GEOSPATIAL PUBLISHING

Creating and Managing Geo-Tagged Knowledge Repositories

Arno Scharl

Know-Center & Graz University of Technology,

Knowledge Management Institute; Inffeldgasse 21a, 8010 Graz, Austria

Keywords: Geospatial Web, Geo-Tagging, Content Production, Knowledge Acquisition.

Abstract: International media have recognized the potential of geo-browsers such as NASA World Wind and Google

Earth, for example when Web and television coverage on hurricane “Katrina” used interactive geospatial

projections to illustrate its path and the scale of destruction. Yet these early applications only hint at the true

potential of geo-browsing technology to build and maintain virtual communities, and to revolutionize the

production, distribution and consumption of media products. Investigating this potential, this paper reviews

the literature on geospatial publishing with a special focus on extracting geospatial context from unstruc-

tured textual resources. A content analysis of online coverage based on a suite of text mining tools then

sheds light on the popularity and adoption of geo-browsing platforms. While such platforms might help en-

rich a company’s portfolio of media products, they also pose a threat for existing players through attracting

new competitors; e.g., independent providers of geospatial metadata or location-based services.

1 INTRODUCTION

Contrary to early predictions of the Internet render-

ing geography irrelevant, the discipline is increas-

ingly gaining importance. Geo-browsers facilitate

the access to vast quantities of geo-referenced and

time-stamped data. Keen competition between well-

known software and media companies surrounds the

provision of two-dimensional geospatial user inter-

faces. Google Maps (maps.google.com), MapQuest

(www.mapquest.com), MS Virtual Earth (Windows

Live Local; local.live.com), Yahoo Local Maps

(maps.yahoo.com) and other online services are add-

ing new functionality, data sources and interface

options in rapid succession. These tools transmit

cartographic data and visualize the context and geo-

graphic distribution of different types of location-

based resources and services.

Three-dimensional geo-browsers combine satel-

lite i

magery with aerial photographs and Shuttle

Radar Topography Mission (SRTM) elevation data.

Using standardized services such as the bitmap-

based WMS (Web Mapping Service) or the vector-

based WFS (Web Feature Service) of the Open Geo-

spatial Consortium (www.opengeospatial.org), im-

age tiles and vector data including geo-positioning

information are retrieved from a central server, ar-

ranged into a real-time mosaic, and mapped onto a

three-dimensional representation of the globe. Alter-

ing the field-of-view angle allows to zoom in and

out on Earth and increase or decrease the level of

detail displayed. Users can seamlessly zoom from

NASA Blue Marble data at 1-kilometer-per-pixel,

for example, to the detailed mosaic of LandSat 7

data at 15-meters-per-pixel (Hogan & Kim, 2004).

Adding the option to tilt the display relative to the

spectator’s point of view adds a third dimension,

altitude. Layers built into the interface provide allow

users to effortlessly switch between detailed views

and highly aggregated representations.

Most providers of geo-browsing platforms offer

Application Programming

Interfaces (APIs) or XML

scripting to facilitate building third-party online ser-

vices on top of their platforms (Roush, 2005). Mul-

tiple layers of icons, paths and images can be pro-

jected via these services – referencing and scaling

icons, for example, positioning them on the globe,

and linking them to external knowledge repositories,

(Web) documents, or photo collections. Latitude and

longitude variables determine the symbols’ position,

while distance above surface values specify whether

symbols hover above ground. A good example is the

data from NASA’s Moderate Resolution Imaging

Spectroradiometer (MODIS), providing daily up-

dated planetary imagery, documenting natural events

such as fires and storms (Hogan & Kim, 2004).

226

Scharl A. (2006).

GEOSPATIAL PUBLISHING - Creating and Managing Geo-Tagged Knowledge Repositories.

