Geodata origin

2010/2011 CGI�GIRS©

Understand and explain the main concepts of spatial

data and spatial data infrastructures

Content

� Acquiring new geodata

� Using/Sharing existing geodata

� Sources

� Framework data

� Metadata

� Standards

Geo�information process

Geodata interest

� Geodata/information is one of the most critical elements underpinning decision making for many disciplines

� ± 90% of all information used by government has spatial characteristics

� Very high costs for geodata collection and maintenance(70�80% cost of many GIS projects)

� same data sets collected by different agencies again and again

Geodata in use

� GEODATA AQUISITION

Creating new data

� Surveying

� Enquiries and Questionnaires

� Photogrammetry

� Remote sensing

� Digitizing maps

Geo�information process

Terrestrial

Acquiring information about a phenomenon by measuring it physically

Acquiring information about a phenomenon by measuring it physically

Good old times

Modern times

Land surveying techniques

Total station

Total Station

GPS

Remote sensing

� Acquiring information about an object without contacting it physically. Methods include aerial photography, radar, and satellite imaging.

Landsat TM (30m) G(4)+R(5)+SWIR(7)

Multi spectral bands

Photogrammetry

Stereo-photographs, normally made from aeroplanes are also a good data source. Not only for geometric data but also for attribute data.

Photogrammetry is the technique to retrieve the data from the images. Most topographic map series are produced by this technique

Stereo pairs:determination of object coordinates, position + elevation

- Central versus Orthogonal projection- Optical versus symbolic image

Optical image /central projectionSymbolic image / orthogonal projection

Photogrammetry

Scanning

Digitizing coordinates

Digitizing

Data acquisition strategy

•PROJECT DEFINITION

•GEO-DATA REQUIREMENTS

• SDI (clearinghouse – portal) search

• MAP search

•DIGITISING / SCANNING

• HARD COPY IMAGES search

•PHOTOGRAMMETRY

•1st ORDER DATA ACQUISITION

•REMOTE SENSING

•TERRESTRIAL

Voluntary Geographical Information

� Voluntary Geographical Information

� „user generated geographic information (Goodchild, 2007)”

� combination of Web 2.0, collective inteligence, neogeography

� „user�generated geographically referenced content (Rinner, 2008)”

� article: „Citizens as Sensors:…” Goodchild, 2007

OpenStreetMap.org

Wikimapia

� EXISTING GEODATA USE

� Executive Order 12906, April 11, 1994

� „Coordinating Geographic Data

Acquisition and Access: The National

Spatial Data Infrastructure,"

� „Development of a National Geospatial

Data Clearinghouse”

� „Electronically accessible”

� „Clearinghouse network”

Definitions of SDI

� Utility view: SDI is a network facility for accessing and sharing spatial data.

� Component view: spatial data, standards, policies, technology and people

� Utility and goal: a network facility for supporting spatial issues in society accessing and sharing spatial data

Policy

Standards

Technology

Geodata People

SDI about connecting People with Geodata

Component 1: Geodata

Geodetic

Digital Elevation ModelTopographicAdministrative boundariesCadastral

RoadsHydrographyRivers and lakesCoastlinesBathymetry

BuildingsPlace namesLand use/land cover/vegetationGeologyReal estate price register

Land valuationSensor data

Spatial data

Metadata

� “Information describing spatial data sets and spatial data services and making it possible to discover, inventory and use them” (INSPIRE directive)

� “The summary information or characteristics of a set

of data” (SDI cookbook)

or

� data about data

Can you mention few metadata about this map?

http://geogratis.cgdi.gc.ca/geogratis/en/collection/metadata.do?id=8916

Metadata

Date 8.01.09

Temp at the time of data coll.

� 11 degrees C

Title ….

Abstract …

Quality …

Resolution …

Why describe spatial datasets with metadata?

Component 2: Policy

Policy Issues relating to Geodata

� Commercialization of public information

� Geodata often public (e.g. Cadastral, Topographic, etc)

� Dillema: sell or gratis

� Protection of investments

� Geodata require investment (money and effort)

� Dillema: how to protect it? Copyright? Licences?

� Privacy

� In Geodata easy to identify info of private character

� Dillema: How to deal with that?

