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25:41 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

istSOS: latest developments and first steps into the OSGeo incubation process

istSOS (http://istsos.org) is an OGC SOS server implementation entirely written in Python. istSOS allows for managing and dispatching observations from monitoring sensors according to the Sensor Observation Service standard. istSOS is released under the GPL License, and should run on all major platforms (Windows, Linux, Mac OS X). The presentation will go through the details of all the new features that will be packed in the next release. In particular the presenters will introduce enhancements that include the Advanced Procedures Status Page and the istSOS Alerts & Web Notification Service. The istSOS Advanced Procedures Status Page is a new section of the Web graphical user Interface, offering at a glance a graphically representation of the Sensor Network health. Administrators can easily figure out common issues related with sensor data acquisition and transmission errors. The istSOS Alert & Web Notification Service are the result of the Google Summer of Code 2014 outputs. This service is a REST implementation that take inspiration from the OGC Web Notification Service (OGC, 2003; OGC, 2006a) and the Sensor Alert Service (OGC, 2006b) which currently are OpenGIS Best Practices. Alerts are triggered by customized conditions on sensor observations and can be dispatched through emails or social networks. This year istSOS is entering into the OSGeo incubation process, this new challenge will permit to enhance the software quality and consolidate the project management procedures. The presenters will present the incubation status and discuss about the next steps.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:56 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Analyzing Fire Department Response with PostGIS

Local government fire departments always face scrutiny of their performance and efficiency. They are continuously asked to do a better job with fewer resources. In this highly technical session we will show how PostGIS is being used to analyze and measure performance throughout the city and plan for future resource requirements. Every city we work with is unique in some way. Some fire departments act as the local ambulance service while other cities contract with private ambulance companies. Emergency “911” response centers are often managed by police/law enforcement departments but not always! Many cities also have “mutual aid” agreements with neighboring cities to assist them when needed. For our customers PostGIS stores and manages the geo-located events (fires, hazardous spills, etc.) and provides details about the departments and individual emergency vehicle performance. It is most interestingly used to create statistical reports about things such as “Effecive Response Force” and “Resource Drawdown”, which are used to measure the efficiency and effectiveness of the department. Please come to learn how PostGIS is used to analyze things such as primary response areas and fire hazard severity zones, allowing our customers to ask more advanced, geographically based questions.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
20:49 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Semantic assessment and monitoring of crowdsourced geographic information

Whilst opensource software allows for the transparent collection of crowdsourced geographic information, in order for this material to be of value it is crucial that it be trusted. A semantic assessment of a feature’s attributes against ontologies representative of features likely to reside in this location provides an indication of how likely it is that the information submitted actually represents what is on the ground. This trust rating can then be incorporated into provenance information to provide users of the dataset an indication of each feature’s likely accuracy. Further to this, querying of provenance information can identify the features with the highest/lowest trust rating at a point in time. This presentation uses crowdsourced data detailing the location of fruit trees as a case study to demonstrate these concepts. Submissions of such crowdsourced information – by way of, say, an OpenLayers frontend – allow for the collection of both coordinate and attribute data. The location data indicates the relevant ontologies – able to be developed in Protégé – that describe the fruit trees likely to be encountered. If the fruit name associate with a submitted feature is not found in this area (e.g. a coconut tree in Alaska) then, by way of this model, the feature is determined to be inaccurate and given a low trust rating. Note that the model does not deem the information wrong or erase it, simply unlikely to be correct and deemed to be of questionable trust. The process continues by comparing submitted attribute data with the information describing the type of fruit tree – such as height – that is contained in the relevant ontologies. After this assessment of how well the submitted feature “fits” with its location the assigned trust rating is added to the feature’s provenance information via a semantic provenance model (akin to the W3C’s OPM). Use of such semantic web technologies then allows for querying to identify lower quality (less trustworthy) features and the reasons for their uncertainty (whether it be an issue with collection – such as not enough attribute data being recorded; time since collection – given degradation of data quality over time, i.e. older features are likely less accurate than newer ones; or because of a major event that could physically alter/remove the actual element, like a storm or earthquake). The tendency for crowdsourced datasets to be continually updated and amended means they are effectively dynamic when compared to more traditional datasets that are generally fixed to a set period/point in time. This requires them to be easily updated; however, it is important that efforts are directed at identifying and strengthening the features which represent the weakest links in the dataset. This is achievable through the use of opensource software and methods detailed in this presentation.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
26:00 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Image Geocoding as a Service

Driven by the ambition of a global geocoding solution, in this paper we present the architecture of an image geocoding service. It takes advantage of the ubiquity of cameras, that are present in almost all smartphones. It is an inexpensive sensor yet powerful, that can be used to provide precise location and orientation. This geocoding service provides an API similar to existing ones for place names and addresses, like Google Geocoding API. Instead of a text based query, images can be submitted to estimate the location and orientation of the user. Developers can use this new API, keeping almost all the existing code already used for other geocoding APIs. Behind the scenes, image features are extracted from the submitted photograph, and compared against a huge database of georeferenced models. These models were constructed using structure from motion (SFM) techniques, and heavily reduced to a representative set of all information using Synthetic Views. Our preliminary results shows that the pose estimation of the majority of the images submitted to our geocoding was successfully computed (more than 60%) with the mean positional error around 2 meters. With this service, an inexpensive outdoor/indoor location service can be provided, for example, for urban environments, where GPS fails.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
32:29 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Magical PostGIS in three brief movements