In Proceedings of the First International Conference on Software and Data Technologies, pages 226-231

DOI: 10.5220/0001313302260231

 SciTePress

Traditionally, the role of geography has been re-

stricted to retrieving information more effectively

and enhancing inference operations, but not for

specification of queries and the presentation of re-

sults. Geo-browsers are about to address this short-

coming by redefining the look and feel of user inter-

faces, leveraging the knowledge about a user’s loca-

tion to unlock organized indices to the physical

world (Kendall, 2005).

2 GEO-TAGGED KNOWLEDGE

REPOSITORIES

Concentrated efforts are underway to geo-tag as

much existing information as possible. Geo-tagging

refers to the process of assigning geospatial context

information, from specific point locations to arbitrar-

ily shaped regions. Sources of geospatial context

information for annotating Web resources include:

• Annotation by the authors (Daviel & Kaegi,

2003), manually or through location-aware de-

vices such as GPS navigation systems, RFID-

tagged products and cellular handsets (Francica,

2005). These devices geo-tag information auto-

matically when it is being created.

• Determining the location of the server – e.g. by

querying the Whois database for domain regis-

trations, monitoring how Internet traffic is

routed, or by analyzing the URL for additional

cues (McCurley, 2001).

• Automated annotation of existing documents:

The processes of recognizing geographic con-

text and assigning spatial coordinates are com-

monly referred to as geo-parsing and geo-

coding, respectively (McCurley, 2001).

Once geospatial context information becomes

widely available, any point in space will be linked to

a universe of commentary on its environmental, his-

torical and cultural context, related community

events and activities, as well as personal stories and

preferences. With the widespread introduction of

commercial applications such as location-based ser-

vices and geospatial gaming environments, even

locative spam will be a common phenomenon (Erle,

Gibson, & Walsh, 2005). At present, however, many

metadata initiatives still suffer from the chicken and

egg problem of wishing that existing content was

retrofitted with metadata (McCurley, 2001). Geo-

tagging projects are no exception. Addressing this

shortcoming, this paper focuses on the third cate-

gory, the automated parsing and coding of existing

resources (online news, for example, and other types

of unstructured textual data found on the Web).

2.1 Geo-Parsing

All human artefacts have a location history, which

commonly includes a creation location and current

location (Spohrer, 1999). Depending on the avail-

ability of metadata, geospatial applications can map

the whole life cycle of such artefacts. Electronic

resources contain the required metadata as explicit

or implicit geographic references. This includes ref-

erences to physical features of the Earth's surface

such as forests, lakes, rivers and mountains, and ref-

erences to objects of the human-made environment

such as cities, countries, roads and buildings (Jones,

Alani, & Tudhope, 2001). Addresses, postal codes,

descriptions of landmarks, and annotated hyperlinks

also allow to pinpoint an exact location (Ding, Gra-

vano, & Shivakumar, 2000; McCurley, 2001).

At least 20 percent of Web documents contain

easily recognizable and unambiguous geographic

identifiers (Delboni, Borges, & Laender, 2005).

News articles are particularly rich in such identifiers,

since they generally report on the location where an

event took place, or where it was reported from

(Morimoto, Aono, Houle, & McCurley, 2003) – a

distinction also referred to as source versus target

geography (Amitay, Har’El, Sivan, & Soffer, 2004).

The BBC article “Vienna marking Mozart mile-

stone” (Bell, 2006), for example, has a target geog-

raphy of E

UROPE/AUSTRIA/VIENNA, and a source

geography of E

UROPE/UNITED KINGDOM/LONDON.

In addition to target and source geography, natural

language processing also allows extracting the geo-

graphic scope (reach) of a Web resource in many

cases (Wang, Xie, Wang, Lu, & Ma, 2005).