� Liability

� Geodata as a basis for decisions

� Dillema: Responsebility for geodata errors?

Example

source: Google Earth

Product Liability

� The goal of product liability laws is to help protect consumers from dangerous products

� Can map be a dangerous product?

� Yes, decision can be taken based on incorrect/inaccurate information that contain errors

gas

Privacy

source: Google Earth

INSPIRE (Infrastructure for Spatial Information in Europe)

� An infrastructure to facilitate the exchange of environmental and geographic information

� Entered into force on 15th May 2007;

� INSPIRE should build upon infrastructures operated by Member States (27);

Policy for European SDI � INSPIRE

� The directive covers general rules for:

� Metadata

� Interoperability of Spatial Data Sets and Services

� Network services

� Data sharing

� Coordination and complementary measures

� Drafting Teams for specific Implementation Rules

Policy for European SDI � INSPIRE

Component 3: Technology

Introduction technology for infrastructure

� (Spatial data) infrastructure

� Infrastructure provides services: (e.g electricity, water, transportation

� SDI provides spatial data services, e.g.� view services,

� download services,

� catalog services

� sensor services

� ….

Service�Oriented Architectures

Internet

Geo�Portal

Usersbrowser

application

processes

Web server

Brokers

Find

serv

ice

Interact

PublishServices

OpenGIS

Server

ArcGIS

Server

Web

service

Webservices: SOA example

Spatial Data Clearinghouse

� Electronic facility for making spatial data accessible to the general public and promoting data sharing (for multiple application domains/disciplines/purposes)

� Facility for searching, viewing, transferring, ordering, advertising and/or disseminating spatial data from numerous sources (agencies) via the Internet

� Yellow pages for spatial data on the Internet

National Clearinghouse

Ireland Slovenia UK

� Clearinghouse at national/federal level recognized by the national government as the country’s main access network

Component 4: Standards

Standards

� Standardisation� development of agreements and rules amongst users

to create unity and clarity, where diversity is unwanted

� Standard� documented agreements by potential users

Standards for SDI/GIS, why?

� Large number of GIS data formats (many vendors)

� GIS software has data conversion functions

� Need for data standards to facilitate exchange

� Efficiency

� Increase connectivity

Organisations

ISO/tc211

CEN/tc278

NEN

OGC

EU (INSPIRE)

National government

Standards

Open Geospatial Consortium (OGC)

� Founded 1994

� Industry consortium

� Developing standards that enable open, vendor and format neutral geo�information discovery, accessand sharing.

� For instance: WMS, WFS, GML,

OGC

� Open Geospatial consortium

� Founded 1994

� Industry consortium

� Implementation specifications

� For instance: WMS, WFS, GML,

� http://www.opengeospatial.org/

OGC Web Mapping Service (WMS) Standard

Component 5: People

Focal or primary � primary

users/producers

adapted from: GeoConnections

Secondary � secondary users

Negligible �occasional or low�priority users

SDI & People (roles)

SDI and organizations

� Questions faced by organizations considering adopting SDI:

� What are the applications of SDI?

� What are the users needs?

� Is investment in SDI justified?

� What changes will SDI cause in the organization?

SDI/GIS organizations in the Netherlands� Geobusiness Nederland (www.geobusiness.nl)

� Support Innovation, Marketing, GII, Education, etc

� ~ 80 members (~300 organizations in GI sector)

� Engineering consultancy

� Planning offices

� Advisory

� Surveying organizations

� Data (service) providers

Summary

� Existing Geo Data

� Spatial data infrastructure (SDI)

� Clearinghouses – geo data portal

� Metadata – standards

Geo�information process

� Creating Geo Data

� Terrestrial

� Remote sensing

� Photogrammetry

� Digitizing

� Crowdsourcing (or VGI)

Study materials:

© Wageningen UR

Theory Chang, 2006

Chapter 6: Data Input

Practical: Exercise Module 1 ‘Working with ArcCatalog’Exercise ‘SDI�concepts’

DATA: WHICH DATA TO CAPTURE ?

� 1st order � ‘field’ work

� via direct or indirect field survey

� measured data

� 2nd order � desk work

� post processed data

� 3rd order � desk work

� derived data

� from 2nd order data