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28:35 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

MapCache: The Fast Tiling Server From The MapServer Project

MapCache is a new member in the family of tile caching servers. It aims to be simple to install and configure (no need for the intermediate glue such as mod-python, mod-wsgi or fastcgi), to be (very) fast (written in C and running as a native module under apache or nginx, or as a standalone fastcgi instance ), and to be capable (services WMTS, googlemaps, virtualearth, KML, TMS, WMS). When acting as a WMS server, it will also respond to untiled requests, by merging its cached tiles vertically (multiple layers) and/or horizontally. Multiple cache backends are included, allowing tiles to be stored and retrieved from file based databases (sqlite, mbtiles, berkeley-db), memcached instances, or even directly from tiled TIFF files. Support of dimensions allows storing multiple versions of a tileset, and time based requests can be dynamically served by interpreting and reassembling entries matching the requested time interval. MapCache can also be used to transparently speedup existing WMS instances, by intercepting getmap requests that can be served by tiles, and proxying all other requests to the original WMS server. Along with an overview of MapCache's functionalities, this presentation will also address real-world usecases and recommended configurations.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
28:04 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

A New Dimension To PostGIS : 3D

Talking about 3D used to sound cool. Used to. But for real GIS use, we really need more than just playing with a globe. 3D in GIS becomes cool as soon as we have the ability to deal with full 3D spatial analysis. Just as we already have in 2D, we need functions like intersection, buffer, triangulation and more ... The GEOS library provides us 2D topological processing for years. The CGAL library could now also provide us some interesting additional 3D topological functions. As CGAL is not fully designed for GIS data models, we provide a library inbetween called SFCGAL, in charge of providing a Simple Feature API on top of CGAL. PostGIS 2.1 now allows to link PostGIS and (SF)CGAL, and already provides several exciting 3D functions (and more and more to come). This thrilling talk about PostGIS 3D will therefore focus on : - What kind of project / application needs 3D GIS analysis ? - What can we do right now with PostGIS 2.1 and (SF)CGAL ? - What we will be able to do soon with PostGIS 3D ? - Some tools used to view and manipulate 3D data (QGIS / WebGL based)
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
24:32 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 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.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
36:34 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 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.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
25:39 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

OpenLayers 3: Under The Hood

OpenLayers 3 is the next generation of web mapping. A radical new architecture and the use of cutting edge JavaScript techniques, libraries, and tools enables a full suite of previously unimaginable functionality while maintaining a compact, high performance library. In this talk we'll show you how to use this functionality in your applications, and peek under the hood to see how OpenLayers 3's architecture makes it possible. We'll include: Virtual globe (Cesium) integration: a carefully designed camera and data source abstractions permit close integration with the virtual globes. Switch between 2D and 3D views of the same data, or display synchronized 2D and 3D views side by side. Multiple rendering back-ends: a pluggable rendering architecture supports multiple renderers for maximum performance and portability. A Canvas 2D renderer provides fast, reliable rendering on current devices, a DOM renderer provides fall-back capabilities for older browsers, and a WebGL renderer opens the door to the next generation of performance for the most demanding applications. Rich data sources: generic and powerful core data representations of tiled, single image, and vector data make it easy to add support for a wide range of geospatial data sources. Smooth and flexible interaction and animation: an optimized rendering path ensures that interaction remains smooth at all times. Compact library size: use of the Closure suite of tools creates keeps the build size small while keeping the source code readable.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:02 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

OpenLayers 3 Showcase

OpenLayers 3 enables a huge range of new web mapping functionality. In this talk, we'll show off many of the cool features of OpenLayers 3, including: Rich interaction and animation Virtual globe integration Raster layer effects Wide-ranging data source support The talk will be light on technical details and heavy with cool demos to show you how OpenLayers 3 opens up new and exciting ways of presenting your geospatial data.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:59 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

Optimising Spatial Data Analysis With PostgreSQL And PostGIS

In this talk we will demonstrate spatial data analysis on the relational database system PostgreSQL (http://www.postgresql.org) equipped with the spatial extension PostGIS (http://www.postgis.org). We will gradually introduce some of the optimisation techniques provided by PostgreSQL, by applying them to the solution of increasingly complex problems belonging to the PostGIS domain. Our aim is to point out as clearly as possible the main ideas behind each example, showing the link in both projects between development of new features and the need to tackle real-world problems. Topics mentioned in this talk include: the special index types GiST and SP-GiST; custom database objects, such as data types, functions and operators; query and workload profiling.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
20:46 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