Identifying and ranking spatial references by

semantically analyzing textual data is a subset of the

more general problem of named entity recognition,

which locates and interprets phrasal units such as the

names of people, organizations, and places (Cowie

& Lehnert, 1996). As with most named entity recog-

nition tasks, false positives are inevitable – e.g.,

documents that quote addresses unrelated to the their

actual content (Morimoto, Aono, Houle, &

McCurley, 2003). Ambiguity, synonymy and

changes in terminology over time further complicate

the geo-parsing of documents (Amitay, Har’El,

Sivan, & Soffer, 2004; Kienreich, Granitzer, & Lux,

2006; Larson, 1996). Identical lexical forms often

refer to distinct places with the same name (V

IENNA

referring to the capital of Austria as well as a town

in Northern Virginia, US), for example, or can have

both geographic and non-geographic meanings –

e.g.,

TURKEY (large gallinaceous bird; bi-continental

country between Asia and Europe), M

OBILE (capa-

ble of moving; city in Alabama, US) and R

EADING

(processing written linguistic messages; town in

Massachusetts, US). The geo-parsing component

GEOSPATIAL PUBLISHING - Creating and Managing Geo-Tagged Knowledge Repositories

227

needs to correctly process references to identical or

similar places that may be referred to by different

names, may be at different levels of the administra-

tive hierarchy, or nearby by some measure of prox-

imity (Jones, Alani, & Tudhope, 2001).

2.2 Geo-Coding

Once a location has been identified, the content

fragments can be assigned precise spatial coordi-

nates – latitude, longitude and altitude – by querying

a structured geographic index (gazetteer) for match-

ing entries (Hill, Frew, & Zheng, 1999; Tochter-

mann, Riekert, Wiest, Seggelke, & Mohaupt-Jahr,

1997). Examples of public geographic indices are

the Geographic Names Information System (GNIS),

the World Gazetteer, the classifications of the

United Nations Group of Experts on Geographical

Names, the Getty Thesaurus of Geographic Names,

and the ISO 3166-1 Country Codes.

While simple gazetteer lookup clearly benefits

from being language-independent, more advanced

algorithms consider lexical and structural linguistics

clues, as well as contextual knowledge contained in

the documents – e.g., dealing with ambiguity by

removing stop-words, identifying references to peo-

ple and organizations (Clough, 2005), and applying

contextual rules such as “co-occurring place names

indicate nearby locations”. For each identified refer-

ence, this process assigns a probability P(name,

place) that a given name refers to a particular place

(Amitay, Har’El, Sivan, & Soffer, 2004). The inter-

pretation with the highest probability is then as-

signed a canonical taxonomy node such as

UROPE/AUSTRIA/VIENNA (48°14’ N; 16°20’ E).

2.3 Managing Geospatial Context

Metadata frameworks often include geospatial at-

tributes, e.g. the Dublin Core Metadata Initiative’s

“Coverage” tag (McCurley, 2001). The need for

controlled vocabularies suggests that ontologies are

going to play a key role in managing geospatial con-

text information. While conflicting definitions of

“ontology” abound (Guarino, 1997), most agree that

the term refers to a designed artefact representing

shared conceptualizations within a specific domain.

Geo-ontologies encode geographical terms and

their semantic relationships – e.g. containment, over-

lap and adjacency (Tochtermann, Riekert, Wiest,

Seggelke, & Mohaupt-Jahr, 1997). In the case of

spatially aware search engines, for example, onto-

logical knowledge supports query term expansion

and disambiguation, relevance ranking and Web

resource annotation (Abdelmoty, Smart, Jones, Fu,

& Finch, 2005). Geo-ontologies can either be repre-

sented through generic markup languages such as

the Web Ontology Language (OWL) endorsed by

the World Wide Web Consortium (Horrocks, Patel-

Schneider, & Harmelen, 2003; Smith, Welty, &

McGuinness, 2004), or more specific approaches

such as the Geographic Markup Language (GML)

developed by the Open Geospatial Consortium

(Lake, Burggraf, Trninic, & Rae, 2004).

