Intro To Geospatial

Introduction to Geospatial Systems
Dan Rickman, Chair, Geospatial Specialist Group

21st January 2010

Agenda

• What is geospatial data and which systems process it?
• Data modelling issues regarding geospatial data
• In search of the BLPU
• Map data
• Geo-parsers/gazetteers/metadata
• Applications
• Standards
• Corporate or cloud?
• The end of privacy?
• Future directions - Location Based Services, social networking applications
• Conclusion – 2010 the year of “geo”

What is Geospatial Data? - 1

• Spatial data which relates to the surface of the Earth
• Geodetic reference system as base e.g. WGS84 used for Global Positioning System
(Earth as an ellipsoid), Latitude and Longitude (Earth as a sphere)
• Ordnance Survey (GB) define National Grid – projection onto flat surface – NB: OS(NI)
use Irish grid
• Engineering projects will use local projections for more accurate measurements
• Spatial relationships – defined around concept of neighbourhood – relates to two “laws”
of geography:
- Most things influence most other things in some way
- Nearby things are usually more similar than things which
are far apart

What is Geospatial Data? - 2

• Unstructured – spaghetti data
• Topology – information structured as networks, polygons
• GeoSpatial information requires metadata – e.g. minimal information such as map
projection used
• GeoSpatial information may also temporal modelling – e.g. farm subsidies vary as
utilisation and legislation change
• Field-based model versus object-based model of space, e.g. rainfall versus buildings on
which rain falls
• GeoSpatial information requires ontology
– What is the “real world”, how classified
• Relates to semantics - important to understand the “conceptual model”

Geospatial data modelling

• Field-based model versus object-based model
• Geographic Information Systems are object-based in practice
• Most common field based information, e.g. Digital Elevation Model (line of sight
applications), attached to objects
• Objects rely on field-based model, i.e. spatial co-ordinates
• Initiatives such as Digital National Framework encourage organisations to structure data
on references to objects, not re-capture and duplicate data
• GeoSpatial equivalent of “referential integrity”
• Nevertheless duplication, lack of (referential) integrity is common place and hard to
eradicate

In search of the BLPU

• Basic Land and Property Unit
• “Holy grail” of industry – no Da Vinci code produced yet!
• Example of Ordnance Survey Master Map (OSMM):
• "St Mary's football stadium, Southampton" is one object
• Typical detached house and its plot of land, likewise
• Complex entities such as "Southampton railway station" are defined in terms
multiple objects: one for the main building, several for the platforms, one more
for pedestrian bridge over the tracks. (NB: See Wikipedia article on TOID)
• Defining the candidate BLPU, their lifecycles and their attribute data and
verifying that these are meaningful/practicable from the wide variety of business
processes which apply to the BLPU and the aggregate entities which are
created from them
• Dependencies so that data sets are based on the BLPU wherever possible
limited by business use, e.g. field use change quite different from a
tenant/owner perspective

Evolution of geographic information

database
records

digital
records

geographic
paper
information
records

digital mapping

paper mapping

1950 1970 1990 2010

Vector map data

• Large scale
– Ordnance Survey Master Map
– UKMap (The GeoInformation Group)
Open source
- Open Street Map – very successful crowd-sourcing project, now being used in Haiti to
provide current maps for emergency services (as it can be easily edited)
- Postcode and medium scale OS data – subject to DCLG consultation, part of Smarter
Government initiative
• Road network data
– ITN (part of Master Map)
– Navteq, TeleAtlas (now part of larger groups Nokia and TomTom respectively)
• Address data
– NLPG versus Address Layer 2 (Master Map) versus UKMap addresses...

Presentation to insert name here 8

Raster map data

• Scanned ortho-rectified map or map-based data – metadata is co-ordinates, projection,
extent
• For example Google Maps/Google Earth, Microsoft Virtual Earth
• Traditionally stored outside the database as external files, analogous to vector data
storage, e.g. Oracle 10g GeoRaster
• Data stored as BLOBs, metadata required regarding number of bytes per pixel,
compression algorithms and so on
• Benefits limited as “intelligence” in map requires interpretation
• Still limited progress on map-based pattern recognition – there are semi-automated
solutions from companies such as 1Spatial

What are GeoSpatial Systems?

• Known as Geographic Information Systems, Spatial Information Systems
– Rebadged as “geospatial” or now “geo” – shorter name more mainstream!
• Enables capture, modelling, storage, retrieval, sharing, manipulation and analysis of
geographically referenced data
• Database is at the heart – as is “attribute” data
• Model developing – perhaps GeoSpatial data better seen as “attribute” of alphanumeric
business information
• Presentation does not have to be map-based in all cases
• Key element is spatial indexing – uses different techniques to alphanumeric indexing,
makes different demands for database storage and management

Structured geo-database

Relational Spatial

Time/Engineering
Database Data
CRM (Attribute data) (proprietary format)

Systems

Real
ERP Spatially extended RDBMS
-Complex data types for spatial data
-Computational geometry
-Spatial indexing
-DDL and DML extensions