Everyone knows you can query a bounding box or even spatially join tables in PostGIS, but what about more advanced magic? This short symphony of PostGIS examples will look at using advanced features of PostGIS and PostgreSQL to accomplish surprising results: * Using full text search to build a spatially interactive web form. * Using raster functionality to look into the future. * Using standard PostgreSQL features to track and visualize versioning in data. PostGIS is a powerful tool on it's own, but combined with the features of PostgreSQL, it is almost magical.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:45 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Building and integrating a Continuous-Integration system within your open source project

So you have an open source project or you want to create a new one. Maybe you have worked on a development project in the past that didn’t have quite the amount of rigor you would have liked. You know you want a build system for your project that is easy to administer, cheap, and powerful, but where do you start? Here is how we implemented our own process using free open source tools. We learned from experience that developers are more focused on solving problems than perceived “housekeeping” tasks. We needed tools that would automate the mundane, repeatable, mechanical, or human-difficult tasks so that developers could focus on what they are good at. We needed a single-sign on through Github to lower any barriers to tool usage that might exist. We needed a dead-simple way to determine if our commits broke functionality anywhere else in code. We needed to track how much of our code was covered by unit tests. Finally, we needed to be able to quickly and easily review each-other’s code and provide feedback. We decided on TravisCI to handle build duties in Maven with a nested project structure and also for its integration with Coveralls. For bug tracking, release scheduling, and task management, we chose WaffleIO for its tight integration with Github issues. One additional feature we desired was static analysis so that simple errors that lie outside of a linter could be caught and reported. This was handled by a combination of Coverity scans and a static analysis tool for Eclipse called Findbugs. Due to our platform support and third-party library (GDAL) requirement, the Github Wiki was the perfect place to keep all setup documents and other helpful articles for end-users and project new-comers. This system for software development worked quite well in most cases. Builds were automated, moderately tested (~40-60% coverage), and complaining to the team loudly via email when things broke. We had a new problem though: build breakages in the master branch and the inability to share code that was not yet fully functional. To alleviate this, we started using the branching and merging functionality that makes Git so valuable. Now, no direct commits occur to the master branch unless in very special circumstances. A developer will see the TravisCI build results before the merge ever occurs, allowing them to adjust code or test cases *before* they cause failures. As a side effect, the merge request workflow allows the team to perform code reviews quickly and easily. Finally, any CI system is not without challenges. Building a continuous integration system has upfront costs that should not be ignored. The payoff from those costs, however, is code/product quality and the avoidance of technical debt. Lastly, some of these CI tools lack support for private repositories.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
26:13 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Advanced Security with GeoServer and GeoFence

The presentation will provide an introduction to GeoServer own authentication and authorization subsystems. We’ll cover the supported authentication protocols, such as from basic/digest authentication and CAS support, check through the various identity providers, such as local config files, database tables and LDAP servers, and how it’s possible to combine the various bits in a single comprehensive authentication tool, as well as providing examples of custom authentication plugins for GeoServer, integrating it in a home grown security architecture. We’ll then move on to authorization, describing the GeoServer pluggable authorization mechanism and comparing it with proxy based solution, and check the built in service and data security system, reviewing its benefits and limitations. Finally we’ll explore the advanced authentication provider, GeoFence, explore the levels on integration with GeoSErver, from the simple and seamless direct integration to the more sophisticated external setup, and see how it can provide GeoServer with complex authorization rules over data and OGC services, taking into account the current user, OGC request and requested layers to enforce spatial filters and alphanumeric filters, attribute selection as well as cropping raster data to areas of interest.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
32:27 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Towards GeoExt 3 – Supporting both OpenLayers 3 and ExtJS 6

GeoExt (http://geoext.github.io/geoext2/) is Open Source and enables building desktop-like GIS applications through the web. It is a JavaScript framework that combines the GIS functionality of OpenLayers with the user interface savvy, rich data-package and architectural concepts of the ExtJS library provided by Sencha. Version 2.1 of GeoExt (currently in alpha-status) is the successor to the GeoExt 1.x-series and brought support for ExtJS 5 and is built atop the following installments of its base libraries: OpenLayers 2.13.1 and ExtJS 5.1.0 (or ExtJS 4.2.1 at your choice). The next version of GeoExt (v3.0.0?) will support OpenLayers 3 and the new and shiny ExtJS 6 (not finally released at the time of this writing). The talk will focus on the following aspects: * Introduction into GeoExt * New features in OpenLayers 3 and ExtJS 6 and how they can be used in GeoExt * The road towards GeoExt 3 * Results of the planned Code Sprint in June (see https://github.com/geoext/geoext3/wiki/GeoExt-3-Codesprint) * Remaining tasks and outlook The new features of OpenLayers (e.g. WebGL-support, rotated views, smaller build sizes, etc.) and Ext JS 6 (Unified code base for mobile and desktop while providing all functionality of ExtJS 5) and the description of the current state of this next major release will be highlighted in the talk. Online version of the presentation: http://marcjansen.github.io/foss4g-2015/Towards-GeoExt-3-Supporting-both-OpenLayers-3-and-ExtJS-6.html#/
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
31:05 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

OSGeo and LocationTech Comparison

We have two great organizations supporting our Free and Open Source Software for Geospatial: The Open Source Geospatial Foundation and LocationTech. Putting on events like FOSS4G is primary responsibility of these software foundations - supporting our great open source software is! This talk will introduce OSGeo and LocationTech, and balance the tricky topic of comparison for those interested in what each organisation offers. We will also look at areas where these organizations are collaboration and explore possibilities for future work. Each of these software foundations support for their existing projects, ranging from "release parties" such as OSGeo Live or the Eclipse Annual Release. We are also interested in the ��incubation�� process each provides to onboard new projects. Review of the incubation provides an insight into an organization's priorities. This talks draws the incubation experience of: * GeoServer (OSGeo), GeoTools (OSGeo), * GeoGig (LocationTech), uDig (LocationTech) If you are an open source developer interested in joining a foundation we will cover some of the resource, marking and infrastructure benefits that may be a factor for consideration. We will also looking into some of the long term benefits a software foundation provides both you and importantly users of your software. If you are a team members faced with the difficult choice of selecting open source technologies this talk can help. We can learn a lot about the risks associated with open source based on how each foundation seeks to protect you. The factors a software foundation considers for its projects provide useful criteria you can use to evaluate any projects.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
18:37 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Satellite Snow Cover Products Evaluation and Validation Platform Developed Entirely With Floss Software