3 GEOSPATIAL PUBLISHING

Technological convergence and the move towards

digital media continue to drive today’s newsrooms

(Pavlik, 1998). While many innovations that gain

ground in the media industry are largely invisible to

the end user, geo-browsers impact the consumption

of news media, change mainstream storytelling con-

ventions, and provide new ways of selecting and

filtering news stories.

3.1 Geospatial Literacy

International media have recognized the potential of

geospatial interfaces, for example when Web and

TV coverage on the hurricane “Katrina” used geo-

browsers to illustrate its path and the scale of de-

struction. Such mainstream coverage is well suited

to increase geospatial literacy, which today exists

only among a small portion of highly educated peo-

ple (Erle, Gibson, & Walsh, 2005). Geospatial liter-

acy includes the ability to understand, create, and

use spatial information and maps in navigating, in

describing phenomena, in problem-solving, and in

artistic expression (Liebhold, 2004).

In light of the explosive growth and diminished

lifespan of information, geospatial literacy is becom-

ing increasingly important, as the thought that needs

to be followed in information discovery tasks is of-

ten spatial in nature (McCurley, 2001).

3.2 Content Production

Google’s purchase of Keyhole and Microsoft’s pur-

chase of GeoTango demonstrate the perceived stra-

tegic potential of three-dimensional geographic

mapping. Hybrid models of individual and collabo-

rative content production are particularly suited for

geo-browsers, which allow to seamlessly integrate

and map individual sources (monographs, commen-

taries, blogs), edited sources (encyclopedias, confer-

ence proceedings, traditional newsrooms), evolu-

tionary sources (Wiki applications, open-source

project documentations), and automated sources

(e.g. news aggregators, news summarizers).

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Geo-browsing technology not only impacts the

production of content, but also its distribution, pack-

aging and consumption. When specifying prefer-

ences for personalized news services, for example,

geo-browsers are effective tools to pinpoint loca-

tions and specify geographic areas to be covered by

the news service. Such services require content that

is correctly annotated along several dimensions:

• spatial (source and target geography),

• semantic (major topics covered, e.g. assigning

terms from a controlled vocabulary),

• temporal (timestamp of the event reported, the

initial publication of the article, as well as sub-

sequent revisions).

Online news can be indexed, searched and navi-

gated along these dimensions (McCurley, 2001).

The geographical scope of an article, for example,

allows filtering and prioritizing content in line with

the user’s area of interest (often different from

his/her actual location).

3.3 Geospatial Media Coverage

Geo-informatics represents an established discipline

that has created an industry with remarkable reve-

nues (Wilk, 2005). Yet only with the launch of

Google Maps, and its brother in crime, Google

Earth, we’ve seen a dramatic increase in public

awareness of the potential of geospatial technology

(Francica, 2005). Spurred by space photography,

global satellite positioning, mobile phones, adaptive

search engines and new ways of annotating Web

content, the “ancient art of cartography is now on

the cutting edge” (Levy, 2004, 56).

Many current articles are shining a spotlight on

geospatial technologies, describing trends in mobile

services, investigating the emerging industry of local

search, and reporting unidentified or unusual objects

found on satellite images. In the past, the process of

collecting and analyzing such articles was time con-

suming, expensive, and often yielded incomplete

data. Nowadays articles are readily available online,

allowing for inexpensive, fast and topical research.

As traditional media extend their dominant posi-

tion to the online world, analyzing their Web sites

reflects an important portion of Web content that the

average Internet user accesses. On a macro-level,

analysts gain insights into publicity through inciden-

tal news coverage by monitoring information flows

within and across media (Scharl, Weichselbraun, &

Liu, 2005). On a micro-level, documents retrieved

from Web sites contain valuable information about

trends and organizational strategies.

