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21:07 FOSS4G Englisch 2013

FOSS4G In Large-scale Projects

The presentation covers experiences and challenges encountered during the implementation of the Kosovo Spatial Data Infrastructure. The SDI consists of GeoPortal, Cadaster and Land Information System and the Address Register, all implemented on the FOSS stack and interconnected via OGC services.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
36:34 FOSS4G Englisch 2013

GDAL/OGR Project Status

An overview of the capabilities of the GDAL/OGR (Geospatial Data Abstraction Library) project will be covered, followed by a focus on new developments in the last two years and future directions for the project.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
09:42 FOSS4G Englisch 2013

GeoCouch: An N-dimensional Index For Apache CouchDB And Couchbase

Databases that support spatial queries are often limited to three dimensions, but the requirements increase. You might want to query in more dimensions, for time ranges or other attributes like trajectories. Documents are represented as JSON. The values that will be stored in the index can be extracted from anywhere within such a JSON document. Even conversions like reprojections are possible. Apache CouchDB and Couchbase are document databases, hence belong to the non-relational space which is also known as “NoSQL”. One of the strengths of Apache CouchDB is the (multi-master) replication. You can keep the data from several different instances easily in sync, even if you change the data on different instances. The replication isn't limited to Apache CouchDB, but it's a whole ecosystem. It's even possible to sync with your web browser and store it in its offline storage. This way the user can access the data offline, without the need to be always connected to the server. In contrast Couchbase has its strong point in working at scale. The data gets automatically sharded across machines. Adding and removing servers at a later stage can be performed through a simple web interface. If a server goes down the system can still work without any interruptions. GeoCouch, Apache CouchDB and Couchbase are open source and licensed under the Apache License 2.0.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
49:15 FOSS4G Englisch 2013

FOSS4G13 Keynote QGIS 2.0

  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
28:47 FOSS4G Englisch 2013

GIS Is Not Dead, It's Coming For You And It's Been Drinking JavaScript

This talk will discuss several super kick-ass ways that JavaScript and the web have re-shaped GIS and are changing how we visualize, analyze and share geospatial data with each other and the world. GIS is dead? No, it’s not, and it’s coming to find you and spatially kick your ass with a big bag of JavaScript. The world changes fast (hello, Internet). Yet, our industry (map making in one form or another) is stuck, and has generally shown itself to be slow to react to new ideas and paradigms that grow rapidly in other spaces. But there is still hope! GIS is coming back, and it’s being re-tooled with lots of shiny new software and geo-weapons. It’s going to make an assault on all of our previous notions of its old self. Of course this new and shiny GIS resembles its former self in many ways, it's also full many new ideas about how we experience maps and data on the web. As we witness a massive resurgence in JavaScript (hello D3 & node.js), and more emphasis placed on the web in general, we see that there are actually still large holes that should be filled the geo-spatial stack. New waves of JavaScript developers have, and will continue to fill these gaps. This talk will discuss several super kick-ass ways that JavaScript and the web have re-shaped GIS and are changing how we visualize, analyze and share geospatial data with each other and the world.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
24:32 FOSS4G Englisch 2013

Getting The Best Performance For GeoJSON Map Visualizations: PostGIS Vs CouchDB Backend

In order to deliver rich user experience to user, features (attribute data and geometries) have to be sent to the client for mouse-over visual effects, synchronization between charts, tables and maps, and on-the-fly classifications. GeoJSON is one of the most popular encodings for the transfer of features for client-side map visualization. The performance of client visualizations depends on a number of factors: message size, client memory allocation, bandwidth, and the speed of the database back-end amongst the main ones. Large GeoJSON-encoded datasets can substantially slow down loading and stylization times, and also crash the browser when too many geometries are requested. A combination of techniques can be used to reduce the size of the data (polygon generalization, compression, etc). The choice of an open-source DBMS for geo-spatial applications used to be easy: PostGIS is powerful, well-supported, robust and fast RDBMS ? On the other hand, unstructured data, such as (Geo)JSON, may be better served by document-oriented DBMS such as Apache CouchDB. The performance of PostGIS and CouchDB in producing GeoJSON polygons with different combination of factors that are known to affect performance was tested: compression of GeoJSON (zip) to reduce transmission times, different levels of geometry generalization (reducing the number of vertices in transferred geometries), precision reduction (the reduction of numbers of decimal digits encoding coordinates), and the use of a topological JSON encoding of geometries (TopoJSON) to avoid redundancy of edges transferred. We present the results of a benchmark exercise testing the performance of an OpenLayers interface backed by a persistence layer implemented using PostGIS and CouchD. Test data were collected using an automated test application based on Selenium, which allowed to gather repeated observations for every combination of factors and build statistical models of performance. These statistical models help to pick the best combination of techniques and DBMS, and to gauge the relative contribution of every technique to the overall performance.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
32:58 FOSS4G Englisch 2013