The monitoring of snow cover extent is important for the management of natural resource, extreme events prediction such as snowmelt floods, avalanches etc. The current status is that the network of weather stations is too sparse in regions with seasonal snow cover to provide reliable snow monitoring and impact applications. Remote sensing can regularly provide maps of snow cover extent, under limitations imposed by satellite cycles or cloud cover. A number of daily or synthesis snow cover extent products, covering Romania, with different resolutions and specifications, are available for free (e.g. GLOBSNOW, CryoLand, H-SAF, IMS). These products were homogenized and included, along with reference and in-situ data, into an application that make possible for user to inspect, process, analyze and validate the information, using a web based interface. The platform, created by National Meteorological Administration of Romania offers services based on Open Geospatial Consortium standards for data retrieval (WMS, WCS, WFS) and server-side processing (WPS, WCPS). The services were built upon open source solutions such as GeoServer, OpenLayers, GeoExt, PostgreSQL, GDAL, rasdaman. The application is composed of several software modules/services. The modules are split into two categories: server-side modules/services and client side modules - responsible for interaction with the user. A typical usage scenario assumes the following steps: 1. The user is operating the client functionality to select a temporal and spatial slice from a product cube (e.g. 5 months archive of daily CryoLand FSC data); 2. The users select a statistic method to be applied; 3. The request is sent to the server side processing applications wrapped as WPS or WCPS calls; 4. The process will trim/slice the coverage cube, perform the statistic operation for the pixels within the ROI for each day in the selected time interval; 5. The results are sent back encoded in a standard file format; 6. The web client display the results in a relevant form.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:33 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

GeoServer for Spatio-temporal Data Handling With Examples For MetOc And Remote Sensing

This presentation will provide detailed information on how to ingest and configure SpatioTemporal in GeoServer to be served using OGC services, with examples from WMS and WCS services. Topics covered are as follows: * Discussion over existing data formats and how to preprocess them for best serving with GeoServer * Configuring SpatioTemporal raster and vector data in GeoServer * Serving SpatioTemporal raster and vector data with OGC Services Tips and techniques to optimize performance and allow maximum exploitation of the available data The attendees will be provided with the basic knowledge needed to preprocess and ingest the most common spatiotemporal data from the MetOc and Remote Sensing field for serving via GeoServer.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:21 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

High-precision open lidar data enable new possibilities for spatial analysis in the canton of Zurich/Switzerland

The department of geoinformation of the canton of Zurich/Switzerland has carried out a high-resolution laser scanning (LIDAR) last year over the entire canton of Zurich. The extensive data (8 pts / m2) have now been evaluated, and a digital surface (DSM) and terrain model (DTM) created (dot grid of 50 cm and horizonal and vertical accuracies of 20 cm, resp. 10 cm. This is the first time high-resolution elevation data is widely available for the entire canton of Zurich. In the past, lidar data have been collected only for small-scale projects. As a novelty, the department has decided to provide the lidar data and its derived products, i.e. DTM and DSM, as open data to the public. With this decision new standards are set not only in terms of accuracy and scope, but also in the usage as open government data. The lidar data can provide valuable support for example in the areas of infrastructure, urban planning, regional planning, natural hazard assessment, forestry, environment, energy, line survey, solar potential analysis, surveying, archeology, agriculture, water or noise. Due to the planned repetition cycle of four years even time series and monitoring projects are possible. Therefore it is not surprising, that since the opening as open data, many interesting applications using this data have been created. The presentation will show the high-resolution data and its possible usage for terrain-visualizations. A selection of the most appealing visualizations will be demonstrated, e.g. an Oculus Rift version enabling the user to navigate through virtual reality. It will further give an insight in the challenge of opening up the LIDAR?data for the public, i.e. setting up an open-data strategy in the cantonal administration of Zurich.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:15 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Using the latest ISO standard for geographic information (ISO19115-1:2014)

Release in April 2014, this talk will introduce the major changes of the new standard for metadata on geographic information and what are the benefits for the data managers. It will be illustrated by its implementation in the latest GeoNetwork 3 version and with examples on how the Wallonia Region in Belgium migrated to it.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
16:51 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Revolutionizing map use in Norwegian newspapers

Norway represents one of the countries with most newspapers and media outlets per person. One topic that has an everlasting interest is land registration data - or more commonly: Who bought which properties and what was the price. Land registration data has always been a public data set. Every citizen can request specific information on who has rights to which properties. Up until 1. January 2014 the digital version of this data set was monopolized by law to one vendor - obviously inhibiting innovation. Starting in 2014 - land registration data has been opened and is now accessible to everyone. Webatlas seized this opportunity and hired two summer interns. The task was fairly easy: "Revolutionize the way land registration data is used in local newspapers." After two hard-working months the resulting web application was used by a local newspaper with great results. The newspaper could finally showcase an interactive leaflet map displaying all real estate transactions in the area of interest. Behind the scenes the interns experienced a steep learning curve using PostGIS, GeoServer, Leaflet and a range of excellent plugins. Some of the more stable parts made it to the general use with an Open Source license on GitHub. Today. The solution is used in the majority of Norways newspapers - now showcasing more maps than ever! All made possible by two excellent interns, open data sets and well proven Open Source software components.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:46 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Use case of a dual open strategy in the canton of Zurich/Switzerland