This study sampled 129 Web sites in quarterly

intervals between May 2005 and January 2006,

drawing upon the Newslink.org, Kidon.com and

ABYZNewsLinks.com directories to compile a list of

international media sites from seven English-

speaking countries: United States, United Kingdom,

Canada, Australia, South Africa, New Zealand and

Ireland. A Web crawler mirrored the Web sites by

following their hierarchical structure until reaching

50 megabytes of textual data, a limit that helped

reduce the dilution of top-level information by con-

tent in lower hierarchical levels (Scharl, 2000). Up-

dates and revisions of news articles often result in

multiple versions of the same content (Kutz & Her-

ring, 2005). The system therefore identified and re-

moved redundant segments such as headlines and

news summaries, whose appearance on multiple

pages would otherwise distort frequency counts.

Media attention was calculated as the relative

number of references to a technology or product,

measured in occurrences per million tokens. A pat-

tern matching algorithm processed a list of regular

expressions, considering common term inflections

while excluding ambiguous expressions.

Figure 1 summarizes the number of occurrences

identified through these regular expressions. Be-

tween Q2/2005 and Q1/2006, coverage on 2D and

3D platforms increased significantly by more than

300 and 1,100 percent, respectively (Wilcoxon

Signed Ranks; p<0.05). While in Q2/2005, coverage

on 2D platforms exceeded coverage on their 3D

counterparts (Mann-Whitney; p<0.05), Q1/2006

showed a different picture. There was no significant

difference between the categories, although 3D plat-

forms took a slight lead with an average relative

frequency of exactly one occurrence per million to-

kens. With 83 percent share of coverage, Google

Earth has been the primary driver behind the observ-

able increase in popularity. This represents a re-

markable feat with a product only launched in June

2005, not receiving any mentions in Q2/2005. As of

January 2006, MapQuest still dominated the 2D

category with 46 percent of total coverage, while

Google Maps and Google Local were catching up

rapidly with a share of 44 percent (in the second

quarter of 2005, MapQuest had received nearly

twice as many mentions).

GEOSPATIAL PUBLISHING - Creating and Managing Geo-Tagged Knowledge Repositories

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05-Q2 05-Q3 05-Q4 06-Q1

0.2

0.4

0.6

0.8

Occurrences per Million Tokens (Mean)

Google Maps/Local

MapQuest

2D Platforms

Google Earth

3D Platforms

Figure 1: Media Coverage of Geospatial Platforms (Q2/2005 – Q1/2006).

4 CONCLUSION AND OUTLOOK

By integrating traditional cartographic geodata with

geo-tagged hypermedia, the Geospatial Web “may

ultimately be the big disruptive innovation of the

coming decade” (Erle, Gibson, & Walsh, 2005,

xxv). As such, it will serve as a catalyst of social

change and enabler of a broad range of as yet un-

foreseen applications.

The introduction of geo-browsing platforms such

as Google Earth and NASA World Wind has popu-

larized the process of “annotating the Planet” (Udell,

2005). This paper presented the underlying technol-

ogy, methods to “geo-enable” existing knowledge

repositories through parsing and coding geospatial

references, and geospatial applications in a media

context. A quarterly snapshot of international media

coverage revealed the increasing popularity of geo-

spatial products and technologies, particularly as far

as three-dimensional platforms are concerned.

Science and technology’s accelerated advance-

ment demands constant media innovation, from idea

to utility (Stapleton & Hughes, 2006). In this com-

petitive environment, geography is emerging as the

fundamental principle for structuring the Web

(Roush, 2005), yielding the world's knowledge

through the lens of location (Levy, 2004, 58). Geo-

tagging aka adding location metadata to existing

databases and using geo-browsing platforms and

location-based services to access the vast amounts of

information stored in these databases weds physical

and virtual spaces, deepening our experiences of

these spaces and incorporating them into our every-

day lives (Roush, 2005).

ACKNOWLEDGEMENTS

The Know-Center is funded by the Austrian Competence

Center program Kplus under the auspices of the Austrian

Ministry of Transport, Innovation and Technology

(www.ffg.at), and by the State of Styria.

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