Development

VGI and Geotechnology for Supporting Blind and Vision-impaired People Using a Localized Gazetteer

Session Type: 
Academic Session
Presenter(s): 
Mr Ahmad Aburizaiza, George Mason University
Dr Matthew Rice

 

Speaker Bio: 

Ahmad Aburizaiza
PhD student at George Mason University
Geography and Geoinformation Science Department
Fairfax, VA, USA

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Beyond Markers: a new approach to interactive realtime weather maps

Session Type: 
Tech Session
Presenter(s): 
Fergal Walsh, National Centre for Geocomputation, NUI Maynooth
Dr Christian Kaiser

Markers must go! At least when things concern continuous-space processes such as weather. Could anyone care less about a sensor with its exact measurement unless it is mounted exactly where the person is? Why not move beyond markers and point measurements and instead show values everywhere as surface overlays? Markers are interactive and can link to a pop-up timeline - but so are the surface overlays! This is now possible thanks to the availability of fast spatial predictors, efficient storage mechanisms and fast client side rendering.

This talk will outline an open source web application for realtime modelling and visualisation of time-varying continuous-space fields. We will discuss the technical challenges of building this application from the server side perspective of data collection, modelling and storage and from the client side perspective of visualisation and interactivity.

We will describe our approach to an integrated spatio-temporal modelling and visualization of temperatures and rainfall. The predicted temperature surfaces and rain radar data are displayed as overlays in OpenLayers using a custom layer which renders the data on the client side using the HTML5 Canvas Element. The timeline for arbitrary spatial location is built upon the Flot plotting library and is rendered the same way. These elements are backed by a server side raster cube, implemented as a georeferenced multidemensional memory mapped Numpy array. We developed this data structure specifically for storing timestamped raster data in a way that allows for very efficient spatial and temporal slicing. And for those curious ones interested in sub-raster resolutions there is always a live server-side stream oracle ready to compute predictions with MapReduce on multicore.

Speaker Bio: 

Fergal Walsh is a Phd student at the National Centre for Geocomputation at NUI Maynooth. His research interests include spatio-temporal data analysis and visualisation and understanding human communication and movement patterns. He is also interested in software development and is the lead developer i2maps, an open source software project at NCG.

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MapQuery and SVG charts: a powerful interface for aggregated data

Session Type: 
Tech Session
Presenter(s): 
Steven Ottens, Geodan

Spatial data traditionally has been displayed using maps and tables. Maps, though good in showing the spatial extent, are not always optimal in showing (aggregated) geo-statistical data. The human mind can easily be tricked into believing that a bigger country has a bigger share of the pie. Tables show the individual records, but still lack the overview of aggregated data, also tables are notoriously hard to read.

To view the information in an aggregated form one has to build complex queries. These are often slow and do not scale well and the user either has to interpret the resulting map or compare numbers in a table. The first being not very precise the second not very intuitive.

Within EuroGeoSource, a cross European project that allows users to identify, access, use and reuse aggregated geographical information on geo energy and mineral resources, we have come up with a new way. The users are not typical GIS experts and do not have the knowledge to build custom spatial queries. Instead based on the user requirements we have determined the most important types of aggregation (eg. by country, by deposit-type etc).

The user can search for one or more commodities. Using MapQuery and gRaphael, an SVG chart library, we than present the aggregated information in interactive (pie) charts. He can use the charts as a selection method, for instance by clicking on a single country in the 'countries chart' he will see all the occurrences of the commodity in that country on the map.

The result is a fast and intuitive way to search for aggregated data. Providing overview on the distribution of data in multiple domains and still giving access to detailed data in a traditional GIS manner.

Speaker Bio: 

Steven Ottens has been involved in the foss4g community since 2005. Developing intuitive high performance webmapping applications and actively contributed to various OSGeo projects. Currently focussing on the UxDesign aspects of (web)GIS.

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WFS and SQL Injection

Session Type: 
Lightning Talk
Presenter(s): 
Olivier Courtin, Oslandia

OGC WFS-T allows client apps to have write access on features stored server side through a Web Service API.

Commonly such features are stored in a spatial databases.

Forthcoming WFS 2.0 would even add stored query sent from the WFS client, which could then execute them on demand.

All theses great features have security counterparst, and could lead to SQL Injection vulnerabilities.

The issues raised and answered in this lightning talk will be :

  • Where are the main SQL Injection risks in WFS specs implementations ? (WFS-T, Filter Encoding and WFS 2.0 ?
  • What tools or tests could help to detect them?

 

Speaker Bio: 

Olivier is the main developper and maintainer of TinyOWS since 2007. He's also involved in PostGIS project, as both projects are somewhere tied.

 
Olivier is with Vincent Picavet owner of Oslandia, a small company focused on Open Source GIS.

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Raster data in GeoServer and GeoTools: Achievements, issues and future developments

Session Type: 
Tech Session
Presenter(s): 
Simone Giannecchini, GeoSolutions
Daniele Romagnoli

The purpose of this presentation is, on a side, to dissect the developments performed during last year as far as raster data support in GeoTools and GeoServer is concerned, while on the other side to introduce and discuss the future development directions.

Advancements and improvements for the management of raster mosaic and pyramids will be introduced and analyzed, as well the latest developments for the exploitation of GDAL raster sources. The presentation will also introduce the jai-tools and ImageIO-Ext projects. jai-tools provides a number of new raster data analysis operators, including powerful and fast raster algebra support. ImageIO-Ext bridges the gap across the Java world and native raster data access libraries providing high performance access to GDAL, Kakadu and other libraries.

The presentation will wrap up providing an overview of unresolved issues and challenges that still need to be addressed, suggesting tips and workarounds allowing to leverage the full potential of the systems.

Speaker Bio: 
GeoSolutions Founder, OSGEO Charter Member, Simone Giannecchini has been involved with geospatial open source software since early 2004, playing an active role sine early 2005.

He has a leadership role in several projects, like GeoServer, GeoTools, ImageIO-Ext and JAI-Tools. 

Schedule info

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