Where used? Examples

• Central government – DEFRA, ODPM, Land Registry, ONS
• Local government – planning, highways authorities
• Utilities – physical and logical network
• Insurance – flood plains
• Health – epidemiology
• Travel - multi-modal route planning, satnav (≠GPS!), navigation, wayfinding
• More widespread use – addresses, postcode based data against regional boundaries,
infrastructure (“geographies” used to divide country, catchment area)
• Fiat boundaries verus “bona fide” boundaries – what is “real world” how do we structure
it? Classic example – system will tell people by a river their nearest resource is on the
other side when there is no bridge

Web-based apps - Trendsmap


Standards

• ISO TC211 – range of ISO geospatial standards
– Best known are WMS/WFS – not web services but similar
• CEN TC/287 – adopts them in Europe
• BSi IST/036 – UK standards committee
• All likely to be swept away as geospatial becomes mainstream by general web standards:
– Web services
– WMS and WFS now developing web services wrapper...
– W3C Geolocation API see an example at:
http://www.edparsons.com/maps/geolocation.html
• Your Location is: 51.591697, -0.172635, within 150m on Thu Jan 21 2010 13:06:24 GMT+0000 (GMT Standard
Time)

• This page demonstrates basic usage of the Geolocation API.

– Note: this requires client-side permission – but only required once!


Corporate or cloud?


Web-based systems

• Structured applications
• Google Earth, Bing Maps, Yahoo Maps (GYM) – all different APIs
• Mapstraction API (http://www.mapstraction.com/) provides generic API
• Mashups – new sources of data available including data.gov.uk launched today,
data.london.gov.uk launched recently by GLA
• Unstructured data – not least photographs on flickr and other sites
• Increasing use of location for search engine results, relevant to both desktop and mobile
uses
• World wide wild west of unstructured data
• Increasing use of systems to control, coordinate and make this accessible
• Geo-enabled semantic web – raises issues of ontology
• www.metacarta.com – provide web-based Geographic Text Search (GTS), has the ability
to confine searches by geography and retrieve information that it detects using the
keywords, and then displays this information geographically on a map interface

Geo-parsers/
gazetteers/metadata
• Geo-parsers: identify spatial tags (geo-tags) in data
• Context sensitivity and patterns of usage required
• E.g. Jordan (country) != Jordan (Katie Price)
• Can see examples at:
• http://unlock.edina.ac.uk/ (Edina unlock uses open source and OS data)
• http://developer.yahoo.com/geo/placemaker/ (Yahoo Place Maker)
• Relies on and populates gazetteer of associated names
• Emerging standards for geo-parsing, e.g. Open GIS Consortium looking at:
– Gazetteer service
– Geo-coder service
– Web services (WMS/WFS)

Privacy - They know where you live

• MetaCarta – technology provider to cloud computing but also...
• MetaCarta(R), Inc., a leading provider of geographic intelligence, announced
today that it had won a one-year contract with … the Department of Homeland
Security [which] identifies and assesses current and future threats to the
homeland, maps those threats against the nation's vulnerabilities, issues timely
warnings and takes preventative and protective action… The product
automatically identifies geographic references using advanced natural language
processing (NLP) from any type of unstructured content in a customer's
archives such as email, web pages, newswires or cables. It assigns a latitude
and longitude to these references so that users can analyze their text archives
using geographic maps, keywords and time as filters. The results of a query are
displayed on a map with icons representing the locations found in the natural
language text of the documents and as a text results list. Both the icons and text
summaries are hyperlinked to the documents they represent.
• Social networking – they know where you tweet...

Tweeps Around

Augmented Reality will
have significantly
encroached on map
based displays by 2015


The future (and summary)

• Geo: The combination of GPS chips in mobile phones, social networks, and increasingly
innovative mobile apps means that geolocation is increasingly becoming a necessary
feature for any killer app. I’m not just talking about social broadcasting apps like
Foursquare and Gowalla. The advent of Geo APIs from Twitter , SimpleGeo, and
hopefully Facebook will change the game by adding rich layers of geo-related data to all
sorts of apps. Twitter just recently launched its own Geo API for Twitter apps and
acquired Mixer Labs, which created the GeoAPI. (TechCrunch blog)
• Open source geospatial systems
• Open geospatial data
• Location based services – now commonly have GPS and compass on mobile devices, will
only get better
• Real time applications (#uksnow on twitter, ushahidi)
• Augmented reality applications emerging
• However – data quality issues will persist
• They will still get it wrong! They just think they know where you live...

Issues – data availability and quality

• Crowd sourced data – flickr, social networking
• Mobile devices – also provide real time data
• Critical issue – understand data and metadata


The future...

• Success of semantic-based approach yet to be determined, experience with geospatial
data indicates there are significant complexities based around our representations of the
“real world”
• One issue is clear – increasingly less privacy, location is already accessible through
mobile phones and linking this to other data can provide significant intelligence
information
• Summary:
– in corporate world you can and now should be exploiting geospatial data both for
conventional uses and for web 2.0 applications (citizen involvement, crowd sourcing
etc)
– In unstructured world, geo is becoming key element for searches, impacts mobile
applications
– In social networking world, geo is becoming a key consideration especially for mobile
applications


Intro To Geospatial

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