With a dual 'open'-strategy the department of geoinformation at the canton of Zurich/Switzerland opts for a strategic orientation towards open source and open data: Open in the sense of an open web-mapping- infrastructure based on open source components: Mapfish Appserver was developed as a framework for building web map applications using OGC standards and the Mapfish REST protocol. It is freely available under the new BSD-license (http://mapfish-appserver.github.io/). The Ruby on Rails gem comes with the following out-of-the box features: - Organize maps by topics, categories, organisational units, keywords and more - Combine maps with background and overlay topics with adjustable opacity - Import UMN Mapserver mapfiles to publish new topics within seconds - Fully customizable legends and feature infos - Creation of complex custom searches - Rich digitizing and editing functionality - Role-based access control on topic, layer and attribute level - Access control for WMS and WFS - Rich library of ExtJS 4 based map components - Multiple customizable viewers from minimal mobile viewer to full featured portal - Multi-site support - Built-in administration backend - Self-organized user groups maps.zh.ch, the official geodata-viewer of the canton of Zurich, was developed using Mapfish Appserver. It contains more than 100 thematic maps and is considered an indispensable working tool for everyone working with spatial data in the canton of Z?rich/Switzerland. 'Open' in the sense of Open Government Data: Zurich is the first canton participating in the national open data portal opendata.admin.ch. The portal has the function of a central, national directory of open data from different backgrounds and themes. This makes it easier to find and use appropriate data for further projects. The department of geoinformatics aims to open as many geo-datasets as possible for the public by publishing them on the national OGD-portal. The open geodata is issued in form of web services ? Web Map Services (WMS), WebFeature Services (WFS) and Web Coverage Services (WCS) - and contains a wide range of geodata from the fields of nature conservation, forestry, engineering, infrastructure planning, statistics to high resolution LIDAR-data.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
24:48 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Sensor up your connected applications with OGC SensorThings API

This introduction will give an introduction and live demonstration of the OGC SensorThings API. The OGC SensorThings API provides an open and unified way to interconnect the Internet of Things (IoT) devices, data, and applications over the Web. The OGC SensorThings API is a new OGC standard candidate. Unlike many existing OGC standards, SensorThings API is very simple and efficient. At the same time, it is also comprehensive and designed to handle complex use cases. It builds on a rich set of proven-working and widely-adopted open standards, such as the OGC Sensor Web Enablement (SWE) standards, including the ISO/OGC Observation and Measurement (O&M) and Sensor Observation Services (SOS). The main difference between the SensorThings API and the OGC SOS is that the SensorThings API is designed specifically for the resource-constrained IoT devices and the Web developer community. As a result, the SensorThings API follows the REST principles, the use of an efficient JSON encoding, and the use of the flexible OASIS OData protocol and URL conventions. In addition to introduce the specification, this talk will also demonstrate an end-to-end IoT application based on the SensorUp IoT platform, an open source implementation of the SensorThings API, including a server, javascript library, web dashboard and a Arduino library.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
20:29 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Opening Address Data around the World

With over 110 million points, OpenAddresses.io has grown to be the largest open database of address data in the world. Governments, developers and businesses are realizing that address data belongs in a commons where it can be easily maintained, used by all, and drive economic growth. These early efforts are now powering some of the world's best commercial geocoding systems, as well as crucial infrastructure like emergency responders. But there's more work to do. We need to reform outdated laws, expand coverage to new cultural contexts, untangle shortsighted licenses, and invent new modes of collaboration between the public and government. We'll cover how OpenAddresses started, how it can be used today, and how we expect it to grow into a definitive global resource.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:57 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Route Planning in your Database with pgRouting

pgRouting extends the PostGIS / PostgreSQL geospatial database to provide shortest path search and other network analysis functionality. This presentation will show the inside and current state of the pgRouting development, from its wide range of shortest path search algorithms to driving distance calculation or Traveling Sales Person (TSP) optimization. Additionally we will give a brief outlook and introduction of upcoming new features like the Vehicle Routing Problem (VRP) solver, and what we have in mind for future releases. We will explain the shortest path search in real road networks and how the data structure is important to get better routing results. Furthermore we will show how you can improve the quality of the search with dynamic costs and make the result look closer to the reality. You will also learn about difficulties and limitations of the library, and when pgRouting might not be not the right tool to solve your routing problem.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:20 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Map publishing with or without programming skills

This presentation will showcase the use of Oskari (http://oskari.org/oskari) in publishing embedded map applications. The typical use case doesn't require any programming skills. You only need to select the map layers and tools that will be available in the application. After that, you can customize the user interface (size, colors, tool layout etc.). As a result the publishing tool will give you a HTML-snippet to embed to any web site. The supported web services are WMS, WMTS, WFS and Esri REST. If your data is not readily available through a web service, you can import data. Shapefiles, KML, GPX and MID/MIF-files are supported. There's an extensive selection of tools at your disposal: index map, centering to user��s location, address and place name search, attribute table (for vector data) to name a few. Integrating the map application with the surrounding web page makes more advanced use cases possible. All you need is a few lines of JavaScript to use the RPC interface (http://www.oskari.org/documentation/bundles/framework/rpc). With RPCs you can control the map application from the parent document and vice-versa. They can also exchange information. This enables you to develop highly interactive web applications with always up-to-date data. In the presentation an example application made using Oskari and D3 will be showcased.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
20:32 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Research client side draggable route selection with pgRouting

pgRouting extends the PostGIS / PostgreSQL geospatial database to provide shortest path search and other network analysis functionality such as alternative K-Shortest path selection. But, in some case, client side draggable route selection (like Google Maps Direction or OSRM) is preferable. This presentation will research what is necessary to realize such client side draggle route selection with pgRouting, then try to implement the functionality to some browser(Leaflet, OpenLayers .etc) and desktop(QGIS .etc) client.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
31:40 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Mapping in GeoServer with SLD and CSS

