Delivering mapping solutions: the open source advantage

Transcription

1 Health and Mapping Delivering mapping solutions: the open source advantage Barry Rowlingson School of Health and Medicine, Lancaster University

2 Note This PDF document is a conversion of the original animated presentation. Most of the navigation and interaction is lost but you may still page through the document.

3 The Open Source Advantage What is 'Open Source'? What software is there? Show me some casestudies!

4 What is Open Source? A Philosophy A Methodology A Community

5 What is Open Source? Code Access Read, Learn, Improve!

6 What is Open Source? Free Distribution Get your code to anyone who wants to use it.

7 Open Standards Proprietary standards give you... Your data......locked by someone's key

8 Open Standards Open standards give you... Your data......as an open book

9 What about support? Proprietary support I can call the vendor! But they don't have to fix it Unless I pay them for a support contract Which they have a monopoly on!

10 Open Source Support? There's no vendor to call......but anyone on the planet can help!!!!!!! As ever, you can always pay for it... From a wide-open market of suppliers!

11 Open Source GeoServices Some OSGeo commercial support companies... OA Digital CampToCamp OSGIS Services Global Image Faunalia WhereGroup OpenApp RadiantBlue Just a few from the osgeo.org support directory of hundreds.

12 Or fix it yourself... You have the source code!

13 Free Support The Developer......is also a user!

14 Free Support Fixing bugs......helps them AND you!

15 Finding Developers Conferences, workshops, meetings Project lists Online chatrooms Want to see a bug fixed in under an hour by an open-source developer?

16 Fixed in 60 Minutes 12:13:30 arkygeek: timlinux: was there an issue with feature info for rasters not staying in front? At 12:13 Jason thinks 12:14:34 ADKPete: arkygeek: feature info? he sees a problem 12:14:51 arkygeek: identify features sorry 12:15:58 ADKPete: arkygeek: ok, that is what I thought but wanted towith a dialog box... double check. Dialog not staying on top? 12:17:46 arkygeek: ADKPete: just checking its happeining in head A minute later Pete 12:18:15 arkygeek: it IS NOT staying in front on head asks for clarification 12:18:37 ADKPete: hmmm...don't get that here what OS? 12:18:39 arkygeek: open a raster, identify feature, then on the second identify attempt it goes to the back 12:18:41 arkygeek: osx Some gentle anti-mac 12:18:50 ADKPete: well there you go... banter follows 12:18:52 ADKPete: :) 12:19:01 arkygeek: :P Jason confirms the 12:19:11 arkygeek: svn updating bug with the latest 12:20:47 arkygeek: it was the same in v.11 revision :21:40 arkygeek: yeah, still there in r :32:30 ADKPete: arkgeek: Think I have the fix for you. building... Pete has a fix 12:43:10 CIA-7: ersts * r9645 /trunk/qgis/src/app/qgsmaptoolidentify.cpp: -Added a raise call to keep A robot notifies the the identify results dialog on top when clicking through rasters chat of Pete's change 12:43:20 ADKPete: arkygeek: try that... 12:54:12 arkygeek: updating Jason tries and it now 12:55:07 arkygeek: compiling works. It's 12:55 12:55:53 arkygeek: ADKPete: that did it. well done :- ) 12:56:02 ADKPete: groovy

17 The Full Stack Clients Interfaces Servers Databases Desktop GIS (Qgis, gvsig, GRASS,...) Web Clients (OpenLayers,...) WFS (feature data) WMS (images) Map Servers (MapServer,...) GeoDatabases (PostGIS, SpatiaLite,...) WCS (grid data) Catalog Servers (GeoNetwork,...) File System (Shapefiles, GML, GeoTiff,...)

18 Desktop GIS (Qgis, gvsig, GRASS,...) Programs that run on your personal computer gvsig is a GIS and mapping package written in Java. QGIS is a GIS and mapping package written in C++ and Python. It can be extended with plugins. more... more... GRASS is a highpowered and technical set of GIS tools. Grass GIS more...

19 Alternatives to Google's Map API, Bing Maps, Yahoo Maps etc Web Clients (OpenLayers, MapServer,...) A purely browserbased web mapping solution in JavaScript more... A client-server web mapping system with many serverside possibilities more... And there are others!

20 OpenLayers This bit of HTML/JS......produces this map in your browser <html> <head> <title>openlayers Example</title> <script src=" </script> </head> <body> <div style="width:100%; height:100%" id="map"> </div> <script defer="defer" type="text/javascript"> var map = new OpenLayers.Map('map'); var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS", " {layers: 'basic'} ); map.addlayer(wms); map.zoomtomaxextent(); </script> </body> </html> That is a complete example. With just a few lines of code you get a dynamic 'slippy map' in your web browser. But wait, there's more...

21 OpenLayers Build complex interactive web sites: Integrate with other javascript widgets Interactive pop-up info bubbles Multiple map data overlays Base layer from many data providers

22 Framework for web mapping Client-server architecture

23 GeoNetwork Spatial Data Catalogue Search Index Catalogue Serve

24 WMS (images) WFS (feature data) WCS (grid data) Serving spatial data over the internet Request WCS (grid data) Server thinks... Browser draws Response WMS (images) WFS (feature data)

25 WMS (images) WFS (feature data) WCS (grid data) Web service mashups Integrate data sources from multiple providers to produce new maps and insights Polygon overlays Background imagery Regional data GPS locations All using open source servers, clients and communications protocols!

