geovisualization of coastal areas from heterogeneous spatio-temporal data (antoine masse)

Antoine Masse, Sidonie Christophe IGN, COGIT Laboratory

France

GeoVIS 2015 - ISPRS Geospatial Week - 10/01/2015

GeoVIS 2015 - ISPRS Geospatial Week - 10/01/2015 2

• Coastal area Between highest astronomical tide (shoreline) and lowest astronomical tide (drying line)

• Spatio-temporal objects & phenomena • Uncertainty: in motion (tides, sands) • Incompleteness of data: underwater observation problems • Imprecision: different definitions of an object at different scale

Sea/Land interface

Shoreline Drying line

Point Reyes, California

Red : DTM data (res. 1m, prec. 0,2m)

Yellow : 1:15,000 topomap Blue : 1:50,000 topomap

Motivation: coastal area geovisualization

Different Shoreline definition

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Different uses & users Different geovis

Limitations: Visual discontinuities and heterogeneity between sea & land Perception of tides and/or water depth for non-specialist users

C-Map®, navigation software

ScanLittoral®, Touristic/Public map

Interactive elevation simulation of lake Erie, USA (NOAA)

Ortho-image of La Grande Motte, Google Maps®

Ocean seafloor map of Hawai'i


Motivation: coastal area geovisualization

Purpose of the talk

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• To convey sea dynamic information to users

Example of tide dynamic for informational purposes

• Hypothesis:

– Using heterogeneous data (maps, ortho-imagery, LiDAR)…

– … to make homogeneous visualizations between sea & land

– … by controlling photo-realism/abstraction

– … to convey tides & water depth perception


Implementation


Lidar acquisition (land/sea) SHOM

0

5

10Water elevation (in meters)

Tidal data, REFMAR® project

DTM (land/sea) SHOM

Resolution: 1m/5m (land/sea) Vertical precision: 0.2m/0.5m (land/sea)

Style

Rendering Engine

Final Rendering

Perception

Geographic feature

External data

Visual Variables

Inspiration sources Colors, …

Maps, ortho-imagery, …

Abstraction, ortho-image-realism

Proposition of geovisualizations

6 GeoVIS 2015 - ISPRS Geospatial Week - 10/01/2015

4 examples for water depth visualization, static and dynamic Same data, different stylization of water depth: - Abstraction maps - (Ortho) photo-realism

0

5

10Water elevation (in meters)

Data

Inspiration

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Inspiration: Map abstraction (1:25,000)

Location: Lanildut, Finistère, France Data: DTM: Litto3D OpenData Tidal data: REFMAR OpenData Cartographic database Color map

1st example: perception of water depth by intervals

Low tide 05/28/2009 14:00

Depth (m) 0 -5 -10 -20

Color

Uses: Tourism, Hiking, Fishing Issues: ≠ producers ≠ uses no tidal information (ex: accessibility of Ile de Melon)


High tide 05/28/2009 19:00

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1st example: perception of water depth intervals

Time x4000


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Inspiration: Map abstraction

2nd example: continuous

perception of water depth

Location: Lanildut, Finistère, France Data: DTM: Litto3D OpenData Tidal data: REFMAR OpenData Cartographic database Colormap (interpolated)

Low tide 05/28/2009 14:00

High tide 05/28/2009 19:00


Depth (m) 0 -5 -10 -20

Color

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2nd example: continuous perception of water depth

Time x4000


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Inspiration: Ortho-image photo-realism

Location: Lanildut, Finistère, France Data: DTM: Litto3D OpenData Tidal data: REFMAR OpenData IGN BD Ortho (land part) Colormap (interpolated)

3rd example: continuous water depth perception

Depth (m) 0 -5 -10 -20

Color

Uses: Exploration, landscape survey, … Issues: Color gaps Depth gaps no tidal information visualization of a specific tidal stage

Low tide 05/28/2009 14:00

High tide 05/28/2009 19:00


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3rd example: water depth perception

Brightness +20% Contrast +40% Time x4000


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Location: Vannes, Morbihan, France Data: DTM: Litto3D® OpenData Tidal data: REFMAR® OpenData IGN BD Ortho® (land part) Colormap (interpolated)

4th example: water depth perception

Depth (m) 0 -5 -10 -20

Color

Uses: Exploration, landscape survey, … Issues: Sands Sea infiltration at high tide

High tide 03/21/2015 16:30

Low tide 03/21/2015 10:20


Inspiration: Ortho-image photorealism

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4th example: water depth perception

Brightness +20% Contrast +40% Time x4000


Conclusion


Goal: Convey sea dynamic information to geovisualization users Thoughts for coastal geovisualization: • Important: Data precision and land/sea visual continuity

improve water depth perception • Static and dynamic visualization -> different use, complementary • Abstraction/Photo-realism: same data, different stylization

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- User Evaluation: uses and users? • readability, handling, adaptation to specific use,

integration in final-user applications, etc. • Task examples: How deep it is? When is it accessible?

- Tool adaptability • Other data for validation • Realism improvements

• With new data (ex: seafloor cover) • With new stylization tools (expressive textures like

waves and sea stream, shaded relief)

Perspectives

Our method with other data Carmel-by-the-sea, CA, USA

NOAA for DTM (sea) / Google Maps (land)

Shaded relief (Yu, 2005)

GeoVIS 2015 - ISPRS Geospatial Week - 10/01/2015 Water texture

Thanks

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mapstyle.ign.fr antoinemasse.fr oxygene-project.sourceforge.net/

nice software nice project nice speaker


geovisualization of coastal areas from heterogeneous spatio-temporal data (antoine masse)

Science