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. For those that like to write their own styles CSS also represents a nice alternatives thanks to its compact-ness and expressiveness. Several topics will be covered, providing examples in both SLD and CSS for each, including: mastering multi-scale styling, 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, using 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 around labels, 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. The presentation aims to provide the attendees with enough information to master SLD/CSS documents and most of GeoServer extensions to generate appealing, informative, readable maps that can be quickly rendered on screen.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:10 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

GIS-modelling of long-term consequences after a nuclear accident.

In order to evaluate consequences of deposited radioactive cesium (and other radioactive substances) in natural systems a GIS based model called Stratos has been developed. This model incorporates information regarding deposition, transfer to vegetation and animals, intervention levels and geographical distribution of animals. The presentation will use a case study which describes the possible environmental consequences for Norway due to a hypothetical accident at the Sellafield complex in the UK. The scenario considered involves an explosion and fire at the B215 facility resulting in a 1 % release of the total HAL 1 inventory of radioactive waste with a subsequent air transport and deposition in Norway. Air transport modeling is based on real meteorological data from October 2008 with wind direction towards Norway and heavy precipitation. This weather is considered to be quite representative as typical seasonal weather. Based on this weather scenario, the estimated fallout in Norway will be ~17 PBq of cesium-137 which is 7 times higher than fallout after the Chernobyl accident. The modeled radioactive contamination is linked with data on transfer to the food chain and statistics on production and hunting to assess the consequences for foodstuffs. The investigation has been limited to the terrestrial environment, focusing on wild berries, fungi, and animals grazing unimproved pastures (i.e. various types of game, reindeer, sheep and goats). The results of a model-run are maps for the chosen products, with categorized colors - giving the degree of consequences. A linked text file gives relevant numeric values for each color. The Stratos model is written in python which calls GRASS-functions and uses as gui for model setup. The model has been used for two reports at the Norwegian Radiation Protection Authority, and is currently being used and developed further in the "Centre for Environmental Radioactivity" (CERAD), cerad.nmbu.no.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
24:20 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Case study: A full-fledged cutting-edge FOSS4G map production system

The development and the usage of National Land Survey of Finland's dynamic and high performance map production system is described in this presentation. The system is currently in use and serves map images both to customers and to NLSFI production systems. The data in the map production system are open data and being updated on a weekly basis. When the data get updated, a RSS-feed is generated. Based on the feed, the map products are updated. Data is stored, updated and replicated in PostGIS. Map pictures are rendered in GeoServer. The visualization of the maps is based on SLD-stylesheets. SLD-stylesheets enable the same data to be visualized in several different ways. GeoServer in conjunction with SLD-stylesheets offers a Web Map Service (WMS). Map images are delivered via a high performance MapCache Web Map Tile Service (WMTS) and as image files via NLSFI download service. The system is designed to be expandable and is currently being further developed to enable the pro-duction of on-demand printed maps.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
23:23 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Open Source and Open Standard based decision support system: the example of lake Verbano floods management.

The Locarno area (Switzerland, Canton Ticino) is exposed to lake floods with a return period of about 7-8 years. The risk is of particular concern because the area is located in a floodplain that registered in the last decades a great increase in settlement and values of the real estates. Moreover small differences in lake altitude may produce a significant increase in flooded area due to the very low average slope of the terrain. While fatalities are not generally registered, several important economic costs are associated, e.g.: damages to real estates, interruption of activities, evacuation and relocation and environmental damages. While important events were registered in 1978, 1993, 2000, 2002 and 2014 the local stakeholder invested time and money in the set-up of an up-to-date decision support system that allows for the reduction of risks. Thanks to impressive technological advances the visionary concept of the Digital Earth (Gore 1992, 1998) is being realizing: geospatial coverages and monitoring systems data are increasingly available on the Web, and more importantly, in a standard format. As a result, today is possible to develop innovative decision support systems which mesh-up several information sources and offers special features for risk scenarios evaluation. In agreement with the exposed view, the authors have recently developed a new Web system whose design is based on the Service Oriented Architecture pattern. Open source software (e.g.: Geoserver, PostGIS, OpenLayers) has been used throughout the whole system and geospatial Open Standards (e.g.: SOS, WMS, WFS) are the pillars it rely on. SITGAP 2.0, implemented in collaboration with the Civil protection of Locarno e Vallemaggia, combines a number of data sources such as the Federal Register of Buildings and Dwellings, the Cantonal Register of residents, the Cadastral Surveying, the Cantonal Hydro-meteorological monitoring observations, the Meteoswiss weather forecasts, and others. As a result of this orchestration of data, SITGAP 2.0 serves features that allows, for example, to be informed on active alarms, to visualize lake level forecasts and associated flooding areas, to evaluate and map exposed elements and people, to plan and manage evacuation by searching for people living in particular areas or buildings, by registering evacuation actions and by searching for evacuated people. System architecture and functionalities, and consideration on the integration and accessibility of the beneath information together with the lesson learnt during the usage of the system during the last floods of November 2014, provides interesting discussion points for the identification of current and future needs.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
21:27 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Decision-making system for grants for maintaning services in rural areas

