R. Calder, and M. Bartlett. “ENC Depth Areas: Quality Control of Sea-bottom Surface Continuity and Error Fixes.” 2020. Canadian Hydrographic
Conference, 24-27 February 2020, Quebec City, QC, Canada.
6. Kastrisios, C., C. Ware, B.R. Calder, T. Butkiewicz, and L. Alexander. 2020. “An Alternative Methodology to the Star Symbols.” IHO Data Quality Working Group, 4-7
February 2020, Monaco.
7. Kastrisios, C., Ware, C., Calder, B., Butkiewicz, T., Alexander, A. L., & O. Hauser. 2020. “Nautical chart data uncertainty visualization as the means for integrating
bathymetric, meteorological, and oceanographic information in support of coastal navigation.” 100th American Meteorological Society Annual Meeting, 18th
Symposium on the Coastal Environment, Boston, MA.
8. Kastrisios, C., B.R. Calder, G. Masetti, and P. Holmberg. 2019. “Validation of the shoal-biased pattern of bathymetric information on nautical charts.” Proceedings
of the 29th International Cartographic Conference, 15-19 July 2019, Tokyo, Japan.
9. Kastrisios, C., B.R. Calder, G. Masetti, and P. Holmberg. 2019. “Towards Automated Validation of Charted Soundings: Existing Tests and Limitations.Geo-spatial
Information Science. Taylor & Francis. DOI: 10.1080/10095020.2019.1618636.
10. Kastrisios, C., B.R. Calder, G. Masetti, and P. Holmberg. 2019. “On the effective validation of charted soundings and depth curves.” Proceedings of the 2019 US
Hydro Conference, 19-21 March 2019, Biloxi, MS, USA.
11. Masetti, G., T. Faulkes, and C. Kastrisios. 2018. “Automated Identification of Discrepancies Between Nautical Charts and Survey Soundings.” ISPRS International
Journal of Geo-Information, vol. 7. MDPI Publishing, Basel, Switzerland, p. 392, 2018.
12. Kastrisios, C., and B. Calder. 2018. “Algorithmic Implementation of the Triangle Test for the Validation of Charted Soundings.Proceedings of the 7th International
Conference on Cartography and GIS, 18-23 June 2018, Sozopol, Bulgaria, p. 569 576.
ResearchGate has not been able to resolve any citations for this publication.
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Depth curves and charted soundings are two structural components of nautical charts, both derived from a more detailed dataset through generalization. Once depth curves are generated, the cartographer makes a selection of soundings that complements the depth curves and other features carrying bathymetric information in the adequate representation of the seabed morphology at the scale of the product. The selection of charted soundings – which is currently either performed fully manually, or partially manually using a computer-assisted solution – must meet the safety constraint, i.e., that no source sounding exists that is shoaler than what the mariner would expect by mentally interpolating the charted bathymetric information. According to International Hydrographic Organization S-4 publication, for well-surveyed areas that is achieved through the “triangular method of selection” and consists of two tests: the Triangle Test and the Edge Test. There are currently no fully automated solutions, so, with the ultimate goal of supporting “cartography at point of use”, we consider the problem of automating the validation of shoal-selected soundings. We discuss an implementation of the triangle test with improved performance near linear features, the first automated implementation of the edge test, and that the edge test may identify shoals that the triangle test fails to detect, confirming its significance in the validation process. We demonstrate an “intrinsic” limitation of the two tests that makes infeasible a fully automated solution based solely on the two tests. Finally, to overcome the intrinsic limitation, we propose a new validation test, named Nautical Surface Test, that captures the local morphology at the appropriate charting resolution as the solution for the automated validation of the charted bathymetric information.
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The selection of soundings to be shown on nautical charts is one of the most important and complicated tasks in nautical cartography. From the vast number of source soundings the cartographer is called to select all those important for the safety of navigation and to verify the “shoal biased” pattern of selection against the source soundings. A long-term goal of the cartographic community has been the automation of the tasks involved in nautical chart production, including that of the selection and validation of charted soundings. With the aim to contribute to that effort, this paper presents an implementation of the triangle test for the automated validation of selected soundings which has improved performance on the detection of shoals near depth curves and coastlines.
Soundings Validation Toolbox: Research to Operations
  • C Kastrisios
  • B R Calder
  • G Masetti
  • B Martinez
  • P Holmberg
Kastrisios, C., B.R. Calder, G. Masetti, B. Martinez, and P. Holmberg. 2020. "Soundings Validation Toolbox: Research to Operations." Canadian Hydrographic Conference, 24-27 February 2020, Quebec City, QC, Canada.