OpenLayers 3 - How To Successfully Run A Crowdfunding Campaign For An OSS Project

The impressive list of OSGeo Projects [1] show the necessity to develop OpenSource software. Behind all lines of code, there is the work of one developer. And, in our capitalist world, work means money. This presentation will underline the challenges of the crowdfunding effort organized for the development of the next major release of OpenLayers 3. OpenLayers is one of the most famous OSGeo library and is widely used for the development of web mapping applications. Its development started in 2007. In 2012, it was clear for the developers that the current release was at the end of its life. The emergence of new technologies implied to create a complete new libraries based on these new technologies. As usual in the OpenSource world, some developers started this work in the middle of 2012. Since a complete rewrite was required, it appeared clearly that the work needed to obtain a library that would allow the migration to the new release was huge. It was estimated to 2’500 hours of work. At this time, swisstopo planned a migration of its web mapping applications. swisstopo decided to use the future release of OpenLayers, which was only a very first prototype. In order to benefit of the advantages of OpenSource developments made by a community, it was not possible for swisstopo to simply mandate a company for the development of this library. The commitment of the OpenLayers community and its committers/developers was needed. So, in order to speed up the development process, swisstopo decided to invest a substantial amount of money and to organize a crowdfunding effort together with companies active in the OpenLayers development scene. Several financement channels were used: micro fundings from individuals and more important fundings from companies and administrations. This presentation will describe the main problems and challenges faced during this crowdfunding effort and how they have been solved. Here is a list of these problems and challenges: - Some key actors had to be convinced to donate in order to convince others to follow the movement. It is important that one or two big players make the first donations. And, since the money is managed by the higher manager, a lot of energy has been put in explaining how an OpenSource community works. The OpenSource development model is still not very well known and the higher management often think that a normal contract with one company is the best way to develop softwares. - The general objective was to be clear and strong enough in order to convince individuals, companies or administrations to invest on something that didn’t exist. - The financial capacities of individuals, companies or administrations are not the same. But all are part of the OpenLayers community. It was important to be able to handle donations of some dollars to some thousand of dollars. - OpenLayers is an OpenSource community, but is not a legal entity. It’s therefore not possible to make a contract with OpenLayers. In order to solve that, the main companies of the OpenLayers development scene decided to create an association in order to simplify the administrative aspects. - The commitments and the resources of the OpenLayers committers was needed in order to ensure that the library could be developed in a short time frame and with the necessary level of quality. - A worldwide communication concept has to be put in place in order to reach all potential crowdfunders. And this only with a few persons working partially on this project. - An organization had to be put in place in order to coordinate the work of persons located all around the world. But at the end, the result is here: more than 350’000 USD have been found and the development of OpenLayers 3 is a reality. And everyone can now benefit of a modern, performant and 2D/3D web mapping library, thanks to all crowdfunders and developers !!!
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
18:59 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2013

Managing update of tiles of dynamic data

Tiling is currently the best solution to achieve high performance and throughput for serving map images. However, because tile images have to be prepared, tiling is often only used for relatively static data. The Dutch national facility for presenting governmental spatial plans, www.ruimtelijkeplannen.nl, is used intensively (app. 15.000 plans) and has high performance demands and therefore wanted to make use of tiling. Because plans often change and are added and deleted from the central database, a special solution was developed to manage the daily update of tiles. The presentation will concentrate on the solution to manage the daily update of tiles, the Tiling Manager. The Tiling Manager software queries the audit trail of plan updates, executes tiling tasks in collaboration with GeoWebCache and monitors progress. We had to deal with several challenges to realize the requirements, such as monitoring progress of tiling tasks in GeoWebCache, run-time generation of GeoWebCache configuration, optimizing WMS performance and assuring that the services will never present old tiles if new plans are available. In addition to the solutions to these challenges the presentation will show the technical architecture of the Tiling Manager.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
28:12 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 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.
  • Published: 2013
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
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Version

AV-Portal 3.7.0 (943df4b4639bec127ddc6b93adb0c7d8d995f77c)