Sweden is a sparsely populated country. Normally market forces would regulate the number and location of both public and commercial services as schools, medical care, grocery stores and pharmacies. In sparsely populated areas these forces does not work. The Swedish government has realized this and gives economical support to some services in order to maintain or in some cases expand the service level. The aim with this grants is to provide conditions for living, working and contribute to economic growth in these in remote areas. To be as effective as possible a decision making system has been developed to support the administrators of the grant. The system allows the administrators to monitor the current situation, update changes in the service structure and simulate fictive scenarios. The system is built on an open source platform and is available through the internet to authorized administrators on the regional level of the Swedish administration. As platform for the system the following open source projects and formats are used GeoExt, Ext JS, Openlayers, Mapfish, Pylons, GEOAlchemy, Mapserver, PostGIS, GeoJSON.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
19:36 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

On simulation and GIS, coupling and hydrology

This presentation shows how to better integrate simulation codes and Geographical Information Systems, and takes the example of Hydrological modelling integration into QGIS. Scientific modelling and simulations are present in a large number of areas. A significant proportion of simulation codes are applied spatially, at different levels, from a neighborhood scale up to worldwide areas. These simulation codes take spatial information as input data, and output results which are related to space too. But most of the time, they do not directly handle GIS data. Data types and data formats are different, and there is therefore a lot of effort to put into pre-processing and post-processing of the data to get it from GIS to the simulation codes and back. For example, determining the diffusion of a pollutant leak into underground water necessitates to get a DEM, location of the leak, geological data and more from the GIS, and transform it to simulation code input format. Then launch a simulation (on finite volumes e.g.), and convert the output into GIS files so that to be able to visualize spatial repartition of the pollutant according to time. The topic of this presentation is therefore to show how to better interact between simulation and GIS. We present the prevalent types of data for simulation, how they differ from GIS, and how we usually transfer from one type to another. Then we show how we worked towards better integration. Polygonal meshes are the most common way of representing 2D geometries for simulation purposes. Integrating simulation to a GIS requires storing georeferenced meshes in a databases (or using standard GIS file formats), and being able to use simulation values interpolated over the elements as a map layer. We show how to modify simulation codes to read directly a mesh from a GIS and write the results into a GIS. We implemented a new type of layer for QGIS, a mesh layer, which enables to display simulation results with high performances. This takes into account the temporal dimension. We also demonstrate how to integrate a simulation code into QGIS Processing so that it can be managed directly from within the desktop application. We illustrate these concepts with a demonstration of a full integration of a Hydrological simulation tool inside QGIS, with simulation management, custom user interface and strong integration of data between the simulation code and GIS data. In this sense the FREEWAT project started mid-2015, which aims at integrating multiple Hydrological codes into QGIS is also a good example of simulation and GIS integration. We end up with the perspectives for more global integration of simulation tools and GIS, and the work still to be done to bridge the gap between those two worlds.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:59 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

ZOO-Project 1.5.0: News about the Open WPS Platform

ZOO-Project is an Open Source Implementation of the OGC Web Processing Service (WPS) available under a MIT/X-11 style license and currently in incubation at OSGeo. ZOO-Project provides a WPS compliant developer-friendly framework to easily create and chain WPS Web services.This talk give a brief overview of the platform and summarize new capabilities and enhancement available in the 1.5.0 release. A brief introduction to WPS and a summary of the Open Source project history with its direct link with FOSS4G will be presented. An overview of the ZOO-Project will then serve to introduce new functionalities and concepts available in the 1.5.0 release and highlight their interests for applications developers and users. Evolutions and enhancements of the ZOO-Project WPS server (ZOO-Kernel) will first be detailed especially regarding compliancy (WPS 1.0.0 and 2.0), performance and scalability. The ZOO-Project optional support for Orfeo Toolbox and SAGA GIS will then be introduced, with details on the numerous new WPS Services (ZOO-Services) they provide. Use and connexion with other reliable open source libraries such as GDAL, GEOS, MapServer, GRASS GIS, CGAL will also be reviewed. Examples of concrete applications will finally be shown in order to illustrate how ZOO-Project components (ZOO-Kernel, ZOO-Services, ZOO-API and ZOO-Client) can be used together as a platform to build standard compliant advanced geospatial applications. Along with the new 1.5 release, this talk will also present how ZOO-Project is being developed, extended and maintained in the context of the EU funded PublicaMundi research project.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:27 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Earning Your Support Instead of Buying it: A How-to Guide to Open Source Assistance

More organisations are moving to use FOSS4G software to cover shrinking budgets. It is very appealing to an organization’s leaders to ditch their current proprietary software solution with the attendant saving on per user licences and ongoing maintenance costs. Obviously, if you switched to FOSS4G to get better features and scalability you should consider buying a support contract from one of the many vendors that offer them, these companies support many of the core developers directly. This way you get all the advantages of open source, prompt support and often the chance to ask for new features. However, if you (or your boss) are looking to save money then you are moving from a cash economy to a gift economy. In a gift culture you need to build up your “capital” before attempting to take too much out. For example, you’ve downloaded the software and installed it, and all looks good. Then disaster hits, you have a demo for the CIO and nothing's working; Time to hit the user list, the developer list, stack exchange. Why can’t you get an answer? Remember just because your issue is urgent to you the developers might be in the middle of a new release or adding a new feature and have more important (or fun) things to do with their time. They will notice they have never seen your name before on the list, or on Stack Exchange that you have a reputation in the single digits – thus you are a newbie. There’s no harm in that but wouldn’t it be better to have got that out of the way before your emergency. You could have built up your reputation by asking some questions earlier especially questions like “what can I do to help?” or “I found an unclear paragraph in the install instructions, how do I fix it for you?” on a mailing list. On StackExchange you can build reputation by asking good questions and by answering other people’s questions. Once you’ve banked some capital there are still good and bad ways of asking a question. Developers are busy people (the GeoTools users list has 20-30 messages a day for example) no one has time to read all of them closely. If you use a poor subject (e.g. "Help!!!!") or don’t provide a clear description of the problem (e.g. “it crashes”) then the odds of being ignored are huge. It can be tempting once you have found a helpful developer to keep emailing them directly, but this is likely to lead a polite(ish) reminder to keep to the list so that everyone can benefit or silence. This talk will show how to be a better open source citizen and get a better answer than RTFM when your project is stuck and the demo is the next day. The author will share his experience with helping users and developers on the GeoTools and GeoServer mailing lists and as a moderator on gis.stackexchange.com.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:44 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Building OpenLayers Applications with QGIS