26 GeoDatabases (PostGIS, SpatiaLite,...) Relational Databases with spatial data functions Databases use SQL... select ADMIN_NAME,GMI_ADMIN,POP_ADMIN from bounds.uk...to get table data ADMIN_NAME GMI_ADMIN POP_ADMIN England GBR-ENG Northern Ireland GBR-NIR Scotland GBR-SCT Wales GBR-WLS

27 GeoDatabases (PostGIS, SpatiaLite,...) Relational Databases with spatial data functions Spatial databases also use SQL... select ADMIN_NAME,GMI_ADMIN,POP_ADMIN,the_geom from bounds.uk...to get table data with geometry! ADMIN_NAME GMI_ADMIN POP_ADMIN the_geom England GBR-ENG Northern Ireland GBR-NIR Scotland GBR-SCT A Wales GBR-WLS B

28 GeoDatabases (PostGIS, SpatiaLite,...) Relational Databases with spatial data functions the_geom stores geography the_geom A B

29 GeoDatabases (PostGIS, SpatiaLite,...) Spatial Queries What is the length of roads fully contained within each municipality? SELECT m.name, sum(st_length(r.the_geom))/1000 as roads_km FROM bc_roads AS r, Spatial query functions bc_municipality AS m WHERE ST_Contains(m.the_geom,r.the_geom) GROUP BY m.name ORDER BY roads_km; name roads_km SURREY VANCOUVER LANGLEY DISTRICT BURNABY PRINCE GEORGE

30 Adds spatial functions to PostgreSQL Access from most GIS (open source and commercial) Keep spatial and non-spatial data in the same DB Client-server model The basis of thousands of spatial data infrastructures worldwide

31 SpatiaLite Lightweight, but fully functional Designed for personal geo-databases Single-user Support building fast! Comes with simple mapping app

32 Vector and Raster mapping Analysis tools Plugin architecture for extensions in Python Reads most spatial data Talks to map servers Talks to database servers

33 Vector and Raster mapping Analysis tools Plugin architecture for extensions in Java Reads most spatial data Talks to map servers Talks to database servers

34 Grass Heavyweight GIS Toolkit Vector, Raster, Network 2d and 3d

35 Case Studies Aegiss A web-based system for mapping symptoms and detecting outbreaks Arlat Modelling and mapping parasite incidence in the field.

36 Case Study: Aegiss eat people and get sick bad food so they call NHS Direct......who figure out what's wrong and help and then file the results away somewhere

37 We want to add value to that data

38 Statistical Analysis cases = prob(outbreak) population Risk surface hi low Case locations, population data

39 Job Get the data from NHS Process it Trigger alerts on possible outbreaks Produce nice maps for health professionals

40 Sending the data NHS Daily symptom data extracted from NHS Direct database NHS Data copied from NHS network to internet PC Data encrypted and ed to Lancaster - using open-source public-key crypto

41 Receiving the data Data comes in to database server and is decrypted Stored in a Postgres database system Midnight job processes daily data Results stored in spatial data files

42 Viewing the data User requests web page using their browser Web server gets data and builds page User interacts with map on web page

43 Web page breakdown Traffic light system shows possible outbreak status Dynamic map made using OpenLayers Switch map layers on and off Calendar built with the OpenSource YUI Toolkit Query data points for drill-down info Hotspot layer highlights possible outbreaks Background image from OpenStreetMap

44 Case Study: Arlat Mectizan protects people from onchocerciasis (river blindness) spread by blackfly

45 Arlat But it can sometimes cause serious adverse effects in people with the relatively harmless Loaloa worm + = So we need to know...

46 Where is the Loaloa??

47 Parasitological Sampling Blood analysis is slow and expensive but it is accurate

48 Questionnaire Surveys Questionnaire sampling ('have you ever had eyeworm?') is quick and cheap but it is imprecise

49 Satellite Data Satellite data tells us about the habitat suitability for Loaloa

50 Combining Data Combining all the data needs some clever statistics - a bivariate binomial model with covariates

51 The Statistics Survey data, old and new bivariate binomial spatially correlated model with covariates Satellite data Parasitology from blood samples Predictions

52 Arlat Needs to be done by non-technical staff Working in the field So built as a plugin to Quantum GIS Using R for computing the statistics Runs on Windows and Linux

53 How does it go? Researcher in the field does questionnaire survey to get quick and cheap Loa-loa estimates

54 How does it go? Researcher puts the data and locations into a spreadsheet

55 How does it go? Data is loaded into Quantum GIS and displayed with background layers

56 How does it go? With a few clicks, a risk exceedence surface appears! Blue all clear Red danger zone Grey more data needed

57 Under the Hood...is written in C and has an embedded Python interpreter......which calls R to do statistics.

58 Under the Hood QGIS handles all the mapping and gives us an interface to map data Python gives us rapid application development and access to GUI functions R provides the statistical functions we need

59 Open Source Power A purely open-source application Combining several best-of-breed applications Even the Windows Installer is Open-Source Zero licensing cost Zero distribution cost Zero usage restrictions