FOSS4G 2013 Keynote

  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
26:25 FOSS4G Englisch 2013

How To Create A Geocoded Town - Monmouthpedia And Gibraltarpedia

Monmouthpedia was the first Wikipedia project to embrace a whole town—specifically, the Welsh town of Monmouth (pron.: /ˈmɒnməθ/ MON-məth; Welsh: Trefynwy). The project aimed to cover every single notable place, person, artefact, plant, animal and other things in Monmouth in as many languages as possible, but with a special focus on Welsh. This was a different scale of wikipedia-project. The project was jointly funded by Monmouthshire County Council and Wikimedia UK, Monmouthshire County Council and it included free town wide Wi-Fi for the project. ” Monmouthpedia uses QRpedia codes, a type of bar code a smartphone can read through its camera (using one of the many free QR readers available) that takes you to a Wikipedia article in your language. QR codes are extremely useful, as physical signs have no way of displaying the same amount of information and in a potentially huge number of languages. Articles have coordinates (geotags) to allow a virtual tour of the town using Wikipedia's mobile apps (or the Wikipedia layer on Google Streetview) and are available in augmented reality software including Layar. Monmouthpedia may not use standard black and white QR codes, in order to differentiate between MonmouthpediA codes and other schemes and individual's codes. There are different kinds of QR code—plaques and labels—all put up with the permission of the council and building owner: GibraltarpediA is the first Wikipedia project to aspiresto bridge two continents. Like Monmouthpedia the project aims to cover every single notable place, person, artefact, plant and animal in Gibraltar in as many languages as possible. This is a large WikiProject; it's at least three times the size of MonmouthpediA. The area of interest includes the British Overseas Territory of Gibraltar, the Strait of Gibraltar, the Spanish municipalities along the coast of the Bay of Gibraltar, the northernmost coast of Morocco and Ceuta. This project also uses NFC technology in addition to QR codes The authors are currently working in Gibraltar to demonstrate geotagging in practise. The project uses open street map to keep track of its progress.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
20:33 FOSS4G Englisch 2013

Implementation Of Standard Web Services For GOCE Data Exploitation

The European Space Agency (ESA) with the launch of the GOCE satellite in 2009 made it possible to study the Earth's gravitational field and estimate the geoid with unprecedented accuracy and resolution on a global scale. In the framework of the GOCE mission a group of experts from Politecnico di Milano, led by Professor Fernando Sansò, is also involved in order to collect, process and distribute data. Access to GOCE data, through common procedures and standard, can bring significant improvement in many fields of Earth sciences: for this reason it was decided to distribute the data using standard web services as specified by OGC (Open Geospatial Consortium). In this work first results of the development of a WPS (Web Processing Service) for spatio-temporal exploration and exploitation of GOCE and GEMMA (GOCE Exploitation for Moho Modeling and Applications) data is presented. The download query can be made for both global data and local data; in the latter case data can be dynamically interpolated from the WPS on the area and at the resolution defined by the user, or evaluated in correspondence of a set of sparse points provided by user. The GOCE service is implemented with free and open source software, GRASS GIS and pyWPS for WPS service and OpenLayers for the web interface. Furthermore the development of WMS and WCS services is on going; a WFS service, built using MapServer and to be used for the data distribution, will be added soon to improve the ASCII Grid and GeoTIFF formats that are currently available and also a new interpolation algorit based on spherical harmonics will be added too. The service is continuously updated from the point of view of the available data, the calculation procedures and data distribution.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
25:25 FOSS4G Englisch 2013

ESA User Services Powered By Open Source

  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
29:53 FOSS4G Englisch 2013

3D Web Services And Models For The Web: Where Do We Stand?

In the past years, numerous open source projects have started to display 3D globes and 3D data on the web. Standardizing web services, data format and representation models is, therefore, a very hot topic. There are in particular ongoing efforts on the OGC side as well as on the W3C side. The OGC has released a draft candidate for a 3D web service W3DS, the ISO X3D standard proposes an XML-based file format for representing 3D computer graphics and the W3C is considering adding X3D rendering into HTML5. Other projects implement their own web services and formats. On the implementation side, Geoserver supports W3DS and X3D, the X3DOM library prototypes a possible implementation of X3D HTML5 integration and last but not least, browsers with WebGL support are fully able to handle the representation of 3D data on the client side. The talk is going to detail the mentioned elements, show demonstrations of existing implementations and try to suggest a possible path into the 3D web for the FOSS4G community.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
28:12 FOSS4G Englisch 2013

Advanced Cartographic Map Rendering In GeoServer

Various software can style maps and generate a proper SLD document for OGC compliant WMS like GeoServer to use. However, in most occasions, the styling allowed by the graphical tools is pretty limited and not good enough to achieve good looking, readable and efficient cartographic output. Topics that will be covered are as follows: - Mastering multi-scale styling, choosing the appropriate style and content for the various map scales - Using GeoServer extensions to build common hatch patterns - Line styling beyond the basics, such as cased lines, controlling symbols along a line and the way they repeat - Leveraging TTF symbol fonts and SVGs to generate good looking point thematic maps, line and fill patterns - Use the full power of GeoServer label lay-outing tools to build pleasant, informative maps on both point, polygon and line layers, including adding road plates to your map - Leverage the labelling subsystem conflict resolution engine to avoid overlaps in stand alone point symbology - Blending charts into a map - Dynamically transform data during rendering to get more explicative maps without the need to pre-process a large amount of views, such as on the fly contours extraction, heat maps, and wind maps from raster data - Leverage the analitic power of spatial databases to build dynamic thematic maps based on SQL views - Perform cross layer filtering and parametrize it to perform informative cross layer containment and neighborhood searches. The presentation aims to provide the attendees with enough information to master SLD documents allowing him to produce amazingly looking maps on his own. At the end of the presentation the SLD will no longer be cartographer's enemy.
  • Erscheinungsjahr: 2013
  • Herausgeber: FOSS4G
  • Sprache: Englisch
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