OpenLayers 3 is a powerful mapping library that can be used to create interactive mapping applications. Although it has a simple, intuitive and well-documented API, it requires knowledge of JavaScript to use, and no tools exist to leverage its functionality for more general GIS users. This presentation introduces an open-source QGIS plugin that creates web applications based on OL3, without the need of writing code manually. Elements of the web app are defined using a simple GUI, and QGIS GUI elements are used as well to define its characteristics (for instance, for defining the styling of layers or the extent of the view). The plugin can create different types of web apps, from simple maps used to browse data layers, to rich ones with GIS-like functionality, as well as others such as narrative maps. Apart from being an interface for writing OL3 code in a graphical way, it automates data deployment, and can import data into a PostGIS database or upload layers to a GeoServer instance. Altogether, these capabilities, along with QGIS data management functionality, allow to create a web app from QGIS in a very short time, as well as modifying or improving it later.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
24:17 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

MapWindow Plug-in of GRM Model Using Open Source Software

This presentation shows the processes and methods for developing distributed rainfall-runoff modeling system using open source softwares. The objective of this study is to develop a MapWindow plug-in for running GRM (Grid based Rainfall-runoff Model) model (MW-GRM) in open source GIS software environment. MW-GRM consists of the GRM model, physically based rainfall-runoff model developed by Korea Institute of Civil Engineering and Building Technology (KICT), for runoff simulation, pre and post processing tools for temporal and spatial data processing, and auto-calibration process. Each component is integrated in the modeling software (MW-GRM), and can be run by selecting the MW-GRM menus. In developing MW-GRM, free software and open source softwares are used. GRM model was developed by using Visual Basic .NET included in Microsoft Visual Studio 2013 express, pre and post processing tools were developed by using MapWindow (Daniel, 2006) and GDAL (Geospatial Data Abstraction Library), and PEST (John, 2010) model was used in the auto-calibration process. The modeling system (MW-GRM) was developed as MapWindow plug-in. System environment was Window 7 64bit. MapWindow GIS ActiveX control and libraries were used to manipulate geographic data and set up GRM input parameters. ESRI ASCII and GeoTIFF raster data formats, supported by MapWindow and GDAL, were applied and shape file (ESRI, 1997) was used in vector data processing. GDAL is a library for translating vector and raster geospatial data. In this study, GDAL execution files were used to develop pre and post processing tools. The tools include data format conversion, spatial interpolation, clipping, and resampling functions for one or more raster layers. PEST is a model-independent parameter estimation software. Parameter estimation and uncertainty analysis can be carried out using PEST for model calibration and sensitive analysis. PEST is developed as an open source software, and single and parallel execution files are provided. This study developed GRM uncertainty analysis GUI as an interface system of GRM and PEST. GRM model had been a DLL type library including APIs to support developing another application. But PEST needs a model execution file, which can run in console execution window without user intervention. This study developed GRM execution file (GRMMP.exe) running in console window. It can simulate runoff using GRM project file, and no user intervention is allowed after the simulation has started. GRM uncertainty analysis GUI makes PEST input files (pcf, pif, ptf, rmf, etc.) by setting GRM parameters, observed data, PEST parameters, and selecting single or parallel PEST and PEST run automatically using GRMMP.exe file. In this study, all the functions necessary to develop GRM modeling system and pre and post processing tools could be implemented by using open source software. And MapWindow plug-in of GRM model can simulate runoff in open GIS environment including automatic model calibration using PEST. The study results can contribute to the wide spread of physically based rainfall-runoff modeling. And this study can present useful information in developing distributed runoff modeling system using open source software.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
19:50 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

WPS Benchmarking Session

The yearly Web Processing Service (WPS) benchmark. Variuos WPS implementations will be tested regarding their capabilities, compliancy to the standard and performance. Traditionally, each participating project designates individuals from their community to participate in this talk to introduce their project and summarize its key features. The focus this year will be on compliancy and interoperability. We will present the test set-up, participating WPS projects and the results of the benchmark.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
20:33 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Saving Rapid Urbanizing Cities using the FOSS4G Based Spatial Analysis for Urban Development

Early stages of urban developments such as housing construction, new town development and urban regeneration are performed through the spatial analysis using the topographic map, cadastral map, zoning map and other various kind of thematic maps for the proposed site analysis, feasibility analysis and evaluation of urban development alternatives. For these analyses, urban developers traditionally have used commercial software like ArcGIS to analyze these kinds of projects. And giant Korean public urban developer like Korea land and Housing Corporation (LH) has support these projects based on the in-house enterprise GIS system. But developing countries facing rapid urbanization near the peripheral areas of metropolitan region cannot handle such problems only using the commercial software. They need knowledge and experience about the urban development rather than complicated software based analysis techniques or large investments on the enterprise GIS system. In this sense, FOSS4G (Free Open Source Software for Geospatial) are very useful tools in that they are easy to learn, use and also relatively cheap to maintain. LH has accumulated a lot of urban development cases and wants to store this knowledge to FOSS4G based spatial analysis as a rule base. By doing so, it can manage the fast growing cities sustainable. In this presentation, we will show some conceived urban development project faced by the rapid urbanizing cities and suggest FOSS4G based spatial analysis method using the FOSS4G like QGIS plug-in.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
27:05 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Utilizing Free Open Source Software and Open Data in the Crop Suitability Analysis of Adlai for Climate Change Adaptation

