Geovisualization

S.M.J.S.SamarasingheSuperintendent of Surveys

Institute of Surveying and MappingDiyatalawa- Sri Lanka

Email: smjss265@gmail.com

Why Maps ?

Introduction

Cartography Geographic data and maps Why maps? Maps and reality Landscape and cartographic model Present and explore Trends

Maps-introduction

Cartography

Cartography

• How do cartographic method technique➡

• I cartographer / map maker ➡

• say symbols / semantics ➡

• what geographic data➡

• to whom audience / purpose➡

• and is it effective does it work?➡

Visualization process

Geographic data and maps

Geographic data

Large amounts of geodata are collected. Some users process raw data, but many rely on data

products to extract useful geo-information. In data products, the raw data can be converted,

harmonized, classified, modeled and stored in a data base, analyzed, visualized….

The demand for geo-information is still increasing

Geographic data

Data / geoinformation

Complex situation in?......

How do producers disseminate geospatial data (i.e. how do they bring the data to the users)? in digital format by means of spoken / written language by means of numbers (e.g. in tables) by means of RS imagery by means of video by means of 3D / Virtual Reality imagery by means of maps or map displays

Dissemination and use of geo-data

Advantages: - Good graphical quality / high resolution - High information density / level of detail - Large formats possible / overview - No need of equipment (e.g. pc or tablet)Disadvantages: - Static - Fixed scale - Physical boundaries to area portrayed - No adjustment to individual demands

Paper maps

Advantages:- Adjustable to individual needs- Links to additional info (multi-media)- Panning and zooming- Seemless- Possibly dynamic (animations)

Disadvantages:- Low screen and colour resolution- Output conditions vary- Limited display size / overview- Equipment required / portability

On screen maps

Access- internet access - accessibility for everyone?

Medium- problems related to computer- no control over final appearance- speed of data transfer

Content- finding web maps and geodata- language

Web maps

321 definitions of a map?

Why Maps ?

How to get knowlegde about our environment? walk around secondary sources (maps / movies, stories etc)

Need for abstraction/ models > maps

Why maps?

Why maps?

Maps are abstractions or models of reality, in which geographic space is represented by map space.

The spatial layout of maps enable users to see: - patterns - relationships - trends

Why maps?

Make invisible things visible

Why maps?

Snow’s map: cholera & water pumps

Understanding maps

• Elementary- referring to a single location / object

• Intermediate- referring to a region or group of similar objects

• Overall- referring to (overview of) all aspects in the area

Maps address geographical questions ofdifferent levels of complexity

Elementary questions

Intermediate questions

Overall questions

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Bad Maps

Maps and reality

Reality: different views: different maps

What to map?

What to map?

Fitness for use?

What is allowed?

What is allowed?

What is allowed?

Map art

Underground Railway system

Understanding how it is mapped

Mapping which reality?

Digital landscape model - Digital cartographic model

• Digital Landscape Model (DLM):- contains a selection from the real world- stores geometry (points, lines, areas, volumes, raster)- stores attributes (linked to geometry)- stores time (linked to geometry)

• • Digital Cartographic Model (DCM)- one or more visualization(s) of the DLM- visualizations are tuned to: the use goals, users, - use environments, representation scales, etc..- also stores graphic attributes (line type, colour, etc)

DLM to DCM: from reality to maps

DLM - DCM at work

A little history of cartography

Present and explore

Cartography

Start:facts to be presented are fixed.Process:choice of appropriate visualization technique.Result:the single best map.Emphasize:on map design.

Maps to present

Start:data without hypothesis about the data.Process:interactive, undirected search for structures and trends.Result:visualization that provides hypothesis, different alternative views.Emphasize:enabling ‘discoveries’.

Maps to explore

Multiple coordinated views

oaúúp,h

Trends

Change

We no longer look at the map to see where we are........But, we tell the map where we are, and the map shapes itself around us.

Problem? a world of change

Trends

Neogeography combines the complex techniques of cartography and GIS and places them within reach of users and developers.

Neogeography ?

Neogeography

Neogeography (literally "new geography") is the use of geographical techniques and tools for personal and community activities or by a non-expert group of users. Application domains of neogeography are typically not formal or analytical.

Neogeography ?

.

El nino

.

Geovisual analytics environment:coordinated multiple views

.

Geovisual analytics tools

.

Sensor Web: Real time water levels

.

... is about people using and creating their own maps, on their own terms and by combining elements of an existing toolset.

VGI• Citizen science• UGGC

Neogeography / community mapping

.

Mash-up: scale / background / symbology?

.

A mashup, in web development, is a web page, or web application, that uses content from more than one source to create a single new service displayed in a single graphical interface.The main characteristics of a mashup are combination, visualization, and aggregation. It is important to make existing data more useful, for personal and professional use. To be able to permanently access the data of other services, mashups are generally client applications or hosted online.

Mash-up?

Does it works

Growing interest and importance.

Broadening of scope: from map use research to user research in geoinformation processing and dissemination.

Not just usability evaluation but user-centred design(UCD).

Use, user and usability research

In case of hard copy maps: as wall map, on the desk top, in the field, ….

in case of on screen maps: on the desk top, on handheld mobile devices stand-alone or network application (e.g. Internet) hard- and software available, interfaces use at one place or distributed collaboration …

Use contexts: e.g. map use environments

World Wide Web Web maps, WMS, distributed GIS, GDI’s

Mobile & wireless devices Smartphones, PDA’s, Pocket PC’s with location

aware applications (LBS). small screens low resolution few colours small data files

New User environments

.

Qualitative Quantitative Interviews Focus groups Thinking aloud Questionnaires Performance analysis fMRI scanning Eye movement registration …..

Research methods and techniques

.

Think aloud method

.

Thank You