U.S. Department of the InteriorU.S. Geological Survey

Multidimensional Data Modeling for Feature Extraction and Mapping

ACSM

April 19, 2004

E. Lynn Useryusery@usgs.gov

http://mcmcweb.er.usgs.gov/carto_research

Outline

Motivation Objectives Approach Theoretical Model Implementation Scale Dependent Feature Rendering Conclusions

Motivation

Conventional GIS model the world in two-dimensions with a map model and geographic features dependent on geometry for definition

This map model limits three-dimensional and temporal analysis, and multidimensional, multi-scale representations

Cognition studies indicate that humans perceive the geographic world as a set of definable entities with spatial, thematic, and temporal attributes associated

Objectives

Provide a theoretical model based on feature orientation

Develop the model to support unique entities with spatial, thematic, and temporal attributes and relations for each feature instance

Implement the model in a feature library and use the library for feature extraction to support The National Map

Approach

Implement the theoretical feature model in an object-oriented library

Develop feature instances for 20 specific features that are relevant to The National Map

Develop attributes and relationships including multiple representations (raster and vector) of attributes for each feature instance

Determine the extraction capability of each feature from various image sources

Feature Model

Feature is geographic entity and object representation

One feature, many objects Multiple resolutions Multiple geometries Access from single identity

Dimensions, Attributes, and Relationships of Geographic Phenomena

Space Theme Time-----------------------------------------------------------------------------------------------------------Attributes , ,Z color, size, date, duration

point, line, area, shape, ph, ... period, ...surface, volume, pixel, voxel, ...

-----------------------------------------------------------------------------------------------------------Relationships topology, topology, topology,

direction, is_a, kind_of, is_a, was_a,distance, ... part_of, ... will_be ...

Definitions

Feature - A set of phenomena with common attributes and relationships. The concept of feature encompasses both entity and object.

Entity - A real-world phenomenon that cannot be subdivided into phenomena of the same kind.

Object - A digital representation of all or a part of an entity. Attribute - Characteristic of a feature or of an attribute value. Relationship - Linkage between features or objects. Feature instance - An occurrence of a feature defined by a unique set

of attributes and relationships.

Databases Supporting Feature Extraction and Map Generation

Feature Attributes and Relationships Image

Image Chips Spectral Responses Digital Number Ranges for Multimodal Images

Map Symbol Specifications Symbol Chips Inclusion Criteria

Feature Library Implementation

Multiple Feature InstanceExample with Actual Data

Feature Instance Implementation with Actual Water Quality Data

Relationship Implementation from NHD

Time Attribute Implementation

National Map Feature Extraction

Camp Lejeune study site 20 features selected All attributes and relationships built based on

DLG-E specifications Image chips extracted for storage as attributes Spectral responses determined (laboratory and

from images)

Table of the 20 Features

Type Features

Point (5) Helipad, Rock, Tank, Tower, Wreck

Line (6) Bridge, Road, Shoreline, Stream/River, Trail, Transmission Line

Polygon (9) Aircraft Facility, Apron/Taxiway, Building, Lake/Pond, Parking Site, Pier/Breakwater/Jetty, Shrub Land, Swamp/Marsh, Trees

Feature Part Representation

Helipad 3 Transportation 0/2-DRock 2 Hydrography 0DTank 6 Built-up 0/2-D

Tower 6 Built-up 0/2-DWreck 2 Hydrography 0DBridge 2 Hydrography 0/1/2-DRoad 3 Transportation 1/2-D

Shoreline 2 Hydrography 1DStream/ River 2 Hydrography 1/2-D

Trail 3 Transportation 1DTransmission Line 6 Built-up 1DAircraft Facility 3 Transportation 2DApron/ Taxiway 3 Transportation 2D

Building 6 Built-up 0/2-DLake/Pond 2 Hydrography 0/2-DParking Site 3 Transportation 2D

Pier/ Breakwater/ Jetty 6 Built-up 1/2-D

Shrubland 10 Veg Surface Cover 2D

Swamp/ Marsh 2 Hydrography 2DTrees 10 Veg Surface Cover 2D

DLG-E Features

Airport -- DOQ

Airport – Ikonos Pan

Airport – Ikonos Pan-sharpened

Airport – Ikonos MX

Airport – SPOT Pan

Airport – CIR Photo

Trail – DOQ

Trail – Ikonos Pan

Trail – Ikonos Pan-sharpened

Trail – Ikonos MX

Trail – SPOT

Trail – CIR Photo

Airport Map Symbol

Trail Map Symbol

Geodatabase for the Study Area in ArcCatalog

Airport Feature

The Study Area – Camp Lejeune, NC

Scale Dependent Renderer

Trees on 1:30,000-Scale Map

Trees on 1:9,000-Scale Map

Buildings Rendered as Polygons 1:5,000-Scale Map

Buildings Rendered as Polygons/Points Based on the Longest Axis -- 1:12,000-Scale Map

Buildings Rendered as Points on 1:28,000-Scale Map

Buildings Not Displayed on 1:55,000- Scale Map

Conclusions

A theoretical model of features existing in the real world as single geographical entities has been developed

This model shows promise for implementing feature extraction methods and scale-dependent rendering for The National Map

Probabilities for extracting specific features from multimodal sources can be developed based on feature attributes and relationships and appearance in various image sources

U.S. Department of the InteriorU.S. Geological Survey

Multidimensional Data Modeling for Feature Extraction and Mapping

ACSM

April 19, 2004

E. Lynn Useryusery@usgs.gov

http://mcmcweb.er.usgs.gov/carto_research