With 43,000 square kilometers of rice producing farm lands, the Philippines is considered as the largest rice importer in the world according to World Rice Statistics (2008). The increasing demand for imported rice in the country has been largely attributed to topography, underutilized farm infrastructures, typhoons and rapid population growth. Given the need to supply a stable food source to Filipinos, the Department of Agriculture (DA) has been studying the feasibility of the mass production of Coix lacryma-jobi L or Adlai, a traditional food source abundantly grown by indiginous people in the country for centuries. In contrast to rice, Adlai is naturally resilient to pests, diseases, droughts and floods, and does not need irrigation. In its study, the Department of Agriculture wanted to evaluate the adaptability of Adlai in different parts of the country for it to become a complementary staple food for Filipinos. The results of the tests in four regions (II, IV, V, and IX) have been very promising. The study found that Adlai does not need fertilizers and insecticides, it can survive with minimal rainfall, and it can be planted in upland areas. To complement the current work of the Department of Agriculture, this study aims to map the agro-edaphic zones or the areas that are suitable for the cultivation of Adlai. It will apply free open source software (QGIS) and open data sources (ASTER GDEM, PhilGIS, and DA). The selected set of variables (slope, elevation, and soil order) will be cross tabulated, and the result will represent generalized classes of associated soil orders in combination with both elevation and slope. The result of this study could then be utilized by the Department of Agriculture to determine areas in Region 11, excluding the arable land for rice, that are suitable for the cultivation of Adlai. Sources: Japan-Space Systems, Phil GIS, Manila Observatory, Environmental Science for Social Change, Department of Agriculture, Bureau of Agricultural Research.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
16:10 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

GIS Policy Map for Local Government in Korea: Story of Dobong-gu, Seoul

Local governments in Korea are trying to solve urban problems using GIS policy map. Through FOSS4G Seoul, I want to introduce example of Dobong-gu, Seoul. Topic 1. Spatial Analysis of Practical Requirements of Parking Lot The residents who live in the old residential zone in Dobong-gu are suffering from shortage of parking spaces every morning and night. Most administrators are using an indicator named ‘a ratio of cars to parking spaces’ to judge seriousness of the problem with parking. But the indicator cannot reflect reality. We measured practical requirements of parking lot spatially, using micro block data and car registration data with addresses. We tried to look at things from the resident’s perspective, not from administrator or provider. Now, Dobong-gu push ahead with sharing parking lot program with houses which have spare parking spaces. Topic 2. Civic Participation Model for Solving Children’s School Walkway Safety Problems. Office of Policy Development of Dobong-gu did a survey with a thousand residents about safety issue, and many of them answered that they feel fear walking down the alley. Although the Office got the policy implication from survey, they couldn’t convince the definition of ‘alley’ and accurate location where the residents feel fear. Office and we redesigned survey paper cooperatively. The improvement point was ‘Map-based Survey’. Elementary school students and their parents participated and they lined school walkway and alleyways where they felt fear on paper map. We migrated all the lines on papers to shape files using QGIS, then we got a very satisfactory outcome. Office of Policy Development added LED lights to the dark street nearby elementary school, Elementary school teachers decided the walkway guidance spot by referring to students often jaywalk.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
24:37 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Gis Server with Golang.

GIS Server architecture with Golang. Find the better way of Golang GIS Server.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
22:50 FOSS4G, Open Source Geospatial Foundation (OSGeo) English 2015

Push it through the wire! Push it more, if it's wireless!

Today's web browsers, their rendering engines and JavaScript interpreters are able to display relatively big amounts of vector data. Moving from DOM rendering (as it was implemented with help of SVG in for examples OpenLayers 2) to Canvas (and further to WebGL -- as we are now having in OpenLayers 3 or Leaflet) enables us to display thousands of complex vector features, with complicated on-client vector data styling. With this possibility, we are facing now new types problems: how to send such amount of data through limited internet connection? If we have closer look at the problem, we can see clearly, that old database paradigm has raised one more time: we can not have all three attributes of data in one pot, but only 2 of them: speed of the delivered data or amount of delivered data or their topicality. If we take this limits into account and decide to deal with big amounts of data in fast way, topicality must be sacrificed. In the talk, we will demonstrate some possible solutions for this problem, using tiled vectors, generalization, aggregation of vector data. Also advantages, disadvantages of various new and popular vector formats, such as GeoJSON, TopoJSON or MapBox will be discussed. Geometric data do not have be rendered all the time in all scales and over whole area of interest, but only necessary portion of them. If displayed in smaller scales, aggregation and generalisation can take place on the server side. That implies, that using vector caching mechanism could be considered as well. But if we need direct interaction of the server input with cached vector data, mechanism for this must be defined as well. Also attribute data have to be transfered separately, if all the optimisation was put in the vector geometries. Also possible steps between cached data and real-time data will be discussed.
  • Published: 2015
  • Publisher: FOSS4G, Open Source Geospatial Foundation (OSGeo)
  • Language: English
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Version

AV-Portal 3.7.0 (943df4b4639bec127ddc6b93adb0c7